Now showing items 51-60 of 192
Nd-Sr isotope composition of lower crustal xenoliths — Evidence for the origin of mid-tertiary felsic volcanics in Mexico
(Springer-Verlag, 1988-05)
Isotopic data were collected on lower crustal xenoliths to constrain the Mexican lower crust as source material for the mid-Tertiary Sierra Madre Occidental, which is one of the largest silicic volcanic piles known. The ...
Strontium isotope composition and petrogenesis of the Kirkpatrick basalt, Queen Alexandra Range, Antarctica
(Springer-Verlag, 1974-09)
The initial 87 Sr/ 86 Sr ratios of twelve basalt flows of Jurassic age on Storm Peak in the Queen Alexandra Range are anomalously high and range from 0.7094–0.7133. The average value is 0.7112±0.0013 (1 σ ). The concentrations ...
Thermodynamics of polymorphic transformations in silica. Thermal properties from 5 to 1070[deg] K and pressure-temperature stability fields for coesite and stishovite
(Elsevier, 1967-12)
Cryogenic heat-capacity measurements on coesite and stishovite provide thermo-dynamic properties from 5 to 350[deg]K. The heat capacities (Cp), entropies (S[deg]), and Gibbs energy functions [-(G[deg] - H[deg]0)/T] are ...
Adakite-like signature of Late Miocene intrusions at the Los Pelambres giant porphyry copper deposit in the Andes of central Chile: metallogenic implications
(Springer-Verlag, 2003-10)
Adakite-like features are recognized in the Late Miocene (~10 Ma) porphyritic intrusions of the Los Pelambres giant porphyry copper deposit, central Chile (32°S). Located within the southern portion of the flat-slab segment ...
Determination of recent sedimentation rates in Lake Michigan using Pb-210 and Cs-137
(Elsevier, 1975-03)
This paper describes the use of 210Pb and 137Cs radioactivity measurements to determine the rates of sedimentation in the Great Lakes. Cores from eight locations in Lake Michigan were chosen for examination to cover as ...
Organic matter and copper mineralization at White Pine, Michigan, U.S.A.
(Elsevier, 1992-09-10)
Indigenous and exogenous organic matter in sediments of the North American Midcontinent Rift were involved in precipitation of Cu-bearing minerals during main- and second-stage mineralization events at White Pine, Michigan. ...
Complete chemical analyses of metamorphic hornblendes: implications for normalizations, calculated H 2 O activities, and thermobarometry
(Springer-Verlag, 1991-10)
Twenty-two hornblendes separated from amphibolites and granulites of the Grenville Orogen of Ontario have been quantitatively analyzed for major and minor elements by electron microprobe, for FeO/Fe 2 O 3 by wet chemistry, ...
Mineralized and unmineralized calderas in Spain; Part II, evolution of the Rodalquilar caldera complex and associated gold-alunite deposits
(Springer-Verlag, 1990-12)
The Rodalquilar caldera complex is located in the western part of the Cabo de Gata volcanic field in southeastern Spain and is the first documented example of epithermal gold-alunite mineralization within a caldera in ...