Mineralogical evidence for a local volcanic origin of the parent material of Bermuda Quaternary paleosols

Article Article scientifique Article Mineralogical evidence for a local volcanic origin of the parent material of Bermuda Quaternary paleosols eng 2011 author Prognon François 650861 author Cojan Isabelle author Kindler Pascal 28210 author Thiry Médard author Demange Michel 256-266 10.1016/j.yqres.2010.08.002 0033-5894 http://linkinghub.elsevier.com/retrieve/pii/S003358941000089X The alternation of carbonate deposits and paleosols compose the emerged part of the Bermuda archipelago. The pedological units present a complex and diversified mineralogy. Former studies demonstrated that the paleosols are not primarily a product of the unique dissolution of the surrounding carbonates, but contain a massive input of allochthonous non-carbonate detrital material. Researchers during more than the past three decades have attributed this flux of insoluble residues (IR) to Saharan dusts. We carried out systematic field and mineralogical analyses on the Quaternary paleosols from the Bermuda archipelago. Their mineralogical assemblage predominantly includes carbonates, clay minerals (kaolinite, chlorite and chlorite/vermiculite), phosphates, and aluminium and iron oxides/hydroxides. This assemblage is strikingly close to the mineralogy of the weathered volcanic substrate of Bermuda, but noticeably different from the mineralogy of Saharan dust. Moreover, we found volcanic lithoclasts in numerous paleosol profiles all over the archipelago and in all the recorded time intervals. We thus consider the volcanic seamount underlying Bermuda as the main source of non-carbonate minerals detected in the paleosols. This hypothesis further resolves the anomalous maturity of Bermudan paleosols compared to their southern counterparts in the Bahamas and Barbados. Bermuda Paleosols Quaternary Volcanism Saharan dust Dewey 550 142 Département de géologie et de paléontologie 151 42 Département des sciences de la Terre 154 false 671 Sedimentology, Biostratigraphy and Micropaleontology Quaternary research 75 1 a2a5dd9a-d4f2-49f0-95d0-18e5f1c047f8 Article (Accepted version) Restricted Prognon et al, 2011.pdf 1788820 application/pdf restrictedAccess Faculté des sciences / Section des sciences de la Terre et de l'Environnement / Département de géologie et de paléontologie Faculté des sciences / Section des sciences de la Terre et de l'Environnement / Département des sciences de la Terre

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Mineralogical evidence for a local volcanic origin of the parent material of Bermuda Quaternary paleosols	Quaternary research			2011	663	0

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Prognon, François