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Miami County Geohydrology

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Geology--Subsurface Stratigraphy

The stratigraphic nomenclature used in this report is that of the State Geological Survey of Kansas and does not necessarily follow the nomenclature of the U.S. Geological Survey.

Sedimentary rocks of Paleozoic and Neogene ages underlie Miami County. The Paleozoic rocks, of Pennsylvanian, Mississippian, Devonian, Silurian, Ordovician, and Cambrian ages, overlie Precambrian igneous and metamorphic rocks. The thickness of the Paleozoic rocks ranges from about 2,000 feet in the southeastern corner of the county to about 2,500 feet in the northwestern corner (Jewett, 1954, p. 290-292). The general thickness and character of the subsurface rocks are known from the study of well logs and samples of drill cuttings from oil and gas wells in the area.

A detailed discussion of the Paleozoic sequence of eastern Kansas was prepared by Lee (1943). More recently, Merriam and Kelly (1960) and Merriam and Smith (1961) prepared regional structural contour maps on the upper surfaces of Mississippian, Hunton, and Arbuckle rocks.

Precambrian Rocks

Quartzite, schist, slate, marble, porphyry, arkose, and granite have been reported in wells drilled into the Precambrian in Kansas. Wells drilled to the Precambrian at three localities in Miami County were reported to have encountered red arkose and granite (Cole, et al., 1961).

The Precambrian surface slopes to the northwest across Miami County from about 1,200 feet below sea level in the southeastern corner to about 1,400 feet below sea level in the northwestern corner (Cole, 1962).

Cambrian Rocks

The Lamotte Sandstone of Late Cambrian age overlies Precambrian rocks throughout Miami County. It is a fine- to coarse-grained sandstone composed of quartz and feldspar and has a maximum thickness of about 100 feet (Jewett, 1954). The Bonneterre Dolomite, which overlies the Lamotte Sandstone, ranges in thickness from about 100 feet in the northwest corner to a somewhat greater thickness in the southeast corner and ranges in thickness from about 100 feet in the southwest corner to more than 150 feet in the northeast corner (Jewett, 1954).

Cambrian and Ordovician Rocks

In Miami County the Arbuckle Group, of Early Ordovician and Late Cambrian ages, includes four recognizable formations. The Eminence Dolomite of Late Cambrian age is the lowestmost formation of the Arbuckle Group.

Lee (1943) differentiated the Ordovician part of the Arbuckle Group into three units: the Van Buren-Gasconade formations, the Roubidoux Formation, and the Jefferson City- Cotter dolomites. The Van Buren-Gasconade sequence ranges in thickness from 150 feet in the southwest corner to about 200 feet in the northeast corner of the county. The Roubidoux ranges in thickness from about 100 feet in the southwest corner to about 80 feet in the northeast corner. The Jefferson City-Cotter sequence ranges in thickness from about 100 feet in the northeast corner to about 200 feet in the southwest corner. Arbuckle rocks in Miami County have an average thickness of 850 feet (Jewett, 1954).

Ordovician Rocks

The Simpson Group and the overlying Viola Limestone of Middle Ordovician age are believed to be present only in northwestern Miami County. The upper part of the Simpson Group is composed of limestone, dolomite, and gray and green shale; the lower part is composed of well-rounded sandstone and gray shale. The maximum thickness of the Simpson Group in Miami County is about 100 feet. The thickness of the Viola Limestone ranges from 0 to about 200 feet (Jewett, 1954).

Silurian and Devonian Rocks

In eastern Kansas undifferentiated Silurian and Devonian limestones and shales are commonly termed the "Hunton Group." According to Merriam and Kelly (1960), Hunton rocks of undetermined thickness occur in the northwest corner of Miami County.

Devonian and Mississippian Rocks

Miami County lies on the northern flank of the Chautauqua Arch. Ordovician rocks, including the Viola Limestone, the Simpson Group, and the Arbuckle Group, are overstepped progressively to the southwest by the Chattanooga Shale, of Late Devonian and Early Mississippian ages. The Chattanooga is believed to be less than 50 feet thick in all parts of the county (Jewett, 1954). It is a silty and partly pyritiferous, greenish-gray, and dark-gray to black shale.

Mississippian Rocks

Mississippian rocks in Miami County range from about 350 feet to slightly more than 450 feet, but they are thinner to the west and south. The Chouteau and Sedalia formations of Kinderhookian age, the Burlington Limestone of Osagian age, and the St. Louis, Salem (1?), and Warsaw limestones of Meramecian age are believed to be present in the county (Lee and Girty, 1940). The Mississippian rocks in Miami County are chiefly limestone and dolomite.

Pennsylvanian Rocks

The Pennsylvanian rocks in Miami County belong to the Desmoinesian, Missourian, and Virgilian stages. The Desmoinesian Stage is composed of the Cherokee and Marmaton groups. The Missourian Stage consists of the Pleasanton, Kansas City, and Lansing groups. The Virgilian is made up of the Douglas, Shawnee, and Wabaunsee groups. Only rocks of the Missourian and Virgilian Stages are exposed; these are described in more detail in the following section.

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Kansas Geological Survey, Miami County Geohydrology
Comments to webadmin@kgs.ku.edu
Web version June 2002. Original publication date June 1966.
URL=http://www.kgs.ku.edu/General/Geology/Miami/04_geol.html