Field-trip co-leader Roland Dechesne explains the regional structure of the excursion area at the meeting point.
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Critical-fracture propagation on stress tip at first coffee stop.
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The group listens to the regional introduction at stop 1.
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Stop 1 panorama.
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Co-leaders Byron Veilleux (left) and Greg Soule explain...
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...the terminology of fracture distribution around an anticline after Stearns 1968.
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Stop 2: One poorly developed fracture set in fine-grained Cretaceous Cardium sandstone. Not a good reservoir rock. Compass points north.
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Walking up to Cardium sandstone at stop 3, Mountain Aire Lodge Anticline.
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Stop 3: Characteristic fracture distribution in Cardium sandstones in hinge of a gentle, hundreds-of-meter scale anticline: Vertical type 1 are orthogonal to rock face; vertical type 2 constitute the rock face and are parallel to it; type 3 are shallowly inclined to bedding. Note that most type 1 fractures terminate at bedding plane. Also note the relationship between fracture spacing and bed thickness.
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Stop 3: Tighly-spaced type 1 fractures.
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Elisabeth Clark puts her hand on a type 2 fracture surface.
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Centre: Prominent type 3 fracture at low angle to bedding as a result of bedding-parallel compression.
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Zoom-up of previous.
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Below scale card: Conjugate set of fractures formed in response to bedding-parallel extension (in outer arc of flexural slip fold).
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Group gathers at stop 4, Bighorn Falls, to look at the Triassic Spray-River formation at the Ya Ha Tinda Ranch.
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Ladder pattern of fractures in Tertiary Spray-River-Group sandstone: The shorter type 2 terminate on type 1. Feet are on bedding plane.
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Skolithos burrows in Spray-River-Group sandstone.
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The final group photo.
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