Mineral Fork Tillite

The Mineral Fork Tillite is located in Lone Peak Mineral Fork Basin. The tillite has not been concretely dated, however it is nearly equivalent to a formation in Washington. Through indirect dating, it is widely believed to be between 1,400 to 800 million years old. There is some dispute among geologists as to the formation of these tillites. They could be deposited by mudslides, landslides, or glaciers. However the majority of scientists believe that the tillites were formed by glaciers. This is one of the leading evidences for the snowball earth theory.

The Snowball Earth theory suggests that at one point in time, most if not all, of the earth was covered in glaciers. These tillites are the leading evidence of the theory. Because the tillites are so wide spread, and are formed by glaciers, it lead the geologists to this new theory. When glaciers traveled along the ground they picked up enormous amounts of random strata. Eventually these glaciers made their way out to sea where they broke off into icebergs. As they floated out to sea, they melted, and released their random payload of rocks and dirts. The rocks fell down to the bottom of the water body and aligned themselves hydrodynamically, then got lodged in the mud. This explains why the rocks appear perpendicular to the resting plane.

The rocks themselves are organized randomly. They have no particular grading. Larger rocks can be found among the finer silts. Many of the rocks are aligned perpendicular to the normal. There is a lower sequence of thick, massive diamictites, with minor lensoid beds of shale-siltstone, sandstone, and conglomerate, and there is an upper sequence of more abundant shale-siltstone and siltstone that displays prominent bedding.