Now showing items 11-20 of 20
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 ...
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 ...
The significance of metamorphic fluorite in the Adirondacks
(Elsevier, 1978-11)
Thermodynamic calculations for selected silicate-oxide-fluorite assemblages indicate that several commonly occurring fluorite-bearing assemblages are restricted to relatively narrow [function of (italic small f)]O2-[function ...
High-pressure transformations in CaSiO 3
(Springer-Verlag, 1974-09)
Wollastonite transforms to a triclinic high-pressure polymorph, wollastonite II, at pressures > 25 kb. The equilibrium boundary [P(bars)=-4.7× T °C+32.810] has a rather flat negative P-T slope. The rapid reactivity of the ...
Solid oxide electrolyte emf cell determination of the standard free energy of Cr2O3 and applications to chromium-bearing mineral systems
(Elsevier, 1975)
Emf measurements are reported on cells using a thoria-yttria solid oxide electrolyte. The measured potentials from two cells, Cr, Cr2O3|ThO2-Y2O3|Co, CoQ and Cr, Cr2O3 |ThO2-Y2O3| Mn, MnO, were used to calculate the standard ...
Application of new thermodynamic data to grossular phase relations
(Springer-Verlag, 1977-01)
Recent low temperature, adiabatic calorimetric heat capacity measurements for grossular have been combined with DSC measurements to give entropies up to 1000 K. In conjunction with enthalpy of solution values for grossular, ...
Stability of pyrope-quartz in the system MgO-Al 2 O 3 -SiO 2
(Springer-Verlag, 1971-03)
Pyrope and quartz are stable with respect to aluminous enstatite and sillimanite at 1400 °C, 20 kb and at 1100 °C, 16 kb. The phase boundary limiting the coexistence of pyrope and quartz towards lower pressures is probably ...
Dawsonite as a daughter mineral in hydrothermal fluid inclusions
(Springer-Verlag, 1971-12)
Traces of dawsonite (NaAlCO 3 (OH) 2 ) are extremely common as a daughter product in fluid inclusions in gold-quartz veins and altered wallrock of the Oriental mine, Alleghany district, California. A very similar daughter ...
Feldspar and oxide thermometry of granulites in the Adirondack Highlands
(Springer-Verlag, 1977-01)
Thermometry of regionally metamorphosed granulites of the Adirondack Highlands has been undertaken using feldspar and iron-titanium-oxide equilibria. Electron microprobe analyses of 20 coexisting oligoclase (An 18–30 ) and ...
Early island-arc intrusive activity, Cordillera Central, Dominican Republic
(Springer-Verlag, 1977-11)
Reconnaissance studies of early island-arc intrusions in the Cordillera Central of the Dominican Republic demonstrate that these rocks are mainly hornblende tonalite with lesser amounts of hornblende diorite, quartz diorite, ...