Publications
Products (journal articles, reports, fact sheets) authored by current and past scientists are listed below. Please check the USGS Pubs Warehouse for other USGS publications.
Filter Total Items: 1952
Effects of interaction between ultramafic tectonite and mafic magma on Nd-Pb-Sr isotopic systems in the Neoproterozoic Chaya Massif, Baikal-Muya ophiolite belt Effects of interaction between ultramafic tectonite and mafic magma on Nd-Pb-Sr isotopic systems in the Neoproterozoic Chaya Massif, Baikal-Muya ophiolite belt
Sm-Nd, Rb-Sr and U-Pb isotopic systems have been studied in minerals and whole rocks of harzburgites and mafic cumulates from the Chaya Massif, Baikal-Muya ophiolite belt, eastern Siberia, in order to determine the relationship between mantle ultramafic and crustal mafic sections. Geological relations in the Chaya Massif indicate that the mafic magmas were emplaced into, and interacted...
Authors
Y. V. Amelin, E. Yu Ritsk, L.A. Neymark
Organics and other molecules in the surfaces of Callisto and Ganymede Organics and other molecules in the surfaces of Callisto and Ganymede
Five absorption features are reported at wavelengths of 3.4, 3.88, 4.05, 4.25, and 4.57 micrometers in the surface materials of the Galilean satellites Callisto and Ganymede from analysis of reflectance spectra returned by the Galileo mission near-infrared mapping spectrometer. Candidate materials include CO2, organic materials (such as tholins containing C???N and C-H), SO2, and...
Authors
T. B. McCord, R. W. Carlson, W. D. Smythe, G. B. Hansen, R. N. Clark, C. A. Hibbitts, F. P. Fanale, J. C. Granahan, M. Segura, D. L. Matson, T. V. Johnson, P. D. Martin
Tertiary igneous rocks and Laramide structure and stratigraphy of the Spanish Peaks Region, South-Central Colorado: Road log and descriptions from Walsenburg to La Veta Tertiary igneous rocks and Laramide structure and stratigraphy of the Spanish Peaks Region, South-Central Colorado: Road log and descriptions from Walsenburg to La Veta
The Spanish Peaks are located in the western part of the Raton basin in south-central Colorado, southwest of Walsenburg. The two peaks, West Spanish Peak (WSP, 13,626 feet) and East Spanish Peak (ESP, 12,683 feet), are located on the upland part of the far western edge of the Great Plains physiographic region. East of Spanish Peaks, a deeply dissected plateau extends into the Great...
Authors
Brian S. Penn, D. A. Lindsay
Alamo megabreccia: Record of a late devonian impact in southern Nevada Alamo megabreccia: Record of a late devonian impact in southern Nevada
The Alamo breccia is probably the most voluminous known outcropping carbonate megabreccia. It occupies ~4000 km2 across 11 mountain ranges in southern Nevada, has an average thickness of ~70 m, and contains a volume of 250+ km3. The breccia is a single bed, of early Frasnian (early Late Devonian) age, that formed in the wake of a giant slide that deposited a lower chaotic debrite...
Authors
John E. Warme, Charles Sandberg
Proterozoic low-Ti iron-oxide deposits in New York and New Jersey: Relation to Fe-oxide (Cu–U–Au–rare earth element) deposits and tectonic implications: Comment and Reply Proterozoic low-Ti iron-oxide deposits in New York and New Jersey: Relation to Fe-oxide (Cu–U–Au–rare earth element) deposits and tectonic implications: Comment and Reply
No abstract available.
Authors
Craig A. Johnson, James McLelland, Michael P. Foose
Controls on 222Rn variations in a fractured crystalline rock aquifer evaluated using aquifer tests and geophysical logging Controls on 222Rn variations in a fractured crystalline rock aquifer evaluated using aquifer tests and geophysical logging
Concentrations of 222Rn in ground water may vary considerably within megascopically homogeneous rocks over relatively short distances. Calculations indicate that different hydraulic apertures of water‐bearing fractures may account for variations in dissolved 222Rn concentration measured in domestic water wells completed in fractured Pikes Peak Granite, assuming that all other factors...
Authors
P. F. Folger, E. Poeter, Richard B. Wanty, D. Frishman, W. Day
Mississippian stratigraphic framework of east-central California and southern Nevada with revision of Upper Devonian and Mississippian stratigraphic units in Inyo County, California Mississippian stratigraphic framework of east-central California and southern Nevada with revision of Upper Devonian and Mississippian stratigraphic units in Inyo County, California
No abstract available.
Authors
Calvin H. Stevens, Darrell S. Klingman, Charles A. Sandberg, Paul Stone, Paul Belasky, Forrest G. Poole, J. Kent Snow
Evidence for Mesoproterozoic basement in the Carolina terrane and speculations on its origin Evidence for Mesoproterozoic basement in the Carolina terrane and speculations on its origin
No abstract available.
Authors
Paul A. Mueller, Marianne Kozuch, Ann L. Heatherington, Joseph L. Wooden, Terry W. Offield, Robert P. Koeppen, Terry L. Klein, Allen P. Nutman
Potential‐field continuation: Past practice vs. modern methods Potential‐field continuation: Past practice vs. modern methods
No abstract available.
Authors
Jeffrey Phillips
Status and metal content of significant metallic mineral deposits in the Pacific Northwest: A contribution to the Interior Columbia Basin Ecosystem Management Project Status and metal content of significant metallic mineral deposits in the Pacific Northwest: A contribution to the Interior Columbia Basin Ecosystem Management Project
No abstract available.
Authors
Arthur A. Bookstrom, Michael L. Zientek, Stephen E. Box, Pamela D. Derkey, James E. Elliott, David Frishman, Roger P. Ashley, Russell C. Evarts, Douglas B. Stoeser, Lorre A. Moyer, Dennis P. Cox, Steve D. Ludington
Devonian conodont biochronology in geologic time calibration Devonian conodont biochronology in geologic time calibration
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...
Authors
Charles Sandberg, W. Ziegler
Determination of 15N/14N and 13C/12C in solid and aqueous cyanides Determination of 15N/14N and 13C/12C in solid and aqueous cyanides
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...
Authors
Craig A. Johnson