How fast are some diagenetical processes? The case of inversion from aragonite to calcite in a stalagmite from Eagle Cave (central Spain)

  1. David Domínguez-Villar 1
  2. R.M. Carrasco 2
  3. J. Pedraza 3
  4. I.J. Fairchild 4
  5. R.L. Edwards 5
  6. P. Pelicon 6
  7. Z. Siketić 6
  1. 1 Centro Nacional de Investigación sobre la Evolución Humana
    info

    Centro Nacional de Investigación sobre la Evolución Humana

    Burgos, España

    ROR https://ror.org/01nse6g27

  2. 2 Universidad de Castilla-La Mancha
    info

    Universidad de Castilla-La Mancha

    Ciudad Real, España

    ROR https://ror.org/05r78ng12

  3. 3 Universidad Complutense de Madrid
    info

    Universidad Complutense de Madrid

    Madrid, España

    ROR 02p0gd045

  4. 4 S. of Geography, Earth and Environmental Sciences, University of Birmingham
  5. 5 University of Minnesota
    info

    University of Minnesota

    Mineápolis, Estados Unidos

    ROR https://ror.org/017zqws13

  6. 6 Institute Jožef Stefan, Slovenia
Journal:
Geotemas (Madrid)

ISSN: 1576-5172

Year of publication: 2012

Issue Title: VIII Congreso Geológico de España, Oviedo, 17-19 de julio, 2012.

Issue: 13

Pages: 695-698

Type: Article

More publications in: Geotemas (Madrid)

Abstract

The inversion diagenetical process in a stalagmite from Eagle Cave (Ávila Province) is studied. The 162 mm long EA5 stalagmite that once upon a time was composed of aragonite has been almost completely transformed to secondary calcite. The process is thought to occur as follow: slightly subsaturated (or equilibrated) drip waters in relation to aragonite and calcite enter the porous aragonite sample and dissolve some aragonite. Outgassing of the solution inside the stalagmite favoured calcite saturation permitting the formation of secondary calcite. Top and base U-Th dates on primary crystals suggest a lapse time for the diagenetical process in the order of ten thousand years. Formation of Mg and Sr bands in some of the secondary calcite crystals suggests an annual nature for the precipitation of such pattern. The compositional bands cannot be the result of drip water chemistry, but it can represent the seasonal change in the rate of water flow and then an evolution of the solution trapped within the stalagmite. Mean bands thickness of 85 ±53m has been measured. This possible rate of diagenesis is in agreement, within one order of magnitude, with the U-Th dates provided for the diagenesis of the entire stalagmite.