A SYSTEMATIC ANALYSIS OF TERTIARY MARINE FAUNA FROM VIEQUES, PUERTO RICO

This paper presents a systematic study of fossils and molds found Puerto Ferro limestone from Vieques, Puerto Rico. The small island of Vieques developed much in the same way as the main island of Puerto Rico (James and Lorente 2009) meaning it had an igneous base covered by shoreline limestone deposits. Fossil specimens for analysis were obtained from two outcrops: Explosion and South beaches. The samples came from 2-3 meters above sea level at each of the sample sites or were located in float from these sections. All of the fossils specimens were in the same condition as would be found on the main island of Puerto Rico, external or internal molds. The limestone matrix has leached away all of the original shell material leaving very detailed molds. Analysis of the bulk collections revealed a total of 19 macroinvertebrates, dominated by corals, bivalves, and gastropods. By comparing the molds to other fossils found in the Caribbean area by others like, Maury (1917) and Woodring (1982), the age ranges of the fossils could be determined. The age ranges that were used are sufficient to show that the most likely relative age of the exposed limestone as Miocene, tending toward the Late Miocene.