St. Peter Sandstone, Illinois Basin

Comments on Geologic Parameters

16 Rock Mineralogy:

A number of authors characterized the mineral and chemical composition of the St. Peter Sandstone (Thiel, 1935; Odom and others, 1976, 1977; Barnes and others, 1992). All authors agreed that the St. Peter Sandstone is a quartzarenite, but some found intervals with appreciable feldspar content (Odom and others, 1976; Barnes and others, 1992). Hoholick and others (1984, their fig. 5) indicated that calcite is the major cement in the central Illinois Basin. Thiel (1935) reported less than 0.05 weight percent of heavy minerals. To characterize the mineralogy, we chose to present a set of graphs from Odom and others (1976). These graphs, which are from samples from Upper Mississippi Valley outcrops, show the proportions of quartz and feldspar and their variation with grain size. These graphs are representative of the proportions of quartz and feldspar presented by other authors.

16 Reference:

Barnes, D. A., Lundgren, C. E., and Longman, M. W., 1992, Sedimentology and diagenesis of the St. Peter Sandstone, central Michigan Basin, United States: American Association of Petroleum Geologists Bulletin, v. 76, p. 1507-1532.

Hoholick, J. D., Metarko, T., and Potter, P. E., 1984, Regional variations of porosity and cement: St. Peter and Mount Simon Sandstones in Illinois Basin: American Association of Petroleum Geologists Bulletin, v. 68, p. 753-764.

Kreutzfeld, J. E., 1982, Pore geometry and permeability of the St. Peter Sandstone in the Illinois Basin: University of Toledo, Master's thesis, 353 p.

Odom, I. E., Doe, T. W., and Dott, R. H., Jr., 1976, Nature of feldspar-grain size relations in some quartz-rich sandstones: Journal of Sedimentary Petrology, v. 46, p. 862-870.

Thiel, G. A., 1935, Sedimentary and petrographic analysis of the St. Peter Sandstone: Geological Society of America Bulletin, v. 46, p. 559-614.