French Mills felsite (new) of Van East group (new). Briefly summarized in report by W.C. Hayes, Precambrian rock units in Missouri, p. 83 (table 1), this volume. New names are credited to Tolman and Robertson (in prep.) [1969, Missouri Div. Geol. Survey Water Res. Rpt. Inv., no. 44 (Contrib. to Precambrian Geol., no. 1)]. Age is Precambrian.
Occurs in St. Francois Mountain area. French Mills is in T. 32 N., R. 5 E., Madison Co., southeastern MO.

Source: Modified from US geologic names lexicon (USGS Bull. 1350, p. 274-275).

French Mills felsite of Van East group. A dark-gray to black felsite containing light-gray feldspar phenocrysts and considerable epidote which occurs as small granular masses and as replacement bodies in phenocrysts. Petrographic analysis indicates unit is quartz latite or dellenite, intermediate between rhyolite and rhyodacite; here called felsite because of ambiguity. Exposed on southern slope of Marlow Mountain and on unnamed hill in sec. 27, T. 32 N., R. 5 E., St. Francois Mountains, Madison Co., southeastern Missouri. On Marlow Mountain, overlies Stouts Creek rhyolite of Van East group. Age is Precambrian.
Named from exposures southeast of town of French Mills, located in sec. 15, T. 32 N., R. 5 E., Madison Co., southeastern MO. (Type locality not designated.)
[GNU remark (Feb. 16, 1990, USGS DDS-6; Denver GNULEX): Thickness not discussed; stratigraphic relationships of units of Van East not discussed in text; geologic map (plate 1) missing from library copy of report.]
[GNC remark (February 29, 2008): It appears that †French Mills felsite of †Van East group has not been applied to these rocks since this publication. Considered abandoned.]

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