Clastic Dikes at Metalline Falls, WA


Olaf P. Jenkins took these photos in 1924 near Metalline Falls, WA. They show Pleistocene-age clastic dikes intruding rippled glaciofluvial/glaciolacustrine sediments of Glacial Lake Pend Oreille 80km NW of Priest River, ID. The lake used to occupy the southern end of the Purcell Trench during the last Ice Age. They are not the sheeted dikes found throughout the Channeled Scabland, but they are unusual and beautifully photographed here.


Photo caption: "Metaline District, differently weathered sand dikes, with limey concentrations [CaCO3 cement] around roots. Sand of old Pend Oreille Lake in roadcut several hundred feet above Metaline Falls, but not at top of bench".

Photo source: Washington Geological Survey Photo Archives (#554).

Photo caption: "Metaline District, sand dikes in ripple structure, sand of Old Pend Orielle Lake".

Photo source: Washington Geological Survey Photo Archives (#553).

Metaline Falls Outcrop. O.P. Jenkins photo of the same outcrop as previous photo with caption, "On road uphill from town of Metaline Falls toward the road which turns off for Sullivan Lake. Ripple marks in sand of Old Lake Pend Orielle-6 inch ruler in picture". Photo source: Washington Geological Survey Photo Archives (#551).

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