Skip to Main content Skip to Navigation

Provenance du matériel à l'origine des formations pédologiques quaternaires des archipels des Bermudes et des Bahamas

François Prognon 
Abstract : Bermudan and Bahamian Quaternary deposits are characterized by the alternation of carbonates and paleosols. Up to now, atmospheric material, especially Saharan dust, was considered as the main component of the pedological formations. XRD analyses revealed that the mineralogical assemblage of the Bermuda paleosols predominantly includes carbonates, clay minerals (kaolinite, chlorite and chlorite/vermiculite), phosphates, aluminium and iron oxides/hydroxides. It is strikingly close to the mineralogy of the altered Bermuda volcanic seamount, but noticeably different from the mineralogy of Saharan dust. Moreover, volcanic lithoclasts are found in numerous paleosol profiles all over the archipelago, in all the recorded time intervals. We thus consider the volcanic seamount as the main source of non-carbonate minerals detected in the paleosols. The atmospheric dust reaching Bermuda all along the Quaternary period is probably diluted by the local flux of insoluble residues and remains undetectable by the XRD method. Carbonates dominate Bahamian paleosols mineralogical assemblage. Recent formations contain kutnahorite, older hydrotalcite. We carried out a comparative study on the evolution of the San Salvador and Eleuthera paleosols mineralogy. It is supported by the speciation model CHESS. It demonstrates that soil evolution is driven by the local platform physiography and by the substratum mineralogy. The clay assemblage from Bahamian paleosols and marine sediments is inherited from North African and probably from North American sources (Mississippi Valley Loess).
Document type :
Complete list of metadata

Cited literature [226 references]  Display  Hide  Download
Contributor : Ecole Mines ParisTech Connect in order to contact the contributor
Submitted on : Tuesday, January 15, 2008 - 8:00:00 AM
Last modification on : Tuesday, September 29, 2015 - 10:32:46 AM
Long-term archiving on: : Thursday, September 30, 2010 - 8:23:26 PM


  • HAL Id : pastel-00003287, version 1



François Prognon. Provenance du matériel à l'origine des formations pédologiques quaternaires des archipels des Bermudes et des Bahamas. Sciences of the Universe [physics]. École Nationale Supérieure des Mines de Paris, 2006. English. ⟨pastel-00003287⟩



Record views


Files downloads