Examples of Clay-Silt Layers
Green River Shales (WY, UT, CO)
Several million pairs (up to 20 million)
Covers over 10,000 square miles
Thickness varies with frequency of sunspot cycle and procession of equinoxes.
Haymond Formation (TX)
15,000 sandstone/shale pairs
Large area, almost a mile thick
How does one get silt to settle quickly?