The Goochland terrane in the central Piedmont Province of Virginia contains two documented units of Mesoproterozoic age, the State Farm Gneiss (ca. 1023–1046 Ma) and the Montpelier Anorthosite (ca. 1045 Ma). The heterogeneous Maidens gneiss, the most extensive unit in the terrane, has previously been assumed to be Mesoproterozoic. This inferred age was based primarily on the presence of locally preserved granulite-facies assemblages (particularly in metapelites), with granulite conditions assumed to reflect metamorphism accompanying the Grenville orogeny. However, we report new U-Pb zircon results for meta-igneous varieties of Maidens gneiss that indicate Paleozoic (Devonian) crystallization ages. Whole-rock major- and trace-element compositions of these and additional samples suggest intermediate igneous protoliths of high-K, calc-alkaline affinity. Our age determinations clearly demonstrate that the protoliths for these samples were not Mesoproterozoic, and could not have been affected by Grenvillian metamorphism. As an alternative, we suggest that the protoliths were plutonic igneous rocks, reflecting deep-seated emplacement of magmas approximately coincident with high-grade metamorphism in associated rocks during the Acadian orogeny. Whether our age results can be applied to the entirety of the Maidens gneiss is uncertain, but if so, a large portion of the Goochland terrane as currently defined is not Mesoproterozoic.

Luminescence techniques can provide ages for deposits undatable by routine geochronometric techniques (e.g., 14 C, K-Ar, fission track). Two classes of events can be dated by luminescence methods: (I) growth of a mineral or its last cooling, and (II) the last exposure to sunlight. Within the past few years, significant advances in procedures, technology, and understanding of the thermoluminescence (TL) behavior of minerals have been made that place luminescence dating techniques on the verge of widespread application to Quaternary deposits. Most progress has come from studies of known-age material deposited under known conditions. Within class I, both distal and proximal tephra deposits have been dated, using TL techniques originally developed for pottery dating. Within class II, loess, buried soils, and waterlaid silts have been successfully dated. Means have been demonstrated for isolating and controlling several major sources of error, such as the type of TL instability known as anomalous fading, as well as the effects of uncertainty about the degree of zeroing of the luminescence signal in certain depositional environments. In particular, because of different sensitivities to light of the TL of quartz and feldspars, feldspars have been shown to be the preferred component for dating most unheated sediments. Of the competing TL methods for dating the last exposure to sunlight, the partial bleach (R-Gamma or R-Beta) technique, when properly applied, has been shown to yield the best results in general. Nevertheless, in future dating studies of unheated sediments, this laborious method may be displaced by a novel technique that uses laser light, rather than heat, to stimulate the luminescence that is a measure of the past ionizing radiation absorbed dose. This new optical (OSL) method of dating promises to be simple, sensitive, and speedy.