The Reed Dolomite, as its name suggests, is mainly composed of medium-gray, yellowish-gray, and pale-yellowish-brown medium to coarse-crystalline dolomite. Within these dolomites, oolites, pisolites and irregular pellets, which all may be algal in origin.
Members
The Reed Dolomite contains three members, which are as follows, in stratigraphic order (lowest to highest):
Lower Member: This member is primarily composed of coarse-crystalline pink dolostone, which is cross-bedded with oolthic horizons and minor domal stromatolite horizons, and was most likely deposited in a sub-tidal to inter-tidal marine environment.
Hines Tongue: The Hines Tongue forms the middle member of the formation, as is a wedge of clastic material, which can get up to 800ft (240m). It contains a number of minerals, but is primarily composed of yellowish-gray or very-pale-orange evenly laminated quartzite and calcareoussandstone, some of which is very fine to fine, and fine to medium grained. There is also medium-gray to pale-yellowish-brown dolomite, limestone, sandy dolomite, and sandy limestone within the wedge. It is also inter-stratified with quartzite and calcareous sandstone. There are also small yellowish-gray to pale-yellowish-brown siltstone, and may have been deposited below a normal wave base, but above the storm base. It also contains a number of trace fossils throughout.
Upper Member: This member is predominately composed of massive dolostones, with minor karstification at the contact point with the overlying Deep Spring Formation. It is also known to contain packstones of Cloudina.
Paleobiota
The Reed Dolomite contains a number of algal structures, as well as the mollusc like fossils Wyattia, and ichnogenera such as the Skolithos burrows.
12Peter Crimes, T. (March 1987). "Trace fossils and correlation of late Precambrian and early Cambrian strata". Geological Magazine. 124 (2): 97–119. doi:10.1017/S0016756800015922.
.jpg)
.jpg)
