90°22'30"W 90°30'00"W 90°27'30"W 90°25'00"W R 5 E R 6 E 38°52'30"N 38°52'30"N 31 32 33 34 35 36 31 35 SURFICIAL MATERIAL GEOLOGIC MAP OF THE ST. CHARLES 7.5' QUADRANGLE Qslt 0 5 4 ST. CHARLES AND ST. LOUIS COUNTIES, MISSOURI 0 45 Qslt 2 Geology and Digital Compilation by 0 45 Qtd David A. Gaunt and Bradley A. Mitchell Qcly «¬94 3 5 6 5 4 2011 Qslt Qtd Qtd Qtd 1 Graus «¬94 Lake OFM-11-593-GS 6 «¬H Qtd 6 Croche 9 10 MISSOURI DEPARTMENT OF NATURAL RESOURCES 8 7 s DIVISION OF GEOLOGY AND LAND SURVEY ai ar 7 M GEOLOGICAL SURVEY PROGRAM Qslt Qtd P.O. BOX 250, ROLLA MO 65402-0250 12 www.dnr.mo.gov/geology B «¬ Qslt 573-368-2100 7 13 THIS MAP WAS PRODUCED UNDER A COOPERATIVE 0 5 AGREEMENT WITH THE UNITED STATES GEOLOGICAL 4 18 38°50'00"N 38°50'00"N SURVEY Qtd Permission must be obtained to visit privately owned land Qslt Qslt PHYSIOGRAPHY 0 5 4 St. Charles County D St. Louis County The St. Charles quadrangle includes part of the large floodplain of the Missouri River and loess covered uplands. N 500 550 A L The floodplain is up to five miles wide in this area. The quadrangle lies within the Dissected Till Plains Section 50 S 5 I 45 6 0 0 0 of the Central Lowland Province of the Interior Plains Physiographic Division. With the exception of a quarry 550 550 500 600 located in the south of the quadrangle, the lowest recorded elevation is slightly less than 420 feet mean sea level 50 Qslt 00 5 N 6 94 60 Ql (msl) and occurs along the edge of the Missouri River near the eastern quadrangle boundary. The highest elevation 550 «¬ A 0 5 Y 5 0 0 650 0 55 Qs 6 0 lt R on the quadrangle occurs on the loess covered uplands and is greater than 650 feet msl in the southeast corner of the «¬370 B 500 quadrangle. Total relief on the St. Charles quadrangle is approximately 230 feet. Ql 15 14 00 0 6 0 5 0 5 5 0 0 55 5 0 5 5 21 22 4 Qtd 22 GEOLOGICAL OVERVIEW 23 6 24 00 0 55 r 0 The St. Charles quadrangle is underlain by Paleozoic limestone and shale. The majority of the quadrangle is underlain 5 e 5 5 5 0 v 0 0 i 5 R Ql i Qslt by the Mississippian-age St. Louis, Salem and Warsaw Formations. The upland area in the southeast of the St. Charles r 0 u 5 5 5 5 5 o 5 0 quadrangle contains the Pennsylvanian-age Cherokee and Marmaton Groups which are cyclic Desmoinesian Series s 0 is M deposits of shale, limestone, sandstone, clay and coal. In areas where surficial materials overly the Warsaw Formation, Ql Qslt the landslide potential is greater. The Warsaw Formation is dominated by shale, which creates a zone of instability 50 550 5 Ql Qslt during high precipitation events. 0 5 4 DESCRIPTION OF MAP UNITS 550 550 94 QUATERNARY CLAY-CAPPED ALLUVIUM – This unit has been deposited by the Missouri River. «¬ HAZELW Ql OOD 38°47'30"N 38°47'30"N 29 28 370 Qcly The approximate upper 15 feet of these deposits are composed predominantly of clay with variable 50 «¬ 0 5 55 k 0 e 0 e amounts of silt and organic material. The material residing below the clay is predominantly sand and 5 r C 5 5 0 gravel to the top of bedrock. The thickness of this unit ranges from 80 to 100 feet. The water table is Ql 0 approximately five to 15 feet below ground surface, resulting in an interval of saturated sand and gravel 550 60 50 5 0 5 greater than 80 feet thick. 5 Qslt 60 ST. CHARLES 0 A' 5 0 5 5 Ql 0 5 0 55 QUATERNARY SILT-CAPPED ALLUVIUM – This unit has been deposited by the Missouri River. 5 550 5 27 T 47 N 0 T 47 N Qslt The approximate upper 15 feet of these deposits are composed predominantly of clay with variable 5 34 00 Qslt amounts of silt and organic material. The material residing below the clay is predominantly sand and 33 550 450 gravel to the top of bedrock. The thickness of this unit ranges from approximately 20 feet where the floodplain 0 Qslt 60 Ql transitions to uplands to more than 120 feet where the Missouri River has incised the Paleozoic bedrock. The Ql 0 5 e 550 500 4 r 550 Qslt i water table is approximately five to 15 feet below ground surface, resulting in an interval of saturated sand m 550 5 w 0 o 550 0 50 C 4 600 and gravel more than 100 feet thick. This unit is included in the cross sections as Quaternary silt-capped Ql 5 alluvium. Qtd 50 A 55 0 0 0 Ql 6 5 5 QUATERNARY LOESS – This unit is a wind-blown deposit of silt and clayey silt with occasional pockets 5 5 0 Qslt 50 0 0 5 55 Ql 0 Ql of clay, sand and gravel. The unit is composed of two separate loess layers, the Roxana below and the 0 500 5 550 600 Peoria above (Goodfield, 1965). The total thickness of the two units may reach 140 feet. The Roxana is 450 50 0 5 Qtd 5 5 §270 higher in clay content and may have a paleosol developed in the upper few feet. The contact between the ¨¦ 00 6 6 0 0 0 55 two units forms a potential slide plane in areas of high topographic relief. The loess overlies Qslt 0 T 46 N 5 4 60 T 46 N 550 6 Mississippian-age bedrock comprised of limestone and shale creating two unique environments. Where 8 Ql 00 0 5 0 the loess is thin, the limestone may be karstic. Where the underlying unit is predominantly shale, water will 5 y 0 0 r 550 0 6 r 6 a perch, destabilizing the contact zone. Where the loess rests upon shale, the slide potential is increased. 0 u 50 ¨¦§70 Q BRID ¤£67 550 GETON 0 0 60 5 5 550 Qslt ty QUATERNARY TERRACE DEPOSIT – The terrace deposits in the quadrangle are slightly different than 6 5 n 0 00 600 u 0 o y Qtd C t Ql previously mapped terrace deposits (Brill, 1991; Harrison, 1997; and Goodfield, 1965). All were deposited n 550 Ql s 0 B 600 u 55 «¬ 0 le o 55 r C Qslt 50 during fluvial events, leaving the terrace above low flow stage of the river. However, the terrace deposits in a 5 5 Qs 5 h is lt 0 C u this quadrangle have a lacustrian signature of sensitive organic clays approximately 20 feet below the surface. t. o L S . Qtd 180 Ql t «¬ 550 550 After high stage flow returned to normal, low lying areas within the terrace were filled with organic clay material. S 0 550 5 6 5 0 0 0 5 0 5 5 This zone has a very low shear wave velocity and underlies many types of infrastructure. 5 38°45'00"N 38°45'00"N 90°30'00"W 90°27'30"W 90°25'00"W R 5 E R 6 E 90°22'30"W Produced by the Missouri Department of Natural Resources, MISSOURI Road and Contour Symbology ^ SCALE 1:24,000 A A' Line locates the placement of the cross section with end line symbols. Division of Geology and Land Survey, Geological Survey Program. MN 1 0.5 0 Kilometers 1 2 §¨¦70 Funded by the United States Geological Survey, National Earthquake GN Interstate Highways ..... N Hazards Reduction Program, Award # G10AP00074, 2010. 1000 500 0 Meters 1000 2000 Missouri Highways ....... Topography was derived from a USGS 10 meter Digital Elevation Model 1° 27’ 1 1/2° Public Land Survey System including Spanish land grants. 27 Mils 1 0.5 0 1 Light Duty Roads........... using contouring software. Features were edited on the USGS, 26 Mils Railroad......................... 38090-G4-TF-024, 1994, St. Charles 7.5' quadrangle and digital aerial Miles Elevation Contour.......... 10 photography from 2007 and 2009. Field checked in 2011. UTM and 1994 Magnetic North 1000 500 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 Universal Transverse Mercator (UTM), Zone 15. Declination at Center of Sheet Index Contour................ 50 2011 Magnetic North Declination North American Datum 1983 (NAD 83). ~ 0° - 45' East, Field Strength: 53110.2 nT Feet QUADRANGLE Contour Interval............. 10 Feet LOCATION BIBLIOGRAPHY Allen, W.H. and Ward, R.A., 1977, Soil, in The Resources of St. Charles County, Missouri, Land, Water, and Minerals; A A' Satterfield, Ira and Harris, Barbara, eds.; Missouri Geological Survey, Department of Natural Resources, 237 p. 180 600 Well Well Well Ql Brill, K.G., 1991, Geologic Map of St. Louis City and County, Missouri; Division of Geology and Land Survey, Tributary HWY 370 Missouri Department of Natural Resources, OFM-91-0259, scale 1:62,500. Tributary Ql Cowmire Creek Ql Tributary Ql Ql Well Well Well Goodfield, A.G., 1965, Pleistocene and surficial geology of the City of St. Louis and the adjacent St. Louis 500 150 Missouri River Canal Railroad Railroad Ql County, Missouri; unpublished Ph.D. dissertation, University of Illinois, Urbana, IL, 206p., 6 pl.