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Ground-water silicification and leaching in sands: Example of the Fontainebleau Sand (Oligocene) in the Paris Basin

1988; Geological Society of America; Volume: 100; Issue: 8 Linguagem: Inglês

10.1130/0016-7606(1988)100 2.3.co;2

1943-2674

Médard Thiry, MIREILLE BERTRAND AYRAULT, JEAN-CLAUDE GRISONI,

CO2 Sequestration and Geologic Interactions

Research Article| August 01, 1988 Ground-water silicification and leaching in sands: Example of the Fontainebleau Sand (Oligocene) in the Paris Basin MÉDARD THIRY; MÉDARD THIRY 1Ecole Nationale Supérieure des Mines de Paris, Centre de Gérologie Générale et Minière, 35 rue Saint Honoré, 77305 Fontainebleau, France Search for other works by this author on: GSW Google Scholar MIREILLE BERTRAND AYRAULT; MIREILLE BERTRAND AYRAULT 2Lycèe François 1 er, 2 rue Victor Hugo, 77300 Fontainebleau, France Search for other works by this author on: GSW Google Scholar JEAN-CLAUDE GRISONI JEAN-CLAUDE GRISONI 3Laboratoire Régional de l'Ouest Parisien, 12 rue Teisserenc de Bort, 78195 Trappes Cedex, France Search for other works by this author on: GSW Google Scholar GSA Bulletin (1988) 100 (8): 1283–1290. https://doi.org/10.1130/0016-7606(1988)100 2.3.CO;2 Article history first online: 01 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 MÉDARD THIRY, MIREILLE BERTRAND AYRAULT, JEAN-CLAUDE GRISONI; Ground-water silicification and leaching in sands: Example of the Fontainebleau Sand (Oligocene) in the Paris Basin. GSA Bulletin 1988;; 100 (8): 1283–1290. doi: https://doi.org/10.1130/0016-7606(1988)100 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 SocietyGSA Bulletin Search Advanced Search Abstract In the Fontainebleau Sand (Oligocene), superposed lenses of quartzite are restricted to outcrops and structurally low zones of the formation. The quartzite lenses result from a silicification process controlled by water-table levels during the recent geomorphologic evolution of the landscape. The quartzite lenses pinch out rapidly under the limestone-capped plateaus and are related to the development of a bleached sand profile. Above the water table, the sand is bleached, and the former quartzite lenses are corroded along their margins. Moreover, flint pebbles are dissolved, and primary smectite and illite are weathered to kaolinite. Dissolved silica can thus reach supersaturated levels, allowing quartz precipitation. Quartz grains are overgrown at the base of the profile in zones of ground-water outflow related to spring lines. The adjustment of the water table during the landscape incision led to formation of quartzite lenses at deeper levels. This silicification process has no climatic significance but is dependent on the stability of the landscape and on its progressive dissection. The rate of quartz cementation, indicated by geomorphologic considerations, is consistent with hydraulic and geochemical calculations; it appears to be very rapid, approximately 30,000 yr for a quartzite lens. 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.