Geological Fieldwork (Pre Fieldwork Study)


Geological Field:

The sensible learn about and statement of geologic features like outcrops, drainage Patterns, folds, faults, and exceptional formations and their diagnostic characteristics, Unconformities and fossils and many others in the discipline is referred to as geological field. Some requirements and precautions are vital for the geological field. Which Are discipline planning, equipments used in field, literature need to be studied of that discipline area.


Field Planning:

This ability to aircraft or to determine for the observations in the field. Some steps are used to discipline plane, which are:


Office preparation: 

It is the practice of discipline earlier than the going to field. The Basic motion is to recognize about that region the place we are going to take a field, means its geologic and geographic literature, then we should have the devices that are used in the field. We have to aircraft about the traverse that we have to take. The next Step is to comprehend about the safety preparations about target area.


Field preparation: 

Field guidance consists of a desirable dressing for the field. As we have to climb over the rocks and folds and additionally from time to time we have to cross the faults and drainage patterns consequently a desirable dressing is the most fundamental thing in the area plane. After that we need to have the association of meals and water with We and additionally a scientific and first resource package in beg.


It is the ultimate step in the subject planning. It is the finishing the field Preparation and going to the field.


Geological area equipments and their uses:

The contraptions and different equipments used at some stage in the discipline are:

1. Topographic sheet

2. Brinton compass

3. Field word book

4. Hand lens

5. Measuring tape

6. Medicine kit

7. Geological map

8. Foot scale

9. Sampling begs

10. Field beg

11. Geological hammer

12. Field shoes

13. HCl (hydrochloric acid)

14. Knife

15. Coin

16. G.P.S (global positioning system)

17. Haversack

18. Altimeter

Uses of discipline equipments:


1. Topographic map is essential device of the geological subject work. It serves as the Base for systemic discipline work and geological mapping. This map suggests the Topographic configuration and aspects like road, railway lines, villages, cities, Valleys and floor smoothness or roughness of land surface.

2. There are many compasses are used in the discipline however Brinton is most fulfilling to others Because of its extra features. Brinton compass is used for the measuring the Direction of dip and strike and genuine north with the assist of needle or clinometers Inside the Brinton.


3. Field notice e book is used to notice down the observations took in the subject like the Exact region of outcrop, nature and attitudes of rock as considered in outcrop, dip and Strike of rock beds, one of a kind structural features, place and description of fossils That gathered correlation and different essential information.


4. Hand lens is used for the magnification of mineral composition of rock samples that should no longer be viewed with necked eyes.

5. Steel or a metal tape of 30 meters size or a pocket metal tape of two meters Length is required for the discipline work. It is used for measuring the thickness of rock Strata, fold thickness, size of ground, traverse strains and veins etc.

6. Medicine package consists of the drug treatments for the wounds, fever, headache etc.

7. Geological map is used for the understanding about the geological points like folds, Faults, rock gadgets and formations etc.

8. Foot scale is used for the size reason at small level.

9. Sampling begs are used for the series of rock samples and fossils that are collected in the field.

10. Field begs is used for the maintaining quintessential area things, like food, drug treatments etc.

11. Hammers are quintessential for cheapening rocks and amassing samples. Generally there are two sorts of hammers are used in the field. One is geological hammer Having one chisel and different flat side. Flat aspect is used for the breaking the rocks. While the chisel facet is used for trimming and sizing the specimens. Other kind of the hammer is paleontological hammer with one noke aspect and different flat side. The noke is used for the casting off the fossils from the rock.

12. Field footwear is essential for the on foot over the rocks. Common footwear may also before at some stage in the field.

13. HCl is used for identification of the clastic and non-clastic rocks, and percentage of the fossils in the field.

14. Knife is used for the willpower of hardness of minerals.

15. Coin is additionally used for the equal reason as knife, for the hardness of minerals.

16. The world positioning device is used for the finding the role of area location in the globe.

17. Haversack is used for the carrying compass, be aware book, knife etc.

18. Altimeter is a barometer used for identifying floor elevation. Along with compass it notably helps in finding outcrops in mountainous areas.

Geological Maps:

A kind of map on which geological aspects like folds, faults, joints, unconformities, and formations and so on are proven is known as geological map. This kind of map shows the geological set-up of a place in phrases of incidence and distribution of various rock types.

Application of geological maps:

Geological maps have a vast vary of utility in mineral projecting, mining and civil engineering works. The purposes of geological maps are:

  1.  They supply a key for appreciation the buildings and geological records of any particular region.
  2. They expose the altitudes and shape of outcrops and their affiliation with topography.
  3.  It suggests the contacts between more than a few rocks.
  4. It suggests the relative a while of strata via index organized in order of lowering age from backside to upward. It suggests the dip and strike, their attitude of inclination and direction.
  5. It additionally suggests different geological constructions and their natures and patterns.


Types of geological maps:

There are 4 sorts of geological maps, which are:

Reconnaissance maps:

 It is a kind of map, which is made to locate out the geology of an unknown place as shortly as possible. Scale used in these sorts of maps is usually 1:250,000. Some reconnaissance maps are made by means of picture geology that is by deciphering geology with aerial photograph. Reconnaissance mapping is also done with the aid of plotting the major geological aspects on a base map from helicopter.


Regional geological maps:

These are the massive scale maps of restricted area, so that the geology may want to be studied in extra element commonly at the scale of 1:250,000 or 1:500,000. Regional maps must be plotted on dependable base, and ought to be done on the floor may additionally be supported by using the systemic photograph geology.


Detailed geological maps:

These are the geological maps which are made to investigate particular geological problems, possibly ensuing from discoveries made during regional mapping or possibly with a financial goal such as dam site or mineral investigation. The scale is used usually is 1:10,000 to upwards.


Specialized geological maps:

 These are giant scale maps made in first-rate element of small areas to report precise geological features. Many are made for economic purpose, such as open pitmine planes at scale from 1:1000 to 1:2500. These are also used for underground geological hassle at scale 1:500 and even massive and engineering web page investigation at equal scale.

Dip and Strike:

The attitude of inclination of rock strata with recognize to horizontal floor is known as dip. The extinction or orientation of rock strata with the horizontal floor is known as strike. The dip and strike are constantly perpendicular to every other. Or they additionally can be described as: DIP is the acute attitude that a rock floor makes with a horizontal plane. STRIKE is the direction of the line fashioned via the intersection of a rock floor with a horizontal plane.


Longitude and latitude:



(shown as a horizontal line) is the angular distance, in degrees, minutes, and seconds of a factor north or south of the Equator. Lines of latitude are frequently referred to as parallels.



(shown as a vertical line) is the angular distance, in degrees, minutes, and seconds, of a factor east or west of the Prime (Greenwich) Meridian. Lines of longitude are frequently referred to as meridians.

Distance between Lines: 

If we divide the circumference of the earth (approximately 25,000 miles) by using 360 degrees, the distance on the earth's floor for every one diploma of latitude or longitude is simply over sixty nine miles, or 111 km.



 As we pass north or south of the equator, the distance between the traces of longitude receives shorter till they honestly meet at the poles. At forty five ranges N or S of the equator, one diploma of longitude is about forty nine miles.

Minutes and Seconds: 

For precision purposes, levels of longitude and latitude have been divided into minutes (') and seconds ("). There are 60 minutes in every degree. Each minute is divided into 60 seconds. Seconds can be similarly divided into tenths, hundredths, or even thousandths.

Identification of folds in the field:

Bends or waves like points in layered rocks are referred to as fold. Rocks are subjected to exclusive stresses and tectonic forces all through the geological time. These forces fold the rocks.


Geometry of the folds:


It is attitude between bedding aircraft of fold with the horizontal surface.


It is an upward arching fold. The rock layers dip away from every other, originate from a frequent point.


It is a downward arching fold. The rock layers dip toward the frequent point.


One facet of fold is known as limb, or distance between crest and adjoining trough is called limb.

Axial limb: 

An imaginary aircraft which divides a fold into two equal components is referred to as axial limb.

Axes of fold: 

The line perpendicular to axial airplane is referred as axes of the fold. On the groundwork of axial airplane folds are categorized into two types. Which are;

Symmetrical fold:

The folds whose axial airplane is vertical with ninety diplomas with the horizontal floor are called symmetrical folds.

Asymmetrical fold:

The fold, who’s which axial aircraft is inclined or now not of the ninety diplomas with the horizontal surface, is known as asymmetrical fold.


Interpreting folds:

Folds manifest in many types and sizes. Some are following:

Open folds: the folds have limbs that dip gently.

Isoclinals folds: The folds whose limbs are parallel to one some other are referred to as isoclinals fold.

Overturned folds: If the limbs of a fold dip in the equal direction, the fold is stated to be overturned fold.

Plunging folds: The folds in which the hinge traces are now not horizontal are referred to as plunging folds.

Recumbent fold: the limbs of these folds are horizontal.

Structural domes: These are the folded dome like constructions of folded rocks and mountains in which beds dip away from a multiplied center.

Structural basins: These are additionally folded depressed or basins like constructions in which beds dip toward a depressed center.

In the discipline folds are recognized on the foundation of two evidences;


1. Dip evidence:

Rocks are deposited in horizontal and unified manner. In the discipline if we have a look at the limbs of rock mattress are dipping in any amount. We can say that this rock mattress is folded.

2. Stratigraphy:

In many instances uncovered rocks or folds are weathered and eroded and no any folded structure observed. Then the ideas of Stratigraphy are applied. Older rocks lie always at the backside and youthful at the top. And if we observed repetition of rock beds then we can say that these beds are the section of any fold.

Identification of faults in the field:

A fracture existing in any rock, alongside which a positive displacement has occurred, is called fault. This displacement can also be various from a centimeter to a number of kilometers. Total horizontal displacement of fault is referred to as dip slip fault or heave, and vertical displacement known as strike slip fault or throw. The complete vertical and horizontal displacement alongside a fault is known as indirect slip fault.


Terminology of faults:

During the learn about of faults we examine specific phrases such as:

Fault block: The rock devices existing on the each facets of faults, which had been identical rock before the fault.

Foot wall block: the block current beneath the fault is referred to as foot wall block.

Hanging wall block: the rock block current above the fault is referred to as putting wall.

Types of faults:

Depending upon the motion of fault blocks, faults are labeled as follows;


Normal fault: A fault in which placing wall block moved downward relative to the foot wall block, is known as regular fault.

Reverse fault: In this kind of faults placing wall block go upward relative to the foot wall block.

Thrust fault: It is a kind of reverse fault in which the dip of fault aircraft is at a low attitude to horizontal Surface.

There are 5 foremost standards on which faults are recognized in the field. They are:

1. Slickenside or striations:

Linear impressions produced by means of motion of fault blocks are referred to as slickenside or striations. They additionally exhibit the route of placing wall.


2. Breccias:

The angular and of unique sized rock fragments current in any discipline are additionally the signal of faults. They may also be produced at some point of the faulting.

3. Gauge:

This is the powder like cloth of rocks produced at some stage in the motion of fault blocks.

4. Repetition of beds:

Fault blocks pass upward or downward. During the area if repetition of beds observed that potential the fault is current here.

5. Streams:

They are the sprigs of water produced due to faulting. The floor water comes out through these springs. It is the principal signal of fault.

Identification of unconformities in the field:

A temporal ruin or interval in sedimentation is referred to as unconformity. An unconformity is a floor that represents a hole in the geologic record, with the rock unit without delay above the contact being notably youthful than the rock unit beneath. Unconformity additionally referred to as contact or unconformable contacts.

Types of unconformities:

There are three kinds of unconformities:

Angular unconformity: 

It is a contact in which youthful strata overlie an erosion floor on tilled or folded layered rock. Older strata is tilled or folded with the aid of extraordinary herbal agencies.

Non conformity:

A non conformity is a contact in which youthful set of sedimentary rocks overlie on older igneous or metamorphic rocks.



In a Disconformity, contact representing lacking rock strata separates, beds that are parallel to one another.

Unconformities can be recognized on the foundation of two fundamental evidences. These are:


1. Lateritic mattress or oxidized layer:

It is the crimson or brown in coloration mattress produced all through the unconformable period. As the oceanic water regretted and rock beds uncovered to terrestrial environment, the atmospheric oxygen started out to react with rock minerals in the presence of daylight and quite a few other environmental factors. Hence appears as crimson or crimson to brown in color.


2. Fossils or paleontological evidences:

If we ought to no longer see any lateritic mattress then we learn about the fossils of rock beds. If we determined a sudden alternate in the fossils between two beds it skill unconformity is present.


Geological sampling:

When we go to area we look at distinctive outcrops. In these outcrops we observe different rock gadgets of distinct ages. To some extent we additionally become aware of the mineral composition and fossil continents of those rock gadgets as we have already examine it in books. To similarly study these rock gadgets their mineral composition, fossil constituents, their age of formation we accumulate special samples of rock devices in the field. This procedure id called the geological sampling.

A small consultant of a big physique is referred to as sample. In geological sampling there are 4 kinds of samples. They are:

1. Rock samples: The samples which are taken from the rocks to have a look at their mineral composition, fossils and age of deposition are referred to as rock sample.

2. Core sample: The pattern which is drawn from sub-surface of the earth of any type is referred to as core sample.

3. Stream sediment sample: The patterns drawn from circulate or river or any source of water that raise sedimented, water to have a look at its sediment load’s nature is called circulate sediment sample.

4. Water sample: The pattern taken from water both floor water of surface Water is known as water sample.

There are three phases in taking the samples. First section is to accumulate samples from Source. Then the 2nd segment is the numbering and labeling of the samples, as later we can perceive them in laboratory. The closing section in the sampling is packing and storage of Samples.

Begs are used for the packing and storage of samples are known as pattern begs are the Basic subject equipment. Normally 4.8 dimensional beg are used for the samples.



Concept, device, or method used in arranging, measuring, or quantifying events, Objects or phenomenon in any sequence is known as scale. Scales may additionally be generally categorized as

(1) Category scale: Sequence of numbers or Words which solely serve to become aware of positive entities or observations and have no Quantitative significance; for example, a numbered or named list, or numbers on the Uniforms of the contributors of a team. It is additionally referred to as nominal scale or qualitative scale.


(2)Interval scale: Sequence of numbers in a constant order representing amount, interval, or Numeric values; for example, a distance or temperature scale. It is additionally known as quantitative Scale.

(3) Sequence scale: Ranked entities or gadgets with a uniform spacing however no Quantitative significance; for example, hardness scale (Moh's scale), pH Scale, or Richter scale. It is additionally known as ordinal scale. Scale in subject geology or in geological mapping is distance on a map smaller than the genuine distance on the floor however constantly undergoes a specific proportion. To say that a Map is drawn to the scale of one inch to one mile capability that one inch on the map Represents one mile on the ground.


Expression of the scale: 

Scale is proven in three methods on a map.

a. The declaration of the scale.

b. The consultant fraction or numerical scale.

c. The linear or airplane scale, additionally acknowledged as image scale or graduated scale. It may also be stated that that commonly all these three types of the scales are given on a Perfect map.


Post a Comment

Post a Comment (0)