SEQUENCE STRATIGRAPHY AND FACIES ANALYSIS OF THE MONTEBELLO MEMBER OF THE CIBAO FORMATION, SAN SEBASTIAN, PUERTO RICO

Using sequence stratigraphy analysis, rock identification and facies analysis the Montebello member of the Cibao formation exposed in the PR-448 San Sebastián, Puerto Rico was analyzed. Monroe first studied the Montebello Member in 1980 showing Oligocene rocks that dip slightly north (Monroe, 1980). He marked the contact between the Montebello Member and the Lares Limestone with an oyster bed. Using field work as part of the methodology for this research it was determined that the member shows series of wackstone, packstone and mudstone rocks with fossils foraminifera, bivalves, oysters, read algae, and corals. The member was interpreted as two parasequences showing progradation of reef environments in shallowing upward cycles. These parasequences were interpreted as part of a transgressive system track (TST) because of the landward movements of facies and a high system track (HST). The oyster bed was not found in the base of the member.