Facies Development and Porosity Relationships in Dundee Limestone of Gladwin County, Michigan: ABSTRACT

Abstract

The Devonian of the Michigan basin was a time of transgressive seas and extensive carbonate deposition, including coral and stromatoporoid buildups. Deposited during the Middle Devonian, the Dundee Limestone represents deposition in subtidal, intertidal, and restricted environments. The Buckeye oil field, located in south-central Gladwin County, is a combined stratigraphic and structural carbonate trap that produces from a series of intertonguing patch reefs, fringing sand bodies, and intertidal island fenestral zones. The major reef-building organisms include stromatoporoids, corals, calcareous algae, brachiopods, and crinoids, with the stromatoporoids providing the major framework. The patch-reef facies is composed of massive stromatoporoid boundstones that contain primary intraparticle porosity. The fringing grainstone sands are composed of coarse crinoid and brachiopod skeletal debris that have interparticle porosity. The intertidal island zone found in the North Buckeye field is represented by a pelletal packstone that has abundant fenestral porosity.