Topic 11

Question 1

– is the branch of geology that deals with the systematic classification and identification of rocks, rock forming minerals and soils. Also includes study of dust, dirt, safe insulation, ceramics and other such materials both natural and artificial.

Answer 1

Petrography

Question 2

also commonly referred to asearthordirt, is amixtureoforganic matter,minerals,gases,liquids, andorganismsthat together support thelifeofplantsandsoil organisms.

Answer 2

Soil

Question 3

means different things to different people. A farmer plants crops in it. An engineer builds with it. A miner takes mineral from it. Criminalist regards soil as the top layer of the earth. It may include any substance on the earth that may stick a person’s clothing or shoes.

Answer 3

Soil

Question 4

may be thought as any distinguished materials natural and / or artificial , that has on or near the earth’s surface.

Answer 4

Soil

Question 5

are essentially decayed and decaying vegetative plants and insects , animal doping’s , animals droppings , animal parts , etc.

Answer 5

Organic

Question 6

• Generally crushed rock and clay materials. These are made up of minerals.

Answer 6

Inorganic

Question 7

• In physical weathering rocks breakdown under the influence of physical factors like

Answer 7

Physical Weathering

Question 8

• Also known as spontaneous Weathering.

Answer 8

Chemical Weathering

Question 9

Light , warm , dry and tend to he acidic and low in nutrients.

Often known as light soils due to their high proportion of sand and little clay.

These soils have quick water drainage and are easy to work with.

Answer 9

Sandy Soil

Question 10

Known as Heavy soils that benefit from high nutrients.

Answer 10

Clay Soil

Question 11

It remains wet and cold in winter and dry out in summer.

Answer 11

Clay Soil

Question 12

hold a high amount of water, because these solids drain slowly and take longer to warm up in summer.

Answer 12

Clay soils

Question 13

It is light and moisture retentive soils with high fertility rating.

As slit soils comprise of medium sized particles the are well drained and hold moisture well particles are fine.

Answer 13

Slit Soil

Question 14

are high in organic matter and retain a large amount of moisture.

Answer 14

Peat Soil

Question 15

Can be either light or heavy but always highly alkaline due to the CaCo3 or lime within its structure.

As these soils are alkaline they will not support the growth of ericaceous plants that require acidic soils to grow.

Answer 15

Chalk Soil

Question 16

are mixture of sand, slit and clay these are combined to avoid the negative effects of each type.

These soils are fertile, easy to work with it and provide good drainage.

Answer 16

Loam Soil

Question 17

A side by side visual comparison of the colour and texture of soil is done.

Answer 17

Preliminary Examination

Question 18

Soil sample can be examined microscopically for their general appearance, presence of minerals, vegetative and other foreign materials.

Answer 18

Preliminary Examination

Question 19

Type of soil, color, texture and presence of the materials are noted down.

Answer 19

Preliminary Examination

Question 20

In order to observe the nature of soil, that may be acidic or alkali, pH measurement test is performed.

pH meter is used to measure the pH of soil sample.

Answer 20

pH measurement of soil

Question 21

Set of sieves of different ranges are used to observe the particle size.

Answer 21

Chemical analysis

Question 22

Place the soil sample on a stage of microscope on glass slide and examine.

Answer 22

Observation of particle size distribution

Question 23

Take an exactly weighed quantity (1 gm) of soil sample from sieve fraction, dried at 105° C is a alumina crucible or porcelain dish and keep it in a muffle furnace
Heat it at temperature between 750 - 800° C for 1 hour.

Answer 23

Ignition Test

Question 24

Identification of micro-organism in soil sample can provide useful information and linking soil sample to its origin.

To see micro-organisms, soil samples can be examined under compound microscope.

Answer 24

Micro - organism Test / Analysis

Question 25

can be conducted on any soil sample because of the mineral present in the soil are different.

Answer 25

DTA - Differential Thermal Analysis

Question 26

The trace elements present in the soil like barium, cobalt, Cr, Cu, etc. can be detected by the various spectroscopy and chromatography techniques.

Answer 26

Spectroscopy and chromatography techniques.

Question 27

Density of soil sample can be measured by densitometer anddensity gradient tube.

Answer 27

Density measurements.

Question 28

The identification of soil is never necessary that all constituents be identified as such or that they are separated

Answer 28

Analysis of Soil

Question 29

Whatever is the origin of dust and wherever it is found it always contain substances derived from substances of plant and animal origin and substances of mineral origin.

Answer 29

Composition of Dust

Question 30

– extremely fine dust particles present in the air everywhere. More abundant in thickly populated and industrial regions. Settle very slowly and ultimately deposited on an exposed surface. Its value in crime detection is insignificant.

Answer 30

Dust Deposited from the Air

Question 31

– produced by the wear and tear of the road surface by vehicular and pedestrian traffic together with particles of soil carried by the wind or rain from adjoining regions.

Answer 31

Road and Footpath Dust

Question 32

– industries like cement, button, powdered gypsum and plaster of paris factories, flour milling paint pigments, involves industrial processes impart a pronounce local character to the dust on the neighboring roads and buildings.

Answer 32

Industrial Dust

Question 33

– some of the finely powdered material may be found on the clothing and footwear of employees engaged in such industries. Aside from this for example, bricklayer will yield brick dust, sand and lime on his clothes. Coal miner will have coal dust on his clothes.

Answer 33

Occupational Dust

Question 34

Wear appropriate personal protective equipment, such as gloves and a mask, to avoid contamination.

Use clean tools to prevent cross-contamination between samples.

Answer 34

Safety Precautions:

Question 35

Identify and document the locations from which soil samples will be collected.

Consider factors such as proximity to the crime scene, potential sources of contamination, and any relevant information about the case.

Answer 35

Selection of Sampling Sites:

Question 36

Use a clean shovel, soil auger, or corer for collecting samples.

For crime scenes, use a grid or random sampling method to ensure representative samples.

Answer 36

Tools for Collection:

Question 37

Collect soil from various depths, especially if the crime involves buried evidence.

Collect both suspect and control samples for comparison.

Take sufficient quantities to allow for multiple analyses.

Answer 37

Sample Collection:

Question 38

Document the date, time, and weather conditions during collection.

Label each sample container with a unique identifier, location details, and other relevant information.

Take photographs of the collection process and the sampling site.

Answer 38

Documentation:

Question 39

Place each sample in a clean, airtight container to prevent contamination.
Seal the containers and label them clearly.

Answer 39

Packaging:

Question 40

Establish and maintain a chain of custody for the samples.

This documents who had possession of the evidence at each stage.

Answer 40

Chain of Custody:

Question 41

Store the samples in a cool, dry place to preserve their integrity.
Avoid exposing samples to extreme temperatures.

Answer 41

Storage:

Question 42

Identify the appropriate forensic or environmental laboratory to submit the samples.

Contact the laboratory to inquire about submission procedures and requirements.

Answer 42

Contact the Relevant Authorities:

Question 43

Complete any necessary forms and documentation required by the laboratory.

Clearly label each sample and provide detailed information about the case.

Answer 43

Submission Documentation:

Question 44

Ensure secure transportation to the laboratory.

Follow any guidelines provided by the laboratory for shipping and handling.

Answer 44

Transportation:

Question 45

Maintain communication with the laboratory to track the progress of the analysis.

Be prepared to provide additional information if requested

Answer 45

Follow-Up:

Question 46

The laboratory will conduct various tests, such as chemical, physical, and biological analyses, depending on the purpose of the investigation.

Answer 46

Laboratory Analysis:

Question 47

Collaborate with experts to interpret the results in the context of the case.

Answer 47

Results Interpretation: