REGIONAL CONTROLS ON DEPOSITIONAL TRENDS IN TIDALLY MODIFIED DELTAS: INSIGHTS FROM SEQUENCE STRATIGRAPHIC CORRELATION AND MAPPING OF THE LOYD AND SEGO SANDSTONES, UINTA AND PICEANCE BASINS OF UTAH AND COLORADO, USA

摘要

Conditions for deposition of tidally influenced facies are most commonly associated with transgression; however, tidal influence can also be observed in regressive deposits. Herein we present a regional study that correlates the Loyd and Sego sandstones across the Uinta-Piceance basins, an area rich in both outcrop and subsurface data. Variable energy conditions in these tidally modified deltas result in a complex arrangement of facies and environments, making it difficult to correlate sequence stratigraphic surfaces. We highlight the controls, including tectonics, eustasy, and sediment supply, on depositional environments and sand distribution in these regressive tidally modified deposits.