Patterned grounds on Ward Hunt Island (M. Paquette)

April 8, 2017 in post by Davesne.G

Patterned Grounds! Among the most interesting features of periglacial areas are these self-organised soil mosaics, which can take a wide range of shapes and size and are created by freeze-thaw cycles. The type of soil and the slope angle is very important in deciding the shape and the size of the patterns. This picture was taken on Ward Hunt Island, looking north, and shows the transition between scree slope colluviums (material moving downslope because of gravity) to the right and drift deposits (material deposited by a glacier) to the left. The colluviums don’t sort well because of the absence of fine sediments in the soil matrix, and we can only see small bulges where the underlying drift emerges from depth. The drift is frost susceptible, and is organized in stripe-like features oriented toward the direction of the slope. The different colours are also caused by the proliferation of biological soil crusts on the drift, as edaphic conditions are modified.

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