Stop 7 at Haughton

A fault plane along the "Lost Valley" wall
Photo: B. Clancy
Scale: Height of person is approximately 1.5-2 meters

The fault plane surface in detail
Photo: G. Osinski, University of Western Ontario
Scale: Length of Swiss Army knife is approximately 8-10 centimeters

The smooth, vertical rock face on which geologist Gordon Osinski is leaning on is called a fault plane. This is a site where blocks of rock on either side of a fault have slid past one other. In this case, the rocks behind Gordon have stayed in the same position, whereas the rocks that should be where Gordon is standing have slid and dropped by as much as 400 meters!

Closer inspection of the fault plane reveals vertical grooves on the surface. These are called slickenside lineations and they tell us how the two blocks of rock slid past each other. In this case, the blocks moved vertically (up or down) with respect to one other. For a diagram explaining the different types of faults, click here.