REVUE I)E MICROPALEONTOLOGIE Vol. 43, n ° 4, d6cembre 2000, pp. 301-318

MIDDLE DEVONIAN-TOURNAISIAN MIOSPORE BIOSTRATIGRAPHY IN THE SOUTHWESTERN OUTCROP BELT OF THE PARNAIBA

BASIN, NORTH-CENTRAL BRAZIL

BIOSTRATIGRAPHIE DES AFFLEUREMENTS DU DJEVONIEN MOYEN-TOURNAISIEN DANS LA PARTIE SUD-OCCIDENTALE

D U BASSIN DE PARNAIBA (BRESIL CENTRE-NORD) ~l L'AIDE DE MIOSPORES

by Stanislas LOBOZIAK*, Mtlrio Vicente CAPUTO**, Jos~ Henriq~e G. MELO***

A B S T R A C T . - - This contribution presents the first detailed account of miospore assemblages from outcrop samples of Devonian and Lower Carboniferous rock units exposed along the Tocantms River valley, on the southwestern border of the Parua lba Basra, Brazil. The miospore assemblages are discussed in the light of zonal schemes currently in use for Euramerican as wcll as western Gondwanan areas.

Eight miospore assemblages arc distinguished based on the recognition of selected index species. The six older assemblages are from the Pimenteira Formation and range in age from early Givetian to late early Frasnian. The seventh miospore assemblage concerns the Cabe~as Formation and indicates a latest Famcnnian age. The eighth and youngest miospore assemblage is restricted to the Longfi Formation and points out to an early middle Tournaisian age.

The miospore results in this paper arc compared to previous biostratlgraphic works in correlative Devonian and Lower Carboniferous sections of the Parnalba Basin. They contribute to a better understanding of complex field relationships of regaonal rock units, part icularly as concerns the latest Famenman diamictltes and the underlying glaeio-eustatic unconformity.

RESUME. -- Cette contribution pr6sentc lc premier mventaire d6tadl6 des assemblages de miospores reconnus dans les affleurements du D6vonien et Carbonif~re inf@ieur expos6s le long de la vall6e du Tocantins, sur la bordurc sud-occidentale du Bassin de Parnalba, Br6sil. Les assemblages de miospores sont dlscut6s par rappor t aux sch6mas de zonation actuellement en usage dans les r6gion~ euram6ricaines ainsi que dans le Gondwana occidental.

Huit assemblages de mlospores, bas6s sur la reconnaissance d'espbces reputes s61ectionn6es, oat 6t6 distingu6s. Les six assemblages les plus anciens appart iennent ~ la Formation Pimenteira et s '6tendent du (16but du Giv6tlen ~ la fin du Frasnien inf@ieur. Le septibme assemblage conccrne la Formation de Cahe~as et indique un ~ge Famennien terminal. Le huitlbme et plus jeune assemblage es! restrcmt fi la Formation Longfi et indique un ~ge tonrnaisien moyen lnfSrieur.

Les r6suhats conccrnant les nnospores obtenus dans cette 6rude sont compar6s aux t ravaux de biostratigraphie r6alis6s aut@ieurcment dans des sections 6quivalentes du D6vonien et Carbonif~re inf6rieur du Bassin de Parnalba. Ils conlribuent ~ une meilleure compr6hension des relations complexes sur le ter ra in entre les unit~s l i thostrat igraphiqnes r6gionales, part lculibrement en ce qm concerne les dianncmes du Famennien le plus r6cent et la discordance glacio-eustatique sous-jacente.

Key-words : Miospores Biostratigraphy Devonian - Tournaistan - Parna lba Basin - Brazil.

Mots-clSs : Miospores Biostratlgraph~e - D6vonien - Tournaisien - Bassin de Parnafl , a - Br~sil.

* USTL, UPRESA 8014 du C.N.R.S., Sciences de la Terre, 59655 Vlllcncnve d'Ascq, France. ** UFPA-Centro de GcociSncias, Campus Universitfirio do Guam' , Av. Augusto Correa s/n, 66075-110 Bcl6m, PA, Braz i l *** PETROBRAS/CENPES/DIVEX/SEBIPE, Cidadc Umverslt~ria, Quadra 7, l lha do Fund~o, 21949-900 R~o de Janeiro, RJ,

Brazil.

302 MIOSPORE BIOSTRATIGRAPHY IN BRAZIL

I N T R O D U C T I O N

The Parnalba Basin, also known as the Maranh~o Basin in the older Brazilian geological l i terature, occupies an area of about 600,000 km 2 in north- northeast and north-central Brazil across the states of Cear~, Piaul, Maranh~o, Bahia, Tocantins and Par~ (G6es and Feij6, 1994). Paleozoic sedimentary rocks ranging in age from Ordovician (?)/Silurian to Permian are extensively developed thoughout the basin. They are exposed along its eastern and western margins in the form of broad, relatively continuous outcrop belts aligned NE-SW and N-S respectively, whereas in the central portions of the basin they underlie a thick cover mainly consisting of Meso- zoic/Cenozoic volcanic and siliciclastic units. Struc- tural highs or arches of post-Paleozoic age separate the Parnalba Basin from adjoining Mesozoic basins to the northwest, north and south (Fig. 1).

The study area is located in the northernmost end of the Tocantins State and is geologically situated in the southwestern par t of the Parnaiba Basin. The area is crossed through by the Tocantins River and the Br-153 federal highway (both aligned approxima- tely N-S), and includes the following cities and vil- lages: Paralso do Tocantins, Palmas (the State capital), Miranorte, Miracema do Tocantins and To- cantlnia, Pedro Afonso, Itacaj~, Tupiratins and Co- linas do Tocantins (Fig. 2).

The outcrop samples investigated have been col- lected by various working groups at different times, viz. : in August 1988 by a Petrobras field par ty under the leadership of one of us (J .H.G.M.), and during the years 1993-1995 in the course of geological mapping campaigns carried out by UFPA undergra- duate students under the supervision of M.V.C. The sampled locations are shown in figure 2 and briefly described in Appendix 1.

The aim of this paper is to provide a detailed biostratigraphic account of Devonian and Early Car- boniferous miospore assemblages from outcrops in the Tocantins River region. The proposed biozona- tion takes into consideration standard miospore zonal schemes erected for coeval sections of southern Eu- ramerica (Richardson and McGregor, 1986; Streel et al . , 1987; Higgs et al . , 1988), which have been successfully applied to correlative stratal successions of Brazil, Bolivia and other western Gondwanan regions (Loboziak et al . , 1988, 1991b, 1992, 1993, 1994a-b, 1997a, 1998a-b ; Loboziak and Streel, 1989, 1995a-b ; P6rez-Leyton, 1991 ; etc.). In addition, pre- vious palynological assessments of the Tocantins val- ley outcrops and subsurface sections elsewhere in the

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FIG. 1. - P a r n a l b a B a s i n i n d e x m a p a n d l o c a t i o n o f t h e s t u d y

a r e a ( d a s h e d r e c t a n g u l a r a r e a e n c o m p a s s i n g the s o u t h w e s t e r n c o r n e r o f t h e b a s i n ) . S t r u c t u r a l h i g h s a n d a r c h e s : A - G u a m ~ ; B - T o c a n t i n s ; C - F e r r e r - U r b a n o S a n t o s ; D - S~o F r a n c i s c o .

Carte index du Bassin de P a r n a l b a et Iocalisation de la r@inn 6tudi6e (aire rec taugulaire hachur6e enve loppan t le coin sud-oc- c idental du bassin). Zones ~tructurales hautes et routes f l e x u r a les : A - G u a m d ; B - Tocant ins ; C - Ferrer - Urbano

San tos ; D S~o Francisco.

Parnalba Basin are briefly reviewed in the light of our new results.

S O M E C O N S I D E R A T I O N S O N T H E D E V O N I A N G E O L O G Y O F T H E T O C A N T I N S R I V E R A R E A

GENERAL CHARACTERIZATION OF INVESTIGATED FORMATIONS

A detailed account of the Paleozoic units exposed along the western/southwestern outcrop belt of the Parna lba Basin is beyond the scope of this contri- bution. In the late 50's to the early 80's the region was the subject of successive geological mapping and revaluations (Lamego, 1958; Aguiar, 1961; Moore, 1963; Barbosa et al . , 1966; Ojeda y Ojeda and Perillo, 1967; Andrade, 1968, 1972; Perillo and Nahass, 1968 ; Andrade and Daemon, 1974 ~ Ribeiro

LOBOZIAK, CAPUTO and MELO 303

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FIG. 2. - Sample location map comprising a portion of the Toeantins-Araguaia valley area, in the northernmost part of Tocantins State, Brazil. Sampling stations are represented by solid (black) circles, and main villages and cities by open circles. The figure also shows the

location of Petrobras well 1-CL-1-MA (black circle near Carolina town, Maranh~o State), which is mentioned in the text.

Carte de localisation des dchantillons comprenant une portion de la r@ion de la vallde du Tocantins-Araguaia. dans la partie la plus septentrionale de l'Etat Tocantins, Br6sil. Les endroits d~chantiUonnage soar reprdsent6s par des points (noirs) pleins, et les principaux villages et villes par des points creux. La figure montre dgalement la localisation du sondage Petrobras 1-CL-1-MA (point noir proche

de la ville de Carolina, Etat de Maranh~to) qui est meationnd dans le texte.

et a l . , 1974 ; Silva et a l . , 1974 ; Schobbenhaus Filho et a l . , 1975; Lima and Leite, 1978; Cunha et a l . , 1981; Scislewski et a l . , 1982. In recent years, additional field work and geoh)gieal mapping in the

same region have been undertaken by undergraduate students of Universidade Federal do Pardi (UFPA) under the supervision of one of us (M.V.C.), but these new data still remain largely unpublished.

304 MIOSPORE BIOSTRATIGRAPHY IN BRAZIL

Rock units cropping out in the study area include the pre-Silurian basement and the Itaim, Pimenteira, Cabe~as, Long~, Piaui and Pedra de Fogo Forma- tions, which range in age from Middle Devonian (Eifelian) to Permo-Carboniferous (G6es and Feij6, 1994). Of these Paleozoic units, only the Pimenteira, Cabe~as and Long~ Formations are considered in the present investigation.

The Pimenteira Formation consists of thick sec- tions of dark grey shales and interbedded medium to fine-grained sandstones usually displaying hummocky cross-stratification. Individual sandstone bodies have lenticular shapes but commonly amalga- mate to form thicker, more tabular complexes of strata. The sandstones are best developed in the older, Middle Devonian part of the formation (e .g . , sampling station BR-18 near Paraiso do Tocantins town), but tend to thin out and even disappear in higher sections which become richer in finely-lami- nated dark shales ( e .g . , sampling station BR-26, north of Miranorte village). This probably reflects the deeper marine settings which, according to Ro- drigues et al. (1995), became widespread in the basin during the Frasnian. The Pimenteira Formation is envisaged as a transgressive systems tract deposited mostly in shallow marine environment from the latest Eifelian to possibly the early Famennian 1 (Loboziak et a l . , 1994a-b) under the eventual influence of storm waves (tempestites, after Della Favera, 1990). Paly- nological data presented herein and in previous contributions (Loboziak et a l . , 1992, 1993) suggest that early sedimentation phases of the formation took place along the western border of the Parnaiba Basin practically at the same time as in the more central parts of the basin, thus indicating a very rapid marine flooding event. Although generally resting on the coastal sandstones of the haim Formation throu- ghout much of the basin, the Pimenteira Formation rests directly on Precambrian crystalline basement rocks in the westernmost part of the study area (e .g . , Guarai region, sampling station BR-29, which is palynologically improductive and therefore not shown in figure 2).

The Cabe~as Formation is a regressive sandy unit which at the basin margins rests upon, and basin- wards grades laterally into, the uppermost pelites of the Pimenteira Formation. It comprises a thick sequence of medium- to fine-grained sandstones with

At least in Petrobras well 1-TM-1-MA (Tem-Medo, State of Maranh~o) the uppermost part of the Pnnenteira Formation is within an interval assigned by Loboziak et al. (1994a) to phase zone "V". This latter ~s nowadays considered to include, in its lower part, the Frasnian/Famennian boundary (Streel et al., in press).

conglomerate layers and floaters (dispersed pebbles) in its upper section. In the eastern part the Parnaiba Basin, conspicuous sigmoidal bedding and interbed- ded tempestites (hummocky cross-stratified beds) often occur in the lowermost Cabe~as sandstones, whereas low-angle cross-stratification and massive sandstones displaying fluidization/slump structures tend to prevail higher up in outcrops along both sides of the basin. The sandstones are topped by dark grey diamictites which in turn are overlain by relatively thin (5-10 m) sandstone beds which may be locally absent. In many areas the diamictites rest upon striated pavements carved on the top of the lower sandstone section. On the western flank of the Parnafba Basin the Cabeqas Formation ranges in age from early(?) to latest Famennian (Loboziak et a t . , 1994a-b), although sedimentation may not have been necessarily continuous during all this time span. However, on the eastern flank, where the unit is much thicker (up to 400 m), its base can be as old as Givetian as suggested by marine megafossil data (Melo, 1988).

The Long~ Formation is a transgressive marine shaly unit which immediately overlies the Cabe~as Formation. It comprises a lower member and an upper member of dark grey to black shales, separa- ted by an intermediate member of fine-grained sands- tones which may be locally absent. Wavy/linsen structures, hummocky cross-stratification and varied ichnofossils are commonly associated with the sil- tier/sandier intervals of the formation. The total age span of the formation is latest Famennian to Tour- naisian (Daemon, 1974, 1976 ; Andrade and Daemon, 1974~ Loboziak et a t . , 1992, 1993, 1994a-b).

THE CABE~AS FORMATION GLACIOGENIC STRATA

The tillites and diamictites in the uppermost part of the Cabe~as Formation are indisputably of glacial and glacio-marine origin (Caputo, 1985 ; Caputo and Crowell, 1985). Available lithological evidence inclu- des diantictites with striated, faceted and polished pebbles, rhythmites with dropstones, erratic boul- ders, striated pavements, and glacially deformed sedimentary rocks (sandstones and lodgement tilli- tes). The glaciogenic beds thus far have been inva- riably dated as latest Famennian or ~Strunian~ on palynological evidence (Daemon, 1974, 1976; An- drade and Daemon, 1974; Loboziak et a l . , 1992, 1993, 1994a-b).

It is noteworthy that in sidecuts along the Picos- Floriano highway, in the southeastern part of the

LOBOZIAK, CAPUTO and MELO 305

basin (well beyond the limits of the study area), latest Famennian tillites of the uppermost Cabeqas Forma- tion fill channel-like depressions carved into thick sandstones of the upper par t of the same unit, thus delineating an erosional surface with differentiated relief in outcrops. In the study area (southwestern flank of the basin), the Cabesas Formation is repre- sented by a much thinner sandstone section (40 m and less) often displaying intense, glacially-induced synsedimentary deformation, and likewise topped by tillites. These variations in thickness could be attri- buted par t ly to the erosional removal of the Cabesas Formation 's upper sandstones during the latest De- vonian glaciation. In par t it could also reflect the fact that the unit 's lower sandstone section (possibly Middle Devonian to Frasnian in age and well deve- loped in the eastern par t of the basin) becomes laterally replaced by Pimenteira Formation pelites towards the western and northwestern margins of the Parnalba Basin (Caputo, 1984).

Fur ther westward in the study area, the Cabeqas Formation sandstones are absent so that the rocks underlying the tillites are shales of the Pimenteira Formation, which become increasingly older towards the west as indicated by the new biostratigraphic data. It can be concluded that in this region, the latest Devonian glaciation has removed varied sec- tions of the Pimenteira Formation plus the whole of the ill-developed Cabe~as Formation sandstones. An extreme case is recorded near Colinas do Tocantins village (sampling station CO-l), where latest Famen- nian diamictites assignable to the Cabeqas Formation rest directly on the Precambrian basement and are overlain by dark grey to black shales of the basal Long~ Formation. The absence of any sedimentary strata underneath the tillites could be attributed to either very deep glacial erosion on a local scale or increased coastal onlap along the basin's western margin during the latest Famennian.

In the course of its structural evolution the study area was subject to intense faulting during the Mesozoic. Furthermore, except for some extensive r iverbank and road-sidecut exposures, outcrops are generally sparse because of the deep weathering of surface rocks. Probably for these reasons, previous workers (e .g . , Lima and Leite, 1978) have invoked faulting to explain all instances in which tillites or diamictites were found directly on the Pimenteira Formation, and have ignored the possibility of a widespread glaciogenic unconformity. The new paly- nostratigraphic data in this paper suggest that, in addition to faulting to explain other major causes should also be taken into consideration, such as glacio-eustatic sea-level fall and the destructive effect

of glacial abrasion on pre-existing Devonian forma- tions. This becomes particularly evident from the palynological content of several Cabe~as Formation diamictites and rhythmites, which include a very high proport ion (as much as 95 %, according to Streel et al . , 1993) of reworked Eifelian-Famennian palyno- morphs. The present investigation also detected a massive amount of reworked pre-<<Strunian>> miospo- res in the diamictite sample CO-1, collected from the Cabe~as Formation.

M I O S P O R E B I O S T R A T I G R A P H Y

In most of the investigated samples miospores are numerous, diversified and relatively well preserved, usually displaying orange to pale yellow colours. Other common components~of the organic residue from Devonian samples, not described in this paper , include marine palynomorphs (acritarchs, prasino- phytes, chitinozoans and scolecodonts) and land plant debris (cuticular scraps and woody matter). The vast majority of the palyniferous samples derive from different levels of the Pimenteira Formation, which indisputably displays the best and most exten- sive exposures in the Tocantins valley region. By contrast, the Cabe~as and Long~i Formations have yielded only one productive sample each, as a consequence of scarcer outcrops and/or unsuitable lithologies.

The distribution of the selected miospore taxa identified in the investigated samples is given in figure 3, and their names are listed alphabetically in Appendix 2. All these taxa are known from Devonian and Lower Carboniferous sections of southern Eura- merica and many western Gondwanan areas. Mio- spores recorded in this study include several zonal species of the palynozonations currently in use in western Europe and Old Red Sandstone Continent regions (Richardson and McGregor, 1986; Streel et al. , 1987; Higgs et al. , 1988). Also present in the studied samples are additional species thus far only found in western Gondwana areas, the inception and total range of which have already been evaluated by comparison with miospore successions from the type marine Devonian of Ardenne-Rhenish regions (Lobo- ziak and Streel, 1995a).

On the basis of the new palynological data the dispersed outcrop samples can be grouped and cor- related with different biostratigraphic intervals, all characterized by the first appearance or presence of well-known miospore species with widespread occur- rence in Brazilian Paleozoic basins. In this way, four

306 MIOSPORE BIOSTRATIGRAPHY IN BRAZIL

successive biozones and two less evident zonal ranges have been identified for exposed sections of the Pimenteira Formation. The two remainding san,pies from the Cabeqas and Long~ Formations can be assigned to a distinct biozone each.

The oldest miospore assemblage is highly diversi- fied and has an obvious Middle Devonian aspect. Amongst the diverse taxa are present numerous large-sized pseudosaccate and zonate miospores with prominent spinose sculpture, such as Craspedispora ghadamisensis, Samarisporites eximius, Grandispo- ra douglastownense, G. megaformis, G. protea and G. permulta. Additional forms include several smal- ler, acavate miospores mainly represented by Verru- cosisporites scurrus and V. premnus, Chelinospora ligurata and C. timanica, along with a complex of other patinate specimens bearing a well-developed verrucate/baculate sctdpture (here collectively ter- med Chelinospora sp.). Together with these miospo- res also occur Geminospora punctata and G. lemu- rata. This latter species has the youngest known inception of all taxa from this oldest assemblage, and in terms of the miospore biozonation of the Ardenne- Rhenish regions its first occurrence characterizes the base of the G. lemurata (Lem) Interval Zone, which is the highest subdivision of the A. acanthomammilla- tus - D. devonicus (AD) Oppel Zone (Streel et al., 1987). In the Eifel Massif this biohorizon is located within the ensensis-obliqttintarginattts conodont Zone (Loboziak et al. 1991a), above but very near the base of the hemiansattts conodont Zone which defines the base of the Givetian stage (Walliser et al., 1995). The appearance of Geminospora lemurata also charac- terizes the base of the lemurata-magnificus Assem- blage Zone of Richardson and McGregor's (1986) miospore zonal scheme for the Old Red Sandstone Continent and adjacent regions.

Most of the above-mentioned species persist throu- ghout younger Pimenteira Formation miospore as- semblages. However the succeeding miospore assem- blage contains Samarisporites triangulattts, the first occurrence of which defines the base of the S. triangulatus - A . ancyrea (TA) Oppel Zone in terms of the miospore hiozonation of the Ardenne-Rhenish regions. In the Eifel Massif Samarisporites triangu- latus first appears within the ensensis-bipennatus

conodont Zone of late early Givetian age (Loboziak et al., 1991a). In the Old Red Sandstone Continent and adjacent areas the appearance of Samarisporites triangulatus also defines the base of the optivus- triangulatus Assemblage Zone of Richardson and McGregor (1986).

The next miopore assemblage is characterized by the presence of Chelinospora concinna, a less com- mon and biostratigraphically less reliable species. Its first occurrence characterizes the base of the T. triangulatus - C. concinna (TCo) Oppel Zone as defined in the Ardenne-Rhenish region, within the middle to upper varcus conodont Zones of early late Givetian age (Loboziak and Streel, 1988; Streel and Loboziak, 1996). In its higher par t the TCo Zone straddles the Givetian/Frasnian boundary. Because of the very limited evidence (one single specimen of Chelinospora concinna recorded in sample TO-2) only an imprecise attribution of this miospore assem- blage to the TA-TCo ? zonal range can be suggested.

Although sharing several miospore taxa with older Pimenteira Formation palynofloras, the next mio- spore assemblage can be distinguished by the occur- rence of forms bearing tabulate sculpture, such as Verrucosisporites buUiferus and Geminospora pilifor- mis, which are indicative of early Frasnian age. In terms of the miospore zonal scheme of the Ardenne- Rhenish regions, the inception of Verrucosisporites bulliferus defines the base of the V. bulliferus - C. jekhovskyi (B J) Oppel Zone, within the transitans or punctata eonodont Zones (Streel and Loboziak, 1996). It also defines the base of the ovalis-bulliferus Assemblage Zone according to the biozonation of the Old Red Sandstone Continent and adjacent regions.

Verrucosisporites bulliferus is a geographically widespread species (Richardson and McGregor, 1986, p. 19) whereas Geminospora piliformis, first descri- bed from the Paran~ Basin (Loboziak et al., 1988), has only been reported from western Gondwana (Loboziak and Streel, 1995a). In this latter region Geminospora piliformis first appears in strata con- sidered to be transitional between the BJ and the succeeding V. bulliferus - L. media (BM) Oppel Zones. The base of the BM Zone is defined by the incoming of Lophozonotriletes media somewhere wi-

FIG. 3. - Mlospore distribution chart. In situ miospore occurrences are represented by solid (black) circles, and rcworked occurrences (only in sample CO-l) by open circles. Due to inaccurate field control samples at t r ibuted to one same biozone (AD Lemo B J, BM) are not shown in stratigraph*c (vertical) succession.

Carte de distribution des mtospores La prdseace des miospores in sita est montr6e par des points (noirs) pleins et celle des miospores rentanides (sealement dans l'6chantillon C0-1) par des points creux. A cause d'un contr~le imprdcis d'~chantillonnage sur le terrain, les 6chantillons attribu6s h une m~me btozoue (AD Leta, B J, BM) ae sont pas montrds darts an ordre stratigraphique (vertical).

L I T H O S T R A T I G R A P H Y

O U T C R O P S E L E C T E D

C O D E S • M I O S P O R E w xo s

01. Grandispora spiculifera 02. Neoraistrickia loganii 03. Radiizonates s p . c f . V. c f . banffensis 04. Raistrickia strumosa 05. Rugospora polyptycha 06 . Spelaeotriletes balteatus 07. Tumulispora malevkensis 08. Vallatisporites splendens 09. Vallatisporites s p . c f . V. c f . splendens 10. Cordylosporites marciae 11. C. spathulatus 12. Knoxisporites hederatus / K. literatus 13. Indotriradites explanatus 14 . Retispora lepidophyta 15. Vallatisporites vallatus 16. V. verrucosus 17. Didueites mucronatus 18 . Lophozonotriletes media 19. Geminospora piliformis 20 . Grandispora daemonii 21. G. tabulata 22. Verrucosisporites bulliferus 23. Chelinospora con¢inna 24 . Samarisporites triangulatus 25. Samarisporites s p . E 26 . Acinosporites acanthomammillatus 27 . A. apiculatus 28. A. lindlarensis 29 . A. macrospinosus 30. Archaeozonotriletes variabilis 31. Camarozonotriletes? concavus 32. Chelinospora ligurata 33. C. paravermiculata 34 . C. timaniea 35 . Chelinospora s p . 36 . Contagisporites optivus 37. Craspedispora ghadamisensis 38. C. paranaensis 39 . Cymbosporites catillus / C. cyathus 40 . Diatomozonotriletes franklinii 41 . Geminospora lemurata 42. G . punetata 43 . Grandispora douglastownense 44. G. gabesensis 45 . G. incognita 46 . G. libyensis 47. G. maerotubereulata / G. mammillata 48 . G. megaformis 49. G. protea 50. G. permulta 51. Rhabdosporites langii / R. parvulus 52. Samarisporites eximius 53. Verrucosisporites premnus 54. V. seurrus

I M I O S P O R E / " ~ U T C R O P L C O D E S •

B I O S T R A T I G R A P H Y

(Miospore b]ozones after STREEL et al 1987 and H~GGS et aI. 1988)

C H R O N O S T R A T I G R A P H Y

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"~ ~--~ --~. --~--- *---.'-~--V- ~ t . . . . ~ ~--o 41 t--+-] ~-~-~-~-~--~--~-~-r--~--~----~--~--,--~-,-~-~-~-~-~--&--~-~ -4--o 42

: , . - ~ - - ~ - - - - 4 - - ~ : ~ , ' , : ~ , ~ - - - ~ 45 • - - ~ - b . . . . . . . . ~ - * : ' '

: i i ' i , i ', * - - ~ - 7 " ! ' ~ ~ 4 7

~ _ _ ~ _ _ ~ _ _ ~ _ - . . . . . . . L _ ~ _ , ~ _ ~ _ ~ _ _ _ : _ _ ~ _ ~ _ _ ~ _ . . . . . - ' - 4 - 4 - - ~ 53

ADLom BJ

%

G i v e t i a n / F r a s n i a n

f B M

r D , ~

• 06 0 7 08 09

~ 10 ~-~ 11 - - * 12

, - ~ 14 • - ~ 15 • - -~ 16

17 18 19 20 21 22 23 24 25 26 2 7 28 2 9 30 31 3 2 33 34 35 36 37 38 39 40

308 MIOSPORE BIOSTRATIGRAPHY IN BRAZIL

thin the upper part of the asymmetricus Zone (= lower hassi in the current standard conodont zonation) of later early Frasnian age (Loboziak and Streel, 1981, fig. 2; Streel et al., 1987, fig. 6). In this study Lophozonotriletes media has been recor- ded in three samples (Fig. 3). Therefore, an attribu- tion to the Oppel BJ can be proposed fi~r those Tocantins samples containing either Verrucosispori- tes buUiferus or Geminospora piliformis (or someti- mes both species). However, in other samples, the joint occurrence of the above taxa with Lophozono- triletes media permits an indisputable assignment to the overlying BM Oppel Zone.

The youngest miospore assemblage in the Pimen- tetra Formation is poorly characterized, and is the- refore tentatively included in a BM-~dV~, ? zonal range based only on the local identification of Didu- cites mucronatus. In the Boulonnais region (northern France) this camerate form first appears at practi- cally the same stratigraphic level as Rugospora bri- cei. The first occurrence of this latter species defines the base of an informal unit, the so-called regional phase zone ~IV~ (Loboziak and Streel, 1981; Lobo- ziak et al., 1983). The earliest occurrence of Ru- gospora bricei is recorded by Streel and Loboziak (1996) somewhere between the upper hassi and the linguiformis conodont Zones of late Frasnian age. However, Rugospora bricei has not been recorded in the present study, so the phase zone ~IV~ remains still unproven in the Tocantins region.

In summary, successive miospore zones recognized on the basis of 29 palyniferous samples from the Pimenteira Formation range biostratigraphically from the Lem Interval Zone to a doubtful, compre- hensive BM-~dV~ ? biozonal interval, thus implying a minimum Givetian-Frasnian age span.

Only one productive sample (CO-1) was obtained from the Cabe~as Formation in the present investi-

gation. Many of the Middle and early Late Devonian miospore species recorded in Pimenteira Formation samples are also present in this sample and their occurrence can he ascribed to reworking on the basis of differential preservation or color. The in situ palynoflora contains Retispora lepidophyta, the key- species tbr the latest Famennian or ~Strunian~. It is locally associated to several zonal or characteristic species, such as Knoxisporites literatus, Indotriradi- tes explanatus, Cordylosporites marciae and C. spa- thulatus, Vallatisporites verrucosus and V. vallatus. Some of these, as for example Vallatisporites vallatus (Van Veen, 1981, fig. 2-4) and Cordylosporites spa- thulatus (Higgs et al., 1988, p. 59), first occur only in the upper part of the Retispora lepidophyta total range, within the R. lepidophyta - V. nitidus (LN) Interval Zone. Thus, despite the absence of Verru- cosisporites nitidus (the second eponymous species of LN) an attribution to this interval zone can be pro- posed for sample CO-1. In western Europe this zone corresponds to the middle and upper praesulcata conodont Zones (Higgs and Streel, 1984, fig. 10; Dreesen et al., 1993, fig. 10; Higgs and Streel, 1994, fig. 2).

One single palyniferous sample (BR-31) was ob- tained from the Longfi Formation. It contains an abundant palynoflora which, amidst several latest Famennian holdovers, includes also younger zonal species of typically Tournaisian age, such as Neorais- trickia loganii, Rugospora polyptycha and Spelaeo- triletes balteatus. The joint occurrence of the latter two permits a correlation of sample BR-31 with a younger part of the S. balteatus - R. polyptycha (BP) Interval Zone of the British miospore zonation (Higgs et al., 1988). According to Higgs et al. (1992), the BP Zone corresponds to the transition between the lower and upper crenulata conodont Zones of early middle Tournaisian age.

P L A T E 1

All the slides are housed m the palynologLcal slide collection of the Biostratigraphy and Paleoecology Sector of PETROBRAS Research Centre (CENPES/DIVEX/SEBIPE), Rio de Janeiro, Brazil.

The miospore locations on the shdes are based on England Finders Graticules. Magnification of illustrated specimens : × 500.

1. Grandispora permulta (DAEMON) LOBOZIAI'~, STREEL and MELO, 1999. Slide 9603106 : K49, sample Pto-17A.

2. Grandispora protea (NAUMOVA) MOREAU-I]ENOIT, 1980. Slide 9603108 : X54/1, sample R.SO-5.

3. Grandispora megaformis (RIEtlARDSON) McGREGOR, 1973. Slide 6842 : Tl8/4, sample BR 19A.

4. Grandispora libyensis MOREAU-BENOIT, 1980. Slide 6842: P19, sample BR-19A.

5. Grandispora daemonii LOBOZIAK, STREEL and BUR JACK, 1988. Shdc 9500228 : J60/4, sample MVC-3.

6. Gran, di~pora tabttlata LOBOZIAK, STREEL and BURJACK, 1988. Slide 9500228 : 049/1, sample MVC-3.

7. Archaeozonotriletes variabilis NAUMOVA emend ALLEN, 1965. Slide 9603103 : D62/1, sample Pto-19.

8. Diatomozonotriletes franklinii McGREGOR and CAMFIELD, 1982. Slide 6896 : L30/I, sample BR-25.

9. Cantarozonotriletes ? concavus LOBOZI~K and STREEL~ 1989. Slide 9603103 : Y59, sample Pto-19.

310 MIOSPORE BIOSTRATIGRAPHY IN BRAZIL

COMPARISON WITH PREVIOUS PALYNOLOGICAL INVESTIGATIONS IN THE PARNAIBA BASIN

The applicability, in the Parnaiba Basin, of mio- spore biozones originally defined in Middle Devonian to Early Carboniferous strata of western Europe has already been demonstrated in previous palynostrati- graphic investigations of several Petrobras wells (Loboziak et a l . , 1992, 1993, 1994a-b ; Streel et a l . , 1993; Rodrigues et al . , 1995; Melo et al . , 1998).

The present study confirms some results already obtained by us from correlative sections elsewhere in the basin, e.g. : the early Givetian age of the lower par t (but probably not the base) of the Pimenteira Formation, the unit 's extension into the late Fras- nian, and previous latest Famennian and middle Tournaisian ages for parts of the Cabeqas and Long~i Formations, respectively. It also permits the recog- nition of biozones formerly unsampled in the basin, such as the late early Frasnian BM Oppel Zone within the Pimenteira Formation. On the other hand, much as demonstrated by Rodrigues et al. (1995), the recognition of the TCo miospore Zone within the same formation remains problematic. This may re- flect either a possible sedimentological gap or sedi- mentary condensation across the Givetian/Frasnian boundary as proposed by Rodrigues et al. (1995), or else a regional scarcity of the zonal marker , Cheli- nospora c o n c i n n a , which is however well documented in the adjacent Paran~i Basin (Loboziak et a l . , 1988).

Previous miospore-based palynological evalua- tions of Devonian-Carboniferous outcrops in the Tocantins valley include three published abstracts based on exactly the same set of samples as this study (Quadros et a l . , 1989; Dino et a l . , 1996; Loboziak

et a l . , 1997b), and two older papers based on independent studies of the same general area (An- drade and Daemon, 1974; Sundaram et a l . , 1982).

Quadros et al. (1989) and Dino et al. (1996) did not identify any miospore zones, but present a list of the main identified palynomorph species (miospo- res, acritarchs and chitinozoans), based on which they assign a Givetian-Frasnian age span to the studied samples. Loboziak et al. (1997b) recognized the AD Lem, TA, BJ and BM miospore Zones in the Pimenteira Formation (early Givetian to late early Frasnian), as well as the early middle Tournaisian BP Zone in the Long~ Formation, but presented no results for the Cabe~as Formation.

Andrade and Daemon (1974) applied Pe t robras ' regional zonal scheme (defined in the Amazon Basin by Daemon anti Contreiras, 1971) to a composite outcrop section in the area of Pedro Afonso and southeast of hacaj~, which includes the Pimenteira, Cabeqas and Long~ Formations. The lowest unit comprises intervals V through VII (Eifelian/Givetian to Famennian), whereas the Cabe~as and Long~ Formations were assigned to intervals VIII and IX, i.e., latest Famennian (~ Strunian~) and Tournaisian, respectively. In addition, Andrade and Daemon (1974) recorded diamictites in Pedro Afonso town which they attributed to the Pimenteira Formation, thus implying that glaciogenic rocks of pre-~Stru- nian~ age could be present below the Cabeqas For- mation. These authors did not clarify whether or not they analyzed the palynological content of the sup- posedly older diamictites at Pedro Afonso. However, Andrade and Daemon (1974, p. 132), based on the ~dntegration of l i tho- and biostratigraphic studies,~, concluded that the diamictites recorded by them around Pedro Afonso and in Petrobras well 1-CL-1- MA (Carolina, State of Maranh~o ; see figure 2) were

P L A T E 2

1. Rhabdosporttes langti (EISENACK) RICHARDSON, 1960. Slide 9603207 : N55/4, sample RSO-1.

2. Acinosporites maerospinosus RICtL~RDSON, 1965. Slide 6845 : P35/1, sample BR 19A.

3. Acinosporites lindlarensis RIEGEL, 1968. Slide 6849 : F27/4, sample BR-20.

4. Chelinospora parttvermiculata LOBOZIAK, STREEI~ and BUR- JACK, 1988. Slide 9603103 : V64/4, sample Pro-19.

5. Chelinospora sp. Slide 9603103 : C41/4, sample Pto-19.

6. Chelinospora concinna ALLEN, 1965. Slide 9500228 : F61/2, sample MVC-3.

7. Chelinospora timanica (NAuMOVA) LOBOZIAK and STREEL, 1989. Slide 9603103 : W42/2, sample Pto-19.

8. Geminospora lemurata BALME emend. PLAYFORD, 1983. Slide 9603108 : Y48, sample RSO-5.

9. Geminospora punctata OWENS, 1971. Slide 9603103 : V68, sample Pro-19.

10. Geminospora pil!formis LOBOZIAK, STREEL and BURJACK, 1988. Slide 9500228 : T65, sample MVC-3.

11. Craspedispora ghadamisensis LoBoz/~xi, and STREEL, 1989. Slide 9603108 : P44, sample RSO-5.

12. Sttmarisporites exintius (ALI,EN) LOBOZIAK and STREEL, 1989. Slide 9603103 : R66/4, sample Pto-19.

13. Samtlrisporites sp. E STREEL and LOBOZIAK, 1987. Slide 9603106 : M59/4, sample Pto-17A.

312 MIOSPORE BIOSTRATIGRAPHY IN BRAZIL

stratigraphically equivalent but not different to the ones mapped by Ojeda y Ojeda and Perillo (1967) and Andrade (1968) under the name Cabesas For- mation in outcrops of the Carolina and Itacaj~i regions.

Reworked but well-preserved pre-~Strunian~ pa- lynomorphs are usually the overwhelming consti- tuents of palynofloras from Cabeqas Formation dia- mictites, a feature which could easily induce local misdatings of the same. Moreover, the apparently older stratigraphic position of the Pedro Afonso diamictites could just reflect the deeper erosion of underlying Pimenteira Formation sediments during the latest Famennian glaciation (Cabeqas depositional time), as often observed in westerly parts of the study area. These reinterpretations are now further sup- ported by palynological results of Loboziak et al. (1994a) from core 31 of well 1-CL-1-MA (depth range 638-644.3 m), which is within the diamictite section formerly assigned by Andrade and Daemon (1974, p. 132) to intervals VI-VII. Based on the joint occurrence (amidst numerous reworked Givetian- Frasnian miospores) of such species as Retispora lepidophyta, Vallatisporites verrucosus, Knoxispori- tes literatus and Spelaeotriletes obtusus, that same diamictite interval - which is currently equated by Petrobras geologists with the Cabeqas Formation - is now attributed to the LN miospore Zone of latest Famennian age. It is likely that a similar situation

could apply to the Pedro Afonso diamictites, which according to Andrade and Daemon (1974) are coeval with those of well 1-CL-1-MA.

Palynological results presented by Sundaram et al. (1982) for outcrop samples from the Miracema do Tocantins/Miranorte and Paraiso do Tocantins areas are very imprecise, so that no detailed compa- risons with our study are possible. This is mainly due to the poor taxonomy and outdated biostratigra- phic data employed by those authors, according to whom <(the assemblage (...) suggests a Lower Devo- nian age [sic] for these sediments with a probabil i ty of extending up to the Eifelian (Middle Devonian)>> (Sundaram et al., 1982, p. 1296). However it is apparent that some of the palynomorphs illustrated in Sundaram et al.'s plates have been misidentified, e.g. : ~Cymbosporites senex~, (their pl. 1, fig. 9, actually a bona f ide specimen of Geminospora lemu- rata, index species of the early Givetian (AD Lem miospore Zone) ; <<Stenozonotriletes sp.>, (their pl. 1, fig. 7, a probable representative of Geminospora punctata, (only known from the Eifelian/Givetian transition upwards); and microphytoplankton ele- ments such as (<Maranhites sp.>~ (their pl. 2, fig. 7, attributable to M. brasiliensis (BRITO) emend. Bur- jack and Oliveira, 1989, a species now regarded as mainly restricted to Givetian and younger Devonian strata according to Burjack and Oliveira, 1989 and Oliveira, 1997).

PLATE 3

1, 2. Samarisporite, triangulatus ALLEN, 1965 10. 1 : Slide 6901 : O15, sample BR-30. 2 : Slide 9603106 : R56/4, sample Pto-17A. 11.

3. VerrucosisporttespremnusRICnARDSON, 1965. Slide 9500228 : J62/2, sample MVC-3. 12.

4. Verrucosisporites buUiferus RICHARDSON and McGREGOR, 1986. Slide 9603106 : 040, sample Pro 17A. 13.

5. Cymbosporites catiUus ALLEN, 1965. Slide 9603108 : X39/3, sample RSO-5. 14.

6. Lophozonotriletes media TAUGOURDEAU-LANTZ, 1967. Slide 9500229 : Z42/2, sample MVC-4. 15.

7. Retispora lepidophyta (Kedo) PtA~'om)~ 1976. Slide 16. 9603094 : R70/4, sample CO-1.

8. Radiizonates sp. cf. Vallatisporites cf. banffensis STAPLIN and 17. JANSONIUS, 1964. Slide 6908 : E28/1, sample BR-31.

9. Vallati~porttes splendens STAPLIN and JANSONIUS, 1964. Shde 18. 6908 : VI2/1, sample BR-31.

VaUatisporites v e r r u c o s u s ~L~CQUERARD, 1957. Slide 6908: M26/4, sample BR-31.

Knoxisporites literatus (Waltz) PLAYFORD, 1963. Slide 9603094 : P48, sample CO-1.

Tumulispora malevkensis (KEDo) TURNAU, 1978. Slide 6909 : G26, sample BR-31.

Raistrickia strumosa PLAYFORD, 1976. Shde 6909: R26/4, sample BR-31.

Cordylosporites spathulatus (WINSLOW) PLAYFORD and SAT TERTBWAIT, 1985. Slide 6909 : K18/3, sample BR-31.

Neoraistrtckia loganii (WINSLOW} COLEMAN and CLAYTON, 1988. Slide 9702018 : D47/2, sample BR-31.

Spelaeotriletes balteatus (PLA~FORD) HIGGS, 1996. Slide 9702018 : P59/3, sample BR-31.

Rugospora polyptycha NEVES and IOANNIDES, 1974. Slide 9702018 : J72/1, sample BR-31.

Indotriradites explanatus (LUBER) PLA~FORD, 1991. Slide 9603094 : E61/1, sample CO-1.

314 MIOSPORE BIOSTRATIGRAPHY IN BRAZIL

C O N C L U S I O N S

The present paper improves the knowledge of the Devonian stratigraphy in the Tocantins region (southwestern margin of the Parnaiba Basin) by providing more accurate biostratigraphic control of exposed sedimentary sections. It also contributes to the elucidation of complex field relationships of regional rock units, such as the Cabeqas Formation diamictites, as well as to estimating the varied magnitude of the pre-diamictite erosion.

In addition, this study demonstrates once again the applicability of western European-defined mio- spore biozones to Devonian and Early Carboniferous stratal successions of northern Brazilian Paleozoic basins. The new palynological results, from outcrop sections show the Pimenteira Formation to range in age from early Givetian to late early or late Frasnian (AD Lem through BM or <<IV>> miospore zonal range). Sampled intervals of the Cabe~as and Long~i Forma- tions give latest Famennian and early middle Tour- naisian ages (respectively LN and BP miospore Zones). All these determinations are consistent with our previous biostratigraphic datings from the sub- surface of the Parnalba Basin.

ACKNOWLEDGEMENTS

The authors are indebted to Mme Netter (UPRE- SA 8014 du CNRS, Lille, France) for typing the final version of the text, to Fernanda F. Roberto (UFRJ Geology graduate student, Rio de Janeiro, Brazil) for preparation of drawings on the computer, and to geologists Mitsuru Arai and Rog6rio Loureiro Antunes (Biostratigraphy and Paleoecology Section, Petrobras Research and Development Centre, Rio de Janeiro, Brazil) for the critical evaluation of the manuscript. J.H.G. Melo thanks Petrobras - Pe- tr61eo Brasileiro S.A. for the permission to pubhsh this paper.

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LOROZIAK S., MEEO J.H.G., QUADROS L.P., DAEI~ION R.F. and BARRILARI I.M.R. (1994a) : Devonian-Dinantian miospore bios tratigraphy of the Solimaes and Parnaiba Basins (with consi- derations on the Devonian of the Paranfi Basin). Petrobras/Cenpes, Rm dc Janeiro, Technical Report, 2 v. (unpubisbed).

LOBOZIAK S.~ MEI,O J.H.G., QUADROS L.P., DAEMON R.F. and BARRILARI I.M.R. (1994b) : Biocronoestratigrafia dos palino- morfos do Devoniano Mddio - Carbonlfero Inferior das Bacms do SolimSes e Parnalba : estado da arte. Atas 2 (' Sintex - Seniinfirio de Interpreta@o Explorat6ria, Rm de Janeiro, p. 51-56. Petrobras/Depex unpublished technical meeting docu~ ment.

LOROZIAK S., MEEO J.H.G., QUaDROS L.P. and STREEL M. (1997a) : Palynological evaluation of the Famenntan Protosal- vinia (Foerstia) Zone m the Amazon Basin, northern Brazil : a preliininary study. Hey. Puhteobot., Palyaol., Amsterdam, vol. 96, p. 31-45.

LOBOZIAK S., DINO R. AND MELO J.H.G. (1997b) : Devonian DI- nanlian miospore successions in outcrop sections of the western Parnalba Basin, Tocantins River valley, north central Brazil. Rev. Univ. Guarulhos, Guarulhos, 2 (n ° especial), p. 209, Abstracts of IX Reuni~o Paleobot. Palin61., Guarulhos.

LOBOZIAK S., MELO J.H.G., MATSUDA N.S. and QUADROS L.P. (1998a) : Miospore biostratigraphy of the type Barreirinha Formation (Curu~i Group, Upper Devonian) in the Tapaj6s River area, Amazon Basin, northern Brazil. Bull. Centre Rech. Expl.-Prod. Elf Aquitaine, Pau, vol. 21, n" 1, p. 187- 205.

LI~I~OZIAK S., MELO J.H.G and STREEL M. (1998b) Reassessment of Vis6an mlospore blostratigraphy in the Amazon Basin, norther,, Brazil. Rev. Palaeobot.. Palynol., Amsterdam, voL 104, p. 143-155.

MELO J.H.G. (1988) : The Malvinokaffric Realm in the Devonian of Brazil. In : N.J. MCMIELAN, A.F. EMURY and D.J. GLASS. Devonian of the World. CSPGMem., Calgary, vol. 14, n ° 1, p. 669-703.

MELO J.H.G., LOBOZiAk S. and STREEL M. (1998) : Latest Devo- nian to early Late Carboniferous biostratigraphy of northern Brazil : an update. Bull. Centre Rech. Expl.-Prod. Elf Aqui- taine, Pau, vol. 22, n ° 1, p. 13-33.

MOORE B. (1963) : Geological reconnaissance of the south west corner of the Maranhgo Basin. Petrobras, Bel6m, Technical Report (unpublished).

OJEDA Y OJEDA n . and PERILLO I.A. (1967) : Bacia do Maranh~o - geologia do sudoeste de Carolina. Petrobras, Bel6m, Tech- nical Report (unpublished).

OLIVEIRA S.F. (3997): Palinologia da sequ6ncia dewmiana da Bacia do Paran~ no Brasil, Paragual e Uruguai : imphcaqges biocronoestratigr~ificas, paleoambientais c paleogeogrfificas. D. Sci. thesis. Univ. S~o Paulo, S~o Paulo, 188 p. (unpubhshed).

PEREZ-LEYTON M. (1991) : Miospores du D6vonien moyen et su- p~rieur de la coupe de Bermejo-La Angostura (sud-est de la Bohvie). Ann. Soc. G6ol. Belgique, Libge, t. 113, fase. 2, p. 371-389.

PERILLO I.A. and NAtIASS S. (1968) : Semidetalhe do sudeste de Pedro Afbnso. Petrobras, Bel6m. Technical Report (unpu- bhshed).

QUADROS L.P., DINO R. and MELO J.H.G. (1989) : Palinomorfos devonianos do vale do Tocantins (Bama do Parnalba, Estado do Tocantins). An. Acad. Bras. Ci., Rio de Janeiro, vul. 61, n ° 4, p. 478, Ahstract.

RIBEIRO E., SOUZA E.P., BARRETO FIE,tO J.A. and ALMEIDA V.J. (1974) : Projeto Tocantlnia - Itacaj~i GO-401. CNEN/CPRM, Goifinia, 4 v. (unpubhshed).

RICHARDSON .I.B. and MCGREGOR D.C. (1986) :Silurian and De- vonian spore zones of the Old Red Sandstone Continent and adjacent regions. Geol. Surv. Canada Bull., Ottawa, Bull. 364, 79 p.

RODRIGUES R., LOBOZIAK S., MELO J.H.G. and ALVES D.B. (1995) : Geochemical characterization and miospore biochronostrati- graphy of the Frasnian anoxic event in the Parnalba Basin, northeast Brazil. Bull. Centre Rech. Expl.-Prod. Elf Aqui- taine, Pau, vol. 19, n ° 2, p. 319 327.

SCIIOBBENHAUS FILHO C., RIBEIRO C.L., OLIVA L.A., TAIC~NOI~ASm J.T., LINDENMAYER Z.G., VASCONCELOS J.B., ORLAND/ V., COR- DANI U.G., HASUI Y., CAMPOS D.A., CAMPOS D.R.B., DERZE

316 M I O S P O R E B I O S T R A T I G R A P H Y IN BRAZIL

G.R. and RtI~EIRO E.P. (1975) : Carta geol6gica do Brasil ao mihon6simo, folha Goi~s (SD.22). DNPM, Brasilia, 114 p.

SCISLEWSKI G., MORETON L.C., LACERDA FILHO J.V. and MATIAS P.V.B. (1982) : Projeto Carv~o Energ6tlco na Bacia Tocan- tins-Araguaia : relat6rio de compila~fio t)ibliogr~ifica. DNPM/CPRM, Goi~nia, 83 p. (unpubhshed).

SILVA G.G., LtMA M.I.C., ANDRADE A.R.F., ISSLER R.S. and GtJt- MARSES G. (1974) : Geologia das folhas SB.22 Araguaia c parte de SC.22 Tocantins. I n : Projeto RADAMRRaSIL. Folha SB.22 Aragua,a e parte da folha SC.22 Tocantins, (Lcvantamcnto de Recursos Naturals, 4). DNPM, Rio de Janeiro, p. I/1-143.

STREEI, n. and LOBOZIAK S. (1996) : Middle Io Upper Devonian miospores. In: J.J. Jansonius and D.C. McGregor (Ed.), Palynology : principles and applications. AASP Foundation, Salt Lake City, vol. 2, p. 575-587.

STREEL n . , HIGGS K., LOBOZtA~ S., RIEGEL W. and STEEMANS P. (1987): Spore stratigraphy and correlation with faunas and floras in the type marine Devonian of the Ardenne Rhenish regions. Rev. Palaeobot., Palynol., Amsterdam, vol. 50, p. 211-229.

STREEL M., LOBOZIAK S., CAPUTO M.V. and THOREZ J. (1993) : Miospores from late Famennian varves and tillites of Brazil. C.I.M.P., Gent, newsletter 45, p. 6, Abstract.

STREEL M., CAPUTO M.V., LOBOZL~ S. and MELO J.H.G. (in press) : Late Frasnian - Famenuian climates based on paly nomorph quantitative analyses and the question of the Late Devonian glaciations. Earth Sci. Rev., Amsterdam,

SUNDARAM D., CARVALHO R.G. and CUNHA B.C.C. (1982) : Mio~ floral analysis of some Devonian sediments of Parnalba Basin, Goi~is State, Brazil. Ann. 32 ° Congr. Bras. Geol., Salvador, vol. 4, p. 1296-1304.

VAN VEEN P.M. (1981) : Aspects of Late Devonmn and Early Carboniferous palynology of Southern Ireland. V : The change in composition of palynologieal assemblages at the Devonian- Carboniferous boundary. Rev. Palaeobot., Palynol., Amster- dam, vol. 34, n ° 1, p. 67-97.

WALLISER o . n . , BULTYNCK P., WEDDIGE K., BECKER R.T. and HOUSE M.R. (1995) : Definition of the Eifelian-Givetian stage boundary. Episodes, Trondhem~, vol. 18, n ° 3, p. 107-115.

A P P E N D I X 1 - L I S T O F I N V E S T I G A T E D

S A M P L E S

PETROBRAS SAMPLES

N o t e : in this paper , all samples collected by the 1988 Pe t robras field pa r ty are dist inguished by the pref ix <<BR->>. Milepost figures (kin) given below for sidecut samples along federa l highway Br-153 are those in use unti l at least the year 1988. They have been la ter changed due to the redesigned state boundar ies arising f rom the creat ion of the new Tocant ins State ( formerly a pa r t of Goi~s State).

B R - 1 8 - F o r m e r km 455.5 at Br-153 federal highway, ca. 15 km nor theas t of Para l so do To- cantins. P imente i ra Format ion .

BR-19 - F o r m e r km 407 at Br-153 federa l highway, ca. 14 km south of Miranor te . P imente i ra F o r m a - tion.

BR-19A - F o r m e r km 403 at Br-153 federal highway, ca. 10 km south of Miranor te . P imen- te i ra Format ion .

BR-20 - F o r m e r km 399 at Br-153 federal highway, ca. 6 km south of Miranor te . P imente i ra Fo rma- tion.

BR-22 - Right bank of Tocant ins River opposite to Se r r inha F a r m housing, mouth of Funi lz inho s t ream, ca. 18 km ups t ream of Miracema do Tocant ins . P imente i ra Format ion .

BR-24 - Tocant in ia village, r ight bank of Tocant ins River . P imentc i ra Format ion .

BR-25 - F o r m e r km 385.5 at Br-153 federa l highway (station FF-03 of Lima and Leite, 1978). P imente i ra Format ion .

BR-26 - F o r m e r km 380.5 at Br-153 federa l highway (station FA-313 of Lima and Leite, 1978). P imen te i r a Format ion .

BR-27 - Right bank of Tocant ins River , 3.7 km nor th of Boa Esperan~a locality (station FA-327 of Lima and Leite, 1978). P imente i ra Format ion .

BR-28 - Guara l - Pequize i ro road near km 01, vi- cinity of Guaral . P imente i ra Format ion .

BR-28T ' - Right bank of Tocant ins River , ups t r eam of Ped ro Afonso. P imente i ra Format ion .

BR-30 - Itacajfi - Ped ro Afonso road , br idge over Soninho River , ca. 82 km f rom I tacaj~ (station AV-92 of Lima and Leite, 1978). P imente i ra For- mat ion.

BR-31 - Left bank of Manuel Alves Pequeno River in Itacaj~i village. Long~ Format ion .

BR-33 - Left bank of Tocant ins River , ca. 54 km downs t ream of Pedro Afonso (site between stations FF-122 and FF-123 of Lima and Leite, 1978). P imen te i r a Format ion .

BR-34 - Left bank of Tocant ins River , ca. 55 km downs t ream of Pedro Afonso (station FF-123 of Lima and Leite, 1978). P imente i ra Format ion .

BR-35 - Right bank of Tocant ins River , ca. 3 km ups t ream of Tupi ra t ins (station FF-125 of Lima and Leite, 1978). P imente i ra Format ion .

U F P A SAMPLES

N o t e : The list below refer to samples collected by Univers idade Federa l do Par~ (UFPA) field mapping par t ies dur ing the years 1993-1995.

CO-1 - Outcrop in Colinas do Tocant ins village. Caheqas Format ion (diamictite).

LOBOZIAK, CAPUTO and MELO 317

MVC-3 - Site approximately 30 km east of Pedro Afonso along road in construction which will link Pedro Afonso to the State of Maranh~o. Pimen- teira Formation.

MVC-4 - Right bank of Tocantins River, ca. 20 km downstream of Pedro Afonso. Pimenteira Forma- tion.

Pto-1 - Site ca. 4 km north of Paralso do Tocantins along Br-153 federal highway. Pimenteira Forma- tion.

Pro-5 - Site ca. 30 km northeast of Paralso do Tocantins along Br-153 federal highway. Pimen- teira Formation.

Pto-6 - Site 60.7 km northeast of Paralso do To- cantins along Br-153 federal highway. Pimenteira Formation.

Pto-7 - Site 67.8 km northeast of Para~so do To- cantins along Br-153 federal highway. Pimenteira Formation.

Pto-17A - Site approximately 19 km north of Mira- notre along Br-153 highway. Pimenteira Forma- tion.

Pto-19 - Site approximately 29 km east of Pedro Afonso along road in construction which will link Pedro Afonso to the State of Maranh~o. Pimen- teira Formation.

R.SO-1 - Pr ivate mooring on right bank of Sono River, ca. 500 m upstream of its mouth into Tocantins River. Pimenteira Formation.

R . S O - 4 - Sono River, site approximately 15 km upstream of its mouth into Tocantins River. Pimenteira Formation.

R.SO-5 - Cascade on minor t r ibutary to the right bank of Sono River, confluence site ca. 30 km upstream of Sono River 's mouth into Tocantins River. Pimenteira Formation.

TO-2 - Right bank of Tocantins River, ca. 10 km upstream of Pedro Afonso. Pimenteira Formation.

TO-6 - Tupirat ins village, Tocantins River. Pimen- teira Formation.

TO.Mi-5 - Tocantins River, site ca. 33 km downs- tream of Tocantlnia. Pimenteira Formation.

A P P E N D I X 2 - L I S T O F M I O S P O R E S P E C I E S C I T E D IN T E X T , F I G . 3 A N D P L A T E C A P T I O N S

Acinosporites acanthomammillatus RICHARDSON, 1965

Acinosporites apiculatus (STREEL) STREEL, 1967 Acinosporites lindlarensis RIEGEL, 1968 Aeinosporites maerospinosus RICHARDSON, 1965

Archaeozonotriletes variabilis NAUMOVA emend. AL= LEN, 1965

Camarozonotriletes ? concavus LOBOZIAK and STREEL, 1989

Chelinospora concinna ALLEN, 1965 Chelinospora ligurata ALLEN, 1965 Chelinospora paravermiculata LOBOZIAK, STREEL

and BURJACK, 1988 Chelinospora timanica (NAUMOVA) LOBOZIAK and

STREEL, 1989 Chelinospora sp. Contagisporites optivus (TCHIBRIKOVA) OWENS, 1971 Cordylosporites marciae PLAYFORD and SATTER-

TIIWAIT, 1985 Cordylosporites spathulatus (WINSLOW) PLAYFORD

and SATTERTHWAIT, 1985 Craspedispora ghadamisensis LOBOZIAK and

STREEL, 1989 Craspedispora paranaensis LOBOZIAK, STREEL and

BURJACK, 1988 ~+ Cymbosporites catillus ALLEN, 1965 Cymbosporites cyathus ALLEN, 1965 Cymbosporites ? senex McGREGOR and CAMFIELD,

1976 Cymbosporites sp. Diatomozonotriletes J~anklinii McGREGOR and

CAMFIELD, 1982 Didncites mucronatns (KEDO) VAN VEEN, 1981 Geminospora lemurata BALME emend. PLAYFORD,

1983 Geminospora piliformis LOBOZIAK, STREEL and BUR-

JACK, 1988 Geminospora punctata OWENS, 1971 Grandispora daemonii LOROZIAK, STREEL and BUR-

JACK, 1988 Grandispora douglastownense McGREGOR, 1973 Grandispora gabesensis LOBOZIAK and STREEL, 1989 Grandispora incognita (KEDO) McGREGOR and

CAMFIELD, 1976 Grandispora libyensis MOREAU-BENOIT, 1980 Grandispora macrotuberculata (ARKHANGELSKAYA)

McGREGOR, 1973 Grandispora mammillata OWENS, 1971 Grandispora megaformis (RICHARDSON) McGREGOR,

1973 Grandispora protea (NAUMOVA) MOREAU-BENOIT,

1980 Grandispora permulta (DAEMON) LOBOZIAK, STREEL

and MELO, 1999 Grandispora spiculifera PLAYFORD, 1976 Grandispora tabulata LOBOZIAK, STREEL and BUR-

JACK, 1988 Indotriradites explanatns (LUBER) PLAYFORD, 1991 Knoxisporites hederatus (ISHCHENKO) PLAYFORD,

1963

318 MIOSPORE BIOSTRATIGRAPHY IN BRAZIL

Knoxisporites literatus (WALTZ) PLAYFORD, 1963 Lophozonotriletes media TAUGOURDEAU-LANTZ, 1967 Neoraistrickia loganii (WINSLOW) COLEMAN and

CLAYTON, 1988 Radiizonates sp. cf. Vallatisporites banffensis STA-

PLIN and JANSONIUS, 1964 Raistrickia strumosa PLAYFORD, 1976 Retispora lepidophyta (KEDO) PLAYFORD, 1976 Rhabdosporites langii (E1SENACK) RICIIARDSON,

1960 Rhabdosporites parvulus RICHARDSON, 1965 Rugospora bricei LOBOZIAK and STREEL, 1989 Rugospora polyptycha NEVES and [OANNIDES, 1974 Samarisporites eximius (ALLEN, 1965) LOBOZIAK and

STREEL, 1989 Samarisporites triangulatus ALLEN, 1965

Samarisporites sp. E STREEL and LOBOZIAK, 1987 Spelaeotriletes balteatus (PLAYFORD) HIGGS, 1996 Spelaeotriletes obtusus ttIGGS, 1975 Stenozonotriletes sp. Tumulispora malevkensis (KEDO) TURNAU, 1978 Vallatisporites splendens STAPLIN and JANSONIUS,

1964 Vallatisporites vallatus HACQUEBARD, 1957 Vallatisporites verrucosus HACQUEBARD. 1957 Verrucosisporites bulliferus RICHARDSON and

McGREGOR, 1986 Verrucosisporites nitidus PLAYFORD, 1964 Verrucosisporites premnus RICHARDSON, 1965 Verrucosisporites scurrus (NAUMOVA) McGREGOR

and CAMFIELD, 1982