GEOLOGICAL TRAIL GUIDE TO THE FALLS LAKE TRAIL: A FIELD TRIP RESOURCE FOR ALL LEVELS

The Falls Lake Trail constitutes a 60-mile portion of the 1,000-mile NC Mountains to the Sea Trail (MST). Beginning at the Falls Lake Dam, it stretches westward through mostly scenic public lands in northern Wake and Durham Counties. The trail is well marked and well maintained, and it passes through two State Parks and one County Park. The 1994 CGS guide has stops in the area, as does the GSA Centennial Field Guide (SE).

We are developing a geological guide, keyed with GPS waypoints, to an existing trail log. The guide is written for the general public, and field excursions may be tailored to different levels. Young children will enjoy discovering soapstone and magnetite; college geology students can learn the basics of geological mapping. The trail traverses parts of the Wake Forest, Bayleaf, Creedmoor, and Northeast Durham 1:24,000-scale Quadrangles, geological maps of which have been published by the NC Geological Survey.

The trail begins in the Falls Leucogneiss of the Raleigh terrane, then winds through the Falls Lake, Crabtree, and Carolina terranes, before entering the Mesozoic Durham sub-basin. Along the trail, the hiker encounters an impressive range of rocks, minerals, and other geological features, including garnet schist, lineated leucogneiss, soapstone, boulder conglomerate, diabase dikes and sills, actinolite, talc, kyanite mineralization, foliations, lineations, folds and faults. There are opportunities to discover map-scale structural features, including crossing the hinge zone of the Raleigh antiform, where dip changes from eastward to flat to westward; walking back and forth across the Mesozoic Jonesboro normal fault, where geomorphic features as well as rock types show the location of the fault; and crossing the ductile Falls Lake fault, where mylonitized granitoid gneiss marks a fundamental terrane boundary.

The field guide will be accessible via smartphone, so that descriptions of features can be viewed on the trail. Future plans include utilizing the location services of smartphones to couple real-time location information with the field guide. We hope the guide may inspire similar efforts along other portions of the MST and adjoining trails. This would give more people, including geologists, teachers, students, and interested hikers access to the educational benefits we envision.