Sandstone Serraria Formation

The aims this study are to elucidate the factors controlling the distribution pattern, mineralogy and geochemical composition of calcite and dolomite cements, and of grain dissolution and kaolin-ization in the fluvial sandstones of the Serraria Formation, northeastern Brazil (Fig. 1). This unit provides an excellent opportunity to examine the influence of variations in the palaeogeographical setting, palaeoclimate and burial history on diagenetic processes. 

Fig. 3. Palaeogeographical reconstructions of Serraria Formation. Early Cretaceous pre-rift sedimentation. (A) At the time of maximum extension of the lacustrine system and beginning of the fluvial sedimentation of the Serraria sandstones (B) at the time of maximum expansion of the Serraria fluvial system. Modified from Garcia (1992).

Fig. 6. QFL detrital composition of the sandstones of the diagenetic domains of the Serraria Formation plotted on a Folk (1968) classification diagram. The proximal domain is closer to the original detrital composition.

Rapid burial during the rift phase brought the Serraria Formation down to a maximum depth of i 1500-2500 m. The diagenetic evolution of the sandstones during this burial phase has varied between the different domains, mainly due to vari-... 

---