Cation-ratio dating of rock varnish: Why does it work?

Research Article| September 01, 1991 Cation-ratio dating of rock varnish: Why does it work? Steven L. Reneau; Steven L. Reneau 1Earth and Environmental Sciences Division, MS D462, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 Search for other works by this author on: GSW Google Scholar Robert Raymond, Jr. Robert Raymond, Jr. 1Earth and Environmental Sciences Division, MS D462, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 Search for other works by this author on: GSW Google Scholar Author and Article Information Steven L. Reneau 1Earth and Environmental Sciences Division, MS D462, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 Robert Raymond, Jr. 1Earth and Environmental Sciences Division, MS D462, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1991) 19 (9): 937–940. https://doi.org/10.1130/0091-7613(1991)019<0937:CRDORV>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Steven L. Reneau, Robert Raymond; Cation-ratio dating of rock varnish: Why does it work?. Geology 1991;; 19 (9): 937–940. doi: https://doi.org/10.1130/0091-7613(1991)019<0937:CRDORV>2.3.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 Cation-ratio dating of rock varnish is an empirical surface-exposure dating method based on decreases in the cation ratio (Ca+K):Ti over time. Although these changes were attributed to the preferential leaching of Ca and K from varnish, the existence of such leaching has not been demonstrated. In varnish collected from the Cima volcanic field, California, distributions of the minor elements used in cation-ratio (CR) dating reflect varnish stratigraphy as defined by the major elements Mn, Fe, and Si. In general, K is associated with Si, Ca with Mn, and Ti with Fe. Because of these associations, variations in CRs both within samples and between samples typically reflect variations in major element composition associated with varnish stratigraphy. No systematic changes with depth or age are present in the ratios K:Si or Ca:Mn as would be expected if K and Ca have been preferentially leached from varnish. Available data suggest that, instead of a leaching process, thickness-dependent changes in the amount of substrate being incorporated into varnish analyses contribute to the empirical trend of decreasing CR with increasing surface age, although further research is required to verify this hypothesis. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.