CONTROLS ON SANDSTONE DITRIBUTIONS AND CONNECTIVITY IN THE SHALLOW-MARINE FOX HILLS SANDSTONE AND LANCE FORMATION (UPPER CRETACEOUS, GREAT DIVIDE BASIN, WYOMING, USA

Open Access
Author:
Jimenez, Martin Matthew
Graduate Program:
Geosciences
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
November 14, 2016
Committee Members:
  • Elizabeth A. Hajek, Thesis Advisor
  • Michael Arthur, Committee Member
  • Mark E Patzkowsky, Committee Member
Keywords:
  • Sequence Stratigraphy
  • Mixed-Process Variability
  • Shallow-marine
  • Sandbody Continuity
Abstract:
The shallow-marine Fox Hills Sandstone and Lower Lance Formation in the Great Divide Basin, south-central Wyoming serves as an opportunity to identify the fundamental controls of sand-body distribution in a shallow-marine depositional setting. This research focuses to understand how shallow-marine depositional processes and sequence-stratigraphic processes combine to control the distribution and continuity of sandstone bodies in shallow-marine shelf settings; this study specifically tests the hypotheses that 1) thickest sand bodies are the most laterally extensive and continuous, and 2) for a given thickness, those with the most evidence of wave reworking will be more continuous than those with evidence of fluvial or tidal influence. Addressing these questions provides significant insight into the shallow-marine depositional sedimentary processes and the predictably of sand body distribution, which are the products of this system. The research of Fox Hills - Lower Lance Formation outcrops was carried out approximately 13 km west of Rawlins, Wyoming. These formations were formed during the Maastrichtian in the Washakie-Great Divide Basin, Wyoming. Data collected for this study includes 3 measured sections totaling 1397 m at 10 cm resolution documenting spatial distributions of architectural elements, thickness trends, and sand body continuity. Two scales of resolution are used to measure stratigraphic sections in this study. The spatial distance from measured sections 1 and 2 is 350 m and sections 1 and 2 are 2.3 km and 2 km apart from measured section 3 respectively. Results indicate that 1) thicker sand bodies (>0.60 m) in the study area are persistently more correlatable than the thinner (<0.60 m) sand bodies and 2) wave influenced marine sand bodies are more correlatable relative to current and tidal marine sandstone bodies in the system.