VISUALIZATION OF A GEOLOGIC MAP WITHIN GOOGLE EARTH: THE WHITE HALL 7.5 MINUTE QUADRANGLE, VIRGINIA AND WEST VIRGINIA

The White Hall 7.5-minute quadrangle is located within the Valley and Ridge province of northern Virginia and the eastern panhandle of West Virginia. The quadrangle is one of several being mapped by the U.S. Geological Survey to investigate the geologic framework and groundwater resources of the northern Shenandoah Valley of Virginia and West Virginia. All bedrock outcrops are clastic and carbonate strata of Paleozoic age ranging from Middle Cambrian to Late Devonian. Surficial materials include unconsolidated alluvium, colluvium, and terrace deposits of Quaternary age, and local paleo-terrace deposits possibly of Tertiary age. The completed geologic map of the White Hall quadrangle was incorporated into Google Earth for ease of visualization and exploration. The map is available online at http://pubs.usgs.gov/of/2010/1265/. Layers included with the KMZ file of the map include 1) bedrock and surficial unit polygons with textural descriptions, 2) fault lines, 3) fold axes, 4) karst features (springs and closed depressions), 5) a shaded relief digital elevation model (DEM) image overlay, 6) photos of targeted localities with textural descriptions, and 7) geologic cross sections, viewable both above and below the Google Earth surface imagery.

The quadrangle lies across the northeast limb of the Great North Mountain anticlinorium and includes several other regional folds. The structural centerpiece of the quadrangle is the northern nose of the Mount Pleasant syncline, a doubly-plunging, slightly overturned syncline that spans all of Frederick County, Va. along the footwall of the North Mountain fault zone. This geology of this quadrangle provides an opportunity to view regional geologic structures within a fold and thrust terrain through digital visualization, as well as four-dimensional (including historical images in time series) spatial relations between geologic structures, surficial geology and hydrologic features. This presentation will provide viewers with an opportunity to interactively explore the geologic map layers, as well as learn the work-flow involved with representing a geologic map in Google Earth using Google tools, smart phone, and tablet computer technologies.