Named for Glaize Creek, a southeast-flowing stream paralleling Jefferson Co Rd M <0.1 mi south of type section. Assigned as lowest of three members of Ordovician (Mohawkian) Hager Limestone (revised), Plattin Group (rank raised). Type section is a roadcut on northwest frontage road at junction of Jefferson Co Rd M and I-55 in SE1/4 NW1/4 sec 30 (projected) T42N, R6E, Herculaneum 7.5 min quad, Jefferson Co, east-central MO. Reference sections in upper part of Fred Weber Crystal City quarry, NW1/4 NW1/4 sec 16, T40N, R6E, Selma 7.5 min quad; exposure on St. Charles Co Rd F, 1.5 mi west of Defiance; first roadcut north of Joachim Creek on I-55 north of Pevely; and in first roadcut on I-55 south of type section. Excellent exposures include roadcuts on Hwy 30 northeast and east of town of House Springs (Weber Hill), House Springs 7.5 min quad, secs 27 and 33 (projected) T43N, R4E, Jefferson Co, MO. Consists of light-tan, light-gray and very light-tan, very light-gray, medium-to thick-bedded calcareous mudstone, often interfingered with thinner fine grainstones (Clement grainstone facies of Thompson and Spreng, 1988). Usually discontinuous large (6-8 in) brown subspherical chert nodules near base. Mostly unburrowed. Distinctive straight actinocerid nautiloid common in upper beds. Weathers to smooth, light gray to nearly white ledges. Total thickness at type is 7 ft, 3 in [2 m]. Abrupt contact with underlying Ordovician (Mohawkian) Beckett Limestone of Plattin Group (revised). Conformably overlain by and sometimes interbedded with Ordovician (Mohawkian) Hely Member (revised) of Hager Limestone (revised) of Plattin Group. Age is well established as Ordovician (Mohawkian). Report includes stratigraphic columns, correlation and nomenclatural charts, and type section maps.

Source: GNU records (USGS DDS-6; Denver GNULEX).