Publications

The island of Puerto Rico, in the northeast Caribbean, lies within a broad deformation zone between the Caribbean and North American plates. The simplest model for the tectonic setting of Puerto Rico has major strike-slip movement on nearly east-west lines in the vicinity of the Puerto Rico Trench coupled to a small counterclockwise rotation of a Puerto Rico block within the broader plate boundary

High-resolution seismic-reflection profiles off the lower Florida Keys reveal a multiple outlier-reef tract system ~0.5 to 1.5 km sea-ward of the bank margin. The system is characterized by a massive, outer main reef tract of high (28 m) unburied relief that parallels the margin and at least two narrower, discontinuous reef tracts of lower relief between the main tract and the shallow bank-margin

The stratigraphy of Late Quaternary geologic units beneath Long Island Sound (LIS) is interpreted from 3,500 km of high-resolution, seismic-reflection profiles supplemented by vibracore data. Knowledge gained from onshore regional geologic studies and previous offshore investigations is also incorporated in these interpretations. Glacial deposits overlie and nearly fill an Inner Lowland which is f

A conference on Antarctica: an Exploitable Resource too Valuable to Develop? took place at the Sir Robert Menzies Centre for Australian studies at the University of London in either late 1989 or early 1990. The papers were compiled into this small book (only 104 pages of text exclusive of useful appendices containing maps, texts of the Antarctic treaty and the Convention on the regulation of Antar

No abstract available.

No abstract available 

Methane may have been released to the atmosphere during the Quaternary from Arctic shelf gas-hydrates as a result of thermal decomposition caused by climatic warming and rising sea-level; this release of methane (a greenhouse gas) may represent a positive feedback on global warming [Revelle, 1983; Kvenvolden, 1988a; Nisbet, 1990]. We consider the response to sea-level changes by the immense amount

High-resolution seismic-reflection profiles of the Quicksands, located along a broad ridge on the platform shelf west of Key West, Florida, indicate a significant deposit of non-oolitic carbonate sand occurs in a belt 47 km long by 28 km wide. The surface of the belt is ornamented by large (5 m), migrating tidal bars, oriented in a north-south direction, on which sand waves, oriented in an east-we

We present a detailed velocity model across the 1.1 billion year old Midcontinent Rift System (MRS) in central Lake Superior. The model was derived primarily from onshore-offshore large-aperture seismic and gravity data. High velocities obtained within a highly reflective half-graben that was imaged on coincident seismic reflection data demonstrate the dominantly mafic composition of the graben fi

The porous limestone bedrock, thin sediment cover, and tectonic stability of the Florida Platform during the past 15 ka BP provide an exceptionally suitable setting for reconstruction of paleoshorelines and onshore projection of future shorelines in a rising-sea scenario. Paleoshorelines for 8, 6, 4 and 2 ka BP show that 1) a series of limestone islands formed, then drowned, along the outer platfo

A mooring containing diverse carbonate and anhydrite substrates was exposed to bottom waters for 9 months at the base of the Florida Escarpment to determine the influence of dissolution on the development of this continental margin. Weight loss was measured on all samples. Etching, pitting, and loss of the original framework components were observed on substrates with known characteristics. Extrap

A study of the barrier islands and wetlands in the deltaic plain of Louisiana is presented. Its purpose was to document rapid changes and to learn more about the processes responsible and the geologic framework within which they operate. It included systematic collection and analysis of precision nearshore hydrographic data, high resolution seismic profiles, surface sediment samples, continuous vi