UBC Theses and Dissertations
Normal faulting in the Indianhead Creek map-area of the Alberta Rocky Mountains Birnie, Thomas A.
The Indianhead Creek map-area is located directly north of the Clearwater River and encompasses a four mile length of the third range of the Alberta Rocky Mountains. The map-area contains one minor thrust fault, a portion of the Third Range thrust fault and a series of four large normal faults. The normal fault blocks are tilted to the south with the lower beds of each fault block being progressively truncated by the slightly northward dipping Third Range thrust fault. Two of these normal faults also cut through the Third Range thrust fault and continue into the underlying formations with a large loss in stratigraphic separation. Two hypotheses are proposed to explain the time relationships and causes of normal faulting. The first hypothesis states that the normal faulting and the tilting of the normal fault blocks occurred before the development of the Third Range thrust fault. Then during thrust faulting, the minor thrust and the progressive truncation of the lower beds of each normal fault block occurred. A recurrence of normal faulting took place after the completion of thrust faulting in which the Third Range thrust fault and the underlying formations were displaced. The second period of normal faulting developed along the planes of the previously existing normal faults. The second hypothesis states that the normal faulting, the tilting of the normal fault blocks, and the thrust faulting developed concurrently. A monoclinal fold in the plane of the Third Range thrust fault is proposed in order to explain the progressively southward truncation of the lower beds of the tilted normal fault blocks and the large loss in stratigraphic separation as two of the normal faults pass through the thrust fault.
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