Origin of the vanadium-uranium geochemical anomalies in the limestones of the Puyango Formation, La Sota (Ecuador): preliminary results


Abstract:

Vanadium (V) and uranium (U) are critical elements for the energy and technology industry. They are characterized by low abundance in the earth crust´s rocks, but can be concentrated and give rise to sedimentary mineral deposits as a result of redox processes during sedimentation and diagenesis. The anomalies of V-U in La Sota, Ecuador, are found in black limestones and black calcareous shales of Cretaceous age. Here we present the results of a geochemical study and a multivariate geostatistical analysis, which enables us to infer four different associations: 1) disseminated organic matter in the limestones that hold V and Zn, probably in the form of organometallic complexes; 2) phosphatic minerals and concentrations of U, HREE and Ni, which may be incorporated as trace elements in the phosphates, compatible with sedimentation in an anoxic environment; 3) Ca in carbonates from a marine environment; and, 4) litophile elements associated with detritic minerals, such as quartz, plagioclase, feldspar, micas, clays and oxyhydroxides of Fe-Mn-Ti, produced by weathering and erosion. Our findings suggest that V is associated mainly with the organic matter of marine origin in the bituminous limestones, while U is associated with P, thereby indicating the formation of uraniferous phosphates during sedimentation.

Año de publicación:

2023

Keywords:

  • factor analysis
  • Organic matter
  • uranium
  • geochemistry
  • Vanadium

Fuente:

scopusscopus

Tipo de documento:

Article

Estado:

Acceso abierto

Áreas de conocimiento:

  • Geoquímica

Áreas temáticas:

  • Ciencias de la tierra
  • Ciencias de la Tierra de otras zonas