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REMOTE SENSING FOR

GEOLOGY

Prepared by

Sutikno Prof. Dr.

WHAT IS REMOTE SENSING?

Remote sensing is:

Science and art of obtaining information

of object, area, of phenomenon through

analysis of data acquired by a device

without contact of the object, area or

phenomenon under investigation.

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WHAT IS REMOTE SENSING FOR GEOLOGY

AND WHAT TYPE OF REMOTE SENSING

IMAGES ARE USUALLY USED

REMOTE SENSING FOR GEOLOGY:

APPLICATION OF REMOTE SENSING FOR OBTAINING

GEOLOGICAL INFORMATION OR DATA: stratigraphy,

lithology and geologic structure.

REMOTE SENSING IMAGE FOR GEOLOGICAL

INVESTIGATION:

AERIAL PHOTOGRAPHS

LANDSAT

SPOT

RADAR

THERMAL INFRA RED

REMOTE SENSINGREMOTE SENSING GEOLOGY

REMOTE SENSING

FOR GEOLOGY

GEOLOGIC

RESOURCESGEOLOGIC

HAZARD

•MINERAL & ROCKS

•WATER

•ENERGY

•LANDFORMS

•MASS MOVEMENT

•VOLCANIC ERUPTION

•EARTHQUAKE

•FLOOD

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WHAT KINDS INFORMATION CAN BE

OBTAINED FROM RS IMAGES

1. Topographic pattern

2. Drainage pattern

3. Landform units

4. Lithogical/rocks units

5. Geological structures

6. Mineral deposits location

7. Susceptible area for erosion, mass-movement, earthquake, volcanic.

WHAT IS THE AIM AND THE STATUS OF THE

GEOLOGICAL REMOTE SENSING IMAGE

INTERPRETATION

The aim is to obtain lithologic,

stratigraphy and geological structure

The status is not as an alternative of

field geology; fieldwork always carried

out to check the result of the image

interpretation; the results of the image

interpretation are supposed similar

with data from other sources.

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WHAT IS THE CONTENT OF THE PRELIMINARY

GEOLOGICAL MAP RESULTING FROM RS IMAGE

INTERPRETATION

1. Lithological units: may composed of single rock or group of rocks

2. Geologic structures indicators: dip slope, bedding plane

3. Continue or discontinue of the bed layers

4. Indicators of fault and unconformity

5. Landform units

6. Drainage pattern, can be used to identify the lithology and structure

7. Control point, important location, ground control

ARE THERE ANY IMAGE CHARACTERISTICS

FOR INTERPRETATION PURPOSES

1. Tone

2. Texture

3. Pattern

4. Shape/form

5. Site

6. Association

7. Shadow

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HOW TO IDENTIFY AND INTERPRETATION

OF GEOLOGICAL DATA FROM RS IMAGES

1. Using element for geological interpretation:a. Outcrop features and distribution

b. Structure in detail

c. Landform

d. Drainage pattern

e. Vegetation

f. Cultural features

2. Using factors for geological features identification:a. Form; for lithology and structure identification

b. Asymmetrical slope: to determine the dip slope of the beds

c. Drainage: to recognize the density and pattern.Drainage density is associate to rock resistance and permeability. Drainage pattern is important for lithological and structural interpretation.

CHARACTERISTICS OF DRAINAGE SYSTEM

IN GEOLOGICAL INTERPRETATION

1. Integration

2. Density or spaciation

3. Homogeneity

4. Orientation and control

5. Pattern

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HOW TO INTERPRETATE THE LITHOLOGY

1. Lithological units are easily to identify from

remote sensing image (especially aerial

photograph):a. Sandstone

b. Shale stone

c. Limestone

d. A certain igneous and metamorphic rocks

e. Unconsolidated material, such as: sand, gravel,

clay

f. Intercalation resistance and non resistance rocks

2. Sedimentary rocks can be identify and

classified based on:a. Texture

b. Mineral composition

c. Color

d. Porosity

e. Permeability

f. Drainage density

g. Drainage pattern (fig.1)

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limestone

sandstone shale

Water soluble

Subsurface drainage

Sinkhole

External drainage

Closed spaced

pattern

Internal drainage

Wide spaced

pattern

Calcareous shale,

marl

Clay limestoneArenaceous

limestone

Calcareous

sandstone

Arenaceous shaleArgillaceous sandstone

Three types of

sedimentary rocks

CARBONATE

COARSE GRAINED CLASTICS FINE GRAINED CLASTICS

Intermediate

lithologies with

mixed

characteristicsResistant,

porous,

permeable

Resistant/

nonresistant,

soluble, karstification, internal and external drainage,jointing; light to medium photo tone

Low

resistant

insoluble

Impervious, external

drainage, high density,

dark to medium photo

tone

depend on cement and

matrix, internal drainage,

low density; frequent joint

system; light or light to

medium photo tone

Fig. Image/photo

characteristic of

sedimentary rocks

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IDENTIFICATION OF SEDIMENTARY ROCKS

FROM IMAGE/AERIAL PHOTOGRAPH

Coarse clastic

sediment:

breccia,conglomerate

sandstone

Fine clastic:

sediment:clay,

shale, siltstone

Carbonate:

limestone and

dolomite, marls

Resistant, depend on cementation

Low permeability and non resistant

In arid resistant, in humid soluble

Form: cuesta, hogbag, mesa

In humid: low hill with rounded topo.

Karst topography

As key horizon for structural analysis

Impervious, external drainage

Sink hole and doline dominant

Joint system well develop Joint system not develop

Joint frequent, longitudinal belt of dark tone/colour

Drainage: low-medium density

Drainage: high density

Low drainage density

Drainage pattern: dendritic, trellis

Dendritic drainage pattern

Partly: underground

Tone: light to medium Gray to dark tone Light to dark photo tone

IMAGE CHARACTERISTICS OF

IGNEOUS ROCKS

1. Based on mineral composition: Acidic: light photo tone

Intermediate: light to medium photo tone

Basic: dark to dark photo tone

2. Extrusive rocks: Associate with volcanic landform

Porosity and permeability: high

External drainage

Basic lava: shield volcano, joint are predominat

Acidic lava: bocca, spatter cone, lava blister

Intermediate lava: strato volcano

3. Intrusive rocks: Homogen

Topography humocky (humid) and sharp (arid)

Joint: frequent

Drainage pattern with low density.

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IMAGE CHARACTERISTICS OF

METAMORPHIC ROCK1. Massive topography, stratigraphy not clearly appear

2. Permeability is low; drainage density high to medium;

drainage pattern: dendritic, trellis or parallel.

3. Quartzite: resistant, massive topography, low permeability,

dendritic, trellis; gray photo tone

4. Marble: in arid and semi arid resistant, in humid similar to

limestone

5. Slates: low resistant, high drainage density, dendritic; dark to

medium gray

6. Gneiss: resistant, massive topography, low

permeability,dendritic, trellis; gray photo tone

GEOLOGIC STRUCTURE IMAGE

INTERPRETATION

1. FLAT-LAYING BEDS: Contrasting tone of different sedimentary rocks

Break of slope along the contour

Dendritic drainage pattern

2. DIPPING BEDS (FOLDS) Topographic surfaces coincide with bedding surface

Asymetrical slope can be used to determine the

direction of the dip

Pattern of outcrop on valley can be used to determine

the direction of the dip

Major stream usually flow parallel to the strike of the

stratified beds.

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3. JOINTS Linear features/lineaments, thin rather than short, in regular

direction

Intersecting joint approximately at right angles (vertically, dipping)

give a blocky pattern of the topography.

In fine grained clastic rocks joint are generally more closely

spaced

4. FAULTS Linear features/lineament

Triangle facet

Alignment of vegetation, straight of river/stream

segment, alignment of lakes, ponds and springs

Changes of tone, drainage and erosional features on

opposite of linear features

Alignment of topography.

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