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Roberto Cameriere - One of the best experts on this subject based on the ideXlab platform.
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Age estimation by tooth pulp ratio in canines by peri apical x rays reliability in Age Determination of spanish and italian medieval skeletal remains
Journal of Archaeological Science, 2010Co-Authors: Stefano De Luca, Inmaculada Aleman, Francesca Bertoldi, Luigi Ferrante, Paola Mastrangelo, Mariano Cingolani, Roberto CameriereAbstract:Abstract Estimation of Age at death is an unavoidable step in the process of human identification, both in forensic practice and in the anthropological and palaeopathological study of skeletal remains. In several cases, in which medical or demographic records are completely lacking, a reliable estimation of the Age at death becomes very important. Skeletal remains from archaeological contexts suffer from several biasing factors such as post-mortem changes, taphonomy and various burial practices depending on Age, sex and social status of the deceased persons. Currently, anthropological methods of Age Determination reveal several possibilities of inaccuracy. Of all the body parts used in Age estimation, teeth are the least affected by any taphonomic process. Although there are many dental methods for Age at death estimation, some of them are very complex and/or destructive and they are not normally used in anthropology. However, study of the apposition of secondary dentine by examining peri-apical X-rays of canines is beginning to supply very interesting results. The aim of this work was to test Cameriere’s method on a large sample of historical subjects from several cemeteries in Spain and Italy. The Spanish sample belongs to the Medieval cemetery of La Torrecilla (Arenas del Rey, Granada) and is housed in the Laboratory of Anthropology, Faculty of Medicine, University of Granada. The Italian samples come from the Medieval cemeteries of Comacchio (Ferrara) and Castel S. Pietro (Bologna). In order to test the reliability of Cameriere’s method, Age estimations of canines were compared with the mean ranges of Age of the most commonly applied anthropological methods such as tooth wear changes in the pubic symphysis or the metamorphosis of the auricular surface of the ilium. Tests on these Middle Ages cemeteries produced satisfactory results, indicating that Cameriere’s method is a reliable tool in determining Age at death in skeletal remains of archaeological context.
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Age estimation by tooth pulp ratio in canines by peri apical x rays reliability in Age Determination of spanish and italian medieval skeletal remains
Journal of Archaeological Science, 2010Co-Authors: Stefano De Luca, Inmaculada Aleman, Francesca Bertoldi, Luigi Ferrante, Paola Mastrangelo, Mariano Cingolani, Roberto CameriereAbstract:Abstract Estimation of Age at death is an unavoidable step in the process of human identification, both in forensic practice and in the anthropological and palaeopathological study of skeletal remains. In several cases, in which medical or demographic records are completely lacking, a reliable estimation of the Age at death becomes very important. Skeletal remains from archaeological contexts suffer from several biasing factors such as post-mortem changes, taphonomy and various burial practices depending on Age, sex and social status of the deceased persons. Currently, anthropological methods of Age Determination reveal several possibilities of inaccuracy. Of all the body parts used in Age estimation, teeth are the least affected by any taphonomic process. Although there are many dental methods for Age at death estimation, some of them are very complex and/or destructive and they are not normally used in anthropology. However, study of the apposition of secondary dentine by examining peri-apical X-rays of canines is beginning to supply very interesting results. The aim of this work was to test Cameriere’s method on a large sample of historical subjects from several cemeteries in Spain and Italy. The Spanish sample belongs to the Medieval cemetery of La Torrecilla (Arenas del Rey, Granada) and is housed in the Laboratory of Anthropology, Faculty of Medicine, University of Granada. The Italian samples come from the Medieval cemeteries of Comacchio (Ferrara) and Castel S. Pietro (Bologna). In order to test the reliability of Cameriere’s method, Age estimations of canines were compared with the mean ranges of Age of the most commonly applied anthropological methods such as tooth wear changes in the pubic symphysis or the metamorphosis of the auricular surface of the ilium. Tests on these Middle Ages cemeteries produced satisfactory results, indicating that Cameriere’s method is a reliable tool in determining Age at death in skeletal remains of archaeological context.
Takafumi Hirata - One of the best experts on this subject based on the ideXlab platform.
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u pb Age Determination for zircons using laser ablation icp mass spectrometry equipped with six multiple ion counting detectors
Journal of Analytical Atomic Spectrometry, 2017Co-Authors: Kentaro Hattori, Shuhei Sakata, Michitaka Tanaka, Yuji Orihashi, Takafumi HirataAbstract:Precise zircon U–Pb Age Determinations have been made on Plesovice zircon using laser ablation-multiple ion counting-inductively coupled plasma-mass spectrometry (LA-MIC-ICP-MS). To achieve high precision and high spatial resolution Age Determination, multiple ion counting using six electron multipliers was employed. The intensities of Hg–Pb–U isotope (202Hg, 204(Hg + Pb), 206Pb, 207Pb, 208Pb, and 238U) signals were monitored simultaneously without mass scanning. In static acquisition mode, the resultant 238U–206Pb concordia Age for Plesovice was 336.3 ± 1.9 Ma, demonstrating improved precision over that achieved using a magnetic sector-based single-collector-ICP-MS, which was 340.3 ± 3.5 Ma for Plesovice. A high duty cycle can be achieved, along with a short integration time or a small sample volume for analysis, allowing high spatial resolution. More importantly, downhole fractionation can be reduced with a shallow ablation pit. To take full advantAge of the setup, a one-second LA analysis (8 laser shots with an 8 Hz repetition rate) was adopted for U–Pb Age Determination. The resultant concordia Age for Plesovice was 339.5 ± 6.7 Ma, demonstrating that the repeatability and laboratory bias precision of the resultant Age data were comparable to conventional ablation with a single-collector-ICP-MS. The depths and crater diameters of the ablation pits were, respectively, about >1 μm and 25 μm. The data presented herein demonstrate clearly that multiple ion counting-ICP-MS can become a fast and user-friendly tool for use in U–Pb zircon geochronology.
Yueheng Yang - One of the best experts on this subject based on the ideXlab platform.
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u pb Age Determination of schorlomite garnet by laser ablation inductively coupled plasma mass spectrometry
Journal of Analytical Atomic Spectrometry, 2018Co-Authors: Yueheng Yang, Jinhui Yang, Roger H Mitchell, Zifu Zhao, Liewen Xie, Chao Huang, Ming Yang, Han ZhaoAbstract:We report the first U–Pb geochronological investigation of schorlomite garnet from carbonatite and alkaline complexes and demonstrate its applicability for U–Pb Age Determination using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) due to its relatively high U and Th abundances and negligible common Pb content. The comparative matrix effects of laser ablation of zircon and schorlomite are investigated and demonstrate the necessity of a suitable matrix-matched reference material for schorlomite geochronology. Laser-induced elemental fractional and instrumental mass discrimination were externally-corrected using an in house schorlomite reference material (WS20) for U–Pb geochronology. In order to validate the effectiveness and robustness of our analytical protocol, we demonstrate the veracity of U–Pb Age Determination for five schorlomite samples from: the Magnet Cove complex, Arkansas (USA); the Fanshan ultrapotassic complex, Hebei (China); the Ozernaya alkaline ultramafic complex, Kola Peninsula (Russia); the Alno alkaline–rock carbonatite complex (Sweden); and the Prairie Lake carbonatite complex, Ontario (Canada). The schorlomite U–Pb Ages range from 96 Ma to 1160 Ma, and are almost identical to Ages determined from other accessory minerals in these complexes and support the reliability of our analytical protocol. Schorlomite garnet U–Pb geochronology is considered to be a promising new technique for understanding the genesis of carbonatites, alkaline rocks, and related rare-metal deposits.
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in situ u pb Age Determination and nd isotopic analysis of perovskites from kimberlites in southern africa and somerset island canada
Lithos, 2010Co-Authors: Yueheng Yang, Roge H Mitchell, Jinhui Yang, Yan Bi ZhangAbstract:Abstract Determination of the emplacement Ages and initial isotopic composition of kimberlite by conventional isotopic methods using bulk rock samples is unreliable as these rocks usually contain diverse clasts of crustal- and mantle-derived materials and can be subject to post-intrusion sub-aerial alteration. In this study, 8 samples from 5 kimberlites in southern Africa and twelve samples from 7 kimberlites from Somerset Island, Canada have been selected for in situ perovskite U–Pb isotopic Age Determination and Nd isotopic analysis by laser ablation using thin sections and mineral separates. These fresh perovskites occur as primary groundmass minerals with grain-sizes of 10–100 μm. They were formed during the early stAge of magmatic crystallization, and record data for the least contaminated or contamination-free kimberlitic magma. U–Pb isotopic data indicate that the majority of the southern Africa kimberlites investigated were emplaced during the Cretaceous with Ages of 88 ± 3 to 97 ± 6 Ma, although one sample yielded an Early Paleozoic Age of 515 ± 6 Ma. Twelve samples from Somerset Island yielded Ages ranging from 93 ± 4 Ma to 108 ± 5 Ma and are contemporaneous with other Cretaceous kimberlite magmatism in central Canada (103–94 Ma). Although whole-rock compositions of the kimberlites from southern Africa have a large range of eNd(t) values (− 0.5 to + 5.1), the analysed perovskites show a more limited range of + 1.2 to + 3.1. Perovskites from Somerset Island have eNd(t) values of − 0.2 to + 1.4. These values are lower than that of depleted asthenospheric mantle, suggesting that kimberlites might be derived from the lower mantle. This study shows that in situ U–Pb and Nd isotopic analysis of perovskite by laser ablation is both rapid and economic, and serves as a powerful tool for the Determination of the emplacement Age and potential source of kimberlite magmas.
Jinhui Yang - One of the best experts on this subject based on the ideXlab platform.
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u pb Age Determination of schorlomite garnet by laser ablation inductively coupled plasma mass spectrometry
Journal of Analytical Atomic Spectrometry, 2018Co-Authors: Yueheng Yang, Jinhui Yang, Roger H Mitchell, Zifu Zhao, Liewen Xie, Chao Huang, Ming Yang, Han ZhaoAbstract:We report the first U–Pb geochronological investigation of schorlomite garnet from carbonatite and alkaline complexes and demonstrate its applicability for U–Pb Age Determination using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) due to its relatively high U and Th abundances and negligible common Pb content. The comparative matrix effects of laser ablation of zircon and schorlomite are investigated and demonstrate the necessity of a suitable matrix-matched reference material for schorlomite geochronology. Laser-induced elemental fractional and instrumental mass discrimination were externally-corrected using an in house schorlomite reference material (WS20) for U–Pb geochronology. In order to validate the effectiveness and robustness of our analytical protocol, we demonstrate the veracity of U–Pb Age Determination for five schorlomite samples from: the Magnet Cove complex, Arkansas (USA); the Fanshan ultrapotassic complex, Hebei (China); the Ozernaya alkaline ultramafic complex, Kola Peninsula (Russia); the Alno alkaline–rock carbonatite complex (Sweden); and the Prairie Lake carbonatite complex, Ontario (Canada). The schorlomite U–Pb Ages range from 96 Ma to 1160 Ma, and are almost identical to Ages determined from other accessory minerals in these complexes and support the reliability of our analytical protocol. Schorlomite garnet U–Pb geochronology is considered to be a promising new technique for understanding the genesis of carbonatites, alkaline rocks, and related rare-metal deposits.
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in situ u pb Age Determination and nd isotopic analysis of perovskites from kimberlites in southern africa and somerset island canada
Lithos, 2010Co-Authors: Yueheng Yang, Roge H Mitchell, Jinhui Yang, Yan Bi ZhangAbstract:Abstract Determination of the emplacement Ages and initial isotopic composition of kimberlite by conventional isotopic methods using bulk rock samples is unreliable as these rocks usually contain diverse clasts of crustal- and mantle-derived materials and can be subject to post-intrusion sub-aerial alteration. In this study, 8 samples from 5 kimberlites in southern Africa and twelve samples from 7 kimberlites from Somerset Island, Canada have been selected for in situ perovskite U–Pb isotopic Age Determination and Nd isotopic analysis by laser ablation using thin sections and mineral separates. These fresh perovskites occur as primary groundmass minerals with grain-sizes of 10–100 μm. They were formed during the early stAge of magmatic crystallization, and record data for the least contaminated or contamination-free kimberlitic magma. U–Pb isotopic data indicate that the majority of the southern Africa kimberlites investigated were emplaced during the Cretaceous with Ages of 88 ± 3 to 97 ± 6 Ma, although one sample yielded an Early Paleozoic Age of 515 ± 6 Ma. Twelve samples from Somerset Island yielded Ages ranging from 93 ± 4 Ma to 108 ± 5 Ma and are contemporaneous with other Cretaceous kimberlite magmatism in central Canada (103–94 Ma). Although whole-rock compositions of the kimberlites from southern Africa have a large range of eNd(t) values (− 0.5 to + 5.1), the analysed perovskites show a more limited range of + 1.2 to + 3.1. Perovskites from Somerset Island have eNd(t) values of − 0.2 to + 1.4. These values are lower than that of depleted asthenospheric mantle, suggesting that kimberlites might be derived from the lower mantle. This study shows that in situ U–Pb and Nd isotopic analysis of perovskite by laser ablation is both rapid and economic, and serves as a powerful tool for the Determination of the emplacement Age and potential source of kimberlite magmas.
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precise u pb and th pb Age Determination of kimberlitic perovskites by secondary ion mass spectrometry
Chemical Geology, 2010Co-Authors: Yu Liu, Jinhui Yang, Roger H MitchellAbstract:article i nfo Perovskite,acommonTh-andU-enrichedaccessorymineralcrystallisedfromkimberliticmagmas,haslongbeen thoughtto bean important geochronometer for dating the emplacement of kimberlite. However, it also contains variably high levels of common Pb, which makes it difficult to obtain a precise measurement of radiogenic Pb/U and Pb/Th isotopic compositions using microbeam techniques such as SIMS and LA-ICP-MS. We present calibration protocols for in situ U-Pb and Th-Pb Age Determination of kimberlitic perovskite using the large double-focusingCamecaIMS1280.Linearrelationshipsarefoundbetweenln( 206 208 Pb⁎ + /Th + ) and ln(ThO + /Th + ), based on which the inter-element fractionation in unknown samples during SIMS analyses can be precisely calibrated against a perovskite standard. The well-characterized IceRiverperovskiteischosenastheU-PbandTh-PbAgestandardinthisstudy.The 204 Pb-correctionmethodwas used to estimate the fraction of common Pb, which is consistent with the results obtained using the 207 Pb-based correction method for the dated perovskites of Phanerozoic Age. A Tazheran perovskite with unusually high U but rather low Th yielded a Concordia U-Pb Age of 462.8±2.5 Ma and a Th-Pb Age of 462±4 Ma. Two perovskite samples from the Iron Mountain kimberlite have identical Concordia U-Pb Ages of 410.8±3.4 Ma and 411.0±2.6 Ma, which are consistent within errors with their corresponding Th-Pb Ages of 409.2±7.2 Ma and 412.3±3.3 Ma, respectively. Two perovskite samples from the WesseltonMineofSouthAfricayieldedindistinguishable 206 Pb/ 238 UAgesof91.5±2.2 Maand90.3±2.9 Ma,and Th-Pb Ages of 90.5±0.8 Ma and 88.4±1.6 Ma, respectively. Accuracy and precision of 1-2% (95% confidence level)forthesemeasurementshavebeendemonstratedbytheconsistencyoftheirU-PbandTh-PbAgeswiththe recommended U-Pb Ages of previous works.
Roger H Mitchell - One of the best experts on this subject based on the ideXlab platform.
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u pb Age Determination of schorlomite garnet by laser ablation inductively coupled plasma mass spectrometry
Journal of Analytical Atomic Spectrometry, 2018Co-Authors: Yueheng Yang, Jinhui Yang, Roger H Mitchell, Zifu Zhao, Liewen Xie, Chao Huang, Ming Yang, Han ZhaoAbstract:We report the first U–Pb geochronological investigation of schorlomite garnet from carbonatite and alkaline complexes and demonstrate its applicability for U–Pb Age Determination using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) due to its relatively high U and Th abundances and negligible common Pb content. The comparative matrix effects of laser ablation of zircon and schorlomite are investigated and demonstrate the necessity of a suitable matrix-matched reference material for schorlomite geochronology. Laser-induced elemental fractional and instrumental mass discrimination were externally-corrected using an in house schorlomite reference material (WS20) for U–Pb geochronology. In order to validate the effectiveness and robustness of our analytical protocol, we demonstrate the veracity of U–Pb Age Determination for five schorlomite samples from: the Magnet Cove complex, Arkansas (USA); the Fanshan ultrapotassic complex, Hebei (China); the Ozernaya alkaline ultramafic complex, Kola Peninsula (Russia); the Alno alkaline–rock carbonatite complex (Sweden); and the Prairie Lake carbonatite complex, Ontario (Canada). The schorlomite U–Pb Ages range from 96 Ma to 1160 Ma, and are almost identical to Ages determined from other accessory minerals in these complexes and support the reliability of our analytical protocol. Schorlomite garnet U–Pb geochronology is considered to be a promising new technique for understanding the genesis of carbonatites, alkaline rocks, and related rare-metal deposits.
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precise u pb and th pb Age Determination of kimberlitic perovskites by secondary ion mass spectrometry
Chemical Geology, 2010Co-Authors: Yu Liu, Jinhui Yang, Roger H MitchellAbstract:article i nfo Perovskite,acommonTh-andU-enrichedaccessorymineralcrystallisedfromkimberliticmagmas,haslongbeen thoughtto bean important geochronometer for dating the emplacement of kimberlite. However, it also contains variably high levels of common Pb, which makes it difficult to obtain a precise measurement of radiogenic Pb/U and Pb/Th isotopic compositions using microbeam techniques such as SIMS and LA-ICP-MS. We present calibration protocols for in situ U-Pb and Th-Pb Age Determination of kimberlitic perovskite using the large double-focusingCamecaIMS1280.Linearrelationshipsarefoundbetweenln( 206 208 Pb⁎ + /Th + ) and ln(ThO + /Th + ), based on which the inter-element fractionation in unknown samples during SIMS analyses can be precisely calibrated against a perovskite standard. The well-characterized IceRiverperovskiteischosenastheU-PbandTh-PbAgestandardinthisstudy.The 204 Pb-correctionmethodwas used to estimate the fraction of common Pb, which is consistent with the results obtained using the 207 Pb-based correction method for the dated perovskites of Phanerozoic Age. A Tazheran perovskite with unusually high U but rather low Th yielded a Concordia U-Pb Age of 462.8±2.5 Ma and a Th-Pb Age of 462±4 Ma. Two perovskite samples from the Iron Mountain kimberlite have identical Concordia U-Pb Ages of 410.8±3.4 Ma and 411.0±2.6 Ma, which are consistent within errors with their corresponding Th-Pb Ages of 409.2±7.2 Ma and 412.3±3.3 Ma, respectively. Two perovskite samples from the WesseltonMineofSouthAfricayieldedindistinguishable 206 Pb/ 238 UAgesof91.5±2.2 Maand90.3±2.9 Ma,and Th-Pb Ages of 90.5±0.8 Ma and 88.4±1.6 Ma, respectively. Accuracy and precision of 1-2% (95% confidence level)forthesemeasurementshavebeendemonstratedbytheconsistencyoftheirU-PbandTh-PbAgeswiththe recommended U-Pb Ages of previous works.