A5088961178- Geological and Geochemical Analysis
- High-pressure geophysics and materials
- earthquake and tectonic studies
- Geochemistry and Geologic Mapping
- Geology and Paleoclimatology Research
- Geological and Geophysical Studies
- Geomagnetism and Paleomagnetism Studies
- Geological and Tectonic Studies in Latin America
- Hydrocarbon exploration and reservoir analysis
- Geological Studies and Exploration
- Methane Hydrates and Related Phenomena
- Metallurgical Processes and Thermodynamics
- Mineralogy and Gemology Studies
- Geochemistry and Elemental Analysis
- Astro and Planetary Science
- Paleontology and Stratigraphy of Fossils
- Nuclear materials and radiation effects
- Pleistocene-Era Hominins and Archaeology
- Geological formations and processes
- Geotourism and Geoheritage Conservation
- Nuclear Materials and Properties
- Mechanics and Biomechanics Studies
- Mercury impact and mitigation studies
- Insurance and Financial Risk Management
- Gas Sensing Nanomaterials and Sensors
Massey University
2015-2024
National Museum of Natural History
2014-2016
Smithsonian Institution
2016
Institute of Earth Sciences, Academia Sinica
2006-2013
Academia Sinica
2006-2013
Lamont-Doherty Earth Observatory
2003-2012
Columbia University
2008-2012
University of Hawaii System
2011
University of Hawaiʻi at Mānoa
2008-2009
University of Bristol
2000-2003
A simple heat balance model for an evolving magma chamber is used to make predictions of the time scales differentiation, which are compared with geological and isotopic constraints on rates crystallization differentiation. In a 10 km3 releasing thermal energy at rate 100 MW, basalt rhyolite magmas should reach 50% after ∼2500 <1500 years, respectively. The tendency phenocrysts remain suspended in cooling increases melt viscosity hence degree differentiation may be estimated basis U-series...
Since 1995, the Soufrière Hills volcano on Montserrat, Lesser Antilles island arc, has erupted crystal-rich andesite magma that is geochemically very similar to volcanic products of at least last 174 ± 3 kyr (1σ). Nomarski images plagioclase phenocrysts from six andesites between 151 4 ka (1σ) and AD 1999 reveal multiple crystal resorption events, major shifts in anorthite content suggest these are due temperature variations. A model developed uses partitioning data for Ba Sr quantify degree...
Abstract The volatile cycle at subduction zones is key to the petrogenesis, transport, storage and eruption of arc magmas. Volatiles control flux slab components into mantle wedge, are responsible for melt generation through lowering solidi materials, influence crystallizing phase assemblages in overriding crust. Globally, magma ponding depths may be partially controlled by contents. also affect rate extent degassing during decompression, rheology therefore style. style eruptions turn...
The geochemical evolution of Montserrat provides an important background to understanding the current activity this island arc volcano. Here we present major and trace element, U-, Th- O-isotope data for rocks generated in last 300 kyr that provide constraints on magmatic processes occurring beneath Samples range from low- medium-K calc-alkaline basalts dacites. Three suites can be distinguished basis element compositions: South Soufrière Hills suite; suite, including lava eruption; mafic...
The Permian (∼260 Ma) Emeishan large igneous province of SW China contains three nearly identical gabbro-granitoid complexes that host giant Fe-Ti oxide deposits. deposits are within the lower portions evolved layered gabbroic intrusions and spatially temporally associated with A-type granitic plutons. 264 ± 3 Ma Taihe intrusion hosts a magmatic deposit is coeval peralkaline, pluton, which dated at 261 2 Ma. Within pluton microgranular enclaves, have compositions intermediate between gabbro...
At volcanic arcs, fluids released from the subducting slab lower solidus of mantle wedge and cause melting. Furthermore, melts may infiltrate wedge, have been suggested to generate adakitic (residual garnet) signatures at some arc volcanoes. However, experimental work indicates that garnet stability field will expand in overriding crust presence somewhat less hydrous melts, suggesting such also develop crustal levels. Here we use geothermometry plagioclase hygrometry mafic eruptives...
Andesite petrogenesis is inextricably linked to plate processing at convergent margins. The details of andesite formation, however, remain poorly understood because the signatures initial arc mantle melts are often modified in overlying crust. To distinguish from crustal magmas, we studied two compositionally zoned Holocene monogenetic volcanoes, Texcal Flow and Volcan Chichinautzin, central Mexican Volcanic Belt (MVB). V. Chichinautzin erupt 'ocean island basalt (OIB)-type', high-Nb (17–36...
Abstract Crystals within volcanic rocks record geochemical and textural signatures during magmatic evolution before eruption. Clues to this history can be examined using crystal size distribution (CSD) studies. The analysis of CSDs is a standard petrological tool, but laborious due manual hand-drawing margins. trainable Weka segmentation (TWS) plugin in ImageJ promising alternative. It uses machine learning image classify an image. We recorded back-scattered electron (BSE) images three...
Abstract Complex zoning in crystals including repeated resorption and overgrowth is characteristic for arc magmas occurs response to closed-system changes magmatic P–T–fO2 conditions open system processes such as magma mixing degassing or regassing. However, over which time frame do occur? Do patterns record occurring during the polybaric ascent of that carry glomerocrysts sourced from variably mushy reservoirs, alternatively indicate uptake antecrysts experienced long periods cold storage...
Abstract This chapter provides an overview of the current state research on orogenic andesites. While their importance as proxies to evolution continental crust has long been recognized, andesite genesis remained highly controversial with a broader consensus yet be reached. The controversy is fuelled by question whether andesites are primary melts slab and mantle materials, or instead derivative products basaltic that differentiate in overlying crust. These hypotheses addressed three...