Athro, Limited Gubik Field Trip Section 20 Cretaceous |
Sediments at the base of Skull Cliff |
You are on the beach, looking in the direction of the green arrow. You are near the base of the cliff as shown by the blue arrow. |
The rocks exposed at the base of the cliff are sandstones that with some interbedded finer grained sediments. Lots of features here suggest the environment in which these sediments were deposited. These rocks are Cretaceous in age, substantialy older than the immediately overlying Neogene sequence.
Irregular bedding in a sandstone. Ripple marks in a lens of sandstone. These look like plant fossils. Plants? This is a thin stringer of coal. Coal FormationAll of these are evidences for environment at the time of the deposition of these rocks. Coal suggests non-marine boggy environments. Accumulations of fossilised logs at the base of a lensoidal sand body suggest floods in a stream.