STRUCTURAL GEOLOGY HATCHER 5

Question 1

Freatures that can aid in measuring the strain present in the rock

Answer 1

Strain markers

Question 2

Total strain of the rock is the result of

Answer 2

Progressive Deformation

Question 3

This relates instantaneous shape of a rock mass at any one time to its initial

Answer 3

Total Finite Strain

Question 4

Final or cumulative state in a series of defromational events

Answer 4

Finite Strain

Question 5

Sepearate steps that occur as small distortion events throgh progressive defromation

Answer 5

Incremental Strain

Question 6

Strain restricted to very small strain

Answer 6

Infinitesimal strain

Question 7

Foliding is what kind of defromation

Answer 7

inhomogenous

Question 8

Requirements for strain markers

Answer 8

1) Dapat known ang orig shape
2) Dapat same mechanical propertes as the rock mass (Kung brittle, brittle)

Question 9

in what types of rocks are reduction spots used as strain markers?

Answer 9

Mudstones and Slates, Shales

Question 10

Strain Markers

Answer 10

Reduction Spots
Pebbles
Ooids and Pisolites
Fossils
Vesicles
Pillows
Burrows

Question 11

Fossils used as strain markes

Answer 11

Trilobites
Belemnite
Graptolites
Skolithos Tubes

Question 12

Masses with a rounding glassy or vesicular top with a coarser grained more massive downard pointing base

Answer 12

Pillow

Question 13

A methods that assumes that ellipsoidal objects are originally spherical and thus measuring strain by obtainig the ratio of the principal planes

Plot of elongation X/Y and flattening Y/Z

Answer 13

Flinn Diagram (Derek Flinn)

Question 14

In Flinn diagram as K approaches infinity the shape of the deformed object becomes

Answer 14

Constricted (Axial Elongation) nagiging hotdog

Question 15

In Flin Diagram, as K approaches zero the shape of the marker becomes

Answer 15

Flattened (Axial Flattening) nagiging hammburger

Question 16

In Flinn Diagram, what is the value of K if the strain is caused by pure or simple shear and the strain is plain and results to trixial ellipsoid

Answer 16

K=1

Question 17

Apparent Flattening

Answer 17

1>K>/=0

Question 18

Aparrent constriction

Answer 18

1

Question 19

A geometric technique that measures angular distotion to set of lines that are originaly perpendicular to each other and which requires a minimum of 10 strain marker oriented randomly in same plane

Answer 19

Wellmans Method

Question 20

Most fit fossil for wellmans methos

Answer 20

Brachiopod and Trilobites

Question 21

Method of determnining homogenous strain in a rock mass containing deformed initially elliptical objects generally results in objects that remain elliptical. The shape of the final ellipse is determined by the intial shape and orientation of the starting ellipse relative to the shape and orientation of the strain ellipse.

In short (since ang ellipse pag nadeform ay ellipse pa rin, we can expect the final ellipse by comparing the starting shape to the strain ellipse)

Answer 21

Rf/theta (John Ramsay)

Question 22

A method which assumes the uniform distribution of aggregeates or grains (ooids, sands, pebbles) which can be used to measure or dertermine the orientation of strain ellipse in the derfoemd aggregate.

This can be done by measuring distance and angles between reference grains and its nearest neighbor.

Answer 22

Center to Center Method

Question 23

A simpler method wich measures angular relationships and distances between PARTICLES as they are indicative of accumulated strain the result is a diagram containig set of points with a circular to elliptical blank area relative to tshape and orienation of the strain ellipse. A circular area means there is no strain

Answer 23

Fry Method

Question 24

Orientation of fibers in a vein indicates

Answer 24

Direction of opening of the vein

Question 25

Curved fibers in a vein indicates

Answer 25

Rotation of the strain field during shear formation