Table 1. Key for General Identification

Step 1.0 Examine the side of the core for the presence of strongly tilted layering, "rolled" bedding or intense fracturing accompanied by slickensides.

1.1 If the core is-

Layered and the layers are inclined at angles of 60 degrees or less from the side of the core (e.g. 89L) or the layering is rolled or folded (e.g. 88R) or the rock is intensely fractured, turn to the Deformed Rocks section of the book.

1.2 If the core-

does not show any of the features described under 1.1, proceed to Step 2.0.

Step 2.0 Examine the side of the core to determine the degree of grittiness or the grain size of the particles.

2.1 If the core is-

sandy or very gritty (e.g. 18R) or is sandy with pebbles of rock or coal (e.g. 41R), proceed to the Sandstones, Pebbly Sandstones and Conglomerates section of this book.

2.2 If it is-

composed of mixtures of sandstone and shale with shale streaks making up at least 20% of the rock (e.g. 50L and 50R), or entirely of fine grained materials (e.g. 58L), proceed to Step 3.0 of this table.

Step 3.0 Determine the hardness of the core by scratching it with your fingernail and by impact.

3.1 If the core is-

easily scratched with the fingernail and breaks readily upon impact (like shale, sandy shale or fireclay), proceed to Step 4.0 of this table.

3.2 If it is-

scratched only with difficulty or is hard, brittle and resists impact, proceed to the Ironstones, Limestones, and Flint Clays section of this book.

Step 4.0 Determine the degree of grittiness of the core by rubbing it lightly with the forefinger or thumb.

4.1 If the core is-

distinctly gritty or mixed gritty and smooth, proceed to the Sandy Shales (Siltstones) and Sandy Fireclays section of this book.

4.2 If it is-

smooth or only slightly gritty, proceed to the Shales and Fireclays section of this book.