The Visibility of Sound: Acoustic Archaeology in the Blue Ridge Mountains

Waterfalls are documented among Indigenous peoples as settings for the intergenerational transfer of knowledge and locations sacred to life transitions. Eastern Woodlands ethnographic literature identifies waterfalls as places where life emerges in the presence of danger, requiring the acknowledgement of those who travel near them. In the Virginia Blue Ridge Mountains, ceramic-bearing Middle and Late Woodland sites near named waterfalls are associated with small sites located outside the topographic parameters of modeled site locations and containing non-local or unique objects. Sound mapping with calibrated decibel meters, survey-grade GPS, and inverse distance weighted interpolation demonstrate a correspondence between the location of the small sites and natural sound magnification. The small sites and the deposited objects may represent the offerings of travelers made aware of the sacred/dangerous place by the sound of the waterfall. Acoustic archaeology is introduced as a practice that takes into consideration sensory experience as central to place identity.

Tectonism and metamorphism along a southern Appalachian transect across the Blue Ridge and Piedmont, USA

ABSTRACT The Appalachian Mountains expose one of the most-studied orogenic belts in the world. However, metamorphic pressure-temperature-time (P-T-t) paths for reconstructing the tectonic history are largely lacking for the southernmost end of the orogen. In this contribution, we describe select field locations in a rough transect across the orogen from Ducktown, Tennessee, to Goldville, Alabama. Metamorphic rocks from nine locations are described and analyzed in order to construct quantitative P-T-t paths, utilizing isochemical phase diagram sections and garnet Sm-Nd ages. P-T-t paths and garnet Sm-Nd ages for migmatitic garnet sillimanite schist document high-grade 460–411 Ma metamorphism extending south from Winding Stair Gap to Standing Indian in the Blue Ridge of North Carolina. In the Alabama Blue Ridge, Wedowee Group rocks were metamorphosed at biotite to staurolite zone, with only local areas of higher-temperature metamorphism. The Wedowee Group is flanked by higher-grade rocks of the Ashland Supergroup and Emuckfaw Group to the northwest and southeast, respectively. Garnet ages between ca. 357 and 319 Ma indicate that garnet growth was Neoacadian to early Alleghanian in the Blue Ridge of Alabama. The P-T-t paths for these rocks are compatible with crustal thickening during garnet growth.

Reflections on Research: Race and the Virginia Blue Ridge

In the 1930s, Shenandoah National Park was established in the Virginia Blue Ridge through the displacement of nearly 500 white families. In recent decades, my scholarship and that of others focused upon the manner in which hackneyed stereotypes about backward mountaineers were mobilized to garner public support for the condemnation of family farms and, in some cases, the institutionalization, sterilization, and incarceration of some of the most impoverished. But, in focusing solely upon the 20th century and the impacts on the white displaced, this research has perpetrated structural violence by obscuring the role of race and racism in the wider Blue Ridge. Archaeological and documentary evidence from the 1990s National Park Service–funded “Survey of Rural Mountain Settlement” is reexamined and reconsidered to begin the process of redressing the silencing of African American histories in the Blue Ridge and surrounding valley and piedmont regions.

Spatially variable syn- and post-Alleghanian exhumation of the central Appalachian Mountains from zircon (U-Th)/He thermochronology

To assess spatial and temporal patterns of Phanerozoic orogenic burial and subsequent exhumation in the central Appalachian Mountains, we present mid-temperature zircon (U-Th)/He (ZHe; closure temperature [TC] = 140–200 °C) dates for 10 samples along a 225 km, strike-perpendicular transect spanning the Appalachian Plateau, Valley and Ridge, Blue Ridge, and Piedmont physiographic provinces in West Virginia and western Virginia. Ranges of single-grain ZHe dates exhibit an eastward younging trend from 455–358 Ma in the Pennsylvanian Appalachian Plateau to 336–209 Ma in the Valley and Ridge, 298–217 Ma in the Blue Ridge, and 186–121 Ma in the Piedmont. Within the Pennsylvanian Appalachian Plateau, detrital ZHe dates are older than corresponding depositional ages, thus limiting postdepositional burial temperatures to less than 160 °C. These ZHe dates capture predepositional mid-Paleozoic cooling signatures, indicating provenance from either recycled Taconic or Acadian basin strata or mid-Paleozoic Appalachian terranes. Across the Valley and Ridge and western Blue Ridge provinces, reset Permian detrital ZHe dates feature flat date-effective uranium correlations that suggest rapid Alleghanian cooling initiating prior to 270 Ma. ZHe dates within the Valley and Ridge are more than 100 m.y. older than previously reported regional apatite fission-track dates, reflecting a protracted period of stable post-Alleghanian thermal conditions within the foreland. By contrast, post-Triassic single-grain ZHe dates in the interior Piedmont document rapid postrift cooling, likely resulting from both the relaxation of an elevated geothermal gradient and exhumation from rift-flank uplift. The spatial discontinuity between stable synrift thermal conditions in the Valley and Ridge and rapid cooling in the Piedmont suggests that rift-flank uplift and cooling were concentrated outboard of the foreland within the Piedmont province.