Modelización de flujo, transporte y sedimentación de evaporitas con el programa SIMSAFADIM: aplicación a la secuencia evaporítica del Vallès-Penedès (Catalunya)
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K. Bitzer [1]
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[1] Departamento de Geología, Universidad de Bayreuth
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- Localización: Geotemas (Madrid), ISSN 1576-5172, Nº. 6, 2, 2004 (Ejemplar dedicado a: IV Congreso Geológico de España), págs. 333-336
- Idioma: español
- Enlaces
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Resumen
Gypsum and anhydrite with up to 60 m thickness have been deposited in the Vilobi sequence in the Vallès-Penedès basin during transgressive-regressive pulses in the upper Burdigalian. While most of the evaporite deposit in the Vilobi sequence is secondary gypsum, the uppermost unit is primary gypsum. The sequence is thought to be deposited mainly in the vadose zone of a Sabkha environment except for the uppermost unit, which shows indications of sediment transport in supersaturated standing water. This contribution applies a mathematical model (SIMSAFADIM) to constrain hydrologic, climatic and paleogeographical conditions, which may have influenced the evolution of these deposits. The simulation model is used to test evaporation driven water circulation systems in the embayment, solute transport and the increase in solute concentration due to evaporation. The assumed paleogeographic configuration of the upper Burdigalian embayment is taken as the initial condition for the simulation runs. Estimates on evaporation outflow and freshwater inflow into the embayment are applied as boundary conditions for the model. Sedimentation of evaporites is calculated in a simplified way, using CaS04 saturation concentrations of a NaCTCaS04 system, which have been calculated using PHREEQ-C. Simulation results show, that freshwater inflow must have been available during the transgessive pulse and that evaporite deposition may have occurred due to a reduction of freshwater inflow
