Paleozoic Stratigraphy and Structure at Iron Point, Nevada: Regional Implications

Erica L. Key, Patricia H. Cashman, and James H. Trexler, Jr.
Department of Geological Sciences and Engineering, University of Nevada, Reno, MS 172, Reno, NV 89557

Existing geologic maps and cross-sections depict contradictory and geometrically impossible relationships at Iron Point, north-central Nevada. The mapped Ordovician units at Iron Point are absent at Edna Mountain, immediately to the west. This suggests that a significant, previously unrecognized, fault separates the two areas. Also, current structural mapping is inadequate to determine whether the well-documented late Paleozoic structures at Edna Mountain are present at Iron Point.

The Ordovician stratigraphy at Iron Point also requires re-evaluation. The type section of the Ordovician Comus Formation is located at Iron Point. However, rocks mapped as the "Comus Formation" elsewhere in the region do not match the type section at Iron Point. This discrepancy has been recognized but not addressed. The "Comus Formation" is the host rock for gold deposits in the Osgood Mountains, so its distribution and regional correlation may have economic significance.

The focus of this study will be to define the deformation history at Iron Point. Detailed structural and stratigraphic analyses are currently in progress. Whether or not the late Paleozoic structures at Edna Mountain are also present at Iron Point will constrain the age and style of movement on the fault separating the two areas. A more in-depth understanding of the "Comus Formation" stratigraphy at Iron Point will be used for regional correlation of the unit.

AAPG Search and Discovery Article #90181©2013 AAPG/SEG Rocky Mountain Rendezvous, University of Wyoming, Laramie, Wyoming, September 27-30, 2013