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The creation of new outcrops through construction is an important source of field data for geologists, especially in parts of the Appalachians with limited rock exposure. Users of Google Earth for field research often encounter disparities between the digital topography and the current-day Earth's surface, as newly formed outcrops may not be represented in the topography. Such is the case along sections of the I-26 corridor in Unicoi County, northeastern Tennessee. Twenty-four kilometers of U.S. 23 (future I-26) was widened to four lanes from Sams Gap at the North Carolina–Tennessee line to the Nolichucky River near Erwin, Tennessee, in the early 1990s. The series of outcrops created along the corridor provide an exceptional traverse through Grenvillian-age basement and cover strata which contain numerous stacked Alleghanian thrust sheets and shear zones. Near mile marker 44 along I-26, an ~250 m-long and 65 m-high outcrop was formed as part of the early 1990s construction. Google Earth satellite and Street View images show the outcrop, but the digital terrain in Google Earth does not reflect the approximate 150,000 m3 of rock removed to form this roadcut. To correct for this, terrain modifications were made with Sketch-Up by copying and virtually excavating the landscape. The SketchUp model was then imported into Google Earth to show the outcrop and interstate as it looks today, with the interstate passing uninterrupted through a ridge rather than draping over hilly topography. This technique can be applied to any area in Google Earth where a mismatch exists between real and virtual topography.

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