Stratigraphic classification and correlation of Rocks

Question 1

Lithostratigraphy

Answer 1

Deals with the lithologic or physical properties of the rocks and their organization into units on the basis of their lithologic properties

Question 2

Biostratigraphy

Answer 2

Is the study of rock units on the basis of the fossils they contain

Question 3

Chronostratigraphy

Answer 3

Deals with the ages of strata and their time correlation

Question 4

Sesmic stratigraphy

Answer 4

Addresses stratigraphic packages of strata bounded by unconformities and their correlative conformable contacts

Question 5

Chemostratigraphy

Answer 5

Is based on correlations using stable isotopes

Question 6

Magnetostratigraphy

Answer 6

Deals with stratigraphic relationships of sed rocks based on their magnetic properties

Question 7

Categories of stratigraphic classification

Answer 7

Lithostratigraphy
Biostratigraphy
Chronostratigraphy
Seismic stratigraphy
Sequence stratigraphy
Chemostratigraphy
Magnetostratigraphy

Question 8

What is correlation?

Answer 8

It is the determination of equivalence in time-stratigraphic or rock-stratigraphic units of the succession of strata found in two or more different places

Question 9

Correlation involves two main tasks?

Answer 9

1. Age determination (relative to one another) of units exposed in an area of interest
2. Determination of where the age of units fits relative to a standard geological time scale

Question 10

What 3 types of correlation are recognized by the North american stratigraphic code?

Answer 10

Lithocorrelation
Biocorrelation
Chronocorrelation

Question 11

Correlation can be regarded as ____ or _____?

Answer 11

Direct - can be established physically and unequivocally. It involves physical tracing of continuous stratigraphic units

Indirect - Can be established by umerous methods such as core/outcrops, well logs, or fossil assemblages

Question 12

Name and briefly describe different ways of correlating rocks.

Answer 12

Lithocorrelation - correlating rocks based on lithology
Well logs- Correlation by similarity of electric records
Correlation by radiometric ages - Correlating rocks by similar absolute ages
Isotope variation - Variations in the ratio of O18 and O16 down through deepsea sediments
Magnetic properties - Important for lavas and finegrained iron rich sediments
Fossils - Correlation using index fossils

Question 13

Index fossils are characterized by:

Answer 13

Wide geographic distribution
Short stratigraphic duration
Easily recognizable
Abundant numerically