All of the theories surrounding the Chasm are plausible, but all of them have definite problems. From the information we gathered, we think that the Chasm was formed from a fault line that moved and created a rip in the area. Then, a glacier moved over the fault line and created the carved out the chasm.

         We know that the area was a fault line because the chasm is so straight, there are displacement scratches on either side (which indicated that the land had moved), and there are markings of scratches on the ground from plates rubbing against each other. Furthermore, the tilting of the rocks indicates a fault line moved them. Also, the metamorphic rocks found in the chasm indicate that there was a fault line here causing the rocks to be foliated over time.

​

​

​

​

​

​

​

​

​

​

​

​

 

 

 

 

 

 

 

 

        After the fault line moved, we know that a glacier moved over the fault and exploited the chasm. Only two things could have moved the material that was originally there. These two things are glaciers or water in the form of a river that moved through the fault line. However, water could not have created the chasm because the rocks on either side of it would have been smoothed over and the material on the bottom of the chasm would have been well sorted. In actuality, the rocks lining the chasm are rough and jagged and the rocks along the bottom are scattered at random. This shows that water could not have moved through the chasm. Also, there are hills surrounding Purgatory, so there is no way water could have moved over the hills and constantly drained into the basin. Finally, the rocks that were moved are far too large to have been moved by water. The glacial scratches, angular and random rocks littering the chasm floor and glacial erosion features prove that a glacier most have moved through the chasm.

         For these reasons, Purgatory Chasm must have been a fault line that was later exploited by a glacier.