A5003547802- Geological and Geochemical Analysis
- earthquake and tectonic studies
- High-pressure geophysics and materials
- Methane Hydrates and Related Phenomena
- Geological and Geophysical Studies
- Geochemistry and Geologic Mapping
- Geology and Paleoclimatology Research
- Astro and Planetary Science
- Geological Studies and Exploration
- Hydrocarbon exploration and reservoir analysis
- Geochemistry and Elemental Analysis
- Astronomical Observations and Instrumentation
- Paleontology and Stratigraphy of Fossils
- Offshore Engineering and Technologies
- Planetary Science and Exploration
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Gravity Measurements
- Geological and Tectonic Studies in Latin America
- Spacecraft and Cryogenic Technologies
- Reservoir Engineering and Simulation Methods
- Astronomy and Astrophysical Research
- Mineralogy and Gemology Studies
- Scientific Research and Discoveries
- Geological formations and processes
- Geological Modeling and Analysis
Australian National University
2015-2024
International Ocean Discovery Program
2015
Environmental Earth Sciences
2006
Woods Hole Oceanographic Institution
2002
Regional Environmental Center for Central and Eastern Europe
2002
Australian Research Council
1999
Queensland University of Technology
1997
University of New England
1992-1995
College Station Medical Center
1992
Newcastle University
1992
This geochemical classification of granitic rocks is based upon three variables. These are FeO/(FeO + MgO) = Fe-number [or FeOtot/(FeOtot Fe*], the modified alkali–lime index (MALI) (Na2O K2O – CaO) and aluminum saturation (ASI) [Al/(Ca 1·67P Na K)]. The (or Fe*) distinguishes ferroan granitoids, which manifest strong iron enrichment, from magnesian do not. granitoids can further be classified into alkalic, alkali–calcic, calc-alkalic, calcic on basis MALI subdivided ASI peraluminous,...
The association of large Au–Cu–Ag ore deposits with convergent margins is commonly attributed to the higher content chalcophile elements in parental magmas generated at subduction zones compared mid-ocean ridges. We present new geochemical data for arc-like, relatively oxidized mantle-derived basalt rhyolite from Pual Ridge and vicinity, Eastern Manus Basin, which show that initial abundances base precious metals basalts are similar those ridge (MORB). contents Au, Cu, Ag built up evolving...
Journal Article The Petrology of Plutonic Blocks and Inclusions from the Lesser Antilles Island Arc Get access RICHARD J. ARCULUS, ARCULUS 1Research School Earth Sciences, Australian National UniversityP.O. Box 4, Canberra, A.C.T. 2600, Australia Search for other works by this author on: Oxford Academic Google Scholar KEVIN A. WILLS * Present address: CRAE, 39598, Darwin, N.T. 5798, Australia. Petrology, Volume 21, Issue November 1980, Pages 743–799,...
Most recent workers attribute the main features of island arc basalt geochemistry to variable contributions at least two source components. The major appears be peridotitic wedge upper mantle overlying subducted slab, but nature second component and processes by which sources become mixed during genesis magmas are in dispute. A metasomatic addition resulting from devolatilization slab is simplest explanation marked enrichment alkali alkaline earth elements with respect rare earths basalts,...
An understanding of the origin depletion in high field strength elements (HFSE), Nb, Zr and Ti, relative to rare earth (REE) arc lavas is critical models both for magmagenesis ares relationship between are magmatism growth continental crust. The presence HFSE bulk crust constitutes some strongest evidence that is/was generated subduction zones, especially if retained REE subducting slab (Saunders et al., 1980; McDonough, 1991). Recently, however, it has been proposed develops during main...
The terms calcalkaline and calcalkalic are currently defined used in multiple non-equivalent ways. Generally, the variation of total Fe as FeO/MgO within evolving subalkaline rock suites is regarded most distinctive character compared with tholeiitic suites, reflecting relative timing phase saturation Fe–Ti oxides, plagioclase, ferromagnesian silicates. Other classification schemes widely used, including a minority adherents to original formalized definition ‘calcalkalic’ by Peacock (1931,...
Documenting the early tectonic and magmatic evolution of Izu–Bonin–Mariana (IBM) arc system in Western Pacific is critical for understanding process cause subduction initiation along current convergent margin between Philippine Sea plates. Forearc igneous sections provide firm evidence seafloor spreading at time (52 Ma) production "forearc basalt". Ocean floor drilling (International Discovery Program Expedition 351) recovered basement-forming, low-Ti tholeiitic basalt crust formed shortly...
The processes of arc initiation at the margin an oceanic plateau are remarkably well preserved along southern coastline eastern Costa Rica and western Panama. We present new results a combined tectonostratigraphic petrologic study with which protoarc (75–73 Ma) (89–85 is documented. Dykes igneous rocks within occurrences widely distributed. These types field observations, geochemical data, paleontologic ages for Late Cretaceous to Eocene fore‐arc Golfito Complex Azuero Marginal (southern...
The Lau Backarc Basin (S.W. Pacific) hosts numerous spreading centers and rifts, including the Rochambeau Rifts (RR), Northwest Spreading Center (NWLSC), Central (CLSC). Samples from NWLSC, RR CLSC show no evidence for a subduction‐derived component in their mantle source regions or S loss during eruption. contents of glasses NWLSC many are lower than MORB at given FeO TOT , indicating melts were initially sulfide‐undersaturated. During differentiation, decrease Cu Ag ∼7 wt% MgO concomitant...
Subduction zone magmas are more oxidised on eruption than those at mid-ocean ridges. This is attributed either to oxidising components, derived from subducted lithosphere (slab) and added the mantle wedge, or oxidation processes occurring during magma ascent via differentiation. Here we provide direct evidence for contributions of slab agents melts trapped in sub-arc mantle. Measurements sulfur (S) valence state peridotites identify sulfate, both as crystalline anhydrite (CaSO4) dissolved...
The Izu-Bonin-Mariana (IBM) island arc formed following initiation of subduction the Pacific plate beneath Philippine Sea at about 52 Ma. Site U1438 IODP Expedition 351 was drilled to sample oceanic basement on which IBM constructed, better understand magmatism prior and during event. igneous Unit 1 (150 m) 1460 m primarily volcaniclastic sediments sedimentary rock. Basement basalts are microcrystalline fine-grained flows form several distinct subunits (1a-1f), all relatively mafic (MgO =...