Abstract
The terrigenous and carbonate facies accumulated in an overall transgressive-regressive sequence. Terrigenous strata are most abundant in the northern and western parts of the area and are divisible into three facies. The low-angle cross stratified very fine sandstone to coarse siltstone facies is an arkose. Sedimentary structures in this facies include: terrigenous-carbonate flaser bedding, vertical burrows, symmetrical and asymmetrical ripples, convoluted and microfaulted laminae, desiccation cracks, and clay drapes. The fine-to-medium sandstone facies displays a quartz-rich, fossiliferous, and intraclastic texture, and exhibits bipolar trough cross-stratification directions. The bioturbated very fine sandstone to coarse siltstone facies, is an arkose. This facies exhibits some terrigenous-carbonate wavy and lenticular bedding. The freshness and abundance of feldspars in the tidal flat and adjacent areas, lack of abundant clay, and salt hopper impressions in clay drapes suggest that arid to semi-arid conditions existed in the source area and that eolian processes provided a high percentage of the terrigenous sediment to the area. The carbonate strata have three facies that are distinguished by their allochemical constituents; the brachiopod-trilobite-pelmatazoan biomicrite facies, the sponge megasclere biomicrite facies, and the oosparite facies. The depositional history of the transgressive Cap Mountain Limestone may be subdivided into two phases, an extensive tidal flat cut by migrating tidal channels and in adjacent, broad, shallow subtidal areas, and shallow subtidal areas, a shallow shelf, sponge organic banks, and oolite shoals.--Modified journal abstract.
