Resumen de Contribución de cianobacterias en la génesis de calcita y dolomita en sistemas lacustres del Mioceno medio. Cuencas del Ebro y Calatayud. NE de España
Antonio Pérez García, Ana Cristina Roc Gargallo, María José Mayayo Burillo, José Ángel Sánchez Navarro, J.M. González
This work shows examples of the genesis of carbonated minerals because of the action ot bacterial in shallow carbonated lacustrine systems. These efects are observed in the development of estromatolitic structures that are asociated with marles and gypsum levels and coated grains. The coated grains are formed by one or more microesparitic envelopes with radial texture. They are formed by calcite and dolomite cristals over they are filaments generated by cyanobacterial action. The stromatolitic crust asociated at carbonated facies rich in dolomite, show tabular o domed forms. In SEM we can observe a perfect cianobacterial mat. These deposits occurs in marginal sectors of shallow lacustrine carbonated areas in conditions of elevated alcalinity.
