DYNAMIC STRATIGRAPHY WORKGROUP

Separating Structural from Depositional complexity in the Paleocene Lower Wilcox “Lobo” sands, Zapata County, Texas

 

People:

Sarah Milewski, Ron Steel

 

Research question(s):

This study aims at unraveling structural and depositional complexity in the Lobo sand delta-lobe packages present in Zapata County, Texas.

 

Summary of work:

This M.S. thesis integrates 3-D seismic, well-logs, thin sections and core. Stratigraphic and structural cross-sections were generated and used to define the depositional history and stratigraphic framework of the study area. These cross-sections show that the delta which deposited these sands was lobate, and the sands are discontinuous even over distances of a few thousand feet. Much of the variation in sand thickness and character is attributed to depositional complexity, aside from the overprint of structural disturbance. Petrography indicates multiple sources for these sands, with Laramide-associated source material from the North and West, and volcanically sourced material from the South and West.