Publications

No abstract available.

No abstract available.

The stable isotopic compositions of nitrogen and carbon in cyanide compounds can be determined by combusting aliquots in sealed tubes to form N2 gas and CO2 gas and analyzing the gases by mass spectrometry. Free cyanide (CN-aq + HCNaq) in simple solutions can also be analyzed by first precipitating the cyanide as copper(II) ferrocyanide and then combusting the precipitate. Reproducibility is ±0.5‰

The pros and cons of the three conodont-based boundaries of the Frasnian and Famennian Stages and their corresponding GSSPs (Global Stratotype Section and Point) are evaluated in terms of current taxonomic, biostratigraphic, and sedimentologic knowledge. Two of these boundaries are based on easily identified pelagic species, which provide excellent bases for global correlation. The third, for the

The Late Neoproterozoic (735-702 Ma) Robertson River Igneous Suite includes at least eight plutons ranging in composition from syenogranite to alkali feldspar granite to alkali feldspar syenite. These plutons intruded Mesoproterozoic (1.2-1.0 Ga) gneissic basement of the Blue Ridge anticlinorium in northern and central Virginia during an early episode of Laurentian rifting. Robertson River plutons

The conodont-based biochronology of the Devonian Period is calibrated herein on the basis of: (1) a recent, reliable radiometric dating (CLAQUE??-LONG et al. 1992) of a stratigraphic position just above the Devonian-Carboniferous boundary; and (2) new calculations of stage durations based on our estimates and those of a large number of other Devonian workers, which pertain to many stratigraphie se

No abstract available.

In the absence of drilling, surface-based geophysical methods are necessary to observe fault zones and fault zone physical properties at seismogenic depths. These in situ physical properties can then be used to infer the presence and distribution of fluids along faults, although such observations are by nature indirect and become less exact with greater depth. Multiple observations of a range of s

No abstract available.

The Summitville Mine, located near the old mining town of Summitville in Rio Grande County, Colorado, operated between July 1986 and December 1992 as a large-tonnage open-pit heap-leach gold mine. During its 6 years of existence the trace metal levels in drainage water from the mine site were elevated over historical (pre-1986) levels (Moran and Wentz, 1974) due to input from three sources—heap le

No abstract available.

The Ruby terrane is an elongate fragment of continental crustal rocks that is structurally overlain by thrust slices of oceanic crust. Our results from the Kokrines Hills, in the south‐central part of the Ruby terrane, demonstrate that the low‐angle schistose fabric formed under high‐P/low‐T conditions, at peak conditions of 10.8‐13.2 kbar and 425‐550° C, consistent with the rare occurrence of gla