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Christopher D. Coath

Bio: Christopher D. Coath is an academic researcher from University of Bristol. The author has contributed to research in topics: Zircon & Chondrite. The author has an hindex of 33, co-authored 76 publications receiving 4648 citations. Previous affiliations of Christopher D. Coath include Thermo Fisher Scientific & University of California, Los Angeles.


Papers
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Journal ArticleDOI
17 Apr 2009-Science
TL;DR: It is infer that thermal processing of molecular cloud material, probably associated with volatile-element depletions in the inner solar system, resulted in selective destruction of thermally unstable, isotopically anomalous presolar components, producing residual isotopic heterogeneity, implying that terrestrial planets accreted from thermally processed solids with nonsolar isotopic compositions.
Abstract: Stable-isotope variations exist among inner solar system solids, planets, and asteroids, but their importance is not understood. We report correlated, mass-independent variations of titanium-46 and titanium-50 in bulk analyses of these materials. Because titanium-46 and titanium-50 have different nucleosynthetic origins, this correlation suggests that the presolar dust inherited from the protosolar molecular cloud was well mixed when the oldest solar system solids formed, but requires a subsequent process imparting isotopic variability at the planetary scale. We infer that thermal processing of molecular cloud material, probably associated with volatile-element depletions in the inner solar system, resulted in selective destruction of thermally unstable, isotopically anomalous presolar components, producing residual isotopic heterogeneity. This implies that terrestrial planets accreted from thermally processed solids with nonsolar isotopic compositions.

487 citations

Journal ArticleDOI
TL;DR: In this paper, an in situ isotopic study of 68 Jack Hills zircons was conducted, in which the Hf and Pb isotope ratios were measured concurrently, allowing a better integration of isotope tracer information (176Hf/177Hf).

390 citations

Journal ArticleDOI
24 Jun 2011-Science
TL;DR: It is concluded that essentially all rocky materials in the inner solar system were enriched in 17O and 18O, relative to 16O, by ~7%, probably via non–mass-dependent chemistry before accretion of the first planetesimals.
Abstract: All planetary materials sampled thus far vary in their relative abundance of the major isotope of oxygen, ^(16)O, such that it has not been possible to define a primordial solar system composition. We measured the oxygen isotopic composition of solar wind captured and returned to Earth by NASA’s Genesis mission. Our results demonstrate that the Sun is highly enriched in ^(16)O relative to the Earth, Moon, Mars, and bulk meteorites. Because the solar photosphere preserves the average isotopic composition of the solar system for elements heavier than lithium, we conclude that essentially all rocky materials in the inner solar system were enriched in ^(17)O and ^(18)O, relative to ^(16)O, by ~7%, probably via non–mass-dependent chemistry before accretion of the first planetesimals.

312 citations

Journal ArticleDOI
TL;DR: In this paper, a new ion microprobe method for dating magmatic zircon growth was proposed based on in situ measurement of the magnitude of 238U-230Th disequilibrium.

308 citations

Journal ArticleDOI
TL;DR: In this article, a Th-Pb ion microprobe dating of monazite was used to determine the age of the Manaslu granite in the High Himalayan leucogranite belt.
Abstract: decompression to achieve the same result appear to require extreme The Manaslu granite is the most studied of the dozen or so plutons conditions not permitted by available geological constraints. that make up the High Himalayan leucogranite belt. The inferred relationship of the Manaslu granite with important Himalayan tectonic structures has inspired repeated attempts to determine its crystallization age, but several geochemical controls have hampered these geochronological investigations. These limitations are circumvented by Th–Pb ion microprobe dating of monazite. We have

265 citations


Cited by
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Journal ArticleDOI
TL;DR: A review of the geologic history of the Himalayan-Tibetan orogen suggests that at least 1400 km of north-south shortening has been absorbed by the orogen since the onset of the Indo-Asian collision at about 70 Ma as discussed by the authors.
Abstract: A review of the geologic history of the Himalayan-Tibetan orogen suggests that at least 1400 km of north-south shortening has been absorbed by the orogen since the onset of the Indo-Asian collision at about 70 Ma. Significant crustal shortening, which leads to eventual construction of the Cenozoic Tibetan plateau, began more or less synchronously in the Eocene (50–40 Ma) in the Tethyan Himalaya in the south, and in the Kunlun Shan and the Qilian Shan some 1000–1400 km in the north. The Paleozoic and Mesozoic tectonic histories in the Himalayan-Tibetan orogen exerted a strong control over the Cenozoic strain history and strain distribution. The presence of widespread Triassic flysch complex in the Songpan-Ganzi-Hoh Xil and the Qiangtang terranes can be spatially correlated with Cenozoic volcanism and thrusting in central Tibet. The marked difference in seismic properties of the crust and the upper mantle between southern and central Tibet is a manifestation of both Mesozoic and Cenozoic tectonics. The form...

4,494 citations

Journal ArticleDOI
TL;DR: In this article, the authors systematically review the essential observations relevant to the along-strike variation of the Himalayan geologic framework and its role in Cenozoic Himalayan exhumation, metamorphism and foreland sedimentation.

1,352 citations

Journal ArticleDOI
08 Jan 2004-Nature
TL;DR: It is found that syngenetic pyrite is present in organic-rich shales of the 2.32-Gyr-old Rooihoogte and Timeball Hill formations, South Africa, indicating that atmospheric oxygen was present at significant levels during the deposition of these units.
Abstract: Several lines of geological and geochemical evidence indicate that the level of atmospheric oxygen was extremely low before 2.45 billion years (Gyr) ago, and that it had reached considerable levels by 2.22 Gyr ago. Here we present evidence that the rise of atmospheric oxygen had occurred by 2.32 Gyr ago. We found that syngenetic pyrite is present in organic-rich shales of the 2.32-Gyr-old Rooihoogte and Timeball Hill formations, South Africa. The range of the isotopic composition of sulphur in this pyrite is large and shows no evidence of mass-independent fractionation, indicating that atmospheric oxygen was present at significant levels (that is, greater than 10-5 times that of the present atmospheric level) during the deposition of these units. The presence of rounded pebbles of sideritic iron formation at the base of the Rooihoogte Formation and an extensive and thick ironstone layer consisting of haematitic pisolites and oolites in the upper Timeball Hill Formation indicate that atmospheric oxygen rose significantly, perhaps for the first time, during the deposition of the Rooihoogte and Timeball Hill formations. These units were deposited between what are probably the second and third of the three Palaeoproterozoic glacial events.

1,277 citations

Journal ArticleDOI
TL;DR: The last 3.85 Gyr of Earth history have been divided into five stages, and atmospheric oxygen levels probably rose to a maximum value of ca 0.3 atm during the Carboniferous before returning to its present value.
Abstract: The last 3.85Gyr of Earth history have been divided into five stages. During stage 1 (3.852.45Gyr ago (Ga)) the atmosphere was largely or entirely anoxic, as were the oceans, with the possible exce...

1,238 citations