CO2 Pulses and Fault Rupture, Gunnison Fault System, Central Utah

Joel Main
The Ohio State University School of Earth Science, 275 Mendenhall Laboratory, 125 South Oval Mall Columbus, Ohio 43210

In the Basin and Range Province (BRP) in central Utah a horst and graben structure is oriented perpendicular to the BRP’s N-S trending horst and graben blocks. The northern fault (Rock Canyon Fault) of this anomalously oriented structure and its related faults rocks are being studied for fault rupture and seal as a natural analogue for carbon capture and storage. The evolution of Rock Canyon Fault is shown through its rocks, travertine and breccias, and their structures. Two brecciation processes have formed the rocks observed: fault void fill and explosive breccias. The structures in the rocks reveal a minimum of four alternating precipitation and brecciation events. Mapping the Rock Canyon fault zone shows a lateral distribution of the composition and thickness of the fault rocks. As Rock Canyon Fault progresses toward the Valley Fault (a BRP fault) it thickens and changes from calcite to primarily travertine. The Rock Canyon fault and Valley fault (main fluid flow conduit) are therefore thought to meet or intersect. The Valley fault is thought to intersect the Navajo formation (Providence oil field resevior) containing 81% carbon dioxide. To better understand fault rupture and seal and how it relates to carbon capture and storage isotope analysis and more kinematic data needs to be collected on both the Rock Canyon fault and Valley fault.

AAPG Search and Discovery Article #90183©2013 AAPG Foundation 2013 Grants-in-Aid Projects