Carbon isotope (δ13Ccarb) heterogeneity in deep-water Cambro-Ordovician carbonates, western Newfoundland
MetadataShow full item record
Carbonates of western Newfoundland span the Cambro-Ordovician interval and preserve a record of slope-basinal deposition in the Cow Head Group near Cow Head. This unit consists of conglomerates and ribbon and laminated limestone interbedded with shale that is well exposed in sea cliffs at Cow Head Peninsula. These conglomerates, although prevalent throughout the section, vary in thickness and abundance stratigraphically and record both local disruption and large-scale episodic sedimentation events. Microfacies drilled for carbon isotope (δ13Ccarb) analysis of conglomerates reveal isotopic heterogeneity within individual samples, in some cases more than 1‰. While this might be an expected outcome of drilling multiple areas of a heterogeneous conglomerate hand sample, permil-level variability was observed both between individual clasts in a sample, between different parts of the same matrix, and between a clast and its surrounding matrix. No associated variation in δ18Ocarb or trace element distributions exists to suggest that this δ13Ccarb variability is the result of later-stage meteoric diagenesis. The δ13Ccarb variability suggests multiple sources of dissolved inorganic carbon (DIC) associated with carbonate precipitation for phases within these individual samples. These data indicate that processes such as local organic matter remineralization and early authigenic carbonate precipitation during lithification at the sediment-water interface (SWI) are either contributing to or controlling δ13Ccarb values in Cambrian carbonates, perhaps more so than at other intervals in Earth history.
© The Author(s), 2015. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Palaeogeography, Palaeoclimatology, Palaeoecology 458 (2016): 52-62, doi:10.1016/j.palaeo.2015.10.004.
The publisher requires that this item be embargoed until 2017-10-09. Please check back after 2017-10-09.
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivatives 4.0 International
Showing items related by title, author, creator and subject.
Influence of biological carbon export on ocean carbon uptake over the annual cycle across the North Pacific Ocean Palevsky, Hilary I.; Quay, Paul D. (John Wiley & Sons, 2017-01-21)We evaluate the influences of biological carbon export, physical circulation, and temperature-driven solubility changes on air-sea CO2 flux across the North Pacific basin (35°N–50°N, 142°E–125°W) throughout the full annual ...
Consequences of considering carbon–nitrogen interactions on the feedbacks between climate and the terrestrial carbon cycle Sokolov, Andrei P.; Kicklighter, David W.; Melillo, Jerry M.; Felzer, Benjamin S.; Schlosser, C. Adam; Cronin, Timothy W. (American Meteorological Society, 2008-08-01)The impact of carbon–nitrogen dynamics in terrestrial ecosystems on the interaction between the carbon cycle and climate is studied using an earth system model of intermediate complexity, the MIT Integrated Global Systems ...
Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks : results from an atmosphere-ocean general circulation model Thornton, Peter E.; Doney, Scott C.; Lindsay, Keith; Moore, J. Keith; Mahowald, Natalie M.; Randerson, James T.; Fung, Inez Y.; Lamarque, J.-F.; Feddema, J. J.; Lee, Y.-H. (Copernicus Publications on behalf of the European Geosciences Union, 2009-10-08)Inclusion of fundamental ecological interactions between carbon and nitrogen cycles in the land component of an atmosphere-ocean general circulation model (AOGCM) leads to decreased carbon uptake associated with CO2 ...