Abstract

Illustrative of the northeastward-trending normal faults in this region is the Hall uplift, a horst that straddles the eastern boundary lines of McCullough County. Fault related flank deposits occur 2-3 miles west along a low escarpment of Smithwick(?) shale and Strawn sandstone capped by flat Cretaceous deposits. The flank deposits consist of limestone cobble and chert pebble conglomerate, which occurs just above and is interbedded with clay shale referred to as Smithwick(?) shale, and is believed to represent downslope failure of structurally elevated detritus. The fossil assemblage indicates a lower Strawn assignment of the beds in question. Similar deposits may occur on the downthrow side of other faults.

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