Classification Of Siliciclastic Rocks

Question 1

Compare and contrast Conglomerates and Breccias

Answer 1

Conglomerates:
Rounded to sub-angular clasts, contain at least 30% gravel sized particles

Breccias: 
Very angular (to angular) clasts

Question 2

What is the difference between extra and intraformational rudites?

Answer 2

Extraformational: formed by a mix of older rocks, usually far from their source

Intraformational: composed of penecontemporaneous units, often weakly consolidated. Similar grains and matrix

Question 3

A Murdock with the following characteristics was found:
~slick texture
~thickly laminated
~illite clay

What can be said about the climate at the time of deposition?

Answer 3

Because illite clay is present, the assumption can be made that the climate was arid to semiarid, and the parent clay could have been smectite, since it alters to illite during burial.