2008 Joint Annual Meeting (5-9 Oct. 2008): Establishing a High Resolution Sequence Stratigraphy & Sea-Level Curve for Tertiary Limestone Formations, Puerto Rico

305-5 Establishing a High Resolution Sequence Stratigraphy & Sea-Level Curve for Tertiary Limestone Formations, Puerto Rico



Wednesday, 8 October 2008
George R. Brown Convention Center, Exhibit Hall E
Diana Ortega-Ariza, Geology, University of Puerto Rico at Mayaguez, PO.BOX 5421, Mayaguez, PR 00681 and Hernán Santos, Department of Geology, University of Puerto Rico-Mayaguez, PO Box 9017, Mayaguez, PR 00660
The Tertiary limestone formations of the North Coast of Puerto Rico have been studied since the early 1900's. Most of these studies concentrated on the lithological characteristics and economic potential of the limestones. One of these studies attempted to show the relationship between the carbonate units in terms of the sequence stratigraphy, consequently they tentatively proposed five major depositional sequences occurring among these units. The sequences were identified by using unconformities, fossils and lithological characters of the units that resulting from relative sea level changes.

A more detailed work using all the information previously reported for these formations will be made. After recognizing the most important boundaries these will be verified by the study of outcrops and cores of the corresponding formations. These will result in a model that will show and explain how the middle Tertiary limestone ramp developed over time and its relationship in global terms.

Using sequence stratigraphy it will be possible to develop a diagram of sea level changes in both, local and regional terms. For this study the units that will be used are the Lares Limestone, Montebello Limestone Member of the Cibao Formation, Aguada (Los Puertos) Limestone, Aymamón Limestone, and the Quebradillas Limestone, following the nomenclature of the USGS (1992).