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|competition=June 2015

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Geological interpretation is one of the critical works in geological field. To get the result of geological interpretation that’s closer to the truth, we need required adequate data and important geological data packaging that will affect the result of interpretation that we got. Geological map is one of geological data presentation that’s most competent and is used for various purposes either for science or exploration of natural resources. Geological map is a map that’s consist of geological information of outer layer of earth [[crust]], they are variation of litology, distribution of geologic structure, stratigraphy and geomorphology. All of that information read by symbols and colors. Detail of geological map depends on the scale that’s choosen, the density of observations in the field, and the accuracy of the observations in the field. The final result from all geological methods is geological map (it’s basic for all geological analysis).

Geological interpretation is one of the critical works in the geological field. To get a geological interpretation that’s closer to the truth, we need adequate data and important geological data packaging. Geological mapping is one geological data presentation that’s most competent and is used for various purposes either for science or exploration of natural resources. A geological map is a map that consists of geological information of the outer layer of earth [[crust]]; they are a variation of [[lithology]], distribution of geologic structure, [[stratigraphy]] and geomorphology. All of that information read by symbols and colors. Details of geological map depend on the its scale, and the density and accuracy of observations in the field. The final result from all [[geological methods]] is a geological map.

==Geological mapping==

==Geological mapping==

To make a good geological map, a geologist must have good skill in geological mapping and know well about how to read geological map. Basic step of geological mapping consists of observation and measurement in field, taking samples, and analyze samples in laboratory. Geological mapping is a multidisciplinary method that combines all geological disciplines such as petrology, structure geology, geomorphology, paleontology, stratigraphy, sedimentology, etc. Geological mapping consists of two kind based on selection trajectory, they are:

To make a good geological map, a geologist must have skill in geological mapping and know about how to read geological map. Basic steps of geological mapping consist of observation and measurement in the field, taking samples, and analyzing samples in a laboratory. Geological mapping is a multidisciplinary method that combines petrology, structural geology, geomorphology, paleontology, [[stratigraphy]], sedimentology, etc. Geological mapping consists of two kind based on selection trajectory:

# Systematic mapping

* Systematic mapping is done by mapping technically only, without considering geomorphology, distribution of geomorphology, or geological structure pattern. While smart mapping is done by considering the results of satellite image or topographical maps analysis, so it would be more efficient in geological mapping according to the desired scale. In this paper we are more focus on the method of smart mapping because this method is most often used by geologists.

# Smart mapping

* Smart mapping is used for several reasons, such as that the mapping area is too large, mapping time is too short, or lithological variations are relatively homogeneous. While systematic mapping is used when variations of lithology are very complex so observation of some point isn’t enough to represent all lithologies and structures in the mapped area and the availability of sufficient time. Therefore it is very important to know the purpose of geological mapping before doing the mapping to desired area.

The key points of smart mapping are:

* Smart mapper will start by looking at aerial photos to determine where the available outcrop is and then make 2-3 traverses across [[strike]] to ground the photo interpretation

 

* Searching patterns will focus in on key areas of interest e.g. [[shear]] zones

 

The key points of smart mapping are :

* Smart mapper will start by looking at aerial photos to determine where the available outcrop is and then make 2-3 traverses across strike to groundtruth the photo interpretation

* Searching patterns will focus in on key areas of interest e.g. shear zones

* Less time is spent in areas where the rocks are uniform and a lower density of observations will serve.

* Less time is spent in areas where the rocks are uniform and a lower density of observations will serve.

* Most useful observations are the predictable geometrical relationships between bedding, cleavage, lineaments and [[fold]]s as well as movement indicators for brittle and ductile shear zones

* Most useful observations are the predictable geometrical relationships between bedding, cleavage, lineaments and [[fold]]s as well as movement indicators for brittle and ductile shear zones

<gallery mode=packed heights=300px widths=300px>

<gallery mode=packed heights=300px widths=300px>

File:UGM_Mapping_Fig_1.png|{{figure number|1}}Illustration of systematic mapping (Derived from Pramumijoyo<ref name=Pruma>Pramumijoyo, S., 2014, Metode Geologi Lapangan. Yogyakarta : Unpublished</ref>)

File:UGM_Mapping_Fig_1.png|{{figure number|1}}Illustration of systematic mapping (Derived from Pramumijoyo<ref name=Pruma>Pramumijoyo, S., 2014, Metode Geologi Lapangan: Yogyakarta, unpublished</ref>)

File:UGM_Mapping_Fig_2.png|{{figure number|2}}Illustration of smart mapping (Derived from Pramumijoyo<ref name=Pruma />)

File:UGM_Mapping_Fig_2.png|{{figure number|2}}Illustration of smart mapping (Derived from Pramumijoyo<ref name=Pruma />)

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'''Geological mapping is a process of problem solving.''' It is known as the system of '''multiple working hypotheses.''' (It is armed with a number of ideas about the geology developed from looking at published maps, literature, satellite image, aerial photographs, topographic map and/or gravity map). Prediction / interpretation is done to an area and field observations is to prove the results of the interpretation. Don’t be too focused to just one model.

'''Geological mapping is a process of problem solving.''' It is known as the system of '''multiple working hypotheses.''' (It is armed with a number of ideas about the geology developed from looking at published maps, literature, satellite image, aerial photographs, topographic map and/or [[gravity]] map). Prediction and interpretation is done to an area and field observations is to prove the results of the interpretation. Don’t be too focused to just one model.

Geological mapping is a '''scientific process''' and corresponds to the classic scientific method: '''theorizing, making predictions''' from the theories and '''designing experiments'' (field observations or [[geochemistry]] analysis) to test the predictions.

Geological mapping is a scientific process and corresponds to the classic scientific method: theorizing, making predictions from the theories, and designing experiments (field observations or [[geochemistry]] analysis) to test the predictions.

Geologic mapping consists of three point stages, they are :

Geologic mapping consists of three point stages:

[[File:UGM_Mapping_Diagram_1.png|400 px]]

[[File:UGM_Mapping_Diagram_1.png|400 px]]

===Analysis of images and topographic maps===

===Analysis of images and topographic maps===

The initial step that should be done is secondary data collection. This data will be the basis for interpretation of pre-mapping. Required secondary data are:

The initial step that should be done is secondary data collection. This data will be the basis for interpretation of pre-mapping. Required secondary data are:

Topographic Map

* Topographic map

* Satellite Images

* Satellite images

* Regional Geological Map

* Regional geological map

* Landuse Map

* Land use map

* Paper or Journal about Geological Research in Area that will be mapped

* Geological research for area that will be mapped

* Geological Maps of mapping area that have been made (if available)

* Geological maps of mapping area (if available)

After all secondary data collected, analysis process can start. Aim of analysis process is to determine the following points:

After all secondary data collected, analysis process can start. The aim of the analysis process is to determine the following points:

* Landscape and [[Strike]]/[[dip]] of bedding

* Landscape and [[strike]]/[[dip]] of bedding

* Distribution of rock units/Formation

* Distribution of rock units or formations

* Geological Structure pattern

* Geological structure pattern

* Tentative maps

* Tentative maps

===How to interpret strike and dip of bedding rocks from images or topographic maps===

===How to interpret strike and dip of bedding rocks from images or topographic maps===

<gallery mode=packed heights=300px widths=300px>

<gallery mode=packed heights=300px widths=300px>

File:UGM_Mapping_Map_1.png

File:UGM_Mapping_Map_1.png

File:UGM_Mapping_Map_2.png

File:UGM_Mapping_Map_2.png

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===Make tentative geomorphological map===

===Make tentative geomorphological map===

[[File:UGM_Mapping_Fig_3.png|thumb|300px|{{figure number|3}}Geomorphology Maps (Source : Geologic Field Method Practice)]]

[[File:UGM_Mapping_Fig_3.png|thumb|300px|{{figure number|3}}Geomorphology Maps (Source: Geologic Field Method Practice)]]

Map that’s used as a basis to draw the boundary unit of geomorphology is a topography map. Topographic maps depict clearly the different reliefs that appear on the surface of the earth. Different reliefs are caused by differences in the type of lithology, geological structure, and exogenic processes that control the morphology. Satellite image and Digital Elevation Model (DEM) can be used as supporting data to clarify the morphology of the mapping area.

A map that’s used as a basis to draw the boundary unit of geomorphology is a topography map. Topographic maps depict clearly the different reliefs that appear on the surface of the earth. Different reliefs are caused by differences in the type of lithology, geological structure, and exogenic processes that control the morphology. Satellite image and Digital Elevation Model (DEM) can be used as supporting data to clarify the morphology of the mapping area.

Tentative geomorphological map is drawn up early because morphology is the the most easily seen and identified appearance. Morphological changes reflect differences in lithology, geological structure, exogenic process, and time.

A tentative geomorphological map is drawn up early because morphology is the the most easily seen and identified appearance. Morphological changes reflect differences in lithology, geological structure, exogenic process, and time.

Determining process of geomorphology unit boundary can be done with following step:

Determining process of geomorphology unit boundary can be done with following steps:

* Create a boundary line unit by taking into differences in density of contour lines (dense and loose)

* Create a boundary line unit by taking into differences in density of contour lines (dense and loose)

* Make a geomorphological section in certain direction to be certain of the limits of morphological unit

* Make a geomorphological section in certain direction to be certain of the limits of morphological unit

To determine the litology that may compose each litological unit can be used several indicators, such as:

To determine the litology that may compose each litological unit can be used several indicators, such as:

* Different kind of vegetations, vegetation sometimes represents the difference of litology. For example teak trees usually grow above carbonate rocks. Although not usually true, but the data is quite useful as a first approximation.

* Different kind of vegetations, vegetation sometimes represents the difference of litology. For example teak trees usually grow above carbonate rocks. Although not usually true, but the data is quite useful as a first approximation.

* Roughness and fineness of the [[contour]] line patterns, contour line pattern may also indicate differences in litology. Dense contour line pattern indicates solid and hard rock such as metamorphic rocks, igneous rocks and sedimentary rocks that are resistant while the smooth contour line pattern indicates sedimentary rocks that are not resistant (e.g. mudstone).

* Roughness and fineness of the [[contour]] line patterns, contour line pattern may also indicate differences in litology. Dense contour line pattern indicates solid and hard rock such as metamorphic rocks, [[igneous rock]]s and sedimentary rocks that are resistant while the smooth contour line pattern indicates sedimentary rocks that are not resistant (e.g. [[mudstone]]).

In the tentative geological map we can also draw a lineament that estimate the geological structures such as faults. Fault is marked by the change of contour line patterns drastically or shifted in a narrow area. Estimated geological structure will facilitate observations in the field to look for evidence of the structure.

In the tentative geological map we can also draw a lineament that estimate the geological structures such as faults. Fault is marked by the change of contour line patterns drastically or shifted in a narrow area. Estimated geological structure will facilitate observations in the field to look for evidence of the structure.

Trajectory mapping is mapping done by combining several observation points. Two things to be noted are: efficiency of trajectory direction and location selection of the observation point. Efficient track direction is the direction perpendicular to the common dip or perpendicular to the longitudinal axis of the fold or spreading of rock or lengthening morphology element. For more efficient, before go to field create a map of the distribution of the main road to the footpath and distribution of streams and valleys Find the intersection direction of the road and the river is approximately perpendicular / angular blunt with unit geomorphic boundary (relief : are allowed so synonymous with boundary of litology units). Plan a cut off point as stop site for observation. While in the field, there are some basic criteria that can be used to make the observation location:

Trajectory mapping is mapping done by combining several observation points. Two things to be noted are: efficiency of trajectory direction and location selection of the observation point. Efficient track direction is the direction perpendicular to the common dip or perpendicular to the longitudinal axis of the fold or spreading of rock or lengthening morphology element. For more efficient, before go to field create a map of the distribution of the main road to the footpath and distribution of streams and valleys Find the intersection direction of the road and the river is approximately perpendicular / angular blunt with unit geomorphic boundary (relief : are allowed so synonymous with boundary of litology units). Plan a cut off point as stop site for observation. While in the field, there are some basic criteria that can be used to make the observation location:

# a common contact / lithology boundary (don’t forget that the geological maps essentially is a map that illustrates the spreading direction contacts!)

# a common contact-lithology boundary (don’t forget that the geological maps essentially is a map that illustrates the spreading direction contacts!)

# The point where the common boundary morphology is sharp (perhaps also the contact between rocks).

# The point where the common boundary morphology is sharp (perhaps also the contact between rocks).

# The place where the common structure (fault, stocky, folds, etc.)

# The place where the common structure (fault, stocky, folds, etc.)

# The point where (1) to (3) don’t exist but there are good outcrops / complete

# The point where (1) to (3) don’t exist but there are good or complete outcrops

# The point where there is found positive geological potential and / or negative potential such as landslide, etc

# The point where there is found positive geological potential and/or negative potential such as landslide, etc

# Point somewhere where possible morphological descriptions in the other direction (from a height in the direction of lower or of the plain towards the hills around

# Point somewhere where possible morphological descriptions in the other direction (from a height in the direction of lower or of the plain towards the hills around

# Points on a map that distance more than 2 cm from another point.

# Points on a map that distance more than 2 cm from another point.

===Make schedule on the field===

===Make schedule on the field===

'''First''' thing to note is the availability of time. Whether to spend one full month? 3 weeks? Decide first. Note to glance topography maps, to see accesibility. Does it take a lot of time or medium?

# Note the availability of time. Whether to spend one full month? 3 weeks? Decide first. Note to glance topography maps, to see accessibility. Does it take a lot of time or medium?

 

# Determine the time design. Is in field for a week, two days off? Or four days field, one day off? Why should there be a day off?  

'''Second,''' determine the time design. Is in field for a week, two days off? Or four days field, one day off? Why should there be a day off? There are some functions, they are:

#* Check field notes. Are they well organized? Sloppy field notes make a messy interpretation. Bad sample management can be a real headache. Working twice in the same stop site could happen.

# With the time off (not go to field / only in basecamp), there will be time to check the fieldnotes. Is it well organized? cluttered fieldnote will only make a mess interpretation. Sample management that’s not good, just be a real headache. Big problem is working twice in the same stop site could happen.

#* Update the field strategy. Plan alternative or new trajectories. The initial trajectory plan may need to be corrected, and your time off is a good time to revise.

# The time off, is also to update the field strategy. Plan alternative / new trajectories. Certainly, the initial trajectory plan needs to be corrected, at the time off is the one you do that revision.

#* Rest

# Takes your body to rest for a moment. Rest for a moment of physical activity and mind tiring.

# Refer to the tentative lithology or geological map. Certainly on the tentative lithology or geological map, will appear relationships of stratigraphic units and the possibility of geological structure.

 

#* Notice possible contacts. Will there be continuing, discontinuing, or interfingering? Strategic locations where outcrop of stratigraphy is found (river valleys, escarpment erosion, mining areas, etc.)

'''Third,''' then refer to the tentative litology / geological map. Certainly on the tentative litology / geological map, will appear relationships of stratigraphic units and the possibility of geological structure.

#* Where is the estimates locations that have interpretive structures on the map? Locations to be visited: the possibility of a fault, peak / fold axis, the wings of fold, etc;

# Notice, where it is possible contacts. Do continue, discontinue, or interfingering? Strategic locations where outcrop of stratigraphy is found (river valleys, escarpment erosion, mining areas, etc.)

#* If you already understand this passage, mark it on the new topographic map (clear) as a sign founded stop site. Create as much as possible in the confines of the unit and structure.

# Where is the estimates locations that have interpretive structures on the map? Locations to be visited : the possibility of a fault, peak / fold axis, the wings of fold, etc;

# The time plan and the distribution of stop site points create relationships between nearby stop site. Tracks should be sequential and don’t jump around. Create a closed path (circular) so that there are trajectory that leave basecamp and back to basecamp. Its function is to crosscheck and facilitate the achievement of the coverage area of study.

# If you already understand this passage, mark it on the new topographic map (clear) as a sign founded stop site. Create as much as possible in the confines of the unit and structure.

 

'''Fourth,''' the time plan and the distribution of stop site points create relationships between nearby stop site. Tracks should be sequential and don’t jump around. Create a closed path (circular) so that there are trajectory that leave basecamp and back to basecamp. Its function is to crosscheck and facilitate the achievement of the coverage area of study.

==Mapping stage==

==Mapping stage==

#* '''Fieldnotes:''' It is used to write all of data and make a sketch. Keep the fieldnotes from water, fire, and anything which will make your lose the data.

#* '''Fieldnotes:''' It is used to write all of data and make a sketch. Keep the fieldnotes from water, fire, and anything which will make your lose the data.

#* '''Map:''' The map can be topographic map or your tentative maps. It is used to make traverse for our track, make a boundaries of lithology, and to write all of field data.

#* '''Map:''' The map can be topographic map or your tentative maps. It is used to make traverse for our track, make a boundaries of lithology, and to write all of field data.

#* '''Grain Comparator:''' Its used to distinguish the grain size. Its very useful for sedimentary rocks. We can knows the grain size more detail.

#* '''Grain Comparator:''' Its used to distinguish the [[grain size]]. Its very useful for sedimentary rocks. We can knows the grain size more detail.

#* '''Jacob Stick:''' It’s used to measure the stratigraphic on the outcrop.

#* '''Jacob Stick:''' It’s used to measure the stratigraphic on the outcrop.

#* '''Stationery:''' To write and make the data collecting easier.

#* '''Stationery:''' To write and make the data collecting easier.

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After collecting geological data (such as lithology, geological structure, and geomorphology) from field observation, the next step that should be done is the poster which consists of points of observation’s map, geological map, geomorphological map, stratigraphic column, geological history, and photos and diagrams from petrography, paleontology and structural geology analysis. Those data and maps should represent your field geologically.

After collecting geological data (such as lithology, geological structure, and geomorphology) from field observation, the next step that should be done is the poster which consists of points of observation’s map, geological map, geomorphological map, [[stratigraphic column]], geological history, and photos and diagrams from petrography, paleontology and structural geology analysis. Those data and maps should represent your field geologically.

The first thing that you need to make is the poster. The poster is consist of:

The first thing that you need to make is the poster. The poster is consist of: