Strain

Question 1

Any deformed feature in a rock mass in which the original shape can be qualitatively compared with the present deformed shape.

Answer 1

Strain Markers

Question 2

Strain Markers: A small, mostly spherical features in fine-grained sediments where the red to reddish-brown oxidized sediment has been chemically reduced to greenish color

Answer 2

Reduction Spots

Question 3

Strain Markers: among the most frequently used strain indicator

Answer 3

Pebbles

Question 4

Strain Markers: good indicator of finite strain.

Answer 4

Ooids and Pisolites

Question 5

Strain Marker: Has been used to considerable advantage in

determining finite strain.

Answer 5

Fossils

Question 6

Enumerate all the possible strain markers that can be used in the field

Answer 6

Burrows, fossils, pebbles, pisolites and oolitics, vesiscles, pillow basalts, reduction spots

Question 7

Flinn diagram

Answer 7

a graphical representation used to plot finite strain ellipsoids

Question 8

Strain-Measurement techniques:

this method is based on angular distorsion of reference lines originally aligned 90 degrees to each other

Answer 8

Wellman’s Method

Question 9

Strain-Measurements Techniques Used in elliptical deformed bodies

Answer 9

𝑹𝒇/φ Method

Question 10

Strain-Measurement techniques:
based on the distance and angular relationship between particles in an aggregate of objects with a statistically uniform initial distribution should help to determine the orientation of the strain ellipse in the deformed aggregates.

Answer 10

Center to center method

Question 11

Strain measurement techniques– a simpler version of the center-to-center method and works on the same principle. Angular relationships and distances between particles are modified according to the nature and amount of accumulated strain.

Answer 11

The Fry Method

Question 12

Aspect of shape change measured as changes in line, length, changes in angular relationshps between lines, or as volume changes

Answer 12

Strain

Question 13

Give the types of Deformation, indicate wether they are homogeneous or inhomogeneous

Answer 13

Homogeneous - rotational, translation pureshear

Inhomogeneous-Subsimple shear and simple shear

Question 14

The displacement field for tectonically drven particle motion and involoves processes by which the particle motions are achieved; it encompass both rigid body rotation and rigid body translation, can be continous or non continuous

Answer 14

Deformation

Question 15

develops when differential movement occurs along a set of parallel lines. The movement is greater parallel to horizontal lines at the tops as compared to the bottm of the rocks mass. As a result, a set of lines initially normal to the horizontal lines is rotated from orthogonality by an 𝜓, the angular shear by;

Answer 15

𝛾 = tan 𝜓, Shear strain

Question 16

it is the change in volume of a material which may occur in three different mechanisms e.g, closing voids between grains, Dissolving away part of the rock mass by pressure solution, Fracturing mass

Answer 16

Dilational Strain or Volume change

Question 17

A dilational strain that produces negative volume change

Answer 17

closing voids between grains and pressure solution

Question 18

A dilational strain that involves producing positive volume change

Answer 18

Fracturing the mass

Question 19

A three dimensional constant volume strain

Answer 19

Simple shear

Question 20

three dimensional homogeneos flattening of a body. it is an example of irrotational in which body strain is elongated in one direction while being shortened perpendicularly

Answer 20

Pure shear