Table 2. Key for Identification of Common Sandstones, Pebbly Sandstones and Conglomerates.

Step 1.0 Examine the side of the core to determine whether the rock is made up mostly of sand grains or contains pebble size pieces of rock or streaks of coal as well as sand.

1.1 If there are-: no or very few pebbles or coal streaks (e.g. 18L and 18R), proceed to step 2.0.
1.2 If there are-: conspicuous or numerous pebbles or coal streaks (e.g. 39L and 41R ), proceed to step 6.0.

Step 2.0 Examine the side of the core to determine its color and test its resistance to impact. If the core is very hard and dark gray or tan, apply a small drop of 10% hydrochloric acid.

2.1 If the core is-: gray, fractures with relative ease and in some cases has abundant mica flakes on broken butt ends (e.g. 18L and lower 28L), and does not effervesce when 10% hydrochloric acid is applied, the rock belongs to the Gray Sandstone group or 540. Proceed to step 3.0.
2.2 If it is-: white or very light gray, often hard and brittle upon impact, with a sparkling or sugary appearance (e.g. 23L) and does not effervesce when 10% hydrochloric acid is applied, the rock belongs to the Crystallized Sandstone group or 550. Proceed to step 4.0.
2.3 If it is-: gray to light gray and somewhat grainy but very hard, dense and tough upon impact (e.g. 24L), and does not effervesce when 10% hydrochloric acid is applied, the rock belongs to the Hard Sandstone group or 560. Proceed to step 5.0.
2.4 If it is-: gray and grainy, hard, dense and tough upon impact (e.g. 26L) and effervesces when 10% hydrochloric acid is applied, the rock is a Gray Carbonate Cemented Sandstone, Calcite or 640 CaC03.
2.5 If it is-: gray and grainy, hard, dense and tough upon impact, and the broken butt end is deep brown with a sugary texture (e.g. 27L and lower 28R), and does not effervesce freely when 10% hydrochloric acid is applied, the rock is a Gray Carbonate Cemented Sandstone, Silderite or 640 FeCO3.

Step 3.0 Examine the side of the core to determine the presence of streaks, lines or spots. If they are present, note their orientation and thickness.

3.1 If the core has-

no streaks, lines or spots (e.g. 18L and 18R), the rock is a Gray Massive Sandstone or 544.

3.2 If it has-

thin streaks or lines that are inclined to the sides of the core (e.g. 29L), the rock is a Gray Crossbedded Sandstone or 541.

3.3 If it has-

thin wavy streaks oriented at right angles, or nearly so, to the sides of the core (e.g. 31R), the rock is a Gray Sandstone with Shale Streaks, Rippled or 543 RIP.

3.4 If it has-

thin flat streaks that are oriented at right angles to the sides of the core (e.g. 33R), the rock is a Gray Sandstone with Shale Streaks, Flat or 543 FLT.

3.5 If it has-

an irregular spotty or mottled appearance with light and dark gray streaks or spots with irregular orientation (e.g. 36L), proceed below:

If the spots or tubes are surrounded by carbonaceous (coaly) films (e.g. 36L) or there are numerous carbonaceous streaks (e.g. 37L), the rock is a Gray Rooted Sandstone or 547.
If they lack carbonaceous films and the rock has a "lumpy" appearance (e.g. 38L and 38R), the rock is a Gray Burrowed Sandstone or 548.*
If they do not clearly show features illustrated on specimens 36L, 36R, 37L, 37R, 38L and 38R and described above, the rock is a Gray Churned Sandstone or 546.*

Step 4.0 Examine the side of the core to determine the presence or absence of streaks, lines or spots. If they are present, note their orientation and thickness.

4.1 If the core has-: no streaks or lines (e.g. 22L), the rock is a Crystallized Massive Sandstone or 554.
4.2 If it has-: thin streaks or lines that are inclined to the sides of the core (e.g. 30L), the rock is a Crystallized Crossbedded Sandstone or 551.
4.3 If it has-: thin wavy streaks oriented at right angles, or nearly so, to the sides of the core (e.g. 34L and 34R), the rock is a Crystallized Sandstone with Shale Streaks, Rippled or 553 RIP.
4.4 If it has-: an irregular spotty appearance with light and dark streaks or spots with irregular orientation, the rock is a Crystallized Churned Sandstone or 556.*

Step 5.0 Examine the side of the core to determine the presence or absence of streaks or lines. If they are present, note their orientation and thickness.

5.1 If the core has-: no streaks or lines (e.g. 25L and 25R), the rock is a Hard Massive Sandstone or 564.
5.2 If it has-: thin streaks or lines that are inclined to the sides of the core (e.g. 30R), the rock is a Hard Crossbedded Sandstone or 561.
5.3 If it has-: thin wavy streaks oriented at right angles, or nearly so, to the sides of the core (e.g. 35R), the rock is a Hard Sandstone with Shale Streaks, Rippled or 563 RIP.
5.4 If it has-: a spotty appearance with light and dark streaks or spots with irregular orientation, the rock is a Hard Churned Sandstone or 566.*

Step 6.0 Examine the core to determine the character of the sandy material between the pebbles.

6.1 If the sandy material is-: gray, grainy and relatively soft (e.g. 41L), proceed to step 7.0.
6.2 If it is-: white or very light gray and very hard and brittle (e.g. 43L and 43R), proceed to step 8.0.
6.3 If it is-: gray to light gray and somewhat grainy but hard and tough upon impact (e.g. 44R), proceed to step 9.0.

Step 7.0 Examine the sides of the core to determine the character of the pebbles.

7.1 If the pebbles are-: large irregularly shaped spars of bright coal (e.g. 39L), the rock is a Gray Sandstone with Coal Spars or 749.
7.2 If they are-: thin flattened pieces of coal, grouped into well defined layers (e.g. 39R), the rock is a Gray Sandstone with Coal Bands or 748.
7.3 If they are-: pieces of shale or sandy shale (e.g. 40L), (may also contain some quartz pebbles and coal), the rock is a Gray Shale Pebble Conglomerate or 742.
7.4 If they are-: round or oblong bodies which are orange or brown (e.g. 40R), (may also contain some quartz pebbles and coal), the rock is a Gray Ironstone Pebble Conglomerate or 743.
7.5 If they are-: pieces of shale and ironstone (e.g. 41L), (may also contain some quartz pebbles and coal), the rock is a Gray Shale and Ironstone Pebble Conglomerate or 741. (This term can also be used when shale and ironstone cannot be differentiated.)
7.6 If they are-: rounded, dark, spotted or streaked pebbles (e.g. 41R), (may also contain some quartz pebbles), the rock is a Gray Rock Pebble Conglomerate or 745.

Step 8.0 Examine the sides of the core to determine the character of the pebbles.

8.1 If the pebbles are-: hard, white or gray quartz pebbles (e.g. 43L and 43R), the rock is a Crystallized Quartz Pebble Conglomerate or 754.

Step 9.0 Examine the sides of the core to determine the character of the pebbles.

9.1 If the pebbles are-: pieces of shale or sandy shale (e.g. 44L), (may also contain some quartz pebbles and coal), the rock is a Hard Shale Pebble Conglomerate or 762.
9.2 If they are-: round or oblong bodies which are brown or orange (e.g. 44R), (may also contain some quartz pebbles or coal), the rock is a Hard Ironstone Pebble Conglomerate or 763.

*These rocks in some cases contain fossil shells. Please see page 79.