Pennsylvanian Morgan Formation overlain by Weber Formation, Warm Springs Cliff, Dinosaur National Monument, CO

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morgan_warmspringscliff

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Cyclic Pennsylvanian Morgan Formation and overlying Weber Sandstone exposed at Warm Springs Cliff, Dinosaur National Monument, Colorado.

 

Paleocene Carmelo Formation, Point Lobos, CA

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Paleocene deep marine sandstone, mudstone, and matrix-supported intraclastic conglomerate within the Carmelo Formation exposed at Point Lobos, California.

Pennsylvanian Morgan Formation, Yampa River Canyon, Dinosaur National Monument, CO

morgan_yampa_canyon

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morgan_yampa_canyon2

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Cyclothems of the Pennsylvanian Morgan Formation exposed in the canyon of the Yampa River, Dinosaur National Monument, Colorado. Alternating intervals of blue-gray limestone and orange cross-stratified sandstone record repeated glacio-eustatic sea level fluctuations. Photosets acquired from raft.

Pennsylvanian Hermosa Group, Highway 550, San Juan Mountains, Colorado

hermosa_hw550

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Roadcut of Pennsylvanian Hermosa Group strata exposed between Molas Pass and Engineer Pass along US 550, San Juan Mountains, Colorado. Amalgamated cross-bedded, lenticular arkosic sandstone bodies and fine-grained mudstone partings with complex bedding relationships.

 

Upper Cambrian Jordan Sandstone and Ordovician Oneota Dolomite, Weaver, MN

weaver_jordan_oneota

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Roadcut of Late Cambrian Jordan Sandstone and overlying Ordovician Oneota Dolomite along Wabasha County 26, near Weaver, MN, illustrating large-scale crossbeds and unconformable formation boundary.

Upper Cambrian Franconia Formation, La Crosse, WI

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Cross-bedded glauconitic sandstone of the Franconia Formation (Tunnel City Group in local lore) exposed on Grandad Bluff, La Crosse, WI.

 

 

Late Cambrian Jordan Sandstone, HW14 roadcut near Lewiston, MN

lewiston_jordan

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Large roadcut of Late Cambrian Jordan Sandstone and overlying Ordovician Oneota Dolomite between Stockton and Lewiston, MN, illustrating low-angle bedding, intraclasts, and several scales of cross-stratification.