Theory of faults

Stan, Neil and Ysabelle paddling out of Flatrock

We all know what faults are; Lord I have many. But the English language is quirky in that the same word describes different ideas. Geologically, a fault is a break in the earth's crust along which there has been movement parallel with the fault surface. There are different types of faults, which I won't explain here. On our paddle last Friday from Flatrock to Pouch Cove, Newfoundland, I got a picture of two types.

Here, the older grey siltstones of the Conception Group are overthrust (thrust fault) upon the younger red Signal Hill Formation sandstones and conglomerates. You can see the edges of the red beds were bend upwards as the siltstones were overthrust. The fault runs at about 45 degrees from the right top corner down towards the lower left.

Here Neil, Stan and Ysabelle paddle past Red Head north of Flatrock. In the foreground are the red beds of the Signal Hill Formation and behind them, the grey siltstones of the Conception Group. When we rounded Red Head I expected to see the darker rocks of the St. John's slate which lie stratigraphically above the red sandstones and conglomerates. Once I got a closer look I recognized the Conception rocks and realized that a fault (strike - slip) had displaced the correct sequence of rocks and positioned the older Conception rocks against the younger Signal hill rocks.

I must have rocks in my head because I find this stuff interesting. All the more interesting when you add a few kayakers in the pictures.

Tony :-)