MICROFOSSILS FROM THE CARBONIFEROUS OCHRE MOUNTAIN LIMESTONE, LAKESIDE MOUNTAINS, UTAH

The Ochre Mountain Limestone is a Carboniferous rock unit exposed in the Lakeside Mountains west of Great Salt Lake in Northern Utah. Previously reported fossils from this area consist primarily of poorly-preserved tabulate and rugosan corals, brachiopods, gastropods, and crinoid fragments. While the macrofossils of the Ochre Mountain Limestone are scarce the limestone itself contains layers of nodular chert that provide a second taphonomic window into this ancient ecosystem.

Thin sections from the chert samples have yielded 13 different categories of identifiable microfossils. Samples include representatives from red algae, green algae, foraminifera, crinoids, acritarchs, scolecodonts, and arthropod cuticle (possibly eurypterid). Additional microfossil specimens have been observed in thin section but have yet to be identified. Predominant fossils in the thin sections indicate this area as a typical late Carboniferous, back reef environment.