Open AccessJournal Article
Evolution of the Sr and C Isotope Composition of Cambrian Oceans
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TLDR
In this paper, the authors present a set of high-resolution, seawater Sr and C isotope curves for the late Early through early Late Cambrian, defined in continuous exposures of marine carbonates in the Great Basin and southern Canadian Rockies, and used to better constrain primary variations in ocean chemistry during this time period.Abstract:
The recent proliferation of chemostratigraphic studies has clearly documented that systematic fluctuations in the strontium and carbon isotope composition of seawater have occurred throughout Earth history across a range of temporal scales. In particular, significant isotopic variation during key intervals of geologic time has provided unprecedented quantitative constraints on crustal and surficial processes, and enhanced chronostratigraphic resolution for intrabasinal and interbasinal correlations. We present the first set of high-resolution, seawater Sr and C isotope curves for the late Early through early Late Cambrian. These curves are defined in continuous exposures of marine carbonates in the Great Basin and southern Canadian Rockies, and they are used to better constrain primary variations in ocean chemistry during this time period. The Sr curve documents a rapid rate of increase through this period that is comparable to that recorded by the late Cenozoic seawater Sr proxy record of uplift and attendant weathering of the HimalayaTibetan Plateau. The Cambrian rise in Sr values is interpreted to record PanAfrican‐Brasiliano orogenesis, andread more
Citations
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Journal ArticleDOI
Strontium Isotope Stratigraphy: LOWESS Version 3: Best Fit to the Marine Sr‐Isotope Curve for 0–509 Ma and Accompanying Look‐up Table for Deriving Numerical Age
TL;DR: An improved and updated version of the statistical LOWESS fit to the marine 87Sr/86Sr record and a revised look-up table (V3:10/99; available from jmcarthur@ucl.ac.uk) is presented in this article.
Book Chapter
Strontium Isotope Stratigraphy
TL;DR: In this paper, a methodology for measuring the 87Sr/86Sr value in fossil precipitates, such as belemnites or foraminifera, can be used to date and to correlate worldwide the marine sedimentary rocks in which the precipitates occur.
Journal ArticleDOI
Explaining the Cambrian "Explosion" of Animals
TL;DR: The Cambrian “explosion” is a unique episode in Earth history, when essentially all the animal phyla first appear in the fossil record and is best understood as being the result of the interplay of the combinatorial bilaterian developmental system and the increase in the number of needs the first bilaterians had to meet as complex ecological interactions developed.
Journal ArticleDOI
Geochemical evidence for widespread euxinia in the Later Cambrian ocean
Benjamin C. Gill,Timothy W. Lyons,Seth A. Young,Lee R. Kump,Andrew H. Knoll,Matthew R. Saltzman +5 more
TL;DR: The SPICE interval is identified as the best characterized ocean anoxic event in the pre-Mesozoic ocean and an extreme example of oxygen deficiency in the later Cambrian ocean, indicating the environmental challenges presented by widespread anoxia may have been a prevalent if not dominant influence on animal evolution in Cambrian oceans.
Book ChapterDOI
The Cambrian Period
TL;DR: The Cambrian Period was characterized by the appearance of metazoans with mineralized skeletons, explosion in biotic diversity and disparity, infaunalization of the substrate, occurrence of metazoan Konservat Fossil-lagerstatten, establishment of most invertebrate phyla, strong faunal provincialism, dominance of trilobites, generally warm climate but with possible glacial-interglacial cycles in the later part, opening of the Iapetus Ocean, progressive equatorial drift and separation of Laurentia, Baltica, Siberia,
References
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Journal ArticleDOI
Interpreting carbon-isotope excursions: carbonates and organic matter
Lee R. Kump,Michael A. Arthur +1 more
TL;DR: In this article, a simple model of the global carbon cycle is employed to simulate a number of different perturbations, each lasting 500 ky, i.e., much longer than the residence times of carbon and phosphorus in the ocean-atmosphere system.
Journal ArticleDOI
The strontium isotope budget of the modern ocean
Martin R. Palmer,John M. Edmond +1 more
TL;DR: In this article, the authors measured the Sr concentration and isotopic composition of most of the world's major rivers and determined the Sr and 87Sr/86Sr ratio of oceanic hydrothermal vent waters from diverse tectonic and volcanogenic environments.
Journal ArticleDOI
The abundance of 13c in marine organic matter and isotopic fractionation in the global biogeochemical cycle of carbon during the past 800 ma
TL;DR: For the later Neoproterozoic, from 800 to 543 Ma (346 analyses), from the Cambrian through the Jurassic (1616 analyses), and from the Cretaceous and Cenozoic (2493 analyses) the abundance of 13 C in marine organic matter has been compiled as discussed by the authors.
Journal ArticleDOI
Sr isotope evolution of seawater: the role of tectonics
TL;DR: In this article, the authors use a high-resolution seawater Sr isotopic evolution curve for the last 100 m.y.d. in conjunction with modern riverine Sr flux measurements, and also geologic, tectonic and geochronological data, to make the case for a close relationship between seawater isotopic composition and the India Asia continental collision.
Journal ArticleDOI
High-resolution stratigraphy with strontium isotopes
TL;DR: Sedimentary rocks composed of accumulated fossil carbonate shells can be dated and correlated with the use of high precision measurements of the ratio of strontium-87 to strontum-86 with a resolution that is similar to that of other techniques used in age correlation.