ABSTRACT

This study is a detailed geological investigation of the characteristics of the Peru Sand outcrop in Catoosa, Oklahoma. The physical characteristics of the rocks of this outcrop are carefully described in order to interpret the depositional and diagenetic history. The outcrop consists of a coarsening upward sequence of mudstone, siltstone, and fine- to medium-grained sandstone. The mudstones and siltstones have a clay matrix, whereas the fine-grained sandstones are calcite cemented. The medium-grained sandstones have a matrix of clay, rock fragments, and calcite. Reservoir properties of the siltstones and fine-grained sandstones are very poor. This outcrop is interpreted as being deltaic. The sequence of depositional environments is seen as prodelta mudstones, delta front siltstones, and distributary mouth bar sandstones. These rocks have undergone a sequence of diagenetic events that involves authigenic clay growth, quartz dissolution and overgrowth, calcite cementation, pyrite growth, and weathering.