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Mineral Resources > Online Spatial Data > Geology > by state > Missouri Geology

Geologic units in Saint Francois county, Missouri

[Additional scientific data in this geographic area]

ROUBIDOUX FORMATION (Phanerozoic | Paleozoic | Ordovician-Early [Ibexian]) at surface, covers 1 % of this area

ROUBIDOUX FORMATION - sandstone, chert and interbedded dolomite

Lithology: sandstone; chert; dolostone (dolomite)

ST. FRANCOIS MOUNTAINS VOLCANIC SUPERGROUP (Precambrian [Y]) at surface, covers 7 % of this area

ST. FRANCOIS MOUNTAINS VOLCANIC SUPERGROUP (chiefly alkali rhyolitic ash - flow tuffs, lava flows, and bedded tuffs, with minor trachytes.

Lithology: rhyolite; trachyte

GASCONADE DOLOMITE (Phanerozoic | Paleozoic | Ordovician-Early [Ibexian]) at surface, covers 4 % of this area

GASCONADE DOLOMITE - coarse - crystalline cherty dolomite with a basal Gunter Sandstone Member.

Lithology: dolostone (dolomite); sandstone

LAMOTTE SANDSTONE (Phanerozoic | Paleozoic | Cambrian-Furongian [Croixian]) at surface, covers 11 % of this area

LAMOTTE SANDSTONE - sandstone with some dolomitic and shaly lenses; coarse - graines to conglomeratic and arkosic at base

Lithology: sandstone

ELVINS GROUP- (INCLUDING DERBY-DOERUN DOLOMITE, DAVIS FORMATION), BONNETERRE DOLOMITE (Phanerozoic | Paleozoic | Cambrian-Furongian [Croixian]) at surface, covers 41 % of this area

ELVINS GROUP - (INCLUDING DERBY - DOERUN DOLOMITE - alternating thin dolomite, siltstone, and shale; DAVIS FORMATION - glauconitic shale with fine - grained sandstone, limestone, and dolomite); BONNETERRE DOLOMITE - dolomite, dolomitic limestone, and limestone; glauconitic in lower part

Lithology: dolostone (dolomite); shale; siltstone; sandstone; limestone; conglomerate

EMINENCE DOLOMITE, POTOSI DOLOMITE (Phanerozoic | Paleozoic | Cambrian-Furongian [Croixian]) at surface, covers 26 % of this area

EMINENCE DOLOMITE - dolomite with some druse - coated chert. POTOSI DOLOMITE - dolomite with abundance of druse - coated chert.

Lithology: dolostone (dolomite); chert

ST. FRANCOIS MOUNTAINS INTRUSIVE SUITE (SUBVOLCANIC, ALKALI GRANITIC RING COMPLEXES) (Precambrian [Y]) at surface, covers 10 % of this area

ST. FRANCOIS MOUNTAINS INTRUSIVE SUITE (SUBVOLCANIC, ALKALI GRANITIC RING COMPLEXES)

Lithology: granite