{"dp_type": "Dataset", "free_text": "Miocene"}
[{"awards": "0838842 Passchier, Sandra", "bounds_geometry": ["POINT(167.0833 -77.8889)"], "date_created": "Mon, 14 Jun 2021 00:00:00 GMT", "description": "This dataset contains measurements of particle-size distributions on four intervals of diamicitites from ANDRILL Site AND-2A. Carbonate, and organic matter were removed through addition of 10mL aliquots of 30% H2O2 and 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.544 (Quartz) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles.", "east": 167.0833, "geometry": ["POINT(167.0833 -77.8889)"], "keywords": "Antarctica; McMurdo Sound; Miocene; Particle Size; Pleistocene; Pliocene", "locations": "Antarctica; McMurdo Sound", "north": -77.8889, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Passchier, Sandra; Hansen, Melissa A.", "project_titles": "Determining Middle Miocene through Pliocene Changes in Paleo Ice-flow and Basal Ice Conditions in East Antarctica through Sedimentological Analyses of Core Samples", "projects": [{"proj_uid": "p0000147", "repository": "USAP-DC", "title": "Determining Middle Miocene through Pliocene Changes in Paleo Ice-flow and Basal Ice Conditions in East Antarctica through Sedimentological Analyses of Core Samples"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -77.8889, "title": "Particle-size measurements for diamictites AND-2A sediment core, McMurdo Sound", "uid": "601452", "west": 167.0833}, {"awards": "0342484 Harwood, David", "bounds_geometry": ["POINT(167 -78)"], "date_created": "Mon, 14 Jun 2021 00:00:00 GMT", "description": "This dataset contains measurements of particle-size distributions on sediment from ANDRILL Site AND-2A. Carbonate, and organic matter were removed through addition of 10mL aliquots of 30% H2O2 and 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.544 (Quartz) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles.", "east": 167.0, "geometry": ["POINT(167 -78)"], "keywords": "Andrill; Antarctica; Continental Shelf; Diamict; McMurdo Sound; Miocene; Paleoclimate; Particle Size", "locations": "McMurdo Sound; Antarctica", "north": -78.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Passchier, Sandra; Candice, Falk", "project_titles": "Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change", "projects": [{"proj_uid": "p0010297", "repository": "USAP-DC", "title": "Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -78.0, "title": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "uid": "601451", "west": 167.0}, {"awards": "1443576 Panter, Kurt", "bounds_geometry": ["POLYGON((-154.1 -86.9,-154.03 -86.9,-153.96 -86.9,-153.89 -86.9,-153.82 -86.9,-153.75 -86.9,-153.68 -86.9,-153.61 -86.9,-153.54 -86.9,-153.47 -86.9,-153.4 -86.9,-153.4 -86.92,-153.4 -86.94,-153.4 -86.96,-153.4 -86.98,-153.4 -87,-153.4 -87.02,-153.4 -87.04,-153.4 -87.06,-153.4 -87.08,-153.4 -87.1,-153.47 -87.1,-153.54 -87.1,-153.61 -87.1,-153.68 -87.1,-153.75 -87.1,-153.82 -87.1,-153.89 -87.1,-153.96 -87.1,-154.03 -87.1,-154.1 -87.1,-154.1 -87.08,-154.1 -87.06,-154.1 -87.04,-154.1 -87.02,-154.1 -87,-154.1 -86.98,-154.1 -86.96,-154.1 -86.94,-154.1 -86.92,-154.1 -86.9))"], "date_created": "Fri, 05 Jun 2020 00:00:00 GMT", "description": "Mt. Early and Sheridan Bluff (87\u00b0S) are the above ice expression of Earth\u2019s southernmost volcanic field that lies approximately 300 km from the South Pole. The dataset supplies the locations and lithological descriptions of the units that the samples were collected from for dating and petrological study. Fundamental compositional information on the mafic volcanic rock samples include whole rock MgO concentrations (wt.%), the forsterite content of olivine and the oxygen isotopic composition of olivine. The dataset also provides a record of what samples have been analyzed for major and trace elements by XRF and ICP-MS, mineral chemistry by EMPA, radiogenic isotopes of Sr, Nd and Pb on whole rock powders by ICP-MS and dating by 40Ar/39Ar method.", "east": -153.4, "geometry": ["POINT(-153.75 -87)"], "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochronology; Glacial Volcanism; Magma Differentiation; Major Elements; Mantle Melting; Solid Earth; Trace Elements; Transantarctic Mountains", "locations": "Transantarctic Mountains; Antarctica", "north": -86.9, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Panter, Kurt", "project_titles": "Investigating Early Miocene Sub-ice Volcanoes in Antarctica for Improved Modeling and understanding of a Large Magmatic Province", "projects": [{"proj_uid": "p0010105", "repository": "USAP-DC", "title": "Investigating Early Miocene Sub-ice Volcanoes in Antarctica for Improved Modeling and understanding of a Large Magmatic Province"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.1, "title": "Volcanological and Petrological measurements on Mt. Early and Sheridan Bluff volcanoes, upper Scott Glacier, Antarctica ", "uid": "601331", "west": -154.1}, {"awards": "1043700 Harry, Dennis", "bounds_geometry": ["POLYGON((-180 -70,-176.5 -70,-173 -70,-169.5 -70,-166 -70,-162.5 -70,-159 -70,-155.5 -70,-152 -70,-148.5 -70,-145 -70,-145 -71,-145 -72,-145 -73,-145 -74,-145 -75,-145 -76,-145 -77,-145 -78,-145 -79,-145 -80,-148.5 -80,-152 -80,-155.5 -80,-159 -80,-162.5 -80,-166 -80,-169.5 -80,-173 -80,-176.5 -80,180 -80,177.5 -80,175 -80,172.5 -80,170 -80,167.5 -80,165 -80,162.5 -80,160 -80,157.5 -80,155 -80,155 -79,155 -78,155 -77,155 -76,155 -75,155 -74,155 -73,155 -72,155 -71,155 -70,157.5 -70,160 -70,162.5 -70,165 -70,167.5 -70,170 -70,172.5 -70,175 -70,177.5 -70,-180 -70))"], "date_created": "Sun, 24 Nov 2019 00:00:00 GMT", "description": "Interpretation of major post-middle Miocene seismic reflections in the Ross Sea are provided in i) ASCII files containing Line, Trace, X, Y, and TWTT (two-way travel) picks and ii) netcdf grid files of structure and isochore maps in two-way travel time and depth or thickness. Data are in the Antarctic Polar Stereographic projection.", "east": -145.0, "geometry": ["POINT(-175 -75)"], "keywords": "Andrill; Antarctica; Marine Geoscience; Ross Sea; Seismic Interpretation; Seismic Reflection; Stratigraphy; Subsidence; Victoria Land Basin", "locations": "Victoria Land Basin; Ross Sea; Antarctica", "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Harry, Dennis L.", "project_titles": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "projects": [{"proj_uid": "p0000467", "repository": "USAP-DC", "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -80.0, "title": "Ross Sea post-middle Miocene seismic interpretation", "uid": "601227", "west": 155.0}, {"awards": "1341585 Sorlien, Christopher", "bounds_geometry": ["POLYGON((-180 -73.22,-179.17 -73.22,-178.34 -73.22,-177.51 -73.22,-176.68 -73.22,-175.85 -73.22,-175.02 -73.22,-174.19 -73.22,-173.36 -73.22,-172.53 -73.22,-171.7 -73.22,-171.7 -73.765,-171.7 -74.31,-171.7 -74.855,-171.7 -75.4,-171.7 -75.945,-171.7 -76.49,-171.7 -77.035,-171.7 -77.58,-171.7 -78.125,-171.7 -78.67,-172.53 -78.67,-173.36 -78.67,-174.19 -78.67,-175.02 -78.67,-175.85 -78.67,-176.68 -78.67,-177.51 -78.67,-178.34 -78.67,-179.17 -78.67,180 -78.67,178.56 -78.67,177.12 -78.67,175.68 -78.67,174.24 -78.67,172.8 -78.67,171.36 -78.67,169.92 -78.67,168.48 -78.67,167.04 -78.67,165.6 -78.67,165.6 -78.125,165.6 -77.58,165.6 -77.035,165.6 -76.49,165.6 -75.945,165.6 -75.4,165.6 -74.855,165.6 -74.31,165.6 -73.765,165.6 -73.22,167.04 -73.22,168.48 -73.22,169.92 -73.22,171.36 -73.22,172.8 -73.22,174.24 -73.22,175.68 -73.22,177.12 -73.22,178.56 -73.22,-180 -73.22))"], "date_created": "Fri, 25 May 2018 00:00:00 GMT", "description": "This data set includes digital 1 km grids of sub-bottom \n\tstratigraphy of most of Ross Sea. In addition to acoustic basement (same as top\n\tsyn-rift sedimentary rocks in Central Trough and probably other basins), these\n\tgrids include Oligocene and Miocene horizons that are unconformities in most\n\tareas. A sea floor grid is also included. Except for the sea floor grid, the\n\tgrids are trimmed to be relatively close to control of interpreted seismic\n\tstratigraphy. The grids are provided in two way travel time and in depth. Math\n\tcan be performed on the corresponding time and depth grids to recreate the 3D\n\tinterval velocity model that was used. The velocity of the water used was 1450\n\tm/s. More detailed descriptions of the work are found in the Final NSF report\n\tfor PLR1341585 by C. Sorlien, B. Luyendyk, and D. Wilson. The grids are\n\tcontinuous so are merged with the sea floor where there is outcrop, or with\n\tbasement if there is onlap, or with a young unconformity where there is\n\tsub-bottom truncation. The filenames include the name of the horizon\n\t(unconformity) and whether they are in time or depth. \\\"etc.\\\" means there are\n\ttwo or more horizons that have been merged. Most of the horizons are named and\n\tdefined in the ANTOSTRAT (1995) atlas. The starting points for many of these\n\thorizons are ANTOSTRAT [1995] near DSDP sites 273, 272, and 270. In other areas\n\twe deviate from the interpretation of ANTOSTRAT [1995]. late Oligocene through\n\tmiddle Miocene horizons, interpreted very close to the ANTOSTRAT [1995] at DSDP\n\tSite 273 in Central Trough, are much deeper in our interpretation within Terror\n\tRift. These horizon grids usually include the sea floor where there is outcrop\n\tor acoustic basement (top syn-rift in some basins) where there is onlap. \n\n\n\tANTOSTRAT (1995), Seismic Stratigraphic Atlas of the Ross Sea, in Geology and\n\tSeismic Stratigraphy of the Antarctic Margin, edited by A. K. Cooper, Barker,\n\tP. F., Brancolini, G., 22 plates, American Geophysical Union, Washington,\n\tD.C.", "east": -171.7, "geometry": ["POINT(176.95 -75.945)"], "keywords": "Antarctica; Continental Margin; Geology/Geophysics - Other; Marine Geoscience; Miocene; Oligocene; Seismic Reflection", "locations": "Antarctica", "north": -73.22, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Sorlien, Christopher; Wilson, Douglas S.", "project_titles": "Subsidence, Tilting, Sedimentation, and Oligocene-middle Miocene paleo-depth of Ross Sea", "projects": [{"proj_uid": "p0000271", "repository": "USAP-DC", "title": "Subsidence, Tilting, Sedimentation, and Oligocene-middle Miocene paleo-depth of Ross Sea"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.67, "title": "Ross Sea unconformities digital grids in depth and two-way time", "uid": "601098", "west": 165.6}, {"awards": "1043700 Harry, Dennis", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation. Broader impacts: The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs.\n", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Andrill; Antarctica; Continental Rift; Geology/Geophysics - Other; Lithosphere; Model; Ross Sea; Solid Earth; Tectonic; Transantarctic Mountains", "locations": "Antarctica; Ross Sea; Transantarctic Mountains", "north": -60.0, "nsf_funding_programs": null, "persons": "Harry, Dennis L.", "project_titles": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "projects": [{"proj_uid": "p0000467", "repository": "USAP-DC", "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -90.0, "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "uid": "600128", "west": -180.0}, {"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": "Southern Ocean; Wilkes Land; Prydz Bay; George V 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": "0739452 Mukhopadhyay, Sujoy", "bounds_geometry": ["POLYGON((161 -76,161.2 -76,161.4 -76,161.6 -76,161.8 -76,162 -76,162.2 -76,162.4 -76,162.6 -76,162.8 -76,163 -76,163 -76.2,163 -76.4,163 -76.6,163 -76.8,163 -77,163 -77.2,163 -77.4,163 -77.6,163 -77.8,163 -78,162.8 -78,162.6 -78,162.4 -78,162.2 -78,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,161 -77.8,161 -77.6,161 -77.4,161 -77.2,161 -77,161 -76.8,161 -76.6,161 -76.4,161 -76.2,161 -76))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This project seeks to answer a simple question: how old are potholes and related geomorphic features found in the uplands of the McMurdo Dry Valleys, Antarctica? Some research suggests that they are over ten million years old and date the growth of the East Antarctic Ice Sheet, the world\u0027s largest. However, some evidence suggests that these are young, erosional features that continuing to evolve to this day. This project uses cosmogenic nuclide dating to determine the age of the pothole floors. The results are important for determining the ice sheet?s history and interpreting the O-isotope record from the marine sediment cores, key records of global climate. Broader impacts include K12 outreach and incorporation of outcomes into university courses.", "east": 163.0, "geometry": ["POINT(162 -77)"], "keywords": "Antarctica; Cosmogenic Dating; Dry Valleys; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Paleoclimate; Sample/collection Description; Sample/Collection Description; Solid Earth", "locations": "Dry Valleys; Antarctica", "north": -76.0, "nsf_funding_programs": null, "persons": "Mukhopadhyay, Sujoy", "project_titles": "Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica", "projects": [{"proj_uid": "p0000461", "repository": "USAP-DC", "title": "Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica", "uid": "600074", "west": 161.0}]
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Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Bounds Geometry | Geometry | Selected | Visible |
---|---|---|---|---|---|---|---|---|---|
Particle-size measurements for diamictites AND-2A sediment core, McMurdo Sound
|
0838842 |
2021-06-14 | Passchier, Sandra; Hansen, Melissa A. |
Determining Middle Miocene through Pliocene Changes in Paleo Ice-flow and Basal Ice Conditions in East Antarctica through Sedimentological Analyses of Core Samples |
This dataset contains measurements of particle-size distributions on four intervals of diamicitites from ANDRILL Site AND-2A. Carbonate, and organic matter were removed through addition of 10mL aliquots of 30% H2O2 and 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.544 (Quartz) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles. | ["POINT(167.0833 -77.8889)"] | ["POINT(167.0833 -77.8889)"] | false | false |
Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound
|
0342484 |
2021-06-14 | Passchier, Sandra; Candice, Falk |
Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change |
This dataset contains measurements of particle-size distributions on sediment from ANDRILL Site AND-2A. Carbonate, and organic matter were removed through addition of 10mL aliquots of 30% H2O2 and 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.544 (Quartz) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles. | ["POINT(167 -78)"] | ["POINT(167 -78)"] | false | false |
Volcanological and Petrological measurements on Mt. Early and Sheridan Bluff volcanoes, upper Scott Glacier, Antarctica
|
1443576 |
2020-06-05 | Panter, Kurt |
Investigating Early Miocene Sub-ice Volcanoes in Antarctica for Improved Modeling and understanding of a Large Magmatic Province |
Mt. Early and Sheridan Bluff (87°S) are the above ice expression of Earth’s southernmost volcanic field that lies approximately 300 km from the South Pole. The dataset supplies the locations and lithological descriptions of the units that the samples were collected from for dating and petrological study. Fundamental compositional information on the mafic volcanic rock samples include whole rock MgO concentrations (wt.%), the forsterite content of olivine and the oxygen isotopic composition of olivine. The dataset also provides a record of what samples have been analyzed for major and trace elements by XRF and ICP-MS, mineral chemistry by EMPA, radiogenic isotopes of Sr, Nd and Pb on whole rock powders by ICP-MS and dating by 40Ar/39Ar method. | ["POLYGON((-154.1 -86.9,-154.03 -86.9,-153.96 -86.9,-153.89 -86.9,-153.82 -86.9,-153.75 -86.9,-153.68 -86.9,-153.61 -86.9,-153.54 -86.9,-153.47 -86.9,-153.4 -86.9,-153.4 -86.92,-153.4 -86.94,-153.4 -86.96,-153.4 -86.98,-153.4 -87,-153.4 -87.02,-153.4 -87.04,-153.4 -87.06,-153.4 -87.08,-153.4 -87.1,-153.47 -87.1,-153.54 -87.1,-153.61 -87.1,-153.68 -87.1,-153.75 -87.1,-153.82 -87.1,-153.89 -87.1,-153.96 -87.1,-154.03 -87.1,-154.1 -87.1,-154.1 -87.08,-154.1 -87.06,-154.1 -87.04,-154.1 -87.02,-154.1 -87,-154.1 -86.98,-154.1 -86.96,-154.1 -86.94,-154.1 -86.92,-154.1 -86.9))"] | ["POINT(-153.75 -87)"] | false | false |
Ross Sea post-middle Miocene seismic interpretation
|
1043700 |
2019-11-24 | Harry, Dennis L. |
Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History |
Interpretation of major post-middle Miocene seismic reflections in the Ross Sea are provided in i) ASCII files containing Line, Trace, X, Y, and TWTT (two-way travel) picks and ii) netcdf grid files of structure and isochore maps in two-way travel time and depth or thickness. Data are in the Antarctic Polar Stereographic projection. | ["POLYGON((-180 -70,-176.5 -70,-173 -70,-169.5 -70,-166 -70,-162.5 -70,-159 -70,-155.5 -70,-152 -70,-148.5 -70,-145 -70,-145 -71,-145 -72,-145 -73,-145 -74,-145 -75,-145 -76,-145 -77,-145 -78,-145 -79,-145 -80,-148.5 -80,-152 -80,-155.5 -80,-159 -80,-162.5 -80,-166 -80,-169.5 -80,-173 -80,-176.5 -80,180 -80,177.5 -80,175 -80,172.5 -80,170 -80,167.5 -80,165 -80,162.5 -80,160 -80,157.5 -80,155 -80,155 -79,155 -78,155 -77,155 -76,155 -75,155 -74,155 -73,155 -72,155 -71,155 -70,157.5 -70,160 -70,162.5 -70,165 -70,167.5 -70,170 -70,172.5 -70,175 -70,177.5 -70,-180 -70))"] | ["POINT(-175 -75)"] | false | false |
Ross Sea unconformities digital grids in depth and two-way time
|
1341585 |
2018-05-25 | Sorlien, Christopher; Wilson, Douglas S. |
Subsidence, Tilting, Sedimentation, and Oligocene-middle Miocene paleo-depth of Ross Sea |
This data set includes digital 1 km grids of sub-bottom stratigraphy of most of Ross Sea. In addition to acoustic basement (same as top syn-rift sedimentary rocks in Central Trough and probably other basins), these grids include Oligocene and Miocene horizons that are unconformities in most areas. A sea floor grid is also included. Except for the sea floor grid, the grids are trimmed to be relatively close to control of interpreted seismic stratigraphy. The grids are provided in two way travel time and in depth. Math can be performed on the corresponding time and depth grids to recreate the 3D interval velocity model that was used. The velocity of the water used was 1450 m/s. More detailed descriptions of the work are found in the Final NSF report for PLR1341585 by C. Sorlien, B. Luyendyk, and D. Wilson. The grids are continuous so are merged with the sea floor where there is outcrop, or with basement if there is onlap, or with a young unconformity where there is sub-bottom truncation. The filenames include the name of the horizon (unconformity) and whether they are in time or depth. \"etc.\" means there are two or more horizons that have been merged. Most of the horizons are named and defined in the ANTOSTRAT (1995) atlas. The starting points for many of these horizons are ANTOSTRAT [1995] near DSDP sites 273, 272, and 270. In other areas we deviate from the interpretation of ANTOSTRAT [1995]. late Oligocene through middle Miocene horizons, interpreted very close to the ANTOSTRAT [1995] at DSDP Site 273 in Central Trough, are much deeper in our interpretation within Terror Rift. These horizon grids usually include the sea floor where there is outcrop or acoustic basement (top syn-rift in some basins) where there is onlap. ANTOSTRAT (1995), Seismic Stratigraphic Atlas of the Ross Sea, in Geology and Seismic Stratigraphy of the Antarctic Margin, edited by A. K. Cooper, Barker, P. F., Brancolini, G., 22 plates, American Geophysical Union, Washington, D.C. | ["POLYGON((-180 -73.22,-179.17 -73.22,-178.34 -73.22,-177.51 -73.22,-176.68 -73.22,-175.85 -73.22,-175.02 -73.22,-174.19 -73.22,-173.36 -73.22,-172.53 -73.22,-171.7 -73.22,-171.7 -73.765,-171.7 -74.31,-171.7 -74.855,-171.7 -75.4,-171.7 -75.945,-171.7 -76.49,-171.7 -77.035,-171.7 -77.58,-171.7 -78.125,-171.7 -78.67,-172.53 -78.67,-173.36 -78.67,-174.19 -78.67,-175.02 -78.67,-175.85 -78.67,-176.68 -78.67,-177.51 -78.67,-178.34 -78.67,-179.17 -78.67,180 -78.67,178.56 -78.67,177.12 -78.67,175.68 -78.67,174.24 -78.67,172.8 -78.67,171.36 -78.67,169.92 -78.67,168.48 -78.67,167.04 -78.67,165.6 -78.67,165.6 -78.125,165.6 -77.58,165.6 -77.035,165.6 -76.49,165.6 -75.945,165.6 -75.4,165.6 -74.855,165.6 -74.31,165.6 -73.765,165.6 -73.22,167.04 -73.22,168.48 -73.22,169.92 -73.22,171.36 -73.22,172.8 -73.22,174.24 -73.22,175.68 -73.22,177.12 -73.22,178.56 -73.22,-180 -73.22))"] | ["POINT(176.95 -75.945)"] | false | false |
Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History
|
1043700 |
2014-01-01 | Harry, Dennis L. |
Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History |
Intellectual Merit: This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation. Broader impacts: The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs. | ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"] | ["POINT(0 -89.999)"] | false | false |
History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris
|
0944489 |
2014-01-01 | Williams, Trevor; Hemming, Sidney R. |
History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris |
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 | ["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))"] | ["POINT(54 -68)"] | false | false |
Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica
|
0739452 |
2009-01-01 | Mukhopadhyay, Sujoy |
Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica |
This project seeks to answer a simple question: how old are potholes and related geomorphic features found in the uplands of the McMurdo Dry Valleys, Antarctica? Some research suggests that they are over ten million years old and date the growth of the East Antarctic Ice Sheet, the world's largest. However, some evidence suggests that these are young, erosional features that continuing to evolve to this day. This project uses cosmogenic nuclide dating to determine the age of the pothole floors. The results are important for determining the ice sheet?s history and interpreting the O-isotope record from the marine sediment cores, key records of global climate. Broader impacts include K12 outreach and incorporation of outcomes into university courses. | ["POLYGON((161 -76,161.2 -76,161.4 -76,161.6 -76,161.8 -76,162 -76,162.2 -76,162.4 -76,162.6 -76,162.8 -76,163 -76,163 -76.2,163 -76.4,163 -76.6,163 -76.8,163 -77,163 -77.2,163 -77.4,163 -77.6,163 -77.8,163 -78,162.8 -78,162.6 -78,162.4 -78,162.2 -78,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,161 -77.8,161 -77.6,161 -77.4,161 -77.2,161 -77,161 -76.8,161 -76.6,161 -76.4,161 -76.2,161 -76))"] | ["POINT(162 -77)"] | false | false |