Catena 76 (2009) 135–154

Contents lists available at ScienceDirect

Catena

j ourna l homepage: www.e lsev ie r.com/ locate /catena

Late Quaternary alluvial fans and paleosols of the Kangra basin, NW Himalaya:Tectonic and paleoclimatic implications

P. Srivastava a,⁎, M.K. Rajak a, L.P. Singh b

a Department of Geology, University of Delhi, Delhi 110007, Indiab Geological Survey of India, Hyderabad 500 068, India

⁎ Corresponding author.E-mail address: pankajps@gmail.com (P. Srivastava).

0341-8162/$ – see front matter © 2008 Elsevier B.V. Aldoi:10.1016/j.catena.2008.10.004

a b s t r a c t

a r t i c l e i n f o

Article history:

The paper describes Late Qu Received 29 June 2008Received in revised form 21 October 2008Accepted 22 October 2008

Keywords:HimalayasAlluvial fansKangraLoess-paleosolsQuaternaryNeotectonics

aternary pedosedimentary sequences of the alluvial fans from the Kangra basinof NW Himalayas for tectonic and paleoclimatic implications. In the proximal part of the Kangra basin threecoalescing alluvial fans, namely Rait-Rihlu fans (~65 km2), Kangra fans (~200 km2), and Palampur fans(~170 km2) from west to east evolved due to reactivation of longitudinal and transverse faults and climaticchanges during the Late Quaternary. The fans are characterised by subsidence of Rait-Rihlu fans, uplift ofKangra fans and tilting of Palampur fans. The thick (~90 m) pedosedimentary sequences exposed along therivers characterise the dominant formative processes over the fans. The stream flow sediments dominate theRait-Rihlu fans, whereas the debris flow sediments dominate the Kangra and Palampur fans. The fansequences are also marked by the formation of strongly developed paleosols on loess (L1–L3 loess paleosols)and weakly developed paleosols on fluvial deposits in response to the tectonics and climate change in NWHimalayas.Formation of the loess in proximal and distal settings of the alluvial fans is related to the cool–dry climatesduring the advance of glaciers in the adjoining areas at 78 ka, 44 ka, 30 ka and 20 ka when climate wasapproaching towards the last glacial maxima. Field characters, micromorphology, grain size and clay mineralsof these loessic deposits suggest strong pedogenesis of the loess during a warm–humid climate after theretreat of glaciers in the NW Himalayan region and are likely related to marine isotope stages (MIS4/5 inproximal and MIS2/3 in distal). The loess-paleosols show some degree of syndepositional pedogenesis inupper horizons and are accretionary in nature. Weakly expressed pedogenic features in fluvial and debrisflow deposits suggest rapid sedimentation over unstable surfaces related to the reactivation of MainBoundary Thrust (MBT) and other regional faults.

© 2008 Elsevier B.V. All rights reserved.

1. Introduction

Alluvial fans are the most significant depositional element offoreland basins and their evolution is mainly controlled by the tectonicsand climate change (Miall, 1981; DeCelles et al., 1987; Jolly et al., 1990;Allen et al., 1991; Rasanen et al., 1992; Pivnic and Johnson, 1995; Cleviset al., 2004). In the Himalayan foreland, the uplift and the climaticfluctuation during the Late Cenozoic had profound effect on geo-morphic, sedimentary and pedogenic processes. The interplay of theseprocesses resulted into development of a series of transverse alluvial fansequences bordering the major thrust sheets (Fig. 1a–c). The fansequences store an important record of geomorphic, pedogenic andsedimentary processes that resulted in response to the tectonics andclimatic changes (Singh et al., 2001; Kumar et al., 2007; Suresh et al.,2007; Srivastava et al., 2007). The Late Quaternary fan building activityover the last 100 ka throughout the foreland is marked by formation of

l rights reserved.

piggyback basin along themajor thrust sheets with varying aggradationand entrenchment in response to climate change and tectonics (Singhet al., 2001; Suresh et al., 2007, Singh and Tandon, 2007). The fansequences are marked by the thick debris flow and stream flowdominated sediments and varying degree of soil development. Recentstudies of the alluvial fans (25–52 km2) from central part of the forelandin Dehradun intermontane basin demonstrate the formation offerruginous paleosols during humid climates on stable surfaces thatwere influenced by the reactivation of theMain Boundary Thrust (MBT)over the last 50 ka (Singh et al, 2001; Srivastava et al., 2007).

The alluvial fan sequences of the Kangra re-entrant in NWpart of theforeland differ from the fans described in Dehradun. They are large (65–200 km2) coalescing type fans with predominance of debris flow andstream flow sediments (Shah and Srivastava, 1992). The presence ofthick paleosols in these alluvial fan sequences makes these fans ofparticular interest to study the relationship between soils, sedimentsand landforms of the Himalayan foreland during the Late Quaternary.However, this relationship has not been explored and there is noinformation available on the formation of paleosols within the Late

Fig. 1. (a) Location of study area in India, (b) Location of Kangra re-entrant, Dehradun intermontane basin along the Main Boundary Thrust (MBT) in the Himalayan foreland (afterGansser, 1964). (c) General geological map of the Kangra re-entrant (simplified from Raiverman et al., 1990).

136 P. Srivastava et al. / Catena 76 (2009) 135–154

Quaternary sedimentary sequences of the Kangra basin. In the presentstudywe explored three alluvial fans of the Kangra basin and report theresults of detailed paleopedological analyses along with geomorphic

and sedimentary features to asses the factors controlling weatheringand formation of paleosols and discuss their tectonic and paleoclimaticimplications.

137P. Srivastava et al. / Catena 76 (2009) 135–154

2. Geologic setting

The Himalayan mountain range is the most prominent and activeintracontinental range in the world. It formed when the Tethys Oceanclosed and the Indian plate collided with Eurasian plate about ~50 Myrago. The convergence has continued ever since resulting into theprogressive development of major thrust sheets in a north–southsequence along the strike length of the Himalayas (Gansser, 1964;Molnar and Tapponnier,1975;Wobus et al., 2005). The outer part of thisrange in south ismarked by an active foreland basin that resulted due tothe thrust loading and subsidencewith synorogenic sedimentation fromthe hinterland (Raiverman et al., 1983; Burbank et al., 1996). It is thelargest terrestrial foreland basin in the world. It consists of foldedsedimentary sequences of Siwaliks in the north and the vast Indo-Gangetic Plains in the south (Parkash et al., 1980; Raiverman et al.,1983;Burbank et al.,1996). Thenorthernedgeof the forelandwasdeformedbyfault propagation folding with a shortening of about 23 km across theSiwaliks in theKangra re-entrant (Powers et al.,1998). Theperturbationscaused sinuosity of the Main Boundary Thrust (MBT) resulting in theformation of several re-entrants and salients throughout the forelandthat store an impressive record of the thrust sheet activities (Tandon and

Fig. 2. (a1–a2) IRSL shine down curves, (b1–b2) growth curves, and (c1–c2) equiv

Rangraj, 1979; Visser and Johnson, 1978; Burbank et al., 1988; Meigset al., 1995; Brozovic and Burbank, 2000; Dubey et al., 2004).

The Kangra re-entrant is one of the largest intermontane basins inthe Himalayan foreland (Fig. 1b, c). The strata exposed in proximal anddistal parts of the Kangra basin provide an important insight into thesedimentation and the evolution of the foreland during the LateCenozoic (Johnson et al.,1983; Meigs et al.,1995; Brozovic and Burbank,2000). Sedimentation in this basin occurred over the last 11 Ma by theaxial rivers thatwere encroached upon by the transverse and southwardflowing streams in response to the reactivation of MBT and climaticchanges. The continuous record of sedimentation in 2.5–3.5 km thicksections of the basin is characterised by an overall coarsening upwardsequence as mudstone and siltstone in the Lower Siwalik, sandstone inthe Middle Siwalik and abrupt change to massive conglomerate in theUpper Siwalik lithofacies (Meigs et al., 1995; Brozovic and Burbank,2000). The massive conglomerate of the Upper Siwalik represents theprogradinggravel front by the southwardflowing streams in response tothe increased rate of subsidence and activity along the MBT (Brozovicand Burbank, 2000). The sedimentation has continued during theQuaternary in the form of transverse alluvial fans along the foothillsfollowingMBT in the north and the fluvial deposits by the axial rivers in

alent dose plateaus for two representative loess-paleosols of the study area.

Table 1Natural radioactivity values, equivalent dose and luminescence age estimates of loess-paleosols of Kangra basin

Sample no. Location, depth 238U (ppm) 232Th (ppm) 40K (%) Dose rate (Gy/ka) ED (Gy) Age (ka)

K-13M Gagal-II, 3 m depth 4.9±2.2 16.5±4.0 2.3 6.0±1.0 119.8±8.1 19.9±3.5K-17M Gagal-II, 5.5 m depth 4.7±2.2 15.8±3.8 2.9 5.7±1.0 177.5±32.1 30.8±7.7K-24M Iku, 16 m depth 8.9±3.0 29.6±5.4 2.4 9.0±1.4 398.5±36.9 44.2±6.2K-26M Iku, 18 m depth 12.3±3.5 41.0±6.4 2.2 11.5±1.7 901.66±151.2 78.6±17.7

138 P. Srivastava et al. / Catena 76 (2009) 135–154

the south (Raiverman et al., 1983, 1990; Singh et al., 2001; Kumar et al.,2007).

3. Study area

The alluvial fans under study are located in the northwestern part ofthe Himalayas in the Kangra re-entrant (Lat 31°40′ to 32°20′N and Long75°40′ to 77°05′E) boundedby snow-cladDhauladhar range (6200m) inthe north and the Siwaliks (1050 m) in south (Fig. 1a–c). Climate is wettemperatewith average annual rainfall of 1800–3000mmand themeanannual temperature varying from 13 °C to 20 °C (IMD, 1989). Duringwinters the temperature drops down to freezing point with a frequentspell of snowfall in upper reaches of the valley. Reconstruction of themaximum extent of glaciers during LGM suggests a drop of snowline(ELA — Equilibrium Line of Altitude) by 1100 m–1200 m and glaciersextended over the Himalayan foreland valleys including Kangra basin(Kuhle, 2001, 2005, 2007).

4. Methods

We delineated the geomorphic features of the alluvial fans using1:50,000 scale remote sensing data (Geocoded False Color Compositeimages of IRS 1C LISS3) and the topographic sheets. Based on thesefeatures and their boundaries we selected critical sections/locations fordetailed fieldwork. The alluvial fan sequences described here resultedfrom variable interaction between sedimentological, pedological anderosional processes over time, and these sequences are therefore, thepedosedimentary sequences. We studied twenty pedosedimentarysequences along the entrenched stream sections and road cuts fordescribing the sediments and the paleosols (Miall, 1981, Nichols andHirst, 1998; Soil Survey Staff, 1999).

Particle sizedistributionwasdeterminedby the pipettemethod afterthe removal of organic carbon and free iron. Sand (2000–50 µm), silt(total silt 50–2 µm, coarse silt 50–20 µm, medium–fine silt 20–2 µm,total clay b2 µm and fine clay b0.2 µm fractions were separatedfollowing Jackson (1979). For micromorphological studies, oriented andundisturbed samples of the paleosols were collected in metal boxes(9×6×6 cm) from different horizons according to the methods ofMurphy (1986). These samples were air-dried and impregnated withcrystic resin (Jongerius and Heintzberger, 1963). Large thin sections

Table 2General geomorphic features of three fans (Rait-Rihlu, Kangra and Palampur fans) as obser

Alluvial fans Dimensions(width, length, area)

Elevation, gradient Remar

Rait-Rihlu Fans Width 12 km 900 m–700 m DistribLength 9 km Qf1 4–5% AggradArea 65 km2 Qf2–Qf3 1–2%

Kangra Fans Width 20 km 1310 m–700 m NarrowLength 14 km Qf1 10–12% IncisedArea 200 km2 Qf2 4–6% Paired

Qf3 2–4%Palampur Fans Width 16 km 1500 m–800 m Distrib

Length 10 km Qf1 6–7% SegmeArea 170 km2 Qf2 4–5% Chann

Qf3 4–5%

(8×6 cm) were described according to the terminology of Bullock et al.(1985). Oriented clay fractions of total clay and fine clay were subjectedto X-ray diffraction analysis using a Philips diffractometer with Ni-filtered, Cu-Kα radiation at a scanning speed of 2°2θ/min. Samples weresaturated with Ca and solvated with ethylene glycol (Ca-Eg) and K at25 °C, 110 °C, 300 °C and 550 °C. Identification of the clay minerals wasdone following Jackson (1979).

Infrared stimulated luminescence (IRSL) technique was used toestimate the depositional age of the fan sediments and the formation ofpaleosols following the general procedures of the luminescencedatingofQuaternary sediments (Aitken 1985; Singhvi and Krbetschek, 1996;Singhvi et al., 2001). Based on time dependent radiant energy stored inminerals due to natural radioactivity, it determines the time elapsedsince the last exposure to sunlight and the most recent burial of thesediments. The stored radiation is released by IRSL as paleodose, i.e. doseacquired after the geological luminescence is set by the sun to near zeroresidual level during the transport. The zeroing of the luminescencesignal for aeolian sediments is easily obtained due to unattenuated solarflux during transport in air (Srivastava et al., 2003). The age of thesediment is obtained by dividing the paleodose with that of the annualdose. In view of this loess-paleosol samples were collected in metallicpipes (15×5 cm) with care to avoid any post-depositional disturbance.Samples were subjected to the sequential treatments of 1 N HCl toremove carbonates, 30% H2O2 to remove organic matter, and defloccula-tion by 0.1 N sodium oxalate to separate the polymineralic fraction (4–11 µm) by Stokes law. The separated fraction was kept in acetone assuspension and was deposited and dried on aluminum discs. Thesamples were analyzed on Daybreak 1100 TL/OSL system using Corning7-58 and BG-39 filters coupled to an EM-9635 QA Photomultiplier tubeat Indian Institute of Technology, Roorkee. Beta irradiation was carriedout using 25 mCi 90Sr/90Y beta source and alpha-irradiation was carriedout in vacuumusing anAmericium-241 source.Multiple aliquot additivedose measurement technique was used to estimate the paleodose with40 disks. The annual dose rate estimation was done using elementalconcentration ofU andThbyZnS(Ag) thick alphasource andKbygammaspectrometry.Water content was assumed to be 10% and cosmic raywastaken as150µGya−1. The estimated ages are reasonablywithin error limitof 10% and can be considered as depositional time of loess. Representa-tive shine curves, growth curves, and age plateaus are given in Fig. 2 andthe data obtained by the luminescence dating is given in Table 1.

ved on FCC images and topographic sheets

ks

utary drainage pattern in fan head, meandering-braided in rest with bifurcating channelsing fans marked by highly sinuous Khauli stream in the central part

incised parallel streamslandforms (Siwaliks and old fan pediments)terraces in proximal and unpaired terraces in distal parts

utary drainage pattern with cone shaped sediment spreadntation by NS Neogal fault and westward tiltingel shifting, paleochannels and unpaired terraces

139P. Srivastava et al. / Catena 76 (2009) 135–154

5. Results

5.1. Geomorphic and sedimentary features of fan sequences

This section describes general geomorphic features and lithologicalcharacters of the three fans. A summary of these characteristics ispresented inTables 2 and3. The catchments for these fans in thenorth ofMBT consist of the Proterozoic low-grade metamorphics and granites,whereas the fans are limited by the Siwaliks in the south. Moderate sizealluvial fans fromwest to east are: Rait-Rihlu fans (~65km2), Kangra fans(~200 km2), and Palampur fans (~170 km2) (Fig. 3a–b). These fans arecoalescing type and are drained by the feeder streams, which originatein the Higher Himalayas and flow through mountain exits at fan headsand are later joined by numerous smaller ephemeral streams sourced onfans (the streams are locally known as ‘Khad’, ‘Nala’, and ‘Nadi’). Thestreams continue further beyond the fans before draining into the axialtrunk the Beas River, which, in turn, joins the Sutlej River flowing inwesterly direction.

The three fans are separated by the transverse faults that act as theboundaries of tectonic blocks covered by the three fans. These transversefaults also offset themajor thrusts, such asMBT in the north and the JT inthe south (Fig. 3). The western block, made up of the Rait-Rihlu fans, ismarked by subsidence, low relief and sedimentation by meanderingstreams. The central and eastern blocks consisting of the Kangra and thePalampur fans, respectively, are marked by the uplift and the isolatedpediments (uplifted-eroded Siwalik hills) surrounded by the fansediments. The isolated pediments are deeply incised with prominentV-shaped valleys. The Palampur fans are also marked by N–S segmenta-tion and tilting with unpaired terraces. The fans typically show convexupward transverse profiles and concave upward longitudinal profiles(Figs. 3c, 4a–e). Three depositional surfaces (Qf1–Qf3) can be identifiedfrom the proximal to the distal parts with varying topographic andsedimentary features. Qf1 represents the oldest depositional surfacerestricted mainly in the proximal parts with regional slope varying from4% to 12% and cone shaped spread of sedimentary deposits. It is partiallyburied by Qf2 deposits inmiddle parts of the fans. In distal parts the fansare covered by the youngest Qf3 deposits with low gradients (2–4%). Thereactivation of regional faults resulted in segmentation of the fans thatcan be recognized as Qf2A–Qf2B in Qf2 and Qf3A–Qf3B in Qf3 surfaces.

The subsided Rihlu-Rait fans with low gradient (b4%) showdistributary pattern in the NW part in Qf1 surface and a meandering

Table 3Lithological features of the three fans (Rait-Rihlu, Kangra and Palampur fans) as observed in

Alluvial fan group Facies Description

Rait-Rihlu Fans Massive sand-mud 0.5–1.0 m thick yellow to reddish browand sand sheets with few pebbles and

Pebbly sand andorganised gravels

0.3–0.5 m thick sheets of pebbly and morganised subrounded clasts and matrix

Organised gravels 2.0–2.5 m thick pebble–cobble, moderastratified, cross bedded and normal gra

Massive silt 2–3m thick loess-paleosol sequence, yereddish brown, massive-subangular blotraces and burrows

Kangra Fans Disorganised clast-supported gravels

2–3 m thick poorly sorted cobble–bouldsubrounded boulders up to 1.5–2 m inand sandy matrix

Disorganised matrix-supported gravels

4–5 m thick, massive, poorly sorted, sucrude stratification and sandy–silty ma

Organised gravels 1 m–2 m thick sheet like deposits, clasgravels with moderate sorting and crudcross bedding with thin lenses of massi

Massive silt 3 m to 8–9 m thick silt with well develthose in Rait-Rihlu fans

Palampur Fans Disorganised clastsupported gravels

Same as in Kangra fans

Organised clast andmatrix supported gravels

Same as in Kangra fans

stream separates Qf2 from Qf3 surfaces in the central part. The Qf1 ischaracterised by the cohesivemudflow sediments of stratified sand andmud with thin sheets of gravels and weakly developed paleosols ofb0.5m thickness. The sediments inQf2 andQf3 are characterised by twotypes of stream flow deposits. The first type includes crudely stratifiedsheets (0.2–0.4 m thick) of clast and matrix-supported pebbles alongwith a few thin (0.2–0.3mthick)paleosols (Fig. 5a, Pathej section). Thesedeposits display normal grading of clasts and low angle cross-stratification. The second type fluvial deposit, occurring in the medianand thedistal parts of the fans, is characterisedby1m–1.5mthick sheetsof sub-rounded pebbles and cobbles that are associated with 1–2 mthick prominent and well developed paleosols (Fig. 5a,b).

Geomorphic features of the Kangra fans in central part of the studyarea are marked by moderate–high relief, V-shaped valleys, incisedlandforms, and lack of well-developed flood plains (Figs. 3, 4). The threedepositional surfaces, identified show steepeningwith increasing age offan surface and the average regional slope varies from 10–12% in Qf1, 4–6% inQf2 and 2–4% inQf3 respectively. These surfaces are drained by thesouthwesterly flowing parallel streams from Higher Himalayas throughthe mountain exits and they are joined by few ephemeral streamsoriginating within fans. Paired terraces are a common feature of thesestreams in proximal part (e.g. Chambi and Gaj river terraces 2–3 level,50–70 mwide and 2–3 m height), and few unpaired terraces in medialand distal parts. It is also marked by incised older fan sediments andSiwalik Hills as pediments in the central part. Sediment assemblage inthe proximal parts is dominated by cohesive debris flows consisting ofsub-angular to sub-rounded pebbles and boulders of granite that aresupportedby the silty–sandymatrix,whichgrades laterally into the clastsupported debris in lower parts (Fig. 5a). In addition, loess-paleosols arecommonly associated with the debris flow having prominent bound-aries (Fig. 5b). Flow-parallel imbrication and crude inverse gradingdefine the internal fabric of this debris. Inmedial and distal parts, fluvialdeposits dominate over the debrisflows andare similar to the sedimentsof the Rait-Rihlu fans. The sequences are characterised by weaklydeveloped thin (b0.5 m thick) paleosols on fluvial deposits and stronglydeveloped paleosols on loess (3–8 m thick loess-paleosol sequences) inproximal and distal parts of the fans (Fig. 5b).

In the eastern part of the Kangra fans, the interfan area is marked byoutcrops of Siwaliks and a N–S trending fault that demarcates thewestern boundary of Palampur fans (Fig. 3a–c). The Palampur fans arecharacterised by the moderate gradient (6–7% in Qf1, 4–5% in Qf2 and

field

Interpretation

n alternating mudweakly developed soils

Fluvial overbank levee deposits with shortsurface exposure for weakly developed soils

assive sand with wellsupported gravels

Braided stream flow in waning conditions inchannel and longitudinal bars

tely sorted and crudelyding

Braided streams channel and braid bar deposition

llowish brown tocky structure, many root

Rapid accumulation of wind blown silt during cold–dry climate followed by limited supply of sedimentsand formation of well developed paleosols duringwarmer–wetter conditions

er beds, sub-angular tosize, inverse grading

Probably deposited by hyper-concentrated debrisflow from slope wash

b-rounded pebble–boulder,trix

Deposited predominantly by cohesive debris flowand its remobilization

t and matrix supportede stratification, low angleve sand bodies

Characteristic gravelly braided stream deposits ofchannel lag and braid bar with short exposure forweakly developed paleosols

oped paleosols similar to Loess-paleosol sequences formed similar to those inRait-Rihlu fansFormed by hyperconcentrated debris flow along slopes

Stream flow by gravelly braided streams with shortexposure for weakly developed paleosols

140 P. Srivastava et al. / Catena 76 (2009) 135–154

Fig. 4. Representative long profiles of the fans surface and streams. (a) Aggrading fansmarked by the long profile of the Khauli River and surface of the Rait-Rihlu fans, (b, c) Dissectingfans marked by the long profiles of Gaj River, Manuni River and the surface of Kangra fans, (d, e) Dissecting fans marked by the long profiles of Neogal river, Awa river and the surfaceof Palampur fans.

141P. Srivastava et al. / Catena 76 (2009) 135–154

Qf3) and cone shaped spread of sediments. The western part of thePalampur fans ismarkedbyprominent segmentation,westward shiftingof the Neogal river together with presence of paleochannels andunpaired terraces (N–S oriented 150–250 m wide and 2–5 m height)(Fig. 3b, c). The streams draining the fans are, in general, marked bydistributary pattern. TheNeogal stream, however, following a transversefault is marked by a change from narrow incised channel in proximalpart to meandering and braided channel in medial and distal parts. Thesedimentary assemblage in Qf1–Qf3 is characterised by cohesive debrisflows of clast and matrix supported gravels that laterally grade fromcobbles–boulders in Qf1 to pebbly gravels in Qf3. The paleosolsoccurring in these deposits are marked by thin (b0.5 m) weaklypedogenised horizons. The segmented part in the west is dominated bythe fluvial deposits and weakly to moderately developed paleosols(Fig. 5a). The terrace sediments are marked by the poorly stratifiedgravels and low angle cross beddings and thin cover of soil (b0.5 m).

Fig. 3. (a) Geomorphic map of the three alluvial fans: Rait-Rihlu fans (RRF), Kangra fanspedosedimentary sequences studied in the field. Representative sequences marked as Pt—lithologs in Fig. 5), (b) Drainage distribution, segmentation, paleochannels and terraces of t

5.2. Ages of the Alluvial fans, Kangra basin

The alluvial cover of the Kangra basin, described as recent alluviumin published geological maps (Raiverman et al., 1983, 1990),unconformably overlies the Upper Siwaliks. Similar such deposits ofgravels from Dehradun intermontane basin were named as “DoonGravels” by Medlicott (1864). The Doon Gravels also overlie the UpperSiwaliks unconformably. The uppermost Siwaliks are assigned an ageof 0.22 Ma on the basis of magnetostratigraphic evidence (Ranga Raoet al., 1988). Our luminescence dating of loess-paleosols from alluvialfans of the Kangra basin suggests that the fans are of Late Pleistoceneage (Table 1). The oldest dates obtained from the lower and the upperparts of a 3 m thick loess-paleosol section, Qf1 surface, proximal partof the Kangra fans are 78.6±17.7 ka and 44.2±6.2 ka, respectively.Other dates obtained were from the lower part (30.8±7.7 ka) andmiddle part (19.9±3.5 ka) of a 8 m thick loess-paleosol section from

KF), Palampur fans (PF) drawn from the IRS 1C LISS3 images along with location ofPathej, D—Dhanotu, I—Iku, G1—Gagal-I, G2—Gagal-II, C—Chimat, P—Paror (same as inhe fans, (c) Relief features of the three fans along AA′ marked in Fig. 3a.

142 P. Srivastava et al. / Catena 76 (2009) 135–154

Table 4Physical–chemical characters of the paleosols form Rait-Rihlu, Kangra and Palampur fans of the Kangra basin

Depth (m) fromtop of paleosols

Horizon Color(Munsell, 1975)

Structure pH(1:2)

Sand(N50 µm)%

Total silt(50–2 µm)%

Co. silt(50–20 µm)%

Med.–fine silt(20–2 µm)%

Total clay(b2 µm)%

Fine clay(b0.2 µm)%

Soil-development

Dhanotu Paleosol (L1 — loess-paleosol sequence) Rait-Rihlu Fans0.6 Bw1 10YR6/6 St sbk 5.5 4.9 63.9 40.5 23.4 31.2 17.6 Sw11.1 Bt1 7.5YR6/6 St sbk 5.8 1.2 60.2 10.2 50.0 37.3 14.8 S11.5 Bt2 7.5YR6/6 St sbk 5.5 2.3 64.5 21.2 43.2 33.2 15.7 S13.5 Bt3 7.5YR6/6 St sbk 6.4 2.9 61.5 17.8 43.8 35.4 20.0 S23.8 Bt4 7.5YR6/6 St sbk 5.8 2.3 59.4 13.0 46.8 38.3 16.4 S24.2 Bt5 7.5YR6/6 St sbk 5.4 5.4 62.5 36.7 25.8 32.1 15.4 S24.5 Bt6 7.5YR6/6 St sbk 6.2 7.6 76.6 22.3 54.3 25.7 11.4 S24.8 Bw2 10YR6/6 St sbk 6.2 6.4 69.8 20.1 49.7 23.5 7.7 Sw25.1 Bw3 10YR6/6 St sbk 5.7 7.7 68.4 23.8 44.6 23.9 8.5 Sw25.3 Bt7 7.5YR6/6 St sbk 5.8 5.7 68.3 19.5 48.8 26.0 10.7 S3

Iku Paleosol (L2 — loess-paleosol sequence) — Kangra Fans0.3 Bw1 5YR6/8 St sbk 5.6 2.7 65.3 33.3 32.0 31.9 17.5 Sw30.6 Bw2 5YR6/8 St sbk 5.8 4.4 64.8 51.5 13.3 30.8 13.4 Sw30.9 Bw3 5YR6/8 St sbk–abk 5.7 4.2 63.0 59.0 4.0 32.6 17.9 Sw31.2 Bw4 5YR6/8 St sbk 5.5 5.6 64.4 55.2 9.2 30.0 16.8 Sw31.5 Bt1 5YR5/8 St sbk–abk 5.8 4.3 66.8 56.3 14.5 28.9 17.3 S41.8 Bt2 5YR5/8 St sbk–abk 5.2 5.8 63.4 44.8 18.6 31.8 16.8 S42.1 Bt3 5YR5/8 St sbk–abk 5.6 4.3 65.8 48.0 18.8 29.8 12.3 S42.4 Bt4 5YR5/8 St sbk–abk 5.0 4.2 66.2 53.0 13.2 29.5 11.8 S42.7 Bt5 5YR5/8 St sbk-platy 5.5 6.7 63.2 49.5 13.7 30.1 13.5 S43.0 Bt6 5YR5/8 St sbk-platy 5.6 5.8 64.3 54.2 10.1 29.8 12.3 S4

Gagal II (L3 — loess-paleosol sequence) — Kangra fans0.4 Bw1 10YR6/6 St sbk 5.8 5.1 74.8 41.3 33.5 19.9 11.4 Sw41.0 Bw2 10YR6/6 St sbk 6.7 7.2 69.4 43.6 25.8 23.3 14.9 Sw41.5 Bw3 10YR6/6 St sbk 5.7 6.8 65.8 42.1 23.7 28.3 16.7 Sw42.0 Bt1 7.5YR6/6 St sbk 5.6 5.2 66.3 50.3 16.0 28.4 15.3 S52.5 Bt2 7.5YR6/6 St sbk-platy 5.6 4.8 65.8 48.6 17.2 29.3 16.4 S53.0 Bt3 7.5YR7/6 St sbk-platy 6.1 3.8 68.9 51.2 17.7 28.6 15.8 S53.5 Bt4 7.5YR6/4 St sbk–abk 6.3 6.7 65.4 45.2 20.2 27.8 16.1 S54.0 Bt5 7.5YR6/4 St sbk 5.8 7.3 68.7 48.2 20.5 24.9 15.3 S54.5 Bt6 7.5YR6/4 St sbk 6.3 4.2 65.2 45.6 19.6 30.5 14.3 S55.0 Bt7 7.5YR6/4 St sbk 6.2 6.4 68.9 44.3 22.6 24.6 11.4 S55.5 Bt8 7.5YR6/6 St sbk-platy 6.4 7.2 69.3 42.3 27.0 24.4 13.2 S56.0 Bt9 7.5YR6/4 St sbk-platy 6.2 8.2 65.6 41.8 23.8 26.1 11.4 S5

Shivnagar Paleosol — Kangra Fans0.5 Bw1 2.5YR3/4 Mod sbk 5.4 28.9 45.5 34.7 10.8 25.5 18.1 Sw51.0 Bw2 2.5YR4/4 Mod sbk 5.5 34.7 39.8 30.3 10.5 25.9 16.4 Sw51.5 Bw3 2.5YR4/4 Mod sbk 5.1 28.3 42.8 33.4 11.4 28.8 17.8 Sw52.1 Bw4 2.5YR3/4 Mod sbk 6.2 30.3 44.3 32.8 11.5 25.3 15.2 Sw5

Gagal I Paleosol — Kangra Fans0.4 Bw1 10YR5/4 Mod sbk 7.6 36.4 52.1 31.8 20.3 11.5 8.9 Sw60.8 Bw2 10YR5/6 Mod sbk 7.4 33.7 46.1 32.0 14.1 20.0 10.5 Sw61.1 Bw3 10YR5/4 Mod sbk 7.4 11.2 79.8 19.4 60.4 8.9 3.4 Sw61.4 Bw4 10YR7/4 Mod sbk 6.1 10.2 77.8 22.6 55.2 12.4 6.5 Sw6

Chimat Paleosol — Palampur Fans0.3 Bw1 10YR6/4 Mas and abk 6.8 8.3 65.0 51.8 13.2 26.6 10.7 Sw70.8 Bw2 10YR5/6 Mas and sbk 6.7 34.8 44.8 31.3 10.5 20.3 10.9 Sw71.3 Bw3 10YR5/6 Mas and sbk 7.5 36.7 35.4 15.2 20.2 27.7 14.8 Sw71.7 Bw4 10YR4/6 Mas 7.6 55.5 20.6 4.7 15.9 24.4 17.8 Sw7

Paror Paleosol — Palampur Fans0.3 Bw1 10YR4/6 Mas and sbk 7.3 45.1 30.5 20.0 5.5 24.3 17.3 Sw80.7 Bw2 10YR4/6 Mas and sbk 6.7 41.8 33.6 26.7 6.9 24.4 12.9 Sw81.4 Bw3 10YR4/4 Mas and sbk 6.7 23.7 55.8 48.9 6.9 34.4 8.9 Sw8

st: Strong, mod: Moderate, mas: Massive, sbk: Subangular blocky, abk: Angular blocky.S1–S5: Strongly developed soils, Sw1–Sw8: Weakly developed soils.

143P. Srivastava et al. / Catena 76 (2009) 135–154

distal part of the fans representing Qf3 depositional surface. Overallthe luminescence age data of the loess-paleosols sequences of thebasin indicate that the deposition of the fan sediments in Qf1 startedprior to 78.6±17.7 ka and continued after 44.2±6.2 ka with reduced

Fig. 5. (a) Representative lithologs of pedosedimentary sequences from Rait-Rihlu fans, Kanloess-paleosol field outcrops showing sharp contacts with gravelly facies: L1— Loess-PaleosoPaleosol from distal part of Kangra fans. Sw1–Sw4: — Weakly developed paleosol, S1–S5: —

rate of sedimentation/depositional breaks and formation of paleosols.The deposition over the younger surfaces extends beyond 30.8±7.7 kaand continues till present with intervening breaks and formation ofpaleosols.

gra fans, and Palampur fans showing gravelly facies and paleosols, (b) Representativel fromRait-Rihlu fans, L2— Loess-Paleosol from proximal part of Kangra fans, L3— Loess-Strongly developed paleosols.

144 P. Srivastava et al. / Catena 76 (2009) 135–154

5.3. Physical and chemical features of paleosols

General features showing physical and chemical characteristics ofthe representative paleosols from Rait-Rihlu, Kangra and Palampur fansare given in Table 4. The loessic paleosols (L1, L2 and L3 loess-paleosolsequences) are marked by multiple episodes of loess formation andvarying degree of pedogenesis (Fig. 5a, b). The L1 loess-paleosol found intheRait-Rihlu fansoverlaps in characterswith L3 loess-paleosol found in

Fig. 6. Particle size distribution of L2 and L3 loess-paleosol sequences showing gradual decreloess formation.

the distal parts of the Kangra fans (Table 4). These are marked bystrongly developedpaleosols (S1, S2, S3 andS5) that are separatedby thepoorly developed (Sw1, Sw2 and Sw4) paleosols. Strongly developedpaleosols of these sequences show reddish-yellow color, strong peds,numerous rhizocretions, dominance of silt fraction (60–70%) and a slightincrease of total clay and fine clay with depth (Table 4). By contrast, thepoorly developed paleosols show yellowish color, weak to moderatepeds, dominant silt (~70%) fraction,with little or no increase in total clay

ase and increase of silt in response to varying strength of cold–dry winds and renowned

145P. Srivastava et al. / Catena 76 (2009) 135–154

and fine clay with depth. The L2 loess-paleosol sequence found inproximal part of the Kangra fans is marked by distinctive pedogenicfeatures in lower (S4) and upper parts (Sw3). In the lower part, it showsreddening (yellowish-red) and well developed pedogenic features(strong peds, numerous rhizocretes, and increase of total clay withdepth). The upper part of this sequence is marked by light color(reddish-yellow), moderate to strong peds with little variation in totalclay and fine clay. In addition, particle size data of these loess-paleosolsshow gradual increase of coarse silt and decrease of fine silt with depth

Table 5Micromorphological characteristics of the paleosols from Rait-Rihlu, Kangra and Palampur

Depth (m) from topof paleosol, horizon

Pedality C/F relateddistribution

b-fabric

L1 — loess-paleosol sequence, Dhanotu, Rait-Rihlu fans0.6 m, Bw1 Weak subangular

blocky20/80, Porphyric Undifferentiated weak

speckled1.1 m, Bt1 Strong subangular

blocky20/80, Porphyric Mod–strong cross-stria

1.5 m, Bt2 Mod–strongsubangular blocky

20/80, Porphyric Moderate cross to reticstriated

4.2 m, Bt5 Strong subangularblocky

10/90, Porphyric Strong cross and reticustriated

4.5 m, Bt6 Mod–strongsubangular blocky

20/80, Porphyric Mod–strong cross-stria

L2 — loess-paleosol sequence, Iku, Kangra Fans0.3 m, Bw1 Weak subangular

blocky30/70, Porphyric Weak stipple speckled

1.5 m, Bt1 Strong subangularblocky and platy

20/80, Porphyric Strong cross and parall

2.1 m, Bt3 Strong subangularblocky and platy

20/80, Porphyric Strong cross and reticustriated

3.0 m, Bt6 Moderate subangularblocky

10/90, Porphyric Moderate to strong croreticulate striated

L3 — loess-paleosol sequence, Gagal-II, Kangra Fans0.4 m, Bw1 Weak subangular

blocky20/80, Porphyric Weak stipple speckled

1.5 m, Bt3 Mod–strongsubangular blocky

30/70, Porphyric Moderate to strong cro

2.5 m, Bt2 Moderate subangularblocky

30/70, Porphyric Moderate to strong cro

3.5 m, Bt4 Strong subangularblocky

30/70, Porphyric Strong cross and reticustriated

4.5 m, Bt6 Strong subangularblocky

30/70, Porphyric Strong cross and reticustriated

Gagal-I Paleosol — Kangra Fans0.4m, Bw1 Apedal to weak

subangular blocky70/30, 100–200 µmquartz, micas

Weak stipple speckled

1.1m, Bw3 Weak subangularblocky

80/20, 100–200 µmquartz, micas

Weak stipple speckled

1.4m, Bw4 Apedal to weaksubangular blocky

80/20, 100–200 µmquartz, micas

Weak stipple speckledstriated

Chimat Paleosol — Palampur Fans0.3m, Bw1 Apedal to weak

subangular blocky40/60, 100–200 µmquartz, mica mineralgrains

Undifferentiated to weaspeckled

0.8m, Bw2 Moderate subangularblocky

20/80, Porphyric Moderate cross and retstriated

1.3m, C1 Apedal and massive 60/40, 100–200 µmquartz, mica, rockfragments

Undifferentiated to weaspeckled

Paror paleosol — Palampur Fans0.3m, Bw1 Apedal and massive 80/20, 200–300 µm

quartz mica mineralgrains

Undifferentiated to weaspeckled

0.7m, Bw2 Weak subangularblocky

80/20, 200–300 µmquartz mica mineralgrains

Weak–moderate stippleand cross striated

(Fig. 6). This variation is likely to have resulted in response to the varyingstrength of prevailing cold–dry winds and renewed deposition of silt.

The other paleosols developed on overbank and debris flowsediments are marked by weakly expressed pedofeatures (Table 4,Fig. 5: Pathej in Rait-Rihlu fans; Gagal-I inKangra fans; Chimat and Parorin Palampur fans). These are characterised by pale yellow to yellowishbrown color, massive to subangular blocky and platy structures, a fewrhizocretes, and varying proportions of silt and sand fractions withdepth.

fans of the Kangra basin

Clay pedofeatures Remarks

stipple Few thin (20–30 µm)clay coatings

Weak pedogenesis with fewmineralized roots

ted 1–2%, thick (100–150 µm)microlaminated clay coatings

Mod–strongly developed pedofeatureswith 2–3% mineralized roots

ulate 1–2%, thick (50–100 µm)impure clay coatings

Mod–strong pedogenesis with 2–3%mineralized roots

late 2–3%, thick (100–200 µm)impure clay coatings

Strong pedogenesis with 3–4%mineralized roots

ted 2–3%, thick (100–200 µm)impure clay coatings

Strong pedogenesis with 3–4%mineralized roots

Few thin (20–30 µm) claycoatings

Weakly developed pedogenic featureswith 2–3% mineralized roots

el striated 1–2% clay coatings of impureclay and silty clay

Strong pedogenesis with mineralizedroots, fragmented clay pedofeatures andfabric features

late 1–2% clay coatings of impureclay and silty clay

Strong pedogenesis with mineralizedroots, fragmented and laminated claypedofeatures

ss and ~1% clay coatings of impureclay

Moderate pedogenesis with few fabricfeatures and laminated clay pedofeatures

Few thin (20–30 µm) claypedofeatures

Weak pedogenic features

ss striated 1–2%, (100–200 µm) thickclay pedofeatures

Strong pedogenesis with 2–3% mineralizedroots and few charcoal fragments

ss striated 1–2%, (100–200 µm) thickclay pedofeatures

Strong pedogenesis with 2–3% mineralizedroots and few charcoal fragments

late 2–3%, (100–500 µm) thickclay pedofeatures

Strong pedogenesis with 2–3% mineralizedroots and few charcoal fragments

late 2–3%, (100–500 µm) thickclay pedofeatures

Strong pedogenesis with 2–3% mineralizedroots and few charcoal fragments

Few thin (20–30 µm) claycoatings

Weak pedogenic features

Few thin (20–30 µm) claycoatings

Weak pedogenic features

and cross Few thin (20–30 µm) claycoatings

Weak pedogenic features with fewmineralized roots

k stipple Few thin (20–30 µm) claycoatings

Weak pedogenic features

iculate Few thin (30–40 µm) claycoatings

Weak to moderate pedogenic features

k stipple No clay pedofeatures No pedogenic features

k stipple No clay pedofeatures No pedogenic features

speckled Few thin (20–30 µm) claypedofeatures

Weak pedogenic features

146 P. Srivastava et al. / Catena 76 (2009) 135–154

5.4. Micromorphology

Fine detailing of these paleosols was carried out by micromor-phological studies of 52 thin sections. The results are summarized inTable 5 and are briefly described here. The loess-paleosols (L1–L3)developed in the proximal and distal settings of the fans showstrongly developed pedofeatures separated by weakly pedogenisedfeatures on loess. Micromorphology of L1 loess-paleosols from Rait-Rihlu fans confirms three distinct strongly developed horizons (S1–

Fig. 7. Representativemicromorphological features of L1–L3 loess paleosols. (a) L1 loess-paleBt2 horizon, 1.5 m depth, (b) Thick (N100 µm) pure clay pedofeatures along voids (marked byarrow), Bt2 horizon, 1.5 m depth, (d) Massive to weak subangular blocky structure with thinby arrow) and stipple speckled b-fabric, Bw2 horizon, 4.8 m depth, fragment, (f) weakmicrostructure, Bw1 horizon, 0.6 m depth, (g) L2 loess-paleosol showing strong pedality wi(N100 µm) pedofeatures, Bt2 horizon (marked by arrow), 1.8 m depth, (i) Strong plasma sepaleosol showing strong angular blocky structure with clay coatings along ped walls, Bt2 ho2.5 m depth, (l) Thick microlaminated clay infillings, Bt2 horizon, 2.5 m depth, (m) Wedge(n) Silty clay pedofeatures along a root channel and weak plasma separation, Bw2 horizon, 0Bw3 horizon, 0.9 m depth.

S3) showing strong pedality, strong plasma separation with cross toreticulate striated b-fabrics, N1% textural pedofeatures, and largeamount of plant remains/macro-fossils (Fig. 7a,b,c). Thin sections fromweakly developed soil horizons (Sw1–Sw2) are marked by weakpedality, undifferentiated plasma and stipple-speckled b-fabrics, anda few thin clay (30–40 µm) pedofeatures (Fig. 7d,e,f). Representativethin sections of L2 and L3 loess-paleosols from proximal and distalparts of the Kangra fans show strongly developed pedofeatures inlower horizons (S4–S5) and weakly developed pedofeatures in upper

osol showing strong pedality as well accommodating subangular to angular blocky peds,arrow), Bt3 horizon, 3.5 m depth, (c) Partially decayed and mineralized root (marked byclay coatings, Bw2 horizon, 4.8 m depth, (e) Thin (20–30 µm) clay pedofeatures (markedplasma separation showing stipple speckled to undifferentiated b-fabric and spongyth well developed subangular blocky structure, Bt2 horizon, 1.8 m depth, (h) thick clayparation marked by reticulate striated b-fabric, Bt2 horizon, 1.8 m depth, (j) L3 loess-rizon, 2.5 m depth, (k) Thick (N500 µm) microlaminated clay pedofeatures, Bt2 horizon,shaped fabric feature consisting of laminated silt and clay, Bw2 horizon, 0.6 m depth,.6 m depth, (o) thin clay pedofeatures along a root channel and weak plasma separation,

147P. Srivastava et al. / Catena 76 (2009) 135–154

horizons (Sw3–Sw4). The strongly developed pedofeatures fromlower horizons are marked by strong pedality, dominance of 50–60 µm size quartz and mica in the coarse faction (c/f at 20 µm limit),reticulate and cross-striated birefringence fabrics, and N1% texturalpedofeatures (Fig. 7g,h,i). The textural pedofeatures are polygeneticand are similar in both the paleosols, but in the distal settings theyoccur in larger amounts (4–5%) and show more thickness (500–1000 µm) (Fig. 7j,k,l). In addition, fabric features of reworked soils asbow-shaped and wedge shaped features, partially to highly decayedroots and charcoal fragments also occur in the strongly developed soilhorizons (Fig. 7m). Upper horizons of these sequences (Sw1–Sw4)show weak pedality, few thin clay pedofeatures and undifferentiatedto stipple speckled b-fabrics (Fig. 7n,o). Overall, weakly expressedpedofeatures in Sw1–Sw4 correspond to Inceptisol order and stronglydeveloped pedofeatures of S1–S3 correspond to Alfisol order.

The thin sections of the paleosols developed on overbank deposits oftheKangra andPalampur fans showweakpedality, fewcarbonized rootsand plant macrofossils (Fig. 8a,b). Groundmass of these paleosols ismarked by a large variation of the grain size with c/f ratio ranging from60/40 to 40/60 (Fig. 8d). The coarse fraction consists of sub angular toangular rock fragments and mineral grains of quartz and feldspars of100–200 µm sizes. The fine fraction consists of impure silty clay andorganic matter and shows only weak plasma separation, which ismarked by undifferentiated to weakly developed stipple speckled b-fabrics (Fig. 8e,f). The clay pedofeatures in these paleosols are b1%, andthey occur as thin (20–30 µm) coatings of clay and silty clay (Fig. 8c,d).Partially decayed roots, charcoal and animal activities also occur in thesepaleosols (Fig. 8e). The pedofeatures of low magnitude and intensitysuggest weak pedogenesis of these sediments over short intervals.Overall, very weak to weak pedogenic features over these paleosolssuggest them in Entisol and Inceptisol orders.

5.5. Clay mineralogy

The XRD diagrams of total clay fractions (b2 µm) of paleosols (L1 toL3 loess-paleosols are marked by mica, 10–14 Å mixed layer minerals,vermiculite, kaolin, quartz, and feldspars (Fig. 9a,b). The 10–14 Å mixedlayer minerals are different in weakly developed horizons (Sw1–Sw4)and the strongly developed horizons (S1–S5) of these sequences.Weakly developed horizons (Sw1–Sw4) are characterised by disap-pearance of 14 Å peak with heat treatment and incomplete collapse of

Fig. 8. Representative micromorphological features of weakly–moderately developed paleoshowing massive to weakly developed subangular blocky structure, Bw2 horizon, 0.8 m dedepth, Chimat paleosol, (c) Thin clay coating as fabric feature (marked by arrow), Bw3 horizfragments, Bw3 horizon, Chimat paleosol, (e) Weakly developed paleosol from Paror showdepth, Paror paleosol, (f) poorly sorted mineral grains and iron rich mottling, Bw2 horizon,

12 Å peak along with reinforcement of 10 Å suggesting the presence ofvermiculite and chlorite layers in the 10–14 Å mixed layer minerals.However, in strongly developed horizons (S1–S5) the vermiculite–chlorite layers do not occur in 10–14 Å mixed layers, but there is amarked increase of interstratified vermiculite-kaolin (Vm/K) (Fig. 9a,b).In the fine clay fraction (b0.2 µm) this pedogenic alteration is morepronounced and is marked by the large amount of interstratifiedminerals (e.g. Vm/K) (Fig. 9b: Fine clay fraction). The presence of Vm/K isindicated bya plateau at low-angle region of kaolin (7.0 Å) peak in the Casaturated samples. On glycolation this peak shifts to 8.0 Å (Fig. 9b).

TheXRDdiagrams of total clay andfine clay fractions of the paleosolsdeveloped on fluvial deposits of Kangra and Palampur fans are markedby well defined peaks of vermiculite, mica, kaolin and feldspars withlittle amount of 10–14 Å minerals (Fig. 9c). The well-defined and sharppeaks of above clay minerals indicate detrital nature and weakpedogenesis of the fluvial overbank deposits.

6. Discussion

6.1. Role of tectonics controlling geomorphology and sedimentology ofthe fans

Evolution of these fan sequences in proximity to the major thrustsheets is related to Late Quaternary alluvial fan building activity of theHimalayan foreland. It began after the cessation of Upper Siwaliksedimentation around 200 ka in response to the development of strongrelief due to the reactivationofMBTand its splays (RangaRaoet al.,1988;Singh et al., 2001). Recent studies of the alluvial fans in the Pinjaur andtheDehradun intermontane valleys in east of the studyarea suggest thatalluvial fan sequences (~96 ka–4.5 ka) evolved unconformably over theUpper Siwaliks with the formation of piggyback basin and reactivationof the major thrust sheets (Singh et al., 2001; Kumar et al., 2003, 2007;Sinha et al., 2007; Suresh et al., 2007).

Present study of the pedosedimentary sequences suggests that thealluvial fan sedimentation in the Kangra basin started prior to 78 ka andcontinues till present in response to tectonics and climatic changes. Thetectonics along theMBTand the transverse faults resulted in subsidenceof the Rait-Rihlu fans and uplift of the Kangra and Palampur fans thatallowed formation of different pedosedimentary sequences over thethree fans. The pedosedimentary sequences over the subsided Rait-Rihlu fans are marked by the dominant fluvial deposits and strongly

sols in Kangra and Palampur fans, (a) weakly developed paleosol from Chimat sectionpth, (b) Massive microstructure with poorly sorted mineral grains, Bw2 horizon, 0.8 mon, Chimat paleosol, (d) Impure silty clay coating (marked by arrow) and large mineraling massive structure and charcoal fragments (marked by arrow), Bw2 horizon, 0.8 m0.8 m depth, Paror paleosol.

148 P. Srivastava et al. / Catena 76 (2009) 135–154

149P. Srivastava et al. / Catena 76 (2009) 135–154

developed loess-paleosols. On other hand, pedosedimentary sequencesover the uplifted Kangra and Palampur fans show predominance ofdebris flows along with strongly developed paleosols on loess andpoorly developed paleosols on overbank deposits. The role of tectonicsin formation of different pedosedimentary sequences in the studyarea issupported fromthe structural historyof theMBT that suggests that it hasbeenactive intermittently since its formation~10Ma (Meigs et al.,1995).The TL dates of the fault gauge also indicate fairly strong reactivation ofMBT during the periods 75–65 ka, 50–35 ka (Singhvi et al., 1994). Theannual average convergence of 14 mm/year noted for the Kangra re-entrant also suggests the area is tectonically active (Powers et al., 1998).Geomorphic and sedimentological features of the alluvial fans describedhere are similar to themarginal alluvial fans affected by the reactivationof fold thrust sheets of the foreland regions from Ebro basin and centralAndes (Horton and DeCelles, 2001; Arenas et al., 2001). For exampleArenas et al. (2001) demonstrated the evolution of alluvial fans withdistributary fluvial system that are marked by progradation of fluvialconglomerate in response to uplift in Pyrenean Ranges.

Role of the tectonics is further documented by the geomorphicexpressions of these fans, which in turn, are related to the dominantsedimentary processes. For example the western part of the presentstudy area is marked by low relief, low gradient, broad channels andfluvial dominated processes. By contrast central and eastern parts arecharacterised by moderate–high relief, steep gradient, incised land-forms, V-shaped channels, and debris flow formative processes. Thetopographic manifestation of the three fans in the longitudinal riverprofiles suggests that the Rait-Rihlu fans are aggradational, whereas theKangra and the Palampur fans are marked by the incision throughoutthe fans (Fig. 4). This is in agreementwith themodel river profiles of theaggrading and dissecting alluvial fans (Harvey,1984,1987,1996). The re-activation of the MBT and its splays and nearly vertical nature ofmovements along the transverse faults played an important role insubsidence/uplift and segmentation that modified relief of these fans.This interpretation is supported by the delineation of several lineamentsand faults that trend parallel and normal to theMBT in the Kangra basinandwere activatedduringQuaternary time (KumarandMahajan, 2001).In addition to several E–W lineaments, Paror Anticline is the majorstructure trending parallel to the MBT in the study area (Fig. 1c). Theanticline is a fault propagation fold plunging southeasterly with avertical-overturned southern limb (Raiverman et al., 1990; Powers et al.,1998). The drainage deflection along the axial trend of this majorstructure over Kangra and Palampur fans (Fig. 3b) and the longitudinalriver profiles (Fig. 4) suggest that the alluvial fans were affected by theright lateral slipmovement along this fault propagation fold (Raiverman,2002). It is likely that movement along this E–Wtrending structure alsopromoted segmentation and incision of the fans by N–S trending faults.

Nearly vertical movement along the N–S trending Chambi-Gaj faultresulted in the subsidence, fluvial dominated aggradation and low reliefover the western block covered by the Rait-Rihlu fans. The adjacentblock coveredby theKangra fanswasuplifted and subjected to extensiveincision and pedimentation. The incision occurring in the Kangra fans ismarked by rapid down cutting, lack of well-developed floodplains andV-shaped channels and erosion in the toe region. In addition, a couple oflarge patches of older fan sediments/Siwaliks hills surrounded by thealluvial fan sediments occur as the prominent pediments in central partof the Kangra fans (Fig. 3a). Formation of these pediments may beattributed to the dynamic equilibrium between the rate of uplift andlateral erosion by the rivers (Bull, 1990; Singh et al., 2001). Thisinterpretation finds support from a recent study by Singh et al. (2001)who reported similar pediments in alluvial fans of Dehradun which isabout 200 km east of the present study area. The segmentation of the

Fig. 9. Representative XRD diagrams of total clay (b2 µm) and fine clay (b0.2 µm), (a) L2 loesfans), (b) L2 loess-paleosol, strongly pedogenised horizon (Bt3 horizon, 2.1m depth, Iku sectio0.7 m depth); I—Ca saturated, II—Ca saturated and glycolated, III—K saturated at 25 °C, IV—K sheated to 550 °C; Vm—Vermiculite, M—Mica, K—Kaolin, Q—Quartz, F—Feldspar, Vm/K—inte

Palampur fans was possibly caused by movement along the N–Strending Neogal fault coupledwith differential uplifting. Itwas followedby westward tilting of the segmented surface that resulted inprogressive shifting of theNeogal river leaving behind unpaired terracesand paleochannels (Fig. 3b,c). The unpaired terraces covered by theimmature soils and lithological sequences similar to the Qf3 sedimentsindicate that segmentation occurred during latter stages of the alluvialfans evolution. The terraces are subject to active deformation inresponse to the differential uplift, tilting and incision (Lave and Avouac,2000). Tilting of the fan segment reported here is in agreementwith theobservation of Singh and Tandon (2007), who recorded SW tilting andmigration of the streamsand the formationof unpaired terraces over thealluvial fans of Pinjaur dun in an area about 150 km SE of the presentarea. The telescopic segmentation and tilting of the alluvial fansdescribed here is similar to the segmentation of the alluvial fans fromthe Sfakian piedmont, Crete in response to the differential uplift andincision (Pope et al., 2008).

The thick gravelly facies of sub-angular to sub-rounded pebbles andboulders occurring as cohesive debris flow deposits in proximal parts ofthe Kangra and Palampur fans, represents the syntectonic growth of thegravelly facies in response to the reactivation and upheaval along theMBT. This is in continuation of the syntectonic gravel progradation thatbegan around 10 Ma in response to the episodic reactivation of MBT(Burbank et al., 1988; Meigs et al., 1995; Brozovic and Burbank, 2000).Luminescencedates (~78ka–44ka) of thewell developed loess-paleosolassociated with these gravels suggest the reactivation of MBT and itsimbricates in the area prior to 78 ka and after 44 ka. This is furthersupported by the fact that the well developed loess-paleosols (~30 ka–20 ka) inmiddle and distal parts are underlain by thick gravelly facies. Itis in agreement with extensive growth of syntectonic gravelly facies indifferent parts of the Himalayan foreland basin during evolution ofQuaternary alluvial fans (Kumar and Tandon, 1985; Kumar et al., 1999,2003, 2007; Singh et al., 2001; Suresh et al., 2007). These observationssuggest that tectonics along the MBT and regional faults has been themajor controlling factor in formation of thesemarginal alluvial fans thatevolved only after the initial structural growth of the Kangra re-entrantand the cessation of Siwalik sedimentation around 200 ka.

6.2. Loess-paleosols of the Kangra basin

The terrestrial sedimentary record of the Quaternary period ismarked by the formation of extensive loess in many parts of the worldsuch as Central Asia, China, North America, South America, Europe,North Africa and New Zealand (Pye,1995; Derbyshire et al.,1995; Kemp,2001; Mason et al., 2008). Formation of the vast loess during theQuaternaryperiod is primarily related to the cold–dryclimateswhen theglaciers advanced followed by pedogenic modification of the loessduring thewarmer–wetter climateswhen glaciers retreated (Catt,1991;Derbyshire et al., 1995; Kemp, 2001). The loess-paleosols of theQuaternary period are generally regarded as one of the best terrestrialequivalents of the marine oxygen isotope records (Catt, 1991; Kemp,2001). The loessic paleosols over the loess plateau of China in particularhave been well studied and provide unparalleled proxy record ofclimatic changes comparable to ocean sediments (Kukla, 1987; Rutteret al., 1990; An et al., 1991; Kemp and Derbyshire, 1998).

The formation of loess also occurred over the southern Himalayas inresponse of the advance and retreat of the glaciers during Quaternarytimewith spread of loess over Potwar Plateau, Peshawar basin, Kashmirintermontane basin, Pinder and Alaknanda river basins, and forelandregions (Porter, 1970; Rendell, 1989; Rendell et al., 1989; Krishnamurthyet al., 1982, Gupta et al., 1991; Shah and Srivastava, 1992; Owen et al.,

s-paleosol, weakly pedogenised horizon (Bw2 horizon, 0.6 m depth, Iku section, Kangran, Kangra fans), (c)Weakly developed paleosol from Paror, Palampur fans (Bw2Horizon,aturated and heated to 110 °C; V—K saturated and heated to 300 °C, VI—K saturated andrstratified vermiculite and kaolin.

150 P. Srivastava et al. / Catena 76 (2009) 135–154

1992; Gardener et al., 1994; Pant et al., 2005). These studies clearlydemonstrate that loessic deposits spread over different parts of thesouthern Himalayas, were derived locally from the matrix rich glacialoutwash, fan surfaces, braided river channels and reworking along theslopes. The loessic deposits are related to weakened monsoon andglacial advance that were subjected to varying degree of pedogenesisduring interglacial periods (Gardener et al., 1994; Pant et al., 2005).Despite these studies from different parts of the southern Himalayasthere is no information available on the pedogenic modification of theloess fromKangra basinwhich lies in closeproximity to thepresent limitof southwest monsoon (Morrill et al., 2003). It is likely that loess-paleosol record from this region holds key to the Late Quaternarypaleoenvironmental details of the NW Himalayas.

Ourfield investigation of the alluvial fans of theKangra basin suggeststhat yellowish-brown to reddish-brown loessic deposits with varyingdegreeof soil formationconstitute an important sedimentarycomponentof the fan deposits in proximal and distal settings. These loess-paleosolsequences show sharp contacts with the underlying and overlyinggravelly sediments (Fig. 5a,b). These are more widespread in the distalparts where they unconformably overlie the gravelly deposits and aresubjected to extensive erosion (Fig. 5b). The twomajor episodes of loess-paleosol sequences (L1, L2/L3) identified from the alluvial fans of theKangra region show similar pedogenic features that formed at differentsettings. In proximal parts formation of loess took place at 78.6±17.7 ka–44.2±6.2 ka, whereas in distal parts it formed at 30.8±7.7–19.9±3.5 katime intervals.

Field characteristics, grain size, micromorphology and clay miner-alogy of these loessic deposits suggest that extensively pedogenisedhorizons in lower parts are separated by unmodified loess to weaklypedogenised loess in upper horizons. This interpretation is supported bythe several observations such as; strongly developed pedofeatures aremore conspicuous in lower horizons in comparison with the weaklypedogenised upper horizons (Fig. 5, Table 4). X-ray diffraction of the claymineral fractions of the lower horizons is marked by a large amount ofinterstratified vermiculite-kaolin (Vm/K) minerals with little or noamount of Vm/K in upper horizons (Fig. 9a,b). Formation of the Vm/K isassociated with soils developed in humid climates where it forms animportant ephemeral stage during transformation of vermiculite tokaolinite (Herbillon et al., 1981; Pal et al., 1987; 1989; Bhattacharyyaet al.,1993; Srivastava et al.,1998). The presenceof large amountof Vm/Kin lower horizons of these loess-paleosols indicates advance stage ofweathering as compared to upper horizons. This is also evident fromweathering features of the minerals that show more weathering ofbiotite in the lower horizons. In addition, the lower horizons also showmore clay pedofeatures than upper horizons. These evidences clearlydemonstrate that extensive pedogenicmodification of the loess in lowerhorizons occurred during warm–humid climate with limited supply ofthe eolian silt. Weakly developed soils in upper horizons suggestacceleration of the loess accumulation and limited pedogenesis whenglaciers readvanced during cold-arid climatic conditions. This inter-pretation alsofinds support from the textural data that showdominanceof silt fraction (50–2 µm) and large variation of coarse and fine silt withdepth indicating varying strength of cold–dry winds and fresh buildupof loess in upper horizons (Fig. 6; Table 4). The loessic deposits describedhere are similar to the southern Himalayan loessic deposits, whichwerederived locally from exposed matrix rich fan surfaces, flood plains,channels and reworking along the valley slopes during colder–direr andwindier conditions.

Here, it becomes important to discuss the role of long distancetransport of the atmospheric dust/aerosol that can influence eolianinput and soils formation as reported fromBarbados islands (Muhs et al.,1987). In lightof themodernand LateQuaternaryaerosol record from icecores of Himalayas and themarine sediment cores fromArabian sea it isdifficult to reconcile that prevailing jet streams could have depositedthick (3–8 m) silt over the Kangra basin, NW Himalayas. This fact isfurther elaborated from the following observations: (i) Modern input of

aerosol in adjoining areas of Kullu-Manali and Nanital was estimated as66–78 µg/m3 of dust that is transported from dry plains by winds at theheight of 3.5–4 km in 5–8 years (Gajananda et al., 2005; Dumka et al.,2008; Basistha et al., in press), (ii) There is no visible break/lithologicaldiscontinuity due to aerosols in the ice cores from Higher and TibetanHimalayas that were transported from the vast arid regions of Asia bythe continental airmass (Thompson et al., 2000; Kanget al., 2002). In icecores fromDasuopu (28°3N, 85°43E, elevation 7200m), Dunde (38°06N,96°25E, elevation 5325 m), Guliya (85°17N, 81°29E, elevation 6200 m)average dust accumulation ranged from 1×105–2×105 particles permilliliter despite its increase over the last 500 years (Thompson et al.,2000; Kang et al., 2002). (iii) Variable input of dust in marine sedimentcores from Arabian Sea suggests an increase of dust influx by 60–80%during LGM compared with modern dust transported by the northwesterly winds (Sirocko et al., 1993; Harrison et al., 2001; Pourmandet al., 2004). In light of these observations, it is unlikely that the longdistance transport of dust could have played any role in deposition of thethick loess over Himalayas during Late Quaternary.We conclude that 3–8 m thick silt in the Kangra basin was derived locally from the drylandmass and by reworking along the valley floors during colder–drierand windier conditions of glacial advance in adjoining areas.

6.3. Paleoclimatic implications of the loess-paleosols in the Kangra basin

The paleosols in loessic deposits have great paleoclimatic signifi-cance, as these are indicative ofwarmer andmoister conditionsbetweencold and arid conditions of loess accumulation (Morrison,1978). Recentresearch on loess-paleosols indicates that presence of paleosols in loessdeposits need not necessarily indicate a break in deposition of loess(McFadden, 1988; Kemp and Derbyshire, 1998; McDonald and Busacca,1990; Kemp, 2001). It is more useful to consider the loess-paleosolsequences in terms of interaction between the variable rates of loessdeposition and formation of soils (McDonald and Busacca, 1990; Kemp,2001). It is most likely that extensive accumulation of loess would occurduring glacials and stadials with appreciable rates of sediment supplyand transport in cold–dry climates, and strong pedogenesis will befavored during interglacials or interstadials when sediment supply andtransport are limited during warmer–wetter climates (McDonald andBusacca, 1990; Kemp, 2001).

The well-developed paleosols in loessic deposits of the Kangrabasin described here represent an important soil-geomorphic settingfrom NW Himalayas that is witness to the landscape stability andclimatic changes during the Late Quaternary. Luminescence date fromlower part of loess-paleosol sequence suggests that accumulation ofloess in proximal part of Kangra basin began prior to 78 ka from thebared slopes of Siwalik andDhauladhar ranges. It is expected that upliftassociated with reactivation of MBTand splays and advance of glaciersduring this period facilitated rapid accumulation of loess from baredlandmass in cold–dry conditions. The glacial advance reported over theNWHimalayas during this period supports our interpretation of cold–dry conditions prevailing at 78 ka in the Kangra basin (Owen et al.,2002). It also finds support from the evidence of increased flux ofatmospheric dust in marine sediments of Arabian Sea indicatingweakening of southwest monsoon during this time (Pourmand et al.,2004). The cold–dry conditions were followed by warmer–wetterclimate that ensured formation of strongly developed paleosols inlower part of the sequencewith relative landscape stability and limitedsupply of eolian silt from the valley floors. The presence of weaklydeveloped paleosols to unmodified loess in upper part of this sequencesuggests that the colder–drier conditions returned with rapidaccumulation of loess in proximal part of the Kangra basin.Luminescence date of this weakly pedogenised loess suggests cold–dry conditions were prevailing at 44 ka, which is again supported bythe paleoclimatic history of glacial advance in NW Himalayas (Owenet al., 2002). OSL dates of the glacial deposits of theNWHimalayas fromSwat and Zanskar area cluster at 77–78 ka and 38–40 ka (Owen et al.,

151P. Srivastava et al. / Catena 76 (2009) 135–154

2002). The loess-paleosol sequence described here resulted inresponse to interaction between the variable rates of supply of eoliansilt and pedogenesis during the Late Quaternary and can be describedas accretionary in nature reflecting some degree of syndepositionalpedogenesis (McDonald and Busacca,1990; An et al., 1991; Markewichet al., 1998; Mestdagh et al., 1999; Kemp, 2001).

Another episode of loess formationoccurred at 30.8±7.7–19.9±3.5 kamainly in distal parts of the fans. The luminescence dates indicative ofthe depositional ages of the loess suggest cold–dry conditions andadvance of glaciers in the NW Himalayas during this time. The loess-paleosol sequence of the distal part is similar to the sequence inproximalpart with extensive pedogenic activity in lower horizons and poorlydeveloped paleosol in upper part. This is also an accretionary loess-paleosol sequence similar to the sequence of proximal part. The greaterthickness of loess-paleosol sequence in distal parts indicates that rate ofloess accumulation in distal parts wasmuch higher than the rate of loessaccumulation in proximal parts.

A correlation of the glacial deposits with marine oxygen isotoperecord and atmospheric dust in marine sediments suggests that theglaciers in NWHimalayas advanced and SWmonsoonweakened duringthe cooling intervals of MIS5 and MIS3 (Owen et al., 2002, 2005;Pourmand et al., 2004). In Kangra basin, rapid build up of loess occurredduring these cold–dry intervals and subsequent pedogenesis took placeduring warmer–wetter episodes. In a recent study it was demonstratedthat pedogenic features of the paleosols found in pedosedimentarysequences of the Himalayan foreland provide important paleoenviron-mental details that can be broadly correlated with the oceanicpaleoclimatic records of global significance (Srivastava et al., 2007).Micromorphology and pedogenic clay minerals of the loess-paleosols ofthe Kangra basin indicate that formation of thick clay pedofeatures andlarge-scale transformation of vermiculite to Vm/K occurred whensouthwest monsoon strengthened and rainfall increased in the NWHimalayas during Late Quaternary. We interpret that ferruginouspaleosols of the proximal parts of the Kangra fans developed duringthewarm–humid interval associatedwithMIS4 and in distal settings the

Fig. 10. Summary diagram showing correlation of pedogenic events of the Himalayan forelaChappell, 2001) andmarine oxygen isotope (MIS after Imbrie et al., 1984), L1–L3:—Loess-palefrom Dehradun intermontane basin (after Singh et al., 2001; Srivastava et al., 2007), GP:—P

thick ferruginous paleosols developed during the warming associatedwithMIS2 andMIS1 stages (Lambeck andChappell, 2001; Lambeck et al.,2002).

The interpretation of our study in the Kangra basin and itscomparison with the Dehradun Intermontane Valley and the borderingGangetic Plains aredepicted Fig.10,whichshows thepedogenic responseof the Himalayan foreland sediments since 78 ka. A comparison of thepedogenic features developed in paleosols of the foreland suggests thatin general 100–150 cm thick Bt horizons with thick clay pedofeaturesformed at 5 ka–10 ka intervals of warm–humid conditions (Srivastavaet al., 1994, 2007). It is possible that in Kangra basin the periods of soilformation in loess were possibly much extended with thicker Bthorizons. At present it is difficult to asses the rate of soil formation inKangra basin and would require a detailed chronological framework.

The current pedogenic and sedimentary processes operating in thebordering Gangetic Plains are considered as themodern analogue of thepast pedosedimentary sequences of the Himalayan foreland (Srivastavaet al., 1994; Kumar et al., 1996; Singh et al., 1998, 2001; Srivastava et al.,2007). The Gangetic Plains are characterised by polygenetic soils(b13,500 years) with thick clay pedofeatures and pedogenic calciumcarbonate that developedduringfluctuating climate between subhumidand semiarid–arid conditions (Srivastava et al., 1994, 2007; Srivastava,2001; Pal et al., 2003). Studies of the pedosedimentary sequences fromKangra and Dehradun areas suggests that fan building activity in theKangra basin started much earlier than in Dehradun basin. The loessicdeposits (L1 at 78 ka and L2/L3 at 30 ka) occur as an integral componentof fan sequences of the Kangra basin in contrast with no loess inDehradun basin. The pedosedimentary sequences of Dehradun regionvary in age from 50 ka to 10 ka with thick ferruginous paleosolsdeveloped on overbank deposits (Singh et al., 2001; Srivastava et al.,2007). The pedogenic features in paleosols of Kangra and Dehradunregions aremarked by thick clay pedofeatures but no pedogenic calciumcarbonate was found in subsoils of these regions. In contrast pedogeniccalcium carbonate is invariably associated with polygenetic soils of theGangetic Plains (Srivastava, 2001). It appears that topographic and

nd paleosols during the last 78 ka with global sea level fluctuations (after Lambeck andosols from the Kangra re-entrant, D1–D5:—Pedogenic events from alluvial fan sequencesolygenetic soils of the Gangetic Plains (after Srivastava et al., 1994, 1998).

152 P. Srivastava et al. / Catena 76 (2009) 135–154

climatic gradients from west to east and prevailing tectonics along theMBT resulted in older fan building and pedogenesis in theKangra regionthan inDehradunregion. It is also supportedby thepaleoclimatic historyof the glaciers in the surrounding regions, in Kangra the glaciersadvanced at 77–78 ka and in surrounding regions of Dehradun glaciersadvanced at 65 ka (Owen et al., 2002). Absence of loess in alluvialsequences of the Dehradun can be assigned to less proximity of theadvancing glaciers and much wetter conditions that caused frequentoverbank deposition and subsequent pedogenesis in contrast withKangra basin.

7. Conclusions

Our study of the alluvial fan sequences of the Kangra basin suggeststhat the reactivation of the MBT and its imbricates, between N78 ka to30 ka, provided a strong relief that resulted into the formation of alluvialfans sequences with syntectonic growth of the gravelly facies.

Reactivation of the MBT, its splays and transverse faults causedsubsidence, uplift and segmentation of the fans. Displacement along thetransverse faults e.g. the Chambi-Gaj fault and the Neogal fault causedthe subsidence of the Rait-Rihlu fans, the uplift of the Kangra fans andthe tilting of the Palampur fans. Reactivation of the E–W trending faultpropagation fold (Paror Anticline) promoted incision andpedimentationover the Kangra fans and telescopic segmentation of the Palampur fanscaused by the transverse faults.

Loessic deposition around 78 ka–44 ka in the proximal settings and,around 30 ka–20 ka in distal settings, occurred due to the prevailingcold-arid conditions and reworkingof valleyfloor sediments in responseto the advance of glaciers in the adjoining areas of the Kangra region.Extensive pedogenic modification of loess occurred during warm–

humid intervals related to MIS4–MIS1 stages. The interaction betweenvariable rates of loess deposition and pedogenesis resulted in accre-tionary paleosols of the Kangra region.

Rapid aggradation of the gravelly facies and less frequent overbankdeposition marked by tectonic activity allowed only weak pedogenesisof the overbank and debris flow deposits.

A comparison of the late Quaternary pedosedimentary sequences ofthe Himalayan foreland in the Kangra basin and the Dehradun basinindicates similarity in terms of the thick ferruginous paleosols similar tothe present pedogenic activity in the Gangetic Plains. However, theformation of pedosedimentary sequences in the Kangra region beganmuch earlier than in theDehradun intermontane basin. Also, theKangraregion is marked by formation of thick loess-paleosols in contrast withthe thick ferruginous paleosols on overbank deposits of the Dehradunbasin. The alluvial fandeposition andpedogenesis in the twoareas of theforeland suggests that the variations were mainly controlled by theclimatic and the topographic gradient from west to east and thereactivation of the MBT.

Acknowledgements

This researchwas supported by the grants to PS from Department ofScience of Technology, New Delhi, India (SR/S4/ES-8/2003). We thankDr. J. Gerrard and an anonymous reviewer for constructive commentsthat improved the quality of the article. We also thank Dr. D.K. Pal ofNBSSLUP, Nagpur, Prof. B. Parkash of IIT Roorkee for several helpfuldiscussions.

References

Aitken, M.J., 1985. Thermoluminescence Dating. Academic Press, London. 359pp.Allen, M.B., Windley, B.F., Zhang, C., 1991. Active alluvial systems in Korla Basin, Tien

Shanan, northwest China, sedimentation in complex foreland basin. Geol. Mag. 128,661–666.

An, Z.S., Kukla, G.J., Porter, S.C., Xiao, J.L., 1991. Magnetic susceptibility evidence ofmonsoon variation on loess Plateau of Central China during last 130,000 years.Quat. Res. 36, 29–36.

Arenas, C., Millan, H., Pardo, G., Pocovi, A., 2001. Ebro Basin continental sedimentationassociated with late compressional Pyrenean tectonics (north-eastern Iberia):controls on basin margin fans and fluvial systems. Basin Res. 13, 65–89.

Basistha, A., Arya, D.S., Goel, N.K. in press. Analysis of historical changes in rainfall in theIndian Himalayas. Int. J. Climatol. doi:10.1002/joc.1706.

Bhattacharyya, T., Pal, D.K., Deshpande, S.B., 1993. Genesis and transformation ofmineral in the formation of red (Alfisols) and black (Inceptisols and Vertisols) soilson Deccan basalt in the Western Ghats, India. J. Soil Sci 44, 159–171.

Brozovic, N., Burbank, D.W., 2000. Dynamic fluvial systems and gravel progradation inthe Himalayan foreland. Geol. Soc. Amer. Bull. 112, 394–412.

Bull, W.B., 1990. Stream-terrace genesis: implications for soil development. Geomor-phology 3, 351–367.

Bullock, P., Fedoroff, N., Jongerius, A., Stoops, G., Tursina, T., 1985. Handbook of Soil ThinSection Description. Waine Research Publication. 152pp.

Burbank, D.W., Beck, R.A., Raynolds, R.G.H., Hobbs, R., Tahirkheli, R.A.K., 1988. Thrustingand gravel progradation in foreland basins: a test of post-thrusting gravel dispersal.Geology 16, 1143–1146.

Burbank, D.W., Beck, R.A., Mulder, T., 1996. The Himalayan foreland basin. In: Yin, A.,Harrison, T.M. (Eds.), The Tectonic Evolution of Asia. Cambridge University Press,Cambridge, pp. 149–188.

Catt, J.A., 1991. Soils as indicators of Quaternary climatic change in mid-latitude regions.Geoderma 51, 167–187.

Clevis, Q., De Boer, P.L., Nijman,W., 2004. Differentiating the effect of episodic tectonismand eustatic sea level fluctuations in foreland basins filled by alluvial fans and axialdeltaic systems: insight from a three dimensional stratigraphic forward model.Sedimentology 51, 809–835.

DeCelles, P.G., Tolson, R.B., Graham, S.A., Smith, G.A., Ingersoll, R.V., White, J., Schimdt,C.J., Rice, R., Moxon, I., Lemke, L., Handschy, J.W., Follo, M.F., Edwards, D.P., Cavazza,W., Cladwell, M., Bargar, E., 1987. Laramide thrust generated alluvial fan sedimenta-tion, Sphinix Conglomerate, southwestern Montana. Am. Assoc. Pet. Geol. Bull. 71,135–155.

Derbyshire, E., Kemp, R.A., Meng, X.M.,1995. Variations in loess and paleosols properties asindicators of paleoclimatic gradients across the loess plateau of North China. Quat. Sci.Rev. 14, 681–697.

Dubey, A.K., Bhakuni, S.S., Selokar, A.D., 2004. Structural evolution of the Kangra recess,Himachal Himalaya: a model based on magnetic and petrofabric strains. J. AsianEarth Sci. 24, 245–258.

Dumka, U.C., Moorthy, K.K., Pant, P., Hegde, P., Sarar, R., Pandey, K., 2008. Physical andoptical characteristics of atmospheric aerosols during IVARB at Manora Peak,Nainital: a sparsely inhabited, high-altitude location in the Himalayas. J. Earth Syst.Sci. 117, 399–405.

Gajananda, K., Kuniyal, J.C., Momin, G.A., Rao, P.S.P., Safai, P.D., Tiwari, S., Ali, S., 2005.Trend of atmospheric aerosols over the north western Himalayan region, India.Atm. Env. 39, 4817–4825.

Gansser, A., 1964. Geology of the Himalayas. Interscience, London. 289pp.Gardener, R.A.M., London, H.M., Brighton, U.K., 1994. Loess, climate and orogenesis:

implications of South Asian loesses. Z. Geomorph. N.F. 38, 169–184.Gupta, S.K., Sharma, P., Juyal, N., Agrawal, D.P., 1991. Loess-paleosol sequence in

Kashmir: correlation of mineral magnetic stratigraphy with the marine paleocli-matic record. J. Quat. Sci. 6, 3–12.

Harrison, S.P., Kohfield, K.E., Roelandt, C., Claquin, T., 2001. The role of dust in climatechange today, at last glacial maximum and in future. Earth Sci. Rev. 54, 43–80.

Harvey, A.M., 1984. Aggradation and dissection sequence on Spanish alluvial fans:influence on morphological development. Catena 11, 289–304.

Harvey, A.M., 1987. Patterns of Quaternary aggradational and dissectional landformdevelopment in the Almeria region, southeast Spain: a dry region tectonicallyactive landscape. Die Erde 118, 193–215.

Harvey, A.M., 1996. The role of alluvial fans in the mountain fluvial systems of southeastSpain: implications of climatic change. Earth Surf. Process. Landf. 21, 543–553.

Herbillon, A.J., Frankart, R., VIievoye, L., 1981. Occurrence of interstratified kaolinite-smectite minerals in red-black soils toposequence. Clay Miner. 16, 195–201.

Horton, B.K., DeCelles, P.G., 2001. Modern and ancient fluvial megafans in the forelandbasin system of the central Andes, southern Bolivia: implications for drainagenetwork evolution in fold-thrust belts. Basin Res. 13, 43–63.

Imbrie, J., Hays, J.D., Martinson, D.G., McIntyre, A., Mix, A.C., Morley, J.J., Pisias, N.G.,Prell, W.L., Shackleton, N.J., 1984. The orbital theory of Pleistocene climate:support from a revised chronology of the marine δ18O record. In: Berger, A.L.,Imbrie, J., Hays, J.D., Kukla, G., Saltzman, B. (Eds.), Milankovich and Climate, Part 1.Reidel, Dordrecht, pp. 269–305.

IMD (Indian Meterological Department), 1989. Climate of Uttar Pradesh. Govt. of IndiaPublication, pp. 372–375.

Jackson, M.L., 1979. Soil Chemical Analysis—Advanced Course. Published by the author,Madison, WI, USA.

Johnson, G.D., Opdyke, N.D., Tandon, S.K., Nanda, A.C., 1983. The magnetic polaritystratigraphy of the Siwalik Group at Hartyalnagar (India) and a new last appearancedatum for Ramapithecus and Shivapithecus in Asia. Palaeogeogr. Palaeoclimatol.Palaeoecol. 44, 223–249.

Jolly, E.J., Turner, P., Williams, G.D., Harteley, A.J., Flint, S., 1990. Sedimentologicalresponse of an alluvial system to Neogene Thrust tectonics, Atacama Desert,Northern, Chile. J. Geol. Soc. Lond. 147, 769–784.

Jongerius, A., Heintzberger, G., 1963. Methods in Soil Micromorphology: A Technique forthe Preparation of Large Thin section. Soil Survey Paper 10. Netherlands Soil SurveyInstitute, Wageningen. The Netherlands.

Kang, S., Mayewski, P.A., Qin, D., Yan, Y., Hou, S., Zhang, D., Ren, J., Kruetz, K., 2002.Glaciochemical records from a Mt. Everest ice core: relationship to atmosphericcirculation over Asia. Atmos. Environ. 36, 3351–3361.

153P. Srivastava et al. / Catena 76 (2009) 135–154

Kemp, R.A., 2001. Pedogenic modification of loess: significance for paleoclimaticreconstructions. Earth Sci. Rev. 54, 145–156.

Kemp, R.A., Derbyshire, 1998. The loess soils of China as records of climatic change. Eur.J. Soil Sci. 49, 525–539.

Krishnamurthy, R.V., DeNiro, M.J., Pant, R.K., 1982. Isotope evidence for Pleistoceneclimatic changes in Kashmir, India. Nature 298, 640–641.

Kuhle, M., 2001. The maximum ice age (LGM) glaciation of the Central- and SouthKarakoram: an investigation of the heights of its glacier levels and ice thickness aswell as lowest prehistoric ice margin positions in Hindukush, Himalaya and in East-Tibet on Minya Konka Massif. In: Kuhle, M. (Ed.), Glaciogeomorphology andPrehistoric Glaciation in the Karakoram and Himalaya. Tibet and High Asia (VI).GeoJournal, vol. 54, pp. 109–396.

Kuhle, M., 2005. In: Kuhle, M. (Ed.), The maximum ice age (Wurmian, Last Ice age, LGM)glaciation of the Himalaya— a glaciogeomorphological investigation of glacier trimlines, ice thickness and lowest former ice margin positions in the Mt. Everest-Makalu-Cho Oyu Massifs (Khumbu and Khumbakarna Himal) including informa-tion on late glacial, neoglacial and historical glacial stages, their snowlinedepressions and ages. Geojournal, vol. 62, pp. 193–650.

Kuhle, M., 2007. The past glacier network in the Himalayas and Tibetan ice sheet duringthe last glacial period and its glacial-isostatic, eustatic and climatic consequences.Tectonophysics 445, 116–144.

Kukla, G., 1987. Loess stratigraphy in Central China. Quat. Sci. Rev. 6, 191–219.Kumar, S., Mahajan, A.K., 2001. Seismotectonics of the Kangra Region, NW Himalayas.

Tectonophysics 331, 359–371.Kumar, R., Tandon, S.K., 1985. Sedimentology of Plio-Pleistocene late orogenic deposits

associated with intraplate subduction—the Upper Siwalik sub-Himalaya, India.Sediment. Geol. 42, 105–158.

Kumar, R., Ghosh, S.K., Sangode, S.J., 1999. Evolution of a fluvial system in a Himalayanforeland basin, India. In: Macfarlane, A., Sorkhabi, R.B., Quade, J. (Eds.), Himalayanand Tibet: Mountain Roots to Mountain Tops. Geol. Soc. Am. Spec. Paper, vol. 328,pp. 239–256.

Kumar, R., Ghosh, S.K., Mazari, R.K., Sangode, S.J., 2003. Tectonic impact on the fluvialdeposits of Plio-Pleistocene Himalayan foreland basin, India. Sediment. Geol. 158,209–234.

Kumar, R., Suresh, N., Sangode, S.J., Kumarvel, V., 2007. Evolution of Quaternary alluvialfan system in the Himalayan foreland basin: implications for tectonic and climaticdecoupling. Quat. Int. 159, 6–20.

Kumar, S., Parkash, B., Manchanda, M.L., Singhvi, A.K., Srivastava, P., 1996. Holocenelandform and soil evolution of the western Gangetic Plains: implications ofneotectonics and climate. Z. Geomorph. N.F. 103, 283–312.

Lambeck, K., Chappell, J., 2001. Sea level change through the last glacial cycle. Science292, 679–686.

Lambeck, K., Esat, T.M., Potter, E., 2002. Links between climate and sea levels for the pastthree million years. Nature 419, 199–206.

Lave, J., Avouac, J.P., 2000. Active folding of fluvial terrace across Siwalik Hills, Himalayasof Central Nepal. J. Geophys. Res. 105, 5735–5770.

Markewich, H.W., Wysocki, D.A., Pavich, M.J., Rutledge, E.M., Millard, H., T. Rich, F.J.,Maat, P.B., Rubin, M., McGeechim, J.P., 1998. Paleopedology plus TL, 10Be, and 14Cdating as tools in stratigraphic and paleoclimatic investigations, Mississippi RiverValley, USA. Quat. Int. 51/52, 141–167.

Mason, J.A., Miao, X., Hanson, P.R., Johnson, W.C., Jacobs, P.M., Goble, R.J., 2008. Loessrecord of the Pleistocene–Holocene transition on the northern and central GreatPlains, USA. Quat. Sci. Rev. 27, 1772–1783. doi:10.1016/j.quascriev.2008.07.004.

McDonald, E.V., Busacca, A.J., 1990. Interaction between aggrading geomorphic surfacesand the formation of a late Pleistocene paleosol in the Palouse loess of easternWashington state. Geomorphology 3, 449–470.

McFadden, L.D., 1988. Climatic influences on rate and processes of soils development inquaternary deposits of southern California. Geol. Soc. Am. Special Paper, vol. 216,pp. 153–177.

Medlicott, H.B.,1864. On geological structure and relations of the southernportion of theHimalayan Ranges between rivers Ganga and Ravi. Geol. Surv. Ind. Mem. 3, 1–86.

Meigs, A.J., Burbank, D.W., Beck, R.A., 1995. Middle late Miocene (N10 Ma) formation ofthe main boundary thrust in the Western Himalaya. Geology 23, 423–426.

Mestdagh, H., Haesaerts, P., Dodonov, A., Hus, J., 1999. Pedosedimentary and climaticreconstruction of the last interglacial and early glacial loess-paleosol sequence insouth Tadzhikistan. Catena 35, 197–218.

Miall, A.D., 1981. Alluvial Sedimentary Basins: tectonic setting and basin architecture.In: Miall, A.D. (Ed.), Sedimentation and Tectonics in Alluvial Basins. Geol. Ass. Can.Spec. Paper, vol. 23, pp. 1–33.

Molnar, P., Tapponnier, P., 1975. Cenozoic tectonics of Asia: effects of a continentalcollision. Science 189, 419–426.

Morrill, C., Overpeck, J.T., Cole, J.E., 2003. A synthesis of abrupt changes in the Asiansummer monsoon since the last deglaciation. The Holocene 13, 465–476.

Morrison, R.B., 1978. Quaternary soil stratigraphy — concepts, methods and problems.In: Mahaney, W.C. (Ed.), Quaternary Soils. Geo Abstracts, Norwich, pp. 77–108.

Muhs, D.R., Crittenden, R.C., Rosholt, J.N., Busch, C.A., Stewart, K.C., 1987. Genesis ofmarine terrace soils, Barbados, West Indies: evidence from mineralogy andgeochemistry. Earth Surf. Process. Landf. 12, 605–618.

Munsell Soil Color Charts, 1975. Munsell Color Macbeth a Division of KollmorgenCorporation, Mayland 21218.

Murphy, C.P., 1986. Thin Section Preparation of Soils and Sediments. AB AcademicPublishers, Berkhamstead. 149pp.

Nichols, G., Hirst, J.P.P., 1998. Alluvial fans and fluvial distributary systems, Oligo-Miocene,northern Spain: contrasting processes and products. J. Sediment. Res. 68, 879–889.

Owen, L.A., White, H., Rendell, H., Derbyshire, E., 1992. Loessic silt deposits in WesternHimalayas: their sedimentology, genesis and age. Catena 19, 493–509.

Owen, L.A., Finkel, R.C., Caffee, M.W., 2002. A note on the extent of glaciation throughoutthe Himalaya during the global Last Glacial Maximum. Quat. Sci. Rev. 21, 147–157.

Owen, L.A., Finkel, R.C., Barnard, P.L., Haizhou, Ma, Asahi, K., Cafee, M.W., Derbyshire, E.,2005. Climatic and topographic controls on the style and timing of Late Quaternaryglaciation throughout the Tibet and Himalaya defined by 10Be cosmogenicradionuclide surface exposure dating. Quat. Sci. Rev. 24, 1391–1411.

Pal, D.K., Deshpande, S.B., Durge, S.L., 1987.Weathering of biotite in some alluvial soils ofdifferent agroclimatic changes. Clay Res. 6, 69–75.

Pal, D.K., Deshpande, S.B., Venugopal, K.R., Kalbande, K.R., 1989. Formation of di- andtrioctahedral smectite as evidence for paleoclimatic changes in southern andcentral peninsular India. Geoderma 45, 175–184.

Pal, D.K., Srivastava, P., Bhattacharyya, T., 2003. Clay illuviation in calcareous soils of thesemi-arid part of the Indo-Gangetic Plains, India. Geoderma 115, 177–192.

Pant, R.K., Basavaiah, N., Juyal, N., Saini, N.K., Yadava, M.G., Appel, E., Singhvi, A.K., 2005.A 20-ka climate record from Central Himalayan loess deposits. J. Quat. Sci. 20,485–492.

Parkash, B., Sharma, R.P., Roy, A.K., 1980. The Siwalik group (Molasse) sediments shed bycollision of continental plates. Sediment. Geol. 25, 127–159.

Pivnic, D.A., Johnson, G.D., 1995. Depositional response to Plio-Pleistocene forelandportioning in northwest Pakistan. Geol. Soc. Amer. Bull. 167, 895–922.

Pope, R., Wilkinson, K., Skourtsos, E., Triantaphyllou, M., Ferrier, G., 2008. Clarifyingstages of alluvial fan evolution along the Sfakian piedmont, southern Crete: newevidence from analysis of post-incisive soils and OSL dating. Geomorphology 94,206–225.

Porter, S.C., 1970. Quaternary Glacial Record in Swat Kohistan, West Pakistan. Geol. Soc.Amer. Bull. 81, 1421–1446.

Pourmand, A., Marcantonio, F., Schulz, H., 2004. Variations in productivity and eolianfluxes in northeastern Arabian Sea during the past 110 ka. Earth Planet. Sci. Lett.221, 39–54.

Powers, P.M., Lillie, R.J., Yeats, R.S., 1998. Structure and shortening of Kangra and DehraDun reentrants, sub-Himalaya, India. Geol. Soc. Amer. Bull. 110, 1010–1027.

Pye, K., 1995. The nature, origin and accumulation of loess. Quat. Sci. Rev. 14, 653–667.Raiverman, V., 2002. Foreland sedimentation in Himalayan tectonic regime: a reelook at

the orogenic process. Published by Bishen Singh Mahendra Pal Singh, Dehradun,India. 398pp.

Raiverman, V., Kunte, S.V., Mukherjea, A., 1983. Basin geometry, Cenozoic sedimenta-tion and hydrocarbon prospects in northwestern Himalayas and Indo-GangeticPlains. Petrol. Asia J. 6, 67–92.

Raiverman, V., Ganju, J.L., Ram, J., Mishra, V.N., 1990. Geological Map of HimalayanFoothills between Ravi and Yamuna rivers, Scale 1:250000, Oil and Natural GasCorporation, Dehradun.

Ranga Rao, A., Agarwal, R.P., Shrama, U.N., Bhalla, M.S., Nanda, A.C., 1988. Magneticpolarity stratigraphy and vertebrate paleontology of upper Siwalik of the JammuHills. J. Geol. Soc. India 32, 109–128.

Rasanen, M., Neller, R., Salo, J., Jungner, H., 1992. Recent and ancient fluvial depositionalsystems in the Amazon foreland basin, Peru. Geol. Mag. 129, 293–306.

Rendell, H.M., 1989. Loess deposition during Late Pleistocene in Northern Pakistan. Z.Geomorph., Suppl. Bd. 76, 247–255.

Rendell, H.M., Gardener, R.A.M., Awarwal, D.P., Juyal, N., 1989. Chronology andstratigraphy of Kashmir loess. Z. Geomorph., Suppl. Bd. 76, 2213–2223.

Rutter, N., Ding, Z., Evans, M.E., Wang, Y., 1990. Magnetostratigraphy of the Baoji loess-paleosol section in the north-central China loess plateau. Quat. Int. 7–8, 97–102.

Shah, M.P., Srivastava, R.A.K., 1992. Morphology and facies of the alluvial-fansedimentation in the Kangra Valley, Himachal Himalaya. Sediment. Geol. 76, 23–42.

Singh, V., Tandon, S.K., 2007. Evidences and consequences of tilting of two alluvial fansin the Pinjaur dun, Northwestern Himalayan foothills. Quat. Int. 159, 21–31.

Singh, L.P., Parkash, B., Singhvi, A.K., 1998. Evolution of the lower Gangetic plainlandforms and soils in West Bengal, India. Catena 33, 75–103.

Singh, A.K., Parkash, B., Mohindra, R., Thomas, J.V., Singhvi, A.K., 2001. Quaternaryalluvial fan sedimentation in the Dehradun piggyback Basin, NW Himalaya:tectonic and paleoclimatic implications. Basin Res. 13, 449–471.

Singhvi, A.K., Krbetschek, M.R., 1996. Luminescence dating: a review and a perspectivefor arid zone sediments. Ann. Arid Zone 35, 249–279.

Singhvi, A.K., Banerjee, D., Pande, K., Gogte, V., Valdia, K.S., 1994. Luminescence studieson neotectonics events in south-central Kumaun Himalaya — a feasibility study.Quat. Sci. Rev. 13, 595–600.

Singhvi, A.K., Bluszcz, A., Bateman, M.D., Rao Someshwar, M., 2001. Luminescencedating of loess-paleosol sequences cover sands: methodological aspects andpaleoclimatic implications. Earth Sci. Rev. 54, 193–211.

Sinha, R., Kumar, R., Sinha, S., Tandon, S.K., Gibling, M.R., 2007. Late Cenozoic fluvialsuccessions in northern and western India: an overview and synthesis. Quat. Sci.Rev. 26, 2810–2822.

Sirocko, F., Sarnthein, M., Erlenkeuser, H., Lange, H., Arnold, M., Duplessy, J.C., 1993.Century-scale events in monsoonal climate over the past 24,000 years. Nature 364,322–324.

Soil Survey Staff, 1999. Key to soil taxonomy: a basic system of soil classification formaking and interpreting soil surveys, 2nd ed. Agriculture Handbook, No. 436, SCS-USDA. US Govt. Printing Office, Washington, D.C.

Srivastava, P., 2001. Paleoclimatic implications of pedogenic carbonates in Holocenesoils of the Gangetic Plains. Palaeogeogr. Palaeoclimatol. Palaeoecol. 177, 207–222.

Srivastava, P., Parkash, B., Sehgal, J.L., Kumar, S., 1994. Role of neotectonics and climate indevelopment of the Holocene geomorphology and soils of the Gangetic Plainsbetween the Ramganga and Rapti Rivers. Sediment. Geol. 94, 129–151.

Srivastava, P., Parkash, B., Pal, D.K., 1998. Clayminerals as evidence for Holocene climaticchanges of the central Indo-Gangetic Plains, north-central India. Quat. Res. 50,230–239.

154 P. Srivastava et al. / Catena 76 (2009) 135–154

Srivastava, P., Singh, I.B., Sharma, M., Singhvi, A.K., 2003. Luminescence chronometryand late Quaternary geomorphic history of the Ganga Plain, India. Palaeogeogr.Palaeoclimatol. Palaeoecol. 197, 15–41.

Srivastava, P., Singh, A.K., Parkash, B., Singh, A.K., Rajak, M.K., 2007. Paleoclimaticimplications of micromorphic features of Quaternary paleosols of NW Himalayasand polygenetic soils of the Gangetic Plains—a comparative study. Catena 70,169–184.

Suresh, N., Bagati, T.N., Thakur, V.C., Kumar, R., Thakur, V.C., 2007. Evolution ofQuaternary fans and terraces in the intermontane Pinjaur Dun, Sub-Himalaya, NWIndia: interaction between tectonics and climate change. Sedimentology 54,809–833.

Tandon, S.K., Rangraj, S., 1979. Sedimentary tectonics of the Siwalik sequence, south eastof Ravi structural reentrant. In: Saklani, P.S. (Ed.), Structural Geology of theHimalaya: New Delhi. Today and Tomorrow's Printers and Publishers, pp. 273–283.

Thompson, L.G., Yao, T., Thompson, M., Davis, M.E., Henderson, K.A., Lin, P.N., 2000. Ahigh resolution millennial record of the south Asian Monsoon from Himalayan icecores. Science 289, 1916–1919.

Visser, C.F., Johnson, G.D., 1978. Tectonic control of late Pliocene sedimentation in aportion of Jhelum reentrant, Pakistan. Geol. Rundsch. 67, 15–37.

Wobus, C., Heimsath, A., Whipple, K., Hodges, K., 2005. Active out of sequence thrustfaulting in Central Nepalese Himalaya. Nature 434, 1008–1011.