Prehistoric Site Discovery on the Outer Continental Shelf, Gulf of Mexico, United States of America

Abstract

In 1984, over a quarter of a century ago, Coastal Environments, Inc., undertook a study designed to locate submerged prehistoric archaeological deposits on the continental shelf of the Gulf of Mexico. This early effort at submerged archaeological site discovery relied on a research strategy and a series of technological approaches that have since become standard in this field of study. The region of interest was the now-filled and submerged stream valley of the Sabine River offshore of Louisiana and Texas. Research involved the collection and synthesis of a large amount of high-resolution seismic data and core records in order to reconstruct the presubmergence landscape of the region. Models of prehistoric site distributions derived from onshore analogs were extended to the offshore landscape to identify the now-submerged landforms with a high likelihood of containing preserved cultural remains. Climate change, reflected principally in sea-level change, was incorporated into the predictive model of site distribution and preserved landform occurrence in the offshore area of interest. More than 70 vibracores were used to collect sediment samples from several identified high-probability landforms. Analyses indicated the existence at one of the sample locations of cultural deposits dating to ca. 8,800 BP. Subsequent research in the region has employed a similar strategy in the search for submerged prehistoric deposits. The methods and techniques employed in this early effort, and the subsequent study, are discussed and their application to future research on submerged prehistoric sites and landscapes in the Gulf of Mexico is considered.