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8 results on '"Tauxe L"'

5. Paleointensity estimates from historic and modern Hawaiian lava flows using glassy basalt as a primary source material

Author

Cromwell, G, Tauxe, L, Staudigel, H, and Ron, H

Subjects
Paleointensity, Volcanic glass, Hawaii, Geomagnetic field, Geochemistry & Geophysics, Geochemistry, Geophysics, Astronomical and Space Sciences
Abstract

Published paleointensity estimates derived from lavas extruded in known fields are highly variable and rarely recover the expected field strength within an accuracy of better than 10%. Inconsistent results on modern volcanic rocks lend even greater uncertainty to intensity experiments performed on lava flows emplaced during periods of unknown geomagnetic field strength. The majority of published paleointensity data are collected from the slowly cooled, massive centers of lava flows, where the magnetic grains are more likely to be multi-domain and produce non-ideal experimental results. Glassy volcanic material (found on subaerial lava flow tops and in sub-aqueous and subglacial environments), however is rapidly cooled, and therefore most likely of all volcanic materials to behave as single-domain particles demanded by Néel theory. We present a new paleointensity study of historic and modern Hawaiian lavas and test the viability of subaerially emplaced glassy basaltic material as an accurate recorder of magnetic field intensity. Six of eight lava flows sampled on the Big Island of Hawaii (1843, 1859, 1935, 1950, 1960, 1990 C.E.) produce well behaved Arai plots and recover an average intensity to within 2.7. μT of the expected field strength or better than 8% accuracy. We apply very strict selection criteria, including a minimum of three specimens per site, to prevent extraneous field estimates from affecting the final results. Individual volcanic glass results from the 1960 C.E. lava flow have a much lower variance than published data from the same volcanic unit. Glassy materials should therefore be collected wherever possible as they allow recovery of geomagnetic field strength with unprecedented accuracy.

Published
2015

6. New constraints on the variation of the geomagnetic field during the late Neolithic period: Archaeointensity results from Sichuan, southwestern China

Author

Cai, S, Chen, W, Tauxe, L, Deng, C, Qin, H, Pan, Y, Yi, L, and Zhu, R

Subjects
archaeointensity, Geochemistry, Geophysics, late Neolithic period, southwestern China, Geology
Abstract

©2015. American Geophysical Union. All Rights Reserved. We have carried out an archaeomagnetic study on a late Neolithic locality (Liujiazhai) in Sichuan, southwestern China. We pull together various dating techniques, including radiocarbon analysis, optically stimulated luminescence dating, stratigraphic information as well as archaeological and archaeomagnetic estimations, to constrain the age of the studied samples. Rock magnetic results indicate thermally stable fine-grained magnetite or titanomagnetite as the dominant magnetic carriers. More than half of the specimens (141/246) in the paleointensity experiment pass the selection criteria and are considered to record robust intensity values. The virtual axial dipole moments range from approximately (2.8 to 7.8) × 10 < sup > 22 < /sup > Am < sup > 2 < /sup > with an average of 5.9 × 10 < sup > 22 < /sup > Am < sup > 2 < /sup > , indicating that the geomagnetic intensity around 3000 before the Common Era (B.C.E.) is overall lower than the present field intensity (9.8 × 10 < sup > 22 < /sup > Am < sup > 2 < /sup > ) of this area. The new results from Liujiazhai are generally consistent with the published data of similar age but deviate from the only available model of CALS10k.1b at certain time periods, making them important for future improvements of the model. Those data are significant for constraining the variation of geomagnetic field intensity between ∼3100 and 2600 B.C.E. and improving the regional model of eastern Asia.

Published
2015
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7. Investigating the Accuracy, Precision, and Cooling Rate Dependence of Laboratory‐Acquired Thermal Remanences During Paleointensity Experiments.

Author

Santos, C. N. and Tauxe, L.

Subjects
BASALT, THERMOREMANENT magnetization, CURVATURE measurements, HYSTERESIS, GEOCHEMISTRY
Abstract

We examine the behavior of natural basaltic and trachytic samples during paleointensity experiments on both the original and laboratory‐acquired thermal remanences and characterize the samples using proxies for domain state including curvature (k) and the bulk domain stability parameters of Paterson (2011, https://doi.org/10.1029/2011JB008369) and Paterson et al. (2017, https://doi.org/10.1073/pnas.1714047114), respectively. A curvature value of 0.164 (suggested by Paterson, 2011, https://doi.org/10.1029/2011JB008369) as a critical threshold that separates single‐domain‐like remanences from multidomain‐like remanances on the original paleointensity data was used to separate samples into "straight" (single‐domain‐like) and "curved" (multidomain‐like) groups. Specimens from the two sample sets were given a "fresh" thermal remanent magnetization in a 70 μT field and subjected to an infield‐zerofield, zerofield‐infield (IZZI)‐type (Yu et al., 2004, https://doi.org/10.1029/2003GC000630) paleointensity experiment. The straight sample set recovered the laboratory field with high precision while the curved set had much more scattered results (70.5 ± 1.5 and 71.9 ± 5.2 μT, respectively). The average intensity of both sets for straight and curved was quite close to the laboratory field of 70 μT, however, suggesting that if experiments contain a sufficient number of specimens, there does not seem to be a large bias in the field estimate. We found that the dependence of the laboratory thermal remanent magnetization on cooling rate was significant in most samples and did not depend on domain states inferred from proxies based on hysteresis measurements and should be estimated for all samples whose cooling rates differ from that used in the laboratory. Plain Language Summary: The strength of the magnetic field is one of the fundamental properties of the Earth, and its behavior over time has implications in disparate fields from geodynamics to archeology. Of all the forms of remanent magnetization found in nature, thermal remanent magnetization has the strongest theoretical basis and natural and archeological materials have been used for decades to estimate ancient field strengths. In this paper, we examine the behavior of a variety of rocks typically used for such experiments to investigate their capacity to retain a record of the field. Our results confirm that while ideally behaved specimens (those that give linear plots relating natural and laboratory partial thermal remanences) can give highly accurate and precise paleofield estimates, those that have curved plots have much more scattered (although unbiased) estimates. Key Points: Paleointensity experiments confirm that ideally behaved specimens can give highly accurate and precise paleofield estimatesExperiments that have curved NRM/TRM plots have much more scattered (although unbiased) estimatesExperiments from a range of domain states exhibited significant dependence of thermal remanence on cooling rate [ABSTRACT FROM AUTHOR]

Published
2019
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8. Large-scale mass wasting on the Miocene continental margin of western India

Author

Sarah Dailey, Yuting Li, Rakesh Saxena, Tara N. Jonell, Anil Kumar, Manish Tiwari, Giancarlo Scardia, Rajeev Saraswat, Paul B. O'Sullivan, Annette Hahn, Gérôme Calvès, Lisa Tauxe, Sergio Andò, Claire M. Routledge, Boo-Keun Khim, Ravi Mishra, Dhananjai Pandey, Elizabeth M. Griffith, Girish Kumar Sharma, H. Liddy, Nikki E. Neubeck, T. Radhakrishna, James A Bendle, Zhaojie Yu, Jerzy S. Blusztajn, Masao Iwai, Kenta Suzuki, Arun Deo Singh, Denise K. Kulhanek, Mitchell W Lyle, G. P. Gurumurthy, A. Ganesh Kumar, Sophia Aharonovich, Stephan Steinke, Z. Xu, Giovanni Coletti, H. Lu, Peng Zhou, Peter D. Clift, Louisiana State Univ, Texas A&M Univ, Woods Hole Oceanog Inst, UCL, Univ Toulouse 3 Paul Sabatier, GeoSep Serv, Univ Queensland, Natl Ctr Polar & Ocean Res, Univ Milano Bicocca, Purdue Univ, Univ Birmingham, Macquarie Univ, Ohio State Univ, Birbal Sahni Inst Palaeosci, Univ Bremen, Kochi Univ, Pusan Natl Univ, Wadia Inst Himalayan Geol, Natl Inst Ocean Technol, Columbia Univ, Nanjing Univ, Oregon State Univ, Natl Ctr Earth Sci Studies, Natl Inst Oceanog, Oil & Nat Gas Commiss, Universidade Estadual Paulista (Unesp), Kumaun Univ, Banaras Hindu Univ, Xiamen Univ, Hokkaido Univ, Scripps Inst Oceanog, Chinese Acad Sci, Louisiana State University (LSU), Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), School of Materials Science and Technology, Institute of Technology, Banaras Hindu University, Banaras Hindu University [Varanasi] (BHU), Dipartimento di Scienze Geologiche e Geotecnologie, Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, BITS Pilani, K. K. Birla Campus, Goa (India), Nanjing University (NJU), DEPLAN/IGCE/UNESP, Instituto de Geociencias e Ciencias Exatas, Universidade de São Paulo (USP)-Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP), Division of Medical Oncology, University of Colorado [Boulder], Indian Institute of Science, Key Laboratory of Marine Geology and Environment [China, Institute of Oceanology [China], Dailey, S, Clift, P, Kulhanek, D, Blusztajn, J, Routledge, C, Calvès, G, O’Sullivan, P, Jonell, T, Pandey, D, Ando', S, Coletti, G, Zhou, P, Yuting, L, Neubeck, N, Bendle, J, Aharonovich, S, Griffith, E, Gurumurthy, G, Hahn, A, Iwai, M, Khim, B, Kumar, A, Liddy, H, Huayu, L, Lyle, M, Mishra, R, Radhakrishna, T, Saraswat, R, Saxena, R, Scardia, G, Sharma, G, Singh, A, Steinke, S, Suzuki, K, Tauxe, L, Tiwari, M, Zhaokai, X, and Zhaojie, Y

Subjects
010504 meteorology & atmospheric sciences, Geochemistry, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Mass-transport, Arabian Sea, IODP, heavy-minerals, Nataraja Slide, Expedition 355, Mass wasting, 010502 geochemistry & geophysics, 01 natural sciences, Continental margin, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Passive margin, 14. Life underwater, Siltstone, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, geography, geography.geographical_feature_category, Continental shelf, Geology, Calcarenite, Geophysics, [SDU]Sciences of the Universe [physics], [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Clastic rock, Siliciclastic
Abstract

Made available in DSpace on 2020-12-10T17:04:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Charles T. McCord Jr Chair in Petroleum Geology at Louisiana State University Ministry of Earth Sciences, Government of India National Centre for Polar and Ocean Research (NCPOR) National Research Foundation of Korea CSIR-National Institute of Oceanography, India A giant mass-transport complex was recently discovered in the eastern Arabian Sea, exceeding in volume all but one other known complex on passive margins worldwide. The complex, named the Nataraja Slide, was drilled by International Ocean Discovery Program (IODP) Expedition 355 in two locations where it is similar to 300 m (Site U1456) and similar to 200 m thick (Site U1457). The top of this mass-transport complex is defined by the presence of both reworked microfossil assemblages and deformation structures, such as folding and faulting. The deposit consists of two main phases of mass wasting, each consisting of smaller pulses, with generally fining-upward cycles, all emplaced just prior to 10.8 Ma based on biostratigraphy. The base of the deposit at each site is composed largely of matrix-supported carbonate breccia that is interpreted as the product of debris-flows. In the first phase, these breccias alternate with well-sorted calcar-enites deposited from a high-energy current, coherent limestone blocks that are derived directly from the Indian continental margin, and a few clastic mudstone beds. In the second phase, at the top of the deposit, muddy turbidites dominate and become increasingly more siliciclastic. At Site U1456, where both phases are seen, a 20-m section of hemipelagic mudstone is present, overlain by a similar to 40-m-thick section of calcarenite and slumped interbedded mud and siltstone. Bulk sediment geochemistry, heavy-mineral analysis, clay mineralogy, isotope geochemistry, and detrital zircon U-Pb ages constrain the provenance of the clastic, muddy material to being reworked, Indus-derived sediment, with input from western Indian rivers (e.g., Narmada and Tapti rivers), and some material from the Deccan Traps. The carbonate blocks found within the breccias are shallow-water limestones from the outer western Indian continental shelf, which was oversteepened from enhanced clastic sediment delivery during the mid-Miocene. The final emplacement of the material was likely related to seismicity as there are modern intraplate earthquakes close to the source of the slide. Although we hypothesize that this area is at low risk for future mass wasting events, it should be noted that other oversteepened continental margins around the world could be at risk for mass failure as large as the Nataraja Slide. Louisiana State Univ, Dept Geol & Geophys, E253 Howe Russell Kniffen Geosci Complex, Baton Rouge, LA 70803 USA Texas A&M Univ, Int Ocean Discovery Program, 1000 Discovery Dr, College Stn, TX 77845 USA Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA UCL, Dept Earth Sci, Gower St, London WC1E 6BT, England Univ Toulouse 3 Paul Sabatier, Geosci Environm Toulouse, 14 Ave Edouard Belin, F-31400 Toulouse, France GeoSep Serv, 1521 Pine Cone Rd, Moscow, ID 83843 USA Univ Queensland, Sch Earth & Environm Sci, St Lucia, Qld 4072, Australia Natl Ctr Polar & Ocean Res, Vasco Da Gama 403804, Goa, India Univ Milano Bicocca, Dept Earth & Environm Sci, Piazza Sci 4, I-20126 Milan, Italy Purdue Univ, Dept Earth Atmospher & Planetary Sci, 550 Stadium Mall Dr, W Lafayette, IN 47907 USA Univ Birmingham, Sch Geog Earth & Environm Sci, Birmingham B15 2TT, W Midlands, England Macquarie Univ, Fac Sci & Engn, Dept Earth & Planetary Sci, N Ryde, NSW 2109, Australia Ohio State Univ, Sch Earth Sci, 275 Mendenhall Lab,125 South Oval Mall, Columbus, OH 43210 USA Birbal Sahni Inst Palaeosci, 53 Univ Rd, Lucknow 226007, Uttar Pradesh, India Univ Bremen, MARUM, Leobener Str, D-28359 Bremen, Germany Kochi Univ, Dept Nat Environm Sci, 2-5-1 Akebono Cho, Kochi 7808520, Japan Pusan Natl Univ, Div Earth Environm Syst, Busan 60973, South Korea Wadia Inst Himalayan Geol, 33 GMS Rd, Dehra Dun 248001, Uttrakhand, India Natl Inst Ocean Technol, Marine Biotechnol Dept, Velacheiy Tambaram Main Rd, Chennai 600100, Tamil Nadu, India Columbia Univ, Ctr Climate Syst Res, 2880 Broadway, New York, NY 10025 USA Nanjing Univ, Sch Geog & Oceanog Sci, 163 Xianlin Ave, Nanjing 210023, Jiangsu, Peoples R China Oregon State Univ, Coll Earth Ocean & Atmospher Sci, 104 CEOAS Adm Bldg, Corvallis, OR 97331 USA Natl Ctr Earth Sci Studies, Geosci Div, Aakkulam Trivandrum 695031, India Natl Inst Oceanog, Geol Oceanog Div, Panaji 403004, Goa, India Oil & Nat Gas Commiss, 11 High,Bandra Sion Link Rd, Mumbai 400017, Maharashtra, India Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, 1515 Ave 24-A, BR-13506900 Rio Claro, SP, Brazil Kumaun Univ, Dept Geol, Naini Tal 263002, India Banaras Hindu Univ, Dept Geol, Varanasi 221005, Uttar Pradesh, India Xiamen Univ, Dept Geol Oceanog, Xiamen 361102, Fujian, Peoples R China Xiamen Univ, State Key Lab Marine Environm Sci, Xiamen 361102, Fujian, Peoples R China Hokkaido Univ, Grad Sch Environm Sci, Kita Ku, N10W5, Sapporo, Hokkaido 0600810, Japan Scripps Inst Oceanog, 9500 Gilman Dr, La Jolla, CA 92093 USA Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, 7 Nanhai Rd, Qingdao 266071, Shandong, Peoples R China Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, 1515 Ave 24-A, BR-13506900 Rio Claro, SP, Brazil National Centre for Polar and Ocean Research (NCPOR): 90/2018 National Research Foundation of Korea: 2016R1A2B4008256 National Research Foundation of Korea: 2019R1A2C1007701

Published
2020
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