Effects of black shale weathering on the mobility of rhenium and platinum group elements

Research Article| May 01, 2000 Effects of black shale weathering on the mobility of rhenium and platinum group elements Bernhard Peucker-Ehrenbrink; Bernhard Peucker-Ehrenbrink 1Woods Hole Oceanographic Institution, MS 25, Woods Hole, Massachusetts 02543-1541, USA Search for other works by this author on: GSW Google Scholar Robyn E. Hannigan Robyn E. Hannigan 1Woods Hole Oceanographic Institution, MS 25, Woods Hole, Massachusetts 02543-1541, USA Search for other works by this author on: GSW Google Scholar Geology (2000) 28 (5): 475–478. https://doi.org/10.1130/0091-7613(2000)282.0.CO;2 Article history received: 22 Oct 1999 rev-recd: 14 Feb 2000 accepted: 23 Feb 2000 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Bernhard Peucker-Ehrenbrink, Robyn E. Hannigan; Effects of black shale weathering on the mobility of rhenium and platinum group elements. Geology 2000;; 28 (5): 475–478. doi: https://doi.org/10.1130/0091-7613(2000)282.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Radiogenic Os from the continents dominates the late Cenozoic marine Os budget. A variety of proposed radiogenic sources includes organic-rich sediments, Precambrian shields, and Re-rich sulfides. Identifying the dominant sources of radiogenic Os to the oceans has a strong impact on past climate models because weathering of silicates acts as a net sink of CO2, whereas weathering of organic matter acts as a source. Here we investigate the effects of black shale weathering on the integrity of the Re-Os isotope system and release of Re and platinum group elements. Time-correlative pairs of fresh (drill core) and weathered (outcrop) black shales of Late Ordovician age (Utica Shale magnafacies, Québec) were analyzed for Re, Os, Ir, Pt, and Pd, as well as total S, N, and C (as Ccarb and Corg). The results indicate that 25%–64% of the initial Re budget, 45%–90% of the Os budget, 14%–65% of the Ir budget, 60%–77% of the Pt budget, 69%–86% of the Pd budget, and 44%–96% of the Corg budget are lost during weathering. We use positive correlations of Os, Pt, and Pd with Corg and N to calculate the respective platinum group element concentrations in the unweathered organic matter end member as ∼3 ng/g Os, ∼9 ng/g Pt, and 11–24 ng/g Pd. Although black shales make up <1% of the continental crust, mass-balance calculations indicate that such facies contribute significantly to the labile Os inventory of the continental crust. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.