Geological Map.ppt

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Ig: kalpajyoti_mazumdar

1. Geological Map
Presented By:
KalpajyotiMazumdar
4th sem, Department of Earth Ecience,
Assam University, Silchar

2. Content
Introduction
Brief history of Geological mapping
Types of Geological Map
How geological maps prepared ?
Field Equipment
Map scale
Map key
Conclusion
Bibliography

3. Introduction
•WhatisaMap?
•AmapisapictureorrepresentationoftheEarth’s
surface,showinghowthingsarerelatedtoeachother
bydistance,direction,andsize.
•Mapsareawayofshowingmanythingsabouta
portionoftheEarth’ssurfaceonaflatpieceofpaper
thatcanbecarriedandtransportedeasily.
•AmapisnotaphotographoftheEarth’ssurface.It
canshowmanythingsthatapicturecan’tshow,and
asaresult,amaplooksdifferentinmanywaysfroma
photographoftheEarth’ssurface

4. What is a Geological Map?
•Geological map is a special purpose map made to show
geological features.
•A geologic map is a made of the different types of rocks or
structures that are on the surface of the Earth.
•Geologic maps are used to interpret the structure,
Stratigraphy , Mineralogy, Paleontology, and the historical
record of the Earth’s crust.

6. Brief history of geological mapping
ThemapindicatingthegoldfieldinEgyptonthe13
th
century,isthefirst
recordedattemptinprovidinggraphicalgeologicalinformation.
Inthe16
th
centuryD.OwenshowedtheCarboniferousoutcropintheform
ofnarrowbeds.
FirstgeologicalmapisknowntohavebeencompiledM.Listeratendofthe
17
th
century.
Thefirststratigraphiclayerbylayergeologicalmapisstartedappearingat
thebeginningofthe18
th
century.
InIndiathefirstgeologicalmapwaspreparedbyDr.HenryWestlyVoysey.
Apt.JDthe1825andthisHerbestpreparedthefirstgeologicalmapofthe
Himalayaninwaspublishedin1842fortheareabetweentheriverSutlejand
Kali.

7. Types of Geological Mapping
There are 3 major types of Geologic Maps
1.Topographic Maps
2.Structural Maps
3.Cross-section map

8. 1.Topographical Maps:
Topographic maps, show a 3 dimensional world
in 2 dimensions, by using contour lines (lines of
equal elevation).
Topographic maps refer to a graphical
representation of the three-dimensional
configuration of the surface of the Earth.
Moreover, such maps show the size, shape, and
distribution of landscape features.

9. 2. Structural mapping
•Structuralmappingistheidentificationandcharacterizationofstructural
expression.Structuresincludefaults,folds,synclinesandanticlinesand
lineaments.Understandingstructuresisthekeytointerpretingcrustal
movementsthathaveshapedthepresentterrain.
•Asynopticviewofregionalscaleisamuchdifferentperspectivethanpoint
groundobservationswhentryingtomapstructuralelements.Remotesensing
offersthisperspectiveandallowsageologisttoexamineotherreference
ancillarydatasimultaneouslyandsynergistically,suchasgeo-magnetic
information.

11. 3. Cross-sectional map
•Across-sectionalmapshowsthecross-sectionfromtheside.Thecross-sectionalmaps
showsthechangesalongthelineshownonthemap.
•Cross-sectionmapsorblockdiagramsisnotamapactuallybutsometimesitisalso
consideredasageologicalmap,becauseofshowingdatasimilartoageologicalmap

14. Some other types of maps

15. Global map of monthly sea surface salinity, May 2022.
NASA's Soil Moisture Active Passive (SMAP) mission

17. Map of the world showing average annual precipitation

19. How Geological maps are prepared?
•Theaimofgeologicmappingistocreateamapwhichsummarizesthe
geologicdatagatheredinthefield.
•Everyplacethatanobservationismade,asampleisgathered,oranytype
oddatacollectiontakesplace,itispositionedonthemapattheappropriate
X–Ycoordinates.
•Themapcanbesmallscaleandshowmuchdetail,orbelargescaleand
generalized.
•Differentgeologicmappingagenciesandauthoritieshavedifferent
standardsforthecolorsandsymbolstobeusedforrocksofdifferenttypes
andages.

20. Field Equipment
A
B
C
D
E
F
G
H
I
J
K

21. Map scale
•Mapscalecanbeexpressedastheratioorproportionbetweena
distanceonamapandtheactualdistanceonthelandsurface.
ThisratioiscalledtheRepresentativeFraction(RF).ARFof
1:100,000indicatesthat1unitofmeasureonthemaprepresents
100,000unitsonthelandsurface(i.e.,1inch=100,000inches,1.58
miles)

26. Conclusion
•Geologicalmappingisthefundamentaltaskofageologiston
thebasisofwhichallsubsequentqualitativeandquantitative
geologicalstudiesarecarriedoutleadingtounderstandingof
evolutionofchosenpartoftheterraininspaceandtime.
•Theinformationisrepresentgraphicallyonachosenscale,by
useofcombinationofcolours/characters,linesandsymbols.

27. Bibliography
1.BasicsofGeologicalmappingJohnW.Barnes,formerlyoftheDepartmentof
EarthScience,UniversityofWalesSwansea
2.StandardsforRegionalGeologicalMapping:ProceduresandGuidelinesfor
workprocessescontenteddigitalattributesforproducts(partII,partI)
RegionalGeologyandGeochemistryDepartmentGeologicalSurveyofEthiopia

28. How to create geological map on
QGIS
Complete guide
•https://youtu.be/I8Wzm2qJsh0