A5089993759- Paleontology and Stratigraphy of Fossils
- Geology and Paleoclimatology Research
- Geological and Geochemical Analysis
- Geological and Geophysical Studies
- Geological Studies and Exploration
- Hydrocarbon exploration and reservoir analysis
- Geochemistry and Geologic Mapping
- Water Resources and Management
- Island Studies and Pacific Affairs
- Soil and Environmental Studies
- Pleistocene-Era Hominins and Archaeology
- High-pressure geophysics and materials
Planetary Science Institute
2018-2021
University of California, Berkeley
2018-2021
On multimillion-year time scales, Earth has experienced warm ice-free and cold glacial climates, but it is unknown whether transitions between these background climate states were the result of changes in carbon dioxide sources or sinks. Low-latitude arc-continent collisions are hypothesized to drive cooling by exhuming eroding mafic ultramafic rocks warm, wet tropics, thereby increasing Earth's potential sequester through chemical weathering. To better constrain global weatherability time,...
Steep topography, a tropical climate, and mafic lithologies contribute to efficient chemical weathering carbon sequestration in the Southeast Asian islands. Ongoing arc-continent collision between Sunda-Banda arc system Australia has increased area of subaerially exposed land region since mid-Miocene. Concurrently, Earth's climate cooled Miocene Climatic Optimum, leading growth Antarctic ice sheet onset Northern Hemisphere glaciation. We seek evaluate hypothesis that emergence islands played...
Research Article| April 26, 2018 The arc of the Snowball: U-Pb dates constrain Islay anomaly and initiation Sturtian glaciation Scott MacLennan; MacLennan 1Department Geosciences, Princeton University, Princeton, New Jersey 08544, USA Search for other works by this author on: GSW Google Scholar Yuem Park; Park 2Earth Planetary Sciences Department, University California, Berkeley, California 94720, Nicholas Swanson-Hysell; Swanson-Hysell Adam Maloof; Maloof Blair Schoene; Schoene Mulubrhan...
Abstract The Tonian-Cryogenian Tambien Group of northern Ethiopia is a mixed carbonate-siliciclastic sequence that culminates in glacial deposits associated with the first Cryogenian glaciations—the Sturtian “Snowball Earth.” deposition occurred atop arc volcanics and volcaniclastics Tsaliet Group. New U-Pb isotope dilution–thermal ionization mass spectrometry (ID-TIMS) dates demonstrate transition between Groups at ca. 820 Ma western exposures 795 eastern exposures, which consistent west to...
Abstract The Tonian supercontinent Rodinia is hypothesized to have included almost all Proterozoic continental blocks. Competing models variably place South China at the core or periphery of separated from it entirely. paleogeographic also vary in whether they incorporate large and rapid oscillatory true polar wander associated with ca. 810–795 Ma Bitter Springs Stage. Here, we present paleomagnetic data paired U‐Pb chemical abrasion isotope dilution thermal ionization mass spectrometry...
One of the hypothesized effects large igneous provinces (LIPs) is planetary cooling on million-year timescales associated with enhanced silicate weathering freshly-emplaced basalt. This study combines reconstructions original surface extent and emplacement ages LIPs, a paleogeographic model, parameterization LIP erosion to estimate area in all latitudinal bands through Phanerozoic. analysis reveals no significant correlation between total area, nor tropics, continental ice sheets. The...