Now showing items 41-50 of 50
Direct measurements of latent heat during crystallization and melting of a ugandite and an olivine basalt
(Springer-Verlag, 1994-06)
Step-scanning calorimetric measurements using a Setaram HT1500 calorimeter were performed between 800 and 1400°C on two natural samples: a ugandite from the East African rift and an olivine basalt from the western Mexican ...
Ion microprobe determination of sulfur isotope variations in iron sulfides from the Post/ Betze sediment-hosted disseminated gold deposit, Nevada, USA
(Elsevier, 1993-04)
Secondary ion mass spectrometric analyses of ore samples from the Post/Betze sedimenthosted disseminated gold deposit were utilized to constrain elemental distribution of Au and As in iron sulfide phases. Most of the Au ...
The europium anomaly of seawater: implications for fluvial versus hydrothermal REE inputs to the oceans
(Elsevier, 1991-10-25)
Seafloor hydrothermal vent fluids are characterized by rare earth element (REE) enrichments and large positive Eu anomalies; however, this input is not recorded by seawater. Hydrothermal sediments from the southeast Pacific ...
Geochemistry of eolian dust in Pacific pelagic sediments: Implications for paleoclimatic interpretations
(Elsevier, 1991-08)
Geochemical data (REEs, Th, Sc) were determined for the operationally defined eolian dust (ODED) fraction (n = 57) from the north and equatorial Pacific Ocean. Paleoclimate studies commonly have assumed that this sediment ...
Phyllosilicates in hydrothermally altered basalts from DSDP Hole 504B, Leg 83 — a TEM and AEM study
(Springer-Verlag, 1992-10)
Phyllosilicates occurring as replacements of olivine, clinopyroxene and interstitial materials and as veins or fracture-fillings in hydrothermally altered basalts from DSDP Hole 504B, Leg 83 have been studied using ...
The Aurora volcanic field, California-Nevada: oxygen fugacity constraints on the development of andesitic magma
(Springer-Verlag; Springer-Verlag Berlin Heidelberg, 1996-10)
The Aurora volcanic field, located along the northeastern margin of Mono Lake in the Western Great Basin, has erupted a diverse suite of high-K and shoshonitic lava types, with 48 to 76 wt% SiO 2 , over the last 3.6 million ...
Magmatic modification of the uppermost mantle beneath the Basin and Range to Colorado Plateau Transition Zone; Evidence from xenoliths, Wikieup, Arizona
(Springer-Verlag; Springer-Verlag Berlin Heidelberg, 1997-06)
Upper mantle xenoliths from Wikieup, AZ, provide abundant evidence for magmatic modification of the uppermost mantle beneath the Transition Zone between the Colorado Plateau and the southern Basin and Range province. Upper ...
Heat capacities of TiO2-bearing silicate liquids: Evidence for anomalous changes in configurational entropy with temperature
(Elsevier, 1993-07)
The heat capacities of several TiO2-bearing silicate glasses and liquids containing Cs2O, Rb2O, Na2O, K2O, CaO, MgO, or BaO have been measured to 1100 K using a differential scanning calorimeter and to 1800 K using a Setaram ...
A transmission electron microscope study of white mica crystallite size distribution in a mudstone to slate transitional sequence, North Wales, UK
(Springer-Verlag, 1990-12)
High-resolution transmission electron microscopy (HRTEM) measurements of the thickness of white mica crystallites were made on three pelite samples that represented a prograde transition from diagenetic mudstone though ...