National Geologic Map Database

Geologic Unit: Matson


Matson Member of Joachim Dolomite (IL*,MO*)
Matson Member of Joachim Dolomite of Ancell Group (IL)

Geologic age:

Late Ordovician (Mohawkian; Turinian)*

Type section, locality, area and/or origin of name:

Type section: quarry and bluff exposures in north bluff of Missouri River Valley, 0.5 mi west of village of Matson, in NE/4 NE/4 NE/4 sec. 4 (projected), T. 44 N., R. 2 E., [Labadie 7.5-min quadrangle], St. Charles Co., eastern MO. Named from village of Matson. Also well exposed in Metz type section (Templeton and Willman, 1963).
Reference sections in MO: (1) roadcuts on U.S. Interstate Highway I-44, in SE/4 SE/4 sec. 1, T. 43 N., R. 2 E., Pacific 7.5-min quadrangle, St. Charles Co.; (2) on MO Highway 30 near Weber Hill, Jefferson Co.; (3) abandoned Missouri Pacific RR cut just east of Glencoe, in SE/4 NW/4 NW/4 sec. 19, T. 44 N., R. 4 E., Manchester 7.5-min quadrangle, St. Louis Co.; (4) roadcut at Lewis Road exit to U.S. Interstate Highway I-44, immediately east of Meramec River bridge, in center W/2 SW/4 sec. 33, T. 44 N., R. 4 E., Manchester 7.5-min quadrangle, St. Louis Co.; and (5) roadcut on U.S. Interstate Highway I-55, in W/2 NW/4 sec. 19, T. 41 N., R. 6 E., Herculaneum 7.5-min quadrangle, Jefferson Co. (Thompson, 1991).

AAPG geologic province:

Illinois basin*
Ozark uplift*

For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).