FACIES AND ARCHITECTURAL ANALYSIS TO INTERPRET AVULSION STYLE AND VARIABILITY: UPPER CRETACEOUS BLACKHAWK FORMATION, WASATCH PLATEAU, CENTRAL UTAH, USA

摘要

Sequence stratigraphic models emphasize the role of external, allogenic controls such as relative sea level, tectonic subsidence, and climate on alluvial to coastal plain stratigraphic architecture, at the expense of internal, autogenic behaviors such as avulsion. These models are tested via sedimentologic analysis of fine-grained floodplain deposits and their relationship to channelized fluvial sandbodies in a well exposed alluvial to coastal plain succession developed under progressively increasing distance from the coeval shoreline and an accompanying decrease in the rate of accommodation creation (Late Cretaceous Blackhawk Formation, Wasatch Plateau, central Utah, U.S.A).