In lithological character, this limestone varies greatly; in one place it is a dark grey, somewhat crystalline limestone, elsewhere it passes into a flaggy, earthy or shaly condition, or even into a mere layer of nodules.
22.
In the Barrovian sequence ( described by George Barrow in zones of progressive metamorphism in Scotland ), metamorphic grades are also classified by mineral assemblage based on the appearance of key minerals in rocks of pelitic ( shaly, aluminous ) origin:
23.
The side road to Aguereberry Point successively traverses the shaly Johnnie Formation, the white Stirling Quartzite, and dark quartzites of the Wood Canyon Formation; at the Point itself is the great light-colored band of Zabriskie Quartzite dipping away toward Death Valley.
24.
Cannel coal ( also called " candle coal " ) is a type of terrestrial shale, which is hydrogen-rich brown to black coal, sometimes with shaly texture, composed of resins, spores, waxes, cutinaceous and corky materials derived from lacustrine planktonic algae.
