Evolution of foreland basin fluvial systems in the mid‐Cretaceous of Utah, USA (upper Cedar Mountain and Naturita formations)

• DOI: 10.1111/sed.12845
• Publication Date: 2021-01-22T22:38:42Z
• Authors: Stephen P. Phillips; John A. Howell; Adrian J. Hartley; Magda Chmielewska; Samuel M. Hudson
• Keywords: Outcrop; Sinuosity

Abstract An analysis of the sedimentary fill a foreland basin can provide information on relative effect tectonics, base‐level fluctuations and climate during development. This study analyzes fluvial strata from upper Cedar Mountain Naturita formations mid‐Cretaceous Utah (USA) to determine effects spatial location within planform architecture. The results document consistent architecture across distal foredeep forebulge depozones flooding Western Interior Seaway suggesting that did not change as function position depozone or result rise. Outcrop data, virtual outcrop models satellite imagery were used perform facies architectural collect dimensional geometric data. Fluvial channel deposits consist coarse‐grained, laterally accreting bars deposited narrow, low moderate sinuosity channels, vertically stacked encased in floodplain fines regardless geographic stratigraphic may represent distributive system. Bar elements increased thickness over time indicating increasing depths enhanced discharge. Palaeohydraulic calculations indicate an increase discharge between 315 1023 1896 5270 m 3 /s, likely due precipitation and/or drainage capture catchment basin. Calculated areas for system 10 4 5 km 2 scale time. uppermost close proximity (≤60 km) contemporaneous shoreface systems expanded; yet backwater are observed, rising base level had no significant These show remained constant despite base‐level, changing climate, different depozones.