Bed 6 : The smallest sedimentary strata unit, commonly ranging in thickness from 1 centimeter to a meter or two and distinguishable from beds above and below
National Park Service, U.S. Department of the Interior, Geologic Resources Division, Natural Resource Program Center, Wolf Trap National Park for the Performing Arts, Geologic Resource Evaluation Report, Natural Resource Report NPS/NRPC/GRD/NRR 2008/041, Technical Geologic Terms, Denver, Colorado, USA 2008. http://www.nature.nps.gov/geology/inventory/public ations/reports/wotr_gre_rpt_view.pdf, (ND/ Lndsld - Amer) {923}