Paul Denney's comments on the Potato Hills are welcomed (Letters, "Not an astrobleme," OGJ, July 23, 2001, p. 10). There appears to be a misinterpretation of the OGJ article he mentions (OGJ, Oct. 30, 2000, p. 35), which was referring to an online article at the University of Oklahoma Institute for Exploration & Development Geosciences (EDGE) website. The title at EDGE is "Potato Hills Gas Production May Be Impact Related."
This article does not propose a meteorite-impact at Potato Hills. The suggested astrobleme model is for the Gulf of Mexico basin itself, of which Potato Hills is a segment of a possible rim remnant from the peripheral Ouachita arc.
Regional Potato Hills models describing thrust faults and uplifted blocks, along with formation fracturing (e.g., Jackfork), are not in conflict with the astrobleme model. This includes the folded thrust proposed by H.D. Miser, which Paul Denney cites. Such conventional structures, as well as erosional-depositional effects, have been documented in both small and large-scale impact events.
As mentioned in the EDGE article, the earliest published astrobleme model for the Gulf of Mexico appears to be in 1953. The first recognized paper was probably in 1968 by two researchers from the US Atomic Energy Commission (now the US Nuclear Regulatory Commission).
The Oklahoma Geological Survey also published a 1989 symposium proceedings that included Potato Hills and mentioned the astrobleme model. Others support an astrobleme origin for the gulf but are unable or unwilling to publish their findings.
I recognize the difficulty in studying a fractional segment, like Potato Hills, of a possible gulf-size astrobleme. The timing of the collision and post-impact activity is quite challenging. However, here's the point: Impact structures, regardless of size or lithology, are viable drilling targets for hydrocarbons.
Given the known morphology of proven impact events, why not consider a speculative model for exploration? Potato Hills is an enormous gas discovery, and there may be additional reservoirs to be found.
Richard Donofrio
Parwest Land Exploration Inc.
Oklahoma City
