Sedimentology and sequence stratigraphy of fan-delta and river-delta deposystems, Pennsylvanian Minturn Formation, Colorado

摘要

Fan-delta and river-delta strata of the middle Pennsylvanian Minturn Formation were deposited in the Central Colorado trough and are well exposed in the Sangre de Cristo Mountains. Proximal fan-delta strata were deposited in lowstand, transgressive, and highstand systems tracts, whereas distal fan-delta strata were deposited in lowstand, highstand, and forced regressive systems tracts. Fan-delta strata were deposited adjacent to coeval westward-dipping thrust faults along the western margin of the Central Colorado trough. Inferred high subsidence rates caused by thrust loading along the western margin of the basin created accommodation space closer to the basin margin and resulted in localized aggradation of fan-delta deposits.