A Carbonate Hardground from the Middle Jurassic Carmel Formation of Kane County, Utah (section authored by Bryan Kinney)

The Carmel Formation carbonate is Middle Jurassic in age and exposed near Kane County, Utah. The weathered surfaces of the hand sample are light tan in color. The Fresh surfaces of the hand sample are a darker tan. Visible grains of calcite and quartz can be seen on the surface of the rock. Weathering of the rock shows oxidation of the exposed calcite. Ooids are coating the exterior of the rock. The folk name given to the sampled rock determined by observing the thin section is oobiosparite. The dunham name for the rock is a grain stone. Ooids and bivalve fragments indicate the depositional environment as shallow marine, in or just under the wave base, and in the photic zone.

Bryan Kinney, Junior at The College of Wooster. Bryan is from Pittsburgh, Pennsylvania.

The photo here shows the grainstone matrix of the rock. Notice the ooids and bivalve fragments the make up the entire slide. These ooids and bivalve fragments are found through out the sample. Width of view: 3.0mm (40x).

The photo here shows a large bivalve shell fragment. This shell fragment was originally aragonite but has been replaced with calcite. Width of view: 3.0 mm (40x).

The photo here shows an ooid with other smaller ooids surrounding the large one. Width of view: 1.2 mm (100x).

This photo shows more happy ooids living together in the shallow marine environment. Notice the small bivalve fragments above the large ooid. Width of view: 1.2 mm (100x).