METHODS OF ESTABLISHING STRATIGRAPHIC UNITS

Generally stratigraphy deals with the study of position of the rock sequence with respect to geological time. The rock types which are determined on their basis of lithology and stratigraphy are called stratigraphic units. So to determine or establish stratigraphic units there exists certain method. So following are the methods of establishing stratigraphic units:

1)             Statement of intension:

This is the first step in establishing staratigraphic units. According to this, the vision must be clear and must show the focus on the interest of study.

2)             Type of stratigraphic unit:

While establishing the stratigraphic units the type must be written clearly. Many stratigraphic units may arise while studying but the exact type of stratigraphic units must be mentioned.

 

3)             Name of stratigraphic unit:

It is the basic but the most important method while establishing startigraphic unit.

The suitable and the clear name of the unit must be written.

 

4)             Historical background:

The geological history of the stratigraphic unit must be written while establishing it. The geological history may include deposition, formation and other geological activities that has been acted on that stratigraphic unit with respect to geological time.

 

5)             Stratotype:

The stratotype of the lithostratigraphic unit must be written while establishing stratigraphic units. Stratotype generally means the naming of the outcrop/exposure of any stratigraphic sequence.

 

6)             Description of units:

The basic description of the startigraphic unit must be written. The description may include composition , texture , sequence and all that describes the unit.

 

7)             Regional aspect:

Regional aspect includes climate, temperature and all the regional conditions that affect the unit. Hence the regional aspect must be described while establishing the startigraphic units.

 

8)      Genesis:

Genesis refers to the mode of formation. Here the genesis must be written while establishing startigraphic units.

 

9)             Correlation:

Generally correlation refers to the relation of one sequence to another. Hence it is necessary to correlate one stratigraphic unit with another while establishing stratigraphic units.

 

10)      Geological age:

The geological age is generally estimated by radiometric dating and must be written while establishing stratigraphic units.

 

11)      References:

Generally reference refers to the additional information about the heading. So the references should be mentioned while establishing stratigraphic units.