Fluvial systems of Upper Cretaceous Mesaverde Group and Paleocene North Horn formation, central Utah: record of transition from thin-skinned deformation in foreland region
Nonmarine strata of the upper part of the Mesaverde Group and North Horn Formation exposed between the Wasatch Plateau and the Green River in central Utah record a late Campanian tectonic transition from thrust-belt deformation to basement-cored uplift. Mesaverde Group sediments were deposited by synorogenic braided and meandering rivers. During most of Campanian time, sediment transport was east and northeast away from the thrust belt across a fluvial coastal plain. Subsequent development of the San Rafael swell, a basement uplift, between western and eastern localities caused erosional thinning of the section. Sandstones within the upper part of the Mesaverde Group form two distinct compositional suites, a lower quartzose petrofacies and an upper lithic petrofacies. Lithic grain populations of the upper petrofacies are dominated by sedimentary lithic grains were derived from the thrust belt, whereas volcanic lithic grains were derived from a volcanic terrane to the southwest. Tributary streams carrying quartzose detritus from the thrust belt entered a northeast-flowing trunk system and caused a basinward dilution of volcanic detritus. Disappearance of volcanic grains and local changes in paleocurrent directions in latest Campanian time reflect initial growth of the San Rafael swell and development of an intermontane trunk-tributary fluvial system. Depositional onlap across the Mesaverde Group by the post-tectonic North Horn Formation indicates a minimum late Paleocene age for uplift of the San Rafael swell.
- Research Organization:
- Sohio Petroleum Co., San Francisco, CA
- OSTI ID:
- 6269426
- Report Number(s):
- CONF-8506201-
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 69:5; Conference: AAPG Rocky Mountain Section meeting, Denver, CO, USA, 2 Jun 1985
- Country of Publication:
- United States
- Language:
- English
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