Search Results

Detailed measured sections and regional stratigraphic cross sections are used to reconstruct facies maps and interpret paleogeographic settings for the interval from the base of Upper Cretaceous Mesaverde Formation to top of lower member of the Paleocene Fort Union Formation in the Wind River Basin, Wyoming. The Mesaverde Formation spans...

The Everglades Depth Estimation Network (EDEN) is an integrated network of real-time water-level monitoring, ground-elevation modeling, and water-surface modeling that provides scientists and managers with current (2000-present), online water-stage and water-depth information for the entire freshwater portion of the Greater Everglades. Continuous daily spatial interpolations of the EDEN network stage...

We observe in 6 key sectors of East and West Antarctica continental margin a change in the geometry of the sedimentary deposits which is characterized by: margin-wide erosion and subsequent progradation on the continental shelf; downlap on the continental slope; major mass wasting deposits on the continental rise. The change occurs in...

Multibeam sonar bathymetry documents a lack of significant channels crossing outer continental shelf and slope of the western Ross Sea. This indicates that movement of bottom water across the shelf break into the deep ocean in this area is mainly by laminar or sheet flow. Subtle, ~20 m deep and...

Flood lavas, by definition, cover vast areas in great sheets of lava, without the construction of major edifices (e.g., Geikie, 1880; Washington, 1922; Tyrrell, 1937; Self et al., 1997). The flat terrain that flood lavas produce has led to the term “plateau volcanism” to be used as a synonym for...

High-resolution digital elevation data acquired by airborne laser scanning (ALS) for the Denton Hills, along the coastal foothills of the Royal Society Range, Transantarctic Mountains, are examined for applications to bedrock and glacial geomorphic mapping. Digital elevation models (DEMs), displayed as shaded-relief images and slope maps, portray geomorphic landscape features...

The stratigraphic cross sections presented in this report were constructed as part of a project conducted by the U.S. Geological Survey to characterize and evaluate the undiscovered oil and gas resources of the Wind River Basin (WRB) in central Wyoming. The primary purpose of the cross sections is to show...

Tampa Bay is a shallow, Y-shaped coastal embayment that is located along the center of the Florida Platform – an expansive accumulation of Cretaceous–Tertiary shallow-water carbonates and evaporites that were periodically exposed during glacio–eustatic sea level fluctuations. As a consequence, extensive karstification likely had a controlling impact on the geologic...

New and existing seismic reflection data in southern McMurdo Sound have been used to investigate Neogene tectonic history of the Terror Rift adjacent to the Transantarctic Mountains and along the western margin of the West Antarctic Rift System. Seismic data image a young rifting episode that is largely unsampled by CRP...

The most completely articulated fossil skeleton heretofore found on the continent of Antarctica is represented by a juvenile plesiosaur. The specimen was found in the Sandwich Bluff area of Vega Island east of the Antarctic Peninsula from Late Cretaceous (Maastrichtian) marine deposits from the upper Snow Hill Island Formation. The...

No abstract available. ...

We present the results of a seismic reflection experiment performed transverse to flow a few tens of kilometers above the main trunk of Kamb Ice Stream, West Antarctica, where we image a basal high surrounded by variable subglacial conditions. This high rises as much as 200 m above the surrounding...

Seventy-eight samples collected from marine shales from the Cretaceous Mowry Shale, the lower part of the Frontier Formation, and the lower shaly and upper sandy members of the Cody Shale in the Wind River Basin, Wyoming, were analyzed using Rock-Eval and total organic carbon analysis to determine the source rock...

Interest in the generation of tsunamis by submarine mass movements has warranted a reassessment of their distribution and the nature of submarine landslides offshore of the eastern U.S. The recent acquisition and analysis of multibeam bathymetric data over most of this continental slope and rise provides clearer view into the...

This volume on continental margin sedimentation brings together an expert editorial and contributor team to create a state-of-the-art resource. Taking a global perspective, the book spans a range of timescales and content, ranging from how oceans transport particles, to how thick rock sequences are formed on continental margins.- Summarizes and...

Initiated in 1995, the Antarctic Digital Magnetic Anomaly Project (ADMAP) produced the first magnetic anomaly map of the Antarctic region south of 60 o S (Golynsky et al., 2001). This map synthesized over 7.1 million line-kms of survey data available up through 1999 from marine, airborne and Magsat satellite observations. Since the...

A small sedimentary deposit near Gneiss Point on the western side of McMurdo Sound, previously identified as shale, is described. The deposit is phillipsite, a zeolite that is believed to have formed from the deposition and alteration of volcanic ash in a small ice-marginal saline lake. Other previously recorded occurrences...

Active geologic processes associated with the Yellowstone hotspot are fundamental in shaping the landscapes of the greater Yellowstone ecosystem (GYE), a high volcanic plateau flanked by a crescent of still higher mountainous terrain. The processes associated with the Yellowstone hotspot are volcanism, faulting, and uplift and are observed in the...

The coastal zone of the United States is a dynamic environment evolving in response to both natural processes and human activities. In order to protect coastal populations and resources, a detailed understanding of the physical setting and of the processes responsible for change is required. A sustained program of mapping...

To date, the majority of evidence indicates that most subsurface environments possess climax ecological communities that are well adapted to the environment in which they live. Like their counterparts on the surface, subsurface ecosystems are characterized by a high degree of microbiological diversity, they possess trophic structure, and they exhibit...

Cenozoic magmatic rocks of the Transantarctic Mountains provide an important window on the tectonic and magmatic processes of the West Antarctic Rift System. Previous aeromagnetic investigations in northern Victoria Land have delineated Cenozoic volcanic and intrusive complexes assigned to the McMurdo Volcanic Group and Meander Intrusives over the Transantarctic Mountains....

Granulite-facies metamorphism is extensively reported in Late Neoproterozoic/Early Palaeozoic time during formation of the East-African-Antarctic orogen (EAAO). Metamorphic data acquired from the Pan-African orogen of central Dronning Maud Land (cDML) are compared with data from northern Mozambique. The metamorphic rocks of cDML are characterised by Opx±Grt-bearing gneisses and Sil+Kfs-bearing metapelites...

This paper discusses a 5.2-0 Ma high-resolution terrigenous particle size record recovered from a sediment drift off East Antarctica. The particle size properties of Hole 1165B are interpreted in the context of previously acquired data on a continental shelf to slope transect drilled by ODP Leg 188 in Prydz Bay...

No abstract available....

More than 15 years of field and laboratory investigations on samples from Terre Adélie to the western part of George Vth Land (135 to 146°E) during the GEOLETA program allow a reassessment of the Terre Adélie Craton (TAC) geology. The TAC represents the largest exposed fragment of the East Antarctic...