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The Frontier Formation and associated rocks of northeastern Utah and northwestern Colorado

Book ·
OSTI ID:6770973

Stratigraphic correlation sections show that the Frontier Formation of the Mancos Group in northeastern Utah and northwestern most Colorado consists (proposed new rank designations) of several facies of marine and nonmarine rocks of Late Cretaceous (Turonian) age that grade eastward into totally marine rocks. A lower Turonian transgressive sandstone at the base of the Frontier unconformably overlies an unnamed Cenomanian( ) shale unit in the southwestern part of the Uinta Mountains area. Elsewhere around the Uinta Mountains, an upper middle Turonian shale member of the Frontier unconformably overlies the lower Cenomanian Mowry Shale (proposed new rank designation; formerly known as Mowry Member of Mancos Shale in all but the Utah part of the north flank of the Uinta Mountains). Apparently the intervening Turonian rocks onlap from west to east.

OSTI ID:
6770973
Country of Publication:
United States
Language:
English