USAP-DC

{"dp_type": "Dataset", "free_text": "Zircon"}

[{"awards": "1918338 VanTongeren, Jill", "bounds_geometry": null, "date_created": "Tue, 18 Nov 2025 00:00:00 GMT", "description": "The ~ 182 Ma Dufek Intrusion of Antarctica, associated with the Ferrar Dolerite Province, is a large layered mafic intrusion that is estimated to be similar in size to the 8-9 km thick Bushveld Complex. Similar to the Bushveld Complex, the Dufek Intrusion displays a consistent stratigraphic progression of fractional crystallization all the way to the roof of the intrusion and contact with overlying granophyre. In this study, we test competing hypotheses for the \u0027big tank\u0027 vs. \u0027out-of-sequence emplacement\u0027 models for layered intrusions by presenting high precision CA-ID-TIMS zircon U-Pb ages, zircon \u03b5Hf, and zircon trace element compositions of 10 samples throughout the Dufek Intrusion stratigraphy. Our results suggest that the majority of zircon found in layered mafic intrusions is crystallized from the interstitial melt within the cumulate mush pile and cannot record the high temperature crystallization of the original magma. Cooling durations to the 800\u00b0C isotherm recorded by the zircons are consistent with 1D thermal modeling of conductive cooling of a single 6-7 km thick magma chamber emplaced in the shallow crust, rather than two separate intrusions as previously proposed. We suggest that there is little to no missing stratigraphy separating the outcrops in the Forrestal Range and Dufek Massif in the Dufek Intrusion, but the two exposures are instead separated by a fault buried beneath the Sallee Snowfield. Our conclusion is consistent with available geochronology, geochemistry and geophysical observations in the region.", "east": null, "geometry": null, "keywords": "Antarctica; Cryosphere; Ferrar Magmatic Province; Geochronology; Zircon", "locations": "Antarctica; Ferrar Magmatic Province", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "VanTongeren, Jill", "project_titles": "The Dufek Intrusion Ages: Crystallization or Cooling?", "projects": [{"proj_uid": "p0010505", "repository": "USAP-DC", "title": "The Dufek Intrusion Ages: Crystallization or Cooling?"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Zircon geochronology constraints on the geometry and solidification timescales of the Dufek layered mafic intrusion, Antarctica", "uid": "601997", "west": null}, {"awards": "1916982 Teyssier, Christian; 1917009 Thomson, Stuart; 1917176 Siddoway, Christine", "bounds_geometry": ["POLYGON((-119.5168 -80.0167,-119.51679 -80.0167,-119.51678 -80.0167,-119.51677000000001 -80.0167,-119.51676 -80.0167,-119.51675 -80.0167,-119.51674 -80.0167,-119.51673 -80.0167,-119.51672 -80.0167,-119.51671 -80.0167,-119.5167 -80.0167,-119.5167 -80.01671,-119.5167 -80.01672,-119.5167 -80.01673,-119.5167 -80.01674,-119.5167 -80.01675,-119.5167 -80.01676,-119.5167 -80.01677000000001,-119.5167 -80.01678,-119.5167 -80.01679,-119.5167 -80.0168,-119.51671 -80.0168,-119.51672 -80.0168,-119.51673 -80.0168,-119.51674 -80.0168,-119.51675 -80.0168,-119.51676 -80.0168,-119.51677000000001 -80.0168,-119.51678 -80.0168,-119.51679 -80.0168,-119.5168 -80.0168,-119.5168 -80.01679,-119.5168 -80.01678,-119.5168 -80.01677000000001,-119.5168 -80.01676,-119.5168 -80.01675,-119.5168 -80.01674,-119.5168 -80.01673,-119.5168 -80.01672,-119.5168 -80.01671,-119.5168 -80.0167))"], "date_created": "Mon, 09 Jun 2025 00:00:00 GMT", "description": "List of supplementary data produced at the University of Arizona under NSF Proposal 1917009 from publication Marschalek, J.W. et al., 2024a, Byrd Ice Core Debris Constrains the Sediment Provenance Signature of Central West Antarctica: Geophysical Research Letters, v. 51, p. e2023GL106958.", "east": -119.5167, "geometry": ["POINT(-119.51675 -80.01675)"], "keywords": "Antarctica; Byrd Ice Core; Cryosphere; Fission Track Thermochronology; Marie Byrd Land; West Antarctic Ice Sheet", "locations": "Antarctica; West Antarctic Ice Sheet; Marie Byrd Land; Antarctica", "north": -80.0167, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Thomson, Stuart", "project_titles": "Collaborative Research: Ice sheet erosional interaction with hot geotherm in West Antarctica", "projects": [{"proj_uid": "p0010386", "repository": "USAP-DC", "title": "Collaborative Research: Ice sheet erosional interaction with hot geotherm in West Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Byrd Ice Core", "south": -80.0168, "title": "Byrd Ice Core Apatite Fission Track and Zircon U-Pb Data", "uid": "601940", "west": -119.5168}, {"awards": "1939146 Siddoway, Christine", "bounds_geometry": ["POLYGON((-109.1 -68.6,-108.94 -68.6,-108.78 -68.6,-108.61999999999999 -68.6,-108.46 -68.6,-108.3 -68.6,-108.14 -68.6,-107.98 -68.6,-107.82 -68.6,-107.66 -68.6,-107.5 -68.6,-107.5 -68.64,-107.5 -68.67999999999999,-107.5 -68.72,-107.5 -68.75999999999999,-107.5 -68.8,-107.5 -68.84,-107.5 -68.88,-107.5 -68.92,-107.5 -68.96,-107.5 -69,-107.66 -69,-107.82 -69,-107.98 -69,-108.14 -69,-108.3 -69,-108.46 -69,-108.61999999999999 -69,-108.78 -69,-108.94 -69,-109.1 -69,-109.1 -68.96,-109.1 -68.92,-109.1 -68.88,-109.1 -68.84,-109.1 -68.8,-109.1 -68.75999999999999,-109.1 -68.72,-109.1 -68.67999999999999,-109.1 -68.64,-109.1 -68.6))"], "date_created": "Tue, 27 Aug 2024 00:00:00 GMT", "description": "The table contains sample identifiers, location data, and geochronology data (U-Pb zircon dates; apatite fission track determinations) from selected intervals of sediment cores obtained at sites U1532 (A, B, C, G) and U1533 (A, B) recovered during IODP Expedition 379 to the outer Amundsen Sea, Antarctica.", "east": -107.5, "geometry": ["POINT(-108.3 -68.8)"], "keywords": "Amundsen Sea; Antarctica; Cryosphere; Geochronology; Marie Byrd Land; Subglacial Bedrock; Thermochronology", "locations": "Amundsen Sea; Antarctica; Amundsen Sea; Marie Byrd Land", "north": -68.6, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Siddoway, Christine", "project_titles": "Collaborative Research: Testing the Linchpin of WAIS Collapse with Diatoms and IRD in Pleistocene and Late Pliocene Strata of the Resolution Drift, Amundsen Sea, Antarctica", "projects": [{"proj_uid": "p0010451", "repository": "USAP-DC", "title": "Collaborative Research: Testing the Linchpin of WAIS Collapse with Diatoms and IRD in Pleistocene and Late Pliocene Strata of the Resolution Drift, Amundsen Sea, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -69.0, "title": "U-Pb zircon and apatite fission track dates for IRD (ice-rafted cobbles and mineral grains) from IODP379 drill sites", "uid": "601828", "west": -109.1}, {"awards": "1543313 VanTongeren, Jill", "bounds_geometry": ["POLYGON((-55 -82,-54.5 -82,-54 -82,-53.5 -82,-53 -82,-52.5 -82,-52 -82,-51.5 -82,-51 -82,-50.5 -82,-50 -82,-50 -82.2,-50 -82.4,-50 -82.6,-50 -82.8,-50 -83,-50 -83.2,-50 -83.4,-50 -83.6,-50 -83.8,-50 -84,-50.5 -84,-51 -84,-51.5 -84,-52 -84,-52.5 -84,-53 -84,-53.5 -84,-54 -84,-54.5 -84,-55 -84,-55 -83.8,-55 -83.6,-55 -83.4,-55 -83.2,-55 -83,-55 -82.8,-55 -82.6,-55 -82.4,-55 -82.2,-55 -82))"], "date_created": "Mon, 29 Oct 2018 00:00:00 GMT", "description": "The dataset contains preliminary CA-ID-TIMS U-Pb zircon ages for 4 samples from the Dufek Intrusion, as well as major element mineral compositions for samples throughout the stratigraphy.", "east": -50.0, "geometry": ["POINT(-52.5 -83)"], "keywords": "Antarctica; Chemical Composition; Chemistry:rock; Chemistry:Rock; Crystallization; Dufek Complex; Geochemistry; Magma Chamber Procesess; Mass Spectrometry; Rocks; Snow/ice; Snow/Ice; Solid Earth; TIMS; Volcanic Deposits", "locations": "Antarctica", "north": -82.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "VanTongeren, Jill", "project_titles": "Collaborative Research: Testing the Hypothesis that Bigger Magma Chambers Crystallize Faster", "projects": [{"proj_uid": "p0000135", "repository": "USAP-DC", "title": "Collaborative Research: Testing the Hypothesis that Bigger Magma Chambers Crystallize Faster"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.0, "title": "U-Pb ages and mineral compositions from Dufek Intrusion", "uid": "601132", "west": -55.0}, {"awards": "1142156 Marschall, Horst", "bounds_geometry": ["POLYGON((-6.44 -71.93,-5.378 -71.93,-4.316 -71.93,-3.254 -71.93,-2.192 -71.93,-1.13 -71.93,-0.068 -71.93,0.994 -71.93,2.056 -71.93,3.118 -71.93,4.18 -71.93,4.18 -71.998,4.18 -72.066,4.18 -72.134,4.18 -72.202,4.18 -72.27,4.18 -72.338,4.18 -72.406,4.18 -72.474,4.18 -72.542,4.18 -72.61,3.118 -72.61,2.056 -72.61,0.994 -72.61,-0.068 -72.61,-1.13 -72.61,-2.192 -72.61,-3.254 -72.61,-4.316 -72.61,-5.378 -72.61,-6.44 -72.61,-6.44 -72.542,-6.44 -72.474,-6.44 -72.406,-6.44 -72.338,-6.44 -72.27,-6.44 -72.202,-6.44 -72.134,-6.44 -72.066,-6.44 -71.998,-6.44 -71.93))"], "date_created": "Thu, 01 Jan 2015 00:00:00 GMT", "description": "Geochemical studies of single mineral grains in rocks can be probed to reconstruct the history of our planet. The mineral zircon (ZrSiO4) is of unique importance in that respect because of its reliability as a geologic clock due to its strong persistence against weathering, transport and changes in temperature and pressure. Uranium-Lead (U-Pb) dating of zircon grains is, perhaps, the most frequently employed method of extracting time information on geologic processes that shaped the continental crust, and has been used to constrain the evolution of continents and mountain belts through time. In addition, the isotopic composition of the element Hafnium (Hf) in zircon is used to date when the continental crust was generated by extraction of magma from the underlying mantle. Melting of rocks in the mantle and deep in the continental crust are key processes in the evolution of the continents, and they are recorded in the Hf isotopic signatures of zircon. Although the analytical procedures for U-Pb dating and Hf isotope analyses of zircon are robust now, our understanding of zircon growth and its exchange of elements and isotopes with its surrounding rock or magma are still underdeveloped. The focus of the proposed study, therefore, is to unravel the evolution of zircon Hf isotopes in rocks that were formed deep in the Earth\u0027s crust, and more specifically, to apply these isotopic methods to rocks collected in Dronning Maud Land (DML), East Antarctica.\n\nDronning Maud Land (DML) occupied a central location during the formation of supercontinents - large landmasses made up of all the continents that exist today - more than 500 million years ago. It is currently thought that supercontinents were formed and dismembered five or six times throughout Earth\u0027s history. The area of DML is key for understanding the formation history of the last two supercontinents. The boundaries of continents that were merged to form those supercontinents are most likely hidden in DML. In this study, the isotopic composition of zircon grains recovered from DML rocks will be employed to identify these boundaries across an extensive section through the area. The rock samples were collected by the investigator during a two-month expedition to Antarctica in the austral summer of 2007-2008. The results of dating and isotope analyses of zircon of the different DML crustal domains will deliver significant insight into the regional geology of East Antarctica and its previous northern extension into Africa. This has significance for the reconstruction of the supercontinents and defining the continental boundaries in DML.\n", "east": 4.18, "geometry": ["POINT(-1.13 -72.27)"], "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Dronning Maud Land; Geochemistry; Geochronology; Solid Earth", "locations": "Antarctica; Dronning Maud Land", "north": -71.93, "nsf_funding_programs": null, "persons": "Marschall, Horst", "project_titles": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica", "projects": [{"proj_uid": "p0000448", "repository": "USAP-DC", "title": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.61, "title": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antarctica", "uid": "600135", "west": -6.44}, {"awards": "1043619 Hemming, Sidney", "bounds_geometry": ["POLYGON((-180 -63.997,-179.7982 -63.997,-179.5964 -63.997,-179.3946 -63.997,-179.1928 -63.997,-178.991 -63.997,-178.7892 -63.997,-178.5874 -63.997,-178.3856 -63.997,-178.1838 -63.997,-177.982 -63.997,-177.982 -66.3324,-177.982 -68.6678,-177.982 -71.0032,-177.982 -73.3386,-177.982 -75.674,-177.982 -78.0094,-177.982 -80.3448,-177.982 -82.6802,-177.982 -85.0156,-177.982 -87.351,-178.1838 -87.351,-178.3856 -87.351,-178.5874 -87.351,-178.7892 -87.351,-178.991 -87.351,-179.1928 -87.351,-179.3946 -87.351,-179.5964 -87.351,-179.7982 -87.351,180 -87.351,172.54273 -87.351,165.08546 -87.351,157.62819 -87.351,150.17092 -87.351,142.71365 -87.351,135.25638 -87.351,127.79911 -87.351,120.34184 -87.351,112.88457 -87.351,105.4273 -87.351,105.4273 -85.0156,105.4273 -82.6802,105.4273 -80.3448,105.4273 -78.0094,105.4273 -75.674,105.4273 -73.3386,105.4273 -71.0032,105.4273 -68.6678,105.4273 -66.3324,105.4273 -63.997,112.88457 -63.997,120.34184 -63.997,127.79911 -63.997,135.25638 -63.997,142.71365 -63.997,150.17092 -63.997,157.62819 -63.997,165.08546 -63.997,172.54273 -63.997,-180 -63.997))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: The PIs proposed a provenance study of glacial deposits in the Ross Embayment that will provide a broad scale geochronologic survey of detrital minerals in till to help characterize bedrock beneath the East Antarctic ice sheet and constrain Antarctica?s glacial history. This project capitalizes on previous investments in field sampling. Analytical tools applied to single mineral grains extracted from existing collections of glacial till will generate ?fingerprints? of East Antarctic outlet glaciers and West Antarctic till to refine paleo-ice flow models for the Ross Embayment during the last glacial maximum, older records from ANDRILL cores, and to assess IRD sources in the Southern Ocean. New provenance tracers will include a suite of geochronological methods that together provide greater insights into the orogenic and erosional history the region. This project will include U/Pb of detrital zircons, (U-Th)/He on a subset of the U/Pb dated zircons, as well as Ar-Ar of detrital hornblende, mica and feldspars.\nBroader Impacts: This research will train one M.S. student at IUPUI, a Ph.D. student at Columbia, and several undergraduates at both institutions. Graduate students involved in the project will be involved in mentoring undergraduate researchers. Incorporation of research discoveries will be brought into the classroom by providing concrete examples and exercises at the appropriate level. Licht and Columbia graduate student E. Pierce are developing outreach projects with local secondary school teachers to investigate the provenance of glacial materials in their local areas. The research will have broad applicability to many fields.", "east": 105.4273, "geometry": ["POINT(143.72265 -75.674)"], "keywords": "Antarctica; East Antarctica; Geochemistry; Ross Sea; Sample/collection Description; Sample/Collection Description; Solid Earth; Southern Ocean; West Antarctica", "locations": "Antarctica; Ross Sea; West Antarctica; East Antarctica; Southern Ocean", "north": -63.997, "nsf_funding_programs": null, "persons": "Hemming, Sidney R.", "project_titles": "Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "projects": [{"proj_uid": "p0000333", "repository": "USAP-DC", "title": "Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.351, "title": "East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "uid": "600124", "west": -177.982}, {"awards": "0944475 Kaplan, Michael", "bounds_geometry": ["POLYGON((-180 -84.1,-176.97 -84.1,-173.94 -84.1,-170.91 -84.1,-167.88 -84.1,-164.85 -84.1,-161.82 -84.1,-158.79 -84.1,-155.76 -84.1,-152.73 -84.1,-149.7 -84.1,-149.7 -84.43,-149.7 -84.76,-149.7 -85.09,-149.7 -85.42,-149.7 -85.75,-149.7 -86.08,-149.7 -86.41,-149.7 -86.74,-149.7 -87.07,-149.7 -87.4,-152.73 -87.4,-155.76 -87.4,-158.79 -87.4,-161.82 -87.4,-164.85 -87.4,-167.88 -87.4,-170.91 -87.4,-173.94 -87.4,-176.97 -87.4,180 -87.4,178.12 -87.4,176.24 -87.4,174.36 -87.4,172.48 -87.4,170.6 -87.4,168.72 -87.4,166.84 -87.4,164.96 -87.4,163.08 -87.4,161.2 -87.4,161.2 -87.07,161.2 -86.74,161.2 -86.41,161.2 -86.08,161.2 -85.75,161.2 -85.42,161.2 -85.09,161.2 -84.76,161.2 -84.43,161.2 -84.1,163.08 -84.1,164.96 -84.1,166.84 -84.1,168.72 -84.1,170.6 -84.1,172.48 -84.1,174.36 -84.1,176.24 -84.1,178.12 -84.1,-180 -84.1))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: The proposed work will investigate changes in the compositional variation of glacial tills over time across two concentric sequences of Pleistocene moraines located adjacent to the heads of East Antarctic outlet glaciers in the Transantarctic Mountains (TAM). The chronologic framework for this work will be generated from cosmogenic exposure ages of boulders on prominent morainal ridges. The PIs hypothesize that variations in till composition may indicate a change in ice flow direction or a change in the composition of the original source area, while ages of the moraines provide a long-term terrestrial perspective on ice sheet dynamics. Both results are vital for modeling experiments that aim to reconstruct the East Antarctic Ice Sheet and assess its role in the global climate system and its potential impact on global sea level rise. The variation of till compositions through time also allows for a more accurate interpretation of sediment cores from the Ross Sea and the Southern Ocean. Additionally, till exposures at the head of some East Antarctic outlet glaciers have been shown to contain subglacial material derived from East Antarctic bedrock, providing a window through the ice to view East Antarctica\u0027s inaccessible bedrock. Till samples will be collected from two well-preserved sequences of moraine crests at Mt. Howe (head of Scott Glacier) and Mt. Achernar (between Beardmore and Nimrod Glaciers). Each size fraction in glacial till provides potentially valuable information, and the PIs will measure the petrography of the clast and sand fractions, quantitative X-ray diffraction on the crushed \u003c2mm fraction, elemental abundance of the silt/clay fraction, and U/Pb of detrital zircons in the sand fraction. Data collection will rely on established methods previously used in this region and the PIs will also explore new methods to assess their efficacy. On the same moraines crests sampled for provenance studies, the PIs will sample for cosmogenic surface exposure analyses to provide a chronologic framework at the sites for provenance changes through time.\nBroader Impact: The proposed research involves graduate and undergraduate training in a diverse array of laboratory methods. Students and PIs will be make presentations to community and campus groups, as well as conduct interviews with local news outlets. The proposed work also establishes a new, potentially long-term, collaboration between scientists at IUPUI and LDEO and brings a new PI (Kaplan) into the field of Antarctic Earth Sciences.", "east": -149.7, "geometry": ["POINT(-174.25 -85.75)"], "keywords": "Antarctica; Cosmogenic Dating; Sample/collection Description; Sample/Collection Description; Solid Earth; Transantarctic Mountains", "locations": "Transantarctic Mountains; Antarctica", "north": -84.1, "nsf_funding_programs": null, "persons": "Kaplan, Michael", "project_titles": "Collaborative Research: Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines", "projects": [{"proj_uid": "p0000459", "repository": "USAP-DC", "title": "Collaborative Research: Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.4, "title": "Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines", "uid": "600115", "west": 161.2}, {"awards": "0944489 Williams, Trevor", "bounds_geometry": ["POLYGON((-55 -58,-33.2 -58,-11.4 -58,10.4 -58,32.2 -58,54 -58,75.8 -58,97.6 -58,119.4 -58,141.2 -58,163 -58,163 -60,163 -62,163 -64,163 -66,163 -68,163 -70,163 -72,163 -74,163 -76,163 -78,141.2 -78,119.4 -78,97.6 -78,75.8 -78,54 -78,32.2 -78,10.4 -78,-11.4 -78,-33.2 -78,-55 -78,-55 -76,-55 -74,-55 -72,-55 -70,-55 -68,-55 -66,-55 -64,-55 -62,-55 -60,-55 -58))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to study the stability and dynamics of the East Antarctic ice sheet during the Pliocene in the area of the Wilkes and Aurora subglacial basins. Models indicate the ice sheet is most sensitive to warming in these low-lying areas. This study is important as there is very little direct evidence about which parts of the East Antarctic ice sheet became unstable under warm conditions. In a pilot study the PIs have shown that the isotopic geochemical signature of downcore ice-rafted debris (IRD) can be linked to continental source areas indicating which parts of the ice sheet reached the coast and calved IRD-bearing icebergs. Their initial results suggest rapid iceberg discharge from the Wilkes Land and Adelie Land coastal areas at times in the late Miocene and early Pliocene. In this study the PIs will analyze IRD from IODP sediment cores collected on the continental rise off East Antarctica. By analyzing 40Ar/39Ar ages of hornblende IRD grains, U-Pb ages of zircons, and Sm-Nd isotopes of the fine fraction of several IRD-rich layers for each core, they will be able to fingerprint continental source areas that indicate ice extent and dynamics on East Antarctica. The PIs will also carry out detailed studies across a few of these layers to characterize the anatomy of the ice-rafting event and better understand the mechanism of ice destabilization. Broader impacts: The data collected will be important for scientists in a broad variety of fields. The project will involve one undergraduate student and one summer intern at LDEO, and a graduate student at Imperial College London. The project will expose to cutting edge methodologies as well as an international research team. Data from the project will be deposited in the online databases (SedDB) and all results and methods will be made available to the scientific community through publications in peer-reviewed journals and attendance at international conferences\n", "east": 163.0, "geometry": ["POINT(54 -68)"], "keywords": "Geochronology; George V Land; IODP U1356; IODP U1361; Marine Sediments; ODP1165; Prydz Bay; Solid Earth; Southern Ocean; Wilkes Land", "locations": "Prydz Bay; George V Land; Southern Ocean; Wilkes Land", "north": -58.0, "nsf_funding_programs": null, "persons": "Williams, Trevor; Hemming, Sidney R.", "project_titles": "History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris", "projects": [{"proj_uid": "p0000353", "repository": "USAP-DC", "title": "History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris", "uid": "600116", "west": -55.0}, {"awards": "1039365 Rimmer, Susan", "bounds_geometry": null, "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "This project studies the Permian-Triassic extinction event as recorded in sedimentary rocks from the Transantarctic Mountains of Antarctica. Two hundred and fifty million years ago most life on Earth was wiped out in a geologic instant. The cause is a subject of great debate. Researchers have identified a unique stratigraphic section near Shackleton glacier laid down during the extinction event. Organic matter from these deposits will be analyzed by density gradient centrifugation (DGC), which will offer detailed information on the carbon isotope composition. The age of these layers will be precisely dated by U/Pb-zircon-dating of intercalated volcanics. Combined, these results will offer detailed constraints on the timing and duration of carbon isotope excursions during the extinction, and offer insight into the coupling of marine and terrestrial carbon cycles. The broader impacts of this project include graduate and undergraduate student research, K12 outreach and teacher involvement, and societal relevance of the results, since the P/T extinction may have been caused by phenomena such as methane release, which could accompany global warming.\n", "east": null, "geometry": null, "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Solid Earth; Transantarctic Mountains", "locations": "Antarctica; Transantarctic Mountains", "north": null, "nsf_funding_programs": null, "persons": "Rimmer, Susan", "project_titles": "Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter", "projects": [{"proj_uid": "p0000507", "repository": "USAP-DC", "title": "Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "The Permian-Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuations in Terrestrial Organic Matter", "uid": "600121", "west": null}, {"awards": "0838722 Reiners, Peter", "bounds_geometry": ["POLYGON((61.9 -67.28,63.218 -67.28,64.536 -67.28,65.854 -67.28,67.172 -67.28,68.49 -67.28,69.808 -67.28,71.126 -67.28,72.444 -67.28,73.762 -67.28,75.08 -67.28,75.08 -67.922,75.08 -68.564,75.08 -69.206,75.08 -69.848,75.08 -70.49,75.08 -71.132,75.08 -71.774,75.08 -72.416,75.08 -73.058,75.08 -73.7,73.762 -73.7,72.444 -73.7,71.126 -73.7,69.808 -73.7,68.49 -73.7,67.172 -73.7,65.854 -73.7,64.536 -73.7,63.218 -73.7,61.9 -73.7,61.9 -73.058,61.9 -72.416,61.9 -71.774,61.9 -71.132,61.9 -70.49,61.9 -69.848,61.9 -69.206,61.9 -68.564,61.9 -67.922,61.9 -67.28))"], "date_created": "Sun, 01 Jan 2012 00:00:00 GMT", "description": "Much of the inventory of East Antarctic bedrock geochronology, as well as a record of its erosional history, is preserved in Cenozoic sediments around its margin. This project is to use these sediments to understand their sub-ice provenance and the erosional history of the shield by measuring ages of multiple geo- and thermochronometers on single detrital crystals and on multiple crystals in detrital clasts (U/Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar). The combination of multi-chronometer ages in single grains and clasts provides a powerful fingerprint of bedrock sources, allowing us to trace provenance in Eocene fluvial sandstones through Quaternary diamicts around the margin. Multiple thermochronometric (cooling) ages in the same grains and clasts also allows us to interpret the timing and rates of erosion from these bedrock sources. Delineating a distribution of bedrock age units, their sediment transport connections, and their erosional histories over the Cenozoic, will in turn allow us to test tectonic models bearing on: (1) the origin of the Gamburtsev Subglacial Mountains, (2) fluvial and topographic evolution, and (3) the history of glacial growth and erosion.\n", "east": 75.08, "geometry": ["POINT(68.49 -70.49)"], "keywords": "Antarctica; Fission Track Thermochronology; Gamburtsev Mountains; Geochronology; Marine Sediments; NBP0101; ODP1166; ODP739; Prydz Bay; Solid Earth; Southern Ocean", "locations": "Southern Ocean; Gamburtsev Mountains; Prydz Bay; Antarctica", "north": -67.28, "nsf_funding_programs": null, "persons": "Gehrels, George; Reiners, Peter; Thomson, Stuart", "project_titles": "Collaborative Research: Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology", "projects": [{"proj_uid": "p0000506", "repository": "USAP-DC", "title": "Collaborative Research: Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -73.7, "title": "Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology", "uid": "600093", "west": 61.9}, {"awards": "0838729 Hemming, Sidney", "bounds_geometry": ["POLYGON((-67.2 -58,-43.98 -58,-20.76 -58,2.46 -58,25.68 -58,48.9 -58,72.12 -58,95.34 -58,118.56 -58,141.78 -58,165 -58,165 -59.2,165 -60.4,165 -61.6,165 -62.8,165 -64,165 -65.2,165 -66.4,165 -67.6,165 -68.8,165 -70,141.78 -70,118.56 -70,95.34 -70,72.12 -70,48.9 -70,25.68 -70,2.46 -70,-20.76 -70,-43.98 -70,-67.2 -70,-67.2 -68.8,-67.2 -67.6,-67.2 -66.4,-67.2 -65.2,-67.2 -64,-67.2 -62.8,-67.2 -61.6,-67.2 -60.4,-67.2 -59.2,-67.2 -58))"], "date_created": "Sat, 01 Jan 2011 00:00:00 GMT", "description": "Much of the inventory of East Antarctic bedrock geochronology, as well as a record of its erosional history, is preserved in Cenozoic sediments around its margin. This project is to use these sediments to understand their sub-ice provenance and the erosional history of the shield by measuring ages of multiple geo- and thermochronometers on single detrital crystals and on multiple crystals in detrital clasts (U/Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar). The combination of multi-chronometer ages in single grains and clasts provides a powerful fingerprint of bedrock sources, allowing us to trace provenance in Eocene fluvial sandstones through Quaternary diamicts around the margin. Multiple thermochronometric (cooling) ages in the same grains and clasts also allows us to interpret the timing and rates of erosion from these bedrock sources. Delineating a distribution of bedrock age units, their sediment transport connections, and their erosional histories over the Cenozoic, will in turn allow us to test tectonic models bearing on: (1) the origin of the Gamburtsev Subglacial Mountains, (2) fluvial and topographic evolution, and (3) the history of glacial growth and erosion.", "east": 165.0, "geometry": ["POINT(48.9 -64)"], "keywords": "Antarctica; Fission Track Thermochronology; Gamburtsev Mountains; Geochronology; Marine Sediments; Solid Earth; Southern Ocean", "locations": "Gamburtsev Mountains; Southern Ocean; Antarctica", "north": -58.0, "nsf_funding_programs": null, "persons": "Hemming, Sidney R.", "project_titles": "Collaborative Research: Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology", "projects": [{"proj_uid": "p0000506", "repository": "USAP-DC", "title": "Collaborative Research: Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -70.0, "title": "Erosion History and Sediment Provenance of East Antarctica from Multi-method Detrital Geo- and Thermochronology", "uid": "600094", "west": -67.2}, {"awards": "0816934 Thomson, Stuart", "bounds_geometry": ["POLYGON((65 -66,72.9 -66,80.8 -66,88.7 -66,96.6 -66,104.5 -66,112.4 -66,120.3 -66,128.2 -66,136.1 -66,144 -66,144 -66.3,144 -66.6,144 -66.9,144 -67.2,144 -67.5,144 -67.8,144 -68.1,144 -68.4,144 -68.7,144 -69,136.1 -69,128.2 -69,120.3 -69,112.4 -69,104.5 -69,96.6 -69,88.7 -69,80.8 -69,72.9 -69,65 -69,65 -68.7,65 -68.4,65 -68.1,65 -67.8,65 -67.5,65 -67.2,65 -66.9,65 -66.6,65 -66.3,65 -66))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This Small Grant for Exploratory Research investigates the origin and evolution of the Gamburtsev subglacial mountains (GSM). These mountains are considered the nucleation point for Antarctica\u0027s largest ice sheets; however, being of indeterminate age, they may postdate ice sheet formation. As well, their formation could reflect tectonic events during the breakup of Gondwana. The project studies GSM-derived detrital zircon and apatite crystals from Prydz Bay obtained by the Ocean Drilling Program. Analytical work includes triple-dating thermochronometry by U/Pb, fission track, and (U/Th)/He methods. The combined technique offers insight into both high and low temperature processes, and is potentially sensitive to both the orogenic events and the subsequent cooling and exhumation due to erosion. In terms of broader impacts, this project supports research for a postdoctoral fellow.", "east": 144.0, "geometry": ["POINT(104.5 -67.5)"], "keywords": "Antarctica; Fission Track Thermochronology; Gamburtsev Mountains; Geochronology; Solid Earth", "locations": "Antarctica; Gamburtsev Mountains", "north": -66.0, "nsf_funding_programs": null, "persons": "Thomson, Stuart", "project_titles": "Collaborative Research: SGER: Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "projects": [{"proj_uid": "p0000210", "repository": "USAP-DC", "title": "Collaborative Research: SGER: Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -69.0, "title": "Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "uid": "600089", "west": 65.0}, {"awards": "0817163 Reiners, Peter", "bounds_geometry": ["POLYGON((72 -66,72.3 -66,72.6 -66,72.9 -66,73.2 -66,73.5 -66,73.8 -66,74.1 -66,74.4 -66,74.7 -66,75 -66,75 -66.3,75 -66.6,75 -66.9,75 -67.2,75 -67.5,75 -67.8,75 -68.1,75 -68.4,75 -68.7,75 -69,74.7 -69,74.4 -69,74.1 -69,73.8 -69,73.5 -69,73.2 -69,72.9 -69,72.6 -69,72.3 -69,72 -69,72 -68.7,72 -68.4,72 -68.1,72 -67.8,72 -67.5,72 -67.2,72 -66.9,72 -66.6,72 -66.3,72 -66))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This Small Grant for Exploratory Research investigates the origin and evolution of the Gamburtsev subglacial mountains (GSM). These mountains are considered the nucleation point for Antarctica\u0027s largest ice sheets; however, being of indeterminate age, they may postdate ice sheet formation. As well, their formation could reflect tectonic events during the breakup of Gondwana. The project studies GSM-derived detrital zircon and apatite crystals from Prydz Bay obtained by the Ocean Drilling Program. Analytical work includes triple-dating thermochronometry by U/Pb, fission track, and (U/Th)/He methods. The combined technique offers insight into both high and low temperature processes, and is potentially sensitive to both the orogenic events and the subsequent cooling and exhumation due to erosion. In terms of broader impacts, this project supports research for a postdoctoral fellow.", "east": 75.0, "geometry": ["POINT(73.5 -67.5)"], "keywords": "Antarctica; Gamburtsev Mountains; Geochronology; Marine Sediments; NBP0101; ODP1166; Prydz Bay; Solid Earth; Southern Ocean", "locations": "Southern Ocean; Prydz Bay; Gamburtsev Mountains; Antarctica", "north": -66.0, "nsf_funding_programs": null, "persons": "Gehrels, George; Reiners, Peter", "project_titles": "Collaborative Research: SGER: Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "projects": [{"proj_uid": "p0000210", "repository": "USAP-DC", "title": "Collaborative Research: SGER: Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -69.0, "title": "Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "uid": "600090", "west": 72.0}]

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