This digital map database consists of the ESRI ARC/INFO Version 7.0.2 coverages used to generate the plates in Professional Paper 1538-M (1994). Base-data is from 1:2,000,000-scale Digital Line Graph (DLG) data (roads, railroads, streams, water bodies,

This digital map database consists of the ESRI ARC/INFO Version 7.0.3 coverages used to generate the maps in Map Series MF-2264 A to E (Rhea and Wheeler, 1994a,b, Rhea and others, 1994, Wheeler and Rhea, 1994, Wheeler and others, 1994) and I-2521 (Rhea an

This cover contains faults in the unconformity at the Cambrian-Precambrian boundary. These data were contributed by Glenn Bear of Indiana University as part of the work on his doctoral thesis. The southern part of the map was produced by James Drahovzal o

This cover contains locations of two COCORP lines that cross the study area.

This cover consists of location and size information for historical and recent earthquakes that caused Modified Mercalli Intensity (MMI) VI (6) or higher in the map area. There were 26 earthquakes that caused that level of damage. The most reknown are the

The structure of and depth to the floor of the Mississippi Valley and Rough Creel Grabens and surrounding regions were interpreted from aeromagnetic data. This cover contains the depth contours for the region within this study area and was clipped from th

Lines in this cover show lineaments or boundaries of large lineaments interpreted from gravity and magnetic data. These lineaments are thought to reflect structures in the crust that may be related to earthquake generation or control of earthquake locatio

This cover contains the location of global positioning system stations that are located within the project boundary. Several GPS networks with various monument spacings are being used to monitor deformation in parts or all of the Mississippi embayment. On

Lines in this cover show where gravity oe aeromagnetic data have been modelled to constrain subsurface structure. Gravity and magnetic signatures result from deep structure, such as might be at hypocentral depths of earthquakes. We show only the lines for

This cover contains the catalog of earthquake locations, within the project boundary, recorded by the Saint Louis University and Memphis State University seismic networks from July 1974 through December 1995.

This data is from the fault printing separate used in publishing the 1988 Geologic Map of Kentucky. Separates for geology, surface faults, and cultural features were scanned and sent via email from U. S. Geological Survey, Reston, VA. The scanned data was

This cover includes locations of alkaline ultramafic igneous rocks. The igneous rocks are evidence for Permian extensional reactivation of the faults of continental rifts in the map area. The igneous rocks are Permian lamprophyres and mica peridotites.

NOTE: Location of one point, near -88.65, 38.95, was incorrect when Sheet A was published. The location is .5 degree south, and is corrected in this dataset. This cover contains locations of places where greatest horizontal compressive stress (S(Hmax)) o

Hildenbrand and Ravat (1997) inferred the locations of near-surface dikes from analyses of high-resolution aeromagnetic data. The lines represent locations of magnetic highs that they interpreted as dikes. Modeling indicates the dikes are vertical, extend

Magnetotelluric soundings give data that can help define the l electricamagnetic properties of rocks, and with other geophysical data help define the structure of the shallow crust where earthquakes occur. The sounding points in this cover show where data

Isoseismals of historic Central U.S. earthquakes are contained in 26 separate coverages. Margaret Hopper provided these isoseismals after reexamining the intensity data and re-calculating the isoseismal contours. She generated isoseismal contours for eac

Although many faults are detected at the surface and in deep structures, they are important in evaluating present seismic hazard only if they show evidence of having recent slip. Older faults may have healed, or movement may have occurred under a differen

The northern part of the map area and large adjacent regions have been severely shaken by one or more moderate to large prehistoric earthquakes. The evidence of these takes the form of paleoliquefaction features, including shaking-induced sandblows and di

The northern part of the map area and large adjacent regions have been severely shaken by one or more moderate to large prehistoric earthquakes. The evidence of these takes the form of paleoliquefaction features, including shaking-induced sandblows and di

The northern part of the map area and large adjacent regions have been severely shaken by one or more moderate to large prehistoric earthquakes. The evidence of these takes the form of paleoliquefaction features, including shaking-induced sandblows and di

Note: this cover is a combination of liq94surv and liqmunsurv. The northern part of the map area and large adjacent regions have been severely shaken by one or more moderate to large prehistoric earthquakes. The evidence of these takes the form of paleoli

Over several summer field seasons from 1990 through 1994, several workers searched ditches and river banks for evidence of liquefaction. They found numerous banks with shaking-induced, pre-historic, earthquake induced sandblows and the dikes that fed them

The northern part of the map area and large adjacent regions have been severely shaken by one or more moderate to large prehistoric earthquakes. The evidence of these takes the form of paleoliquefaction features, including shaking-induced sandblows and di

Over several summer field seasons from 1990 through 1994, several workers searched ditches and river banks for evidence of prehistoric earthquake liquefaction. They found numerous banks with shaking-induced sandblows and the dikes that fed them. "liq94sur

This cover contains locations with intensity values associated with felt reports from damaging earthquakes in the lower Wabash Valley occurring from 1811 through 1987. Margaret Hopper collated these data from historical data gathered from previous resear

This cover includes seismic reflection lines that have geophysical cross-sectional interpretations constraining subsurface structures that may penetrate to hypocentral depths. Lines were gathered from theses, dissertations, and publications.

This cover includes seismic refraction lines that have geophysical cross sectional interpretations constraining subsurface structures that may penetrate to hypocentral depths. Lines were gathered from theses, dissertations, and publications.

This cover contains station locations of the New Madrid Seismic Network within the study boundary. The network is a cooperative project of Saint Louis University and Memphis State University. Operation of the network has been continuous since June 1975, b

This cover contains locations of strong motion accelerograph instruments located in the lower Wabash Valley. The instruments are operated by Lamont-Doherty Geological Observatory, the University of Kentucky, and the U.S. Army Corps of Engineers Strong Mot

This cover contains structure contours of the elevations of the unconformity at the Cambrian-Precambrian boundary. These data were contributed by Glenn Bear of Indiana University as part of the work on his doctoral thesis. The southern part of the map was

This cover contains structure contours of the elevations of the unconformity at the Cambrian-Precambrian boundary. These data were contributed by Glenn Bear of Indiana University as part of the work on his doctoral thesis. The southern part of the map wa

This cover consists of surface and near-surface faults compiled by the Illinois Basin Consortium in a multiyear project. This part of the project ended around 1994 and resulted in a publication by the Gas Research Institute. The report, cited in a cross-

This data is from the geologic map of the Paducah 1°x2° Sheet, digitized by the Illinois State Geological Survey, John Nelson directing. We obtained the digitized, exported coverage of faults and geology from Barb Stiff (stiff@geoserv.isgs.uiuc.edu) 199

This cover contains the locations of stations deployed in the temporary network by M.W. Hamburger, G.L.Povlis, and others at Indiana University from October 1995 through June 1996. 20 three-component digital instruments were deployed near the Wabash River

This cover contains wells identified by Dart as having useful information for defining the Paleozoic basement in the New Madrid region. Some wells had borehole breakout data that were useful for interpreting the regional stress field. These locations are

These wells assist in characterizing structures at hypocentral depths in the Wabash Valley. We show locations of 32 wells that provided information about depths to basement, the rifting history of the Rough Creek Graben and Reelfoot rift, coeval rifting e