ORCID Profile
0000-0003-4218-4365
Current Organisation
University of Leeds
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 09-2014
Publisher: Proceedings of the National Academy of Sciences
Date: 10-04-2017
Abstract: We document organic matter encapsulated in rock clasts from a oceanic serpentinite mud volcano above the Izu–Bonin–Mariana subduction zone (Pacific Ocean). Although we cannot pinpoint the exact origin of the organic matter, chemical analysis of the constituents resembles molecular signatures that could be produced by microbial life deep within or below the mud volcano. Considering the known temperature limit for life, 122 °C, and the subduction zone forearc geotherm where such mud volcanoes are located, we estimate that life could exist as deep as ∼10,000 m below the seafloor. This is considerably deeper than other active serpentinizing regions such as midocean ridges and could have provided sheltered ecosystems for life to survive the more violent phases of Earth’s history.
Publisher: Wiley
Date: 09-2008
Publisher: Elsevier BV
Date: 03-2017
Publisher: Springer Science and Business Media LLC
Date: 30-01-2009
Publisher: Elsevier BV
Date: 02-2012
Publisher: Springer Science and Business Media LLC
Date: 24-08-2015
DOI: 10.1038/NGEO2515
Publisher: Mineralogical Society of America
Date: 24-06-2011
DOI: 10.2138/AM.2011.3709
Publisher: Elsevier BV
Date: 06-2016
Publisher: Springer Science and Business Media LLC
Date: 29-04-2016
DOI: 10.1038/NGEO2704
Publisher: Springer Science and Business Media LLC
Date: 19-03-2021
DOI: 10.1038/S41467-021-21980-0
Abstract: The magmatic character of early subduction zone and arc development is unlike mature systems. Low-Ti-K tholeiitic basalts and boninites dominate the early Izu-Bonin-Mariana (IBM) system. Basalts recovered from the Amami Sankaku Basin (ASB), underlying and located west of the IBM’s oldest remnant arc, erupted at ~49 Ma. This was 3 million years after subduction inception (51-52 Ma) represented by forearc basalt (FAB), at the tipping point between FAB-boninite and typical arc magmatism. We show ASB basalts are low-Ti-K, aluminous spinel-bearing tholeiites, distinct compared to mid-ocean ridge (MOR), backarc basin, island arc or ocean island basalts. Their upper mantle source was hot, reduced, refractory peridotite, indicating prior melt extraction. ASB basalts transferred rapidly from pressures (~0.7-2 GPa) at the plagioclase-spinel peridotite facies boundary to the surface. Vestiges of a polybaric-polythermal mineralogy are preserved in this basalt, and were not obliterated during persistent recharge-mix-tap-fractionate regimes typical of MOR or mature arcs.
Publisher: Copernicus GmbH
Date: 19-08-2011
Abstract: Abstract. Observations show that the fractional solubility of Fe (FS-Fe, percentage of dissolved to total Fe) in dust aerosol increases considerably from 0.1 % in regions of high dust mass concentration to 80 % in remote regions where concentrations are low. Here, we combined laboratory geochemical measurements with global aerosol model simulations to test the hypothesis that the increase in FS-Fe is due to physical size sorting during transport. We determined the FS-Fe and fractional solubility of Al (FS-Al) in size-fractionated dust generated from two representative soil s les collected from known Saharan dust source regions using a customized dust re-suspension and collection system. The results show that the FS-Fe is size-dependent and ranges from 0.1–0.3 % in the coarse size fractions ( μm) to ~0.2–0.8 % in the fine size fractions ( μm). The FS-Al shows a similar size distribution to that of the FS-Fe. The size-resolved FS-Fe data were then combined with simulated dust mass concentration and size distribution data from a global aerosol model, GLOMAP, to calculate the FS-Fe of dust aerosol over the tropical and subtropical North Atlantic Ocean. We find that the calculated FS-Fe in the dust aerosol increases systematically from ~0.1 % at high dust mass concentrations (e.g., μg m−3) to ~0.2 % at low concentrations ( μg m–3) due to physical size sorting (i.e., particle gravitational settling). These values are one to two orders of magnitude smaller than those observed on cruises across the tropical and sub-tropical North Atlantic Ocean under an important pathway of Saharan dust plumes for similar dust mass concentrations. Even when the FS-Fe of sub-micrometer size fractions (0.18–0.32 μm, 0.32–0.56 μm, and 0.56–1.0 μm) in the model is increased by a factor of 10 over the measured values, the calculated FS-Fe of the dust is still more than an order of magnitude lower than that measured in the field. Therefore, the physical sorting of dust particles alone is unlikely to be an important factor in the observed inverse relationship between the FS-Fe and FS-Al and the atmospheric mineral dust mass concentrations. The results suggest that processes such as chemical reactions and/or mixing with combustion particles are the main mechanisms to cause the increased FS-Fe in long-range transported dust aerosols.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Ivan Savov.