|Image Name||Width x Height||Size|
|SIA3565.jpg||640 x 443||98K|
|SIA3565.jpg||1200 x 829||269K|
|SIA3565.jpg||3504 x 2418||1M|
The white layer interbedded with sandstone and shale is volcanic ash deposited from a volcanic eruption northwest of Colorado. It has been dated to be 105.6 (+/- 1.3) million years old or early Cretaceous in the geologic time.