Even thick sequences of sediments in marine depositional basins contain only limited segments of the record of chlorophyll diagenesis. Extracts from Pleistocene deep-sea sediments (Baker and Smith, 1973a) yielded extensive information concerning early chlorin transformations. Investigations of marine sediments of Pliocene and Miocene age resulted in the first reports of free base porphyrins occ...

A geologic map is a 2-dimensional representation of an interpretation of 3-D phenomena. The work of a geologist consists mainly in (i) inferring subsurface structures from observed surface phenomena and (ii) building abductive models of events and processes that shaped them during the geologic past. In order to do this, chains of explanations are used to reconstruct the Earth history step-by-st...

The nature of Re–platinum-group element (PGE; Pt, Pd, Ir, Os, Ru) transport in the marine environment was investigated by means of marine sediments at and across the Cretaceous–Tertiary boundary (KTB) at two hemipelagic sites in Europe and two pelagic sites in the North and South Pacific. A traverse across the KTB in the South Pacific pelagic clay core found elevated levels of Re, Pt, Ir, Os, a...

Currently, bioavailable iron (Fe) controls CO 2 uptake in about half of the world's oceans. Furthermore, Fe fluxes to Fe-limited regions have been responsible for phytoplankton blooms and global cooling in the geologic past. The uptake process of Fe from fluxes of various speciation and solubility is not well known, but highly critical. The study of inorganic particulate Fe and its interactions...

Coordinated research efforts are underway on three continents (North America, Europe, Australia) to study naturally occurring carbon dioxide deposits, in order to address fundamental questions and concerns about the long-term storage of CO2 in geologic formations. Natural accumulations of carbon dioxide exist in many geologic basins. Some deposits are stored in secure and impermeable traps, whe...

The late Pliocene, ~3.3–3.0 Ma, is the most recent interval of sustained global warmth in the geologic past. This window is the focus of climate reconstruction efforts by the U.S. Geological Survey’s Pliocene Research, Interpretation, and Synoptic Mapping (PRISM) Data/Model Cooperative, and may provide a useful climate analog for the coming century. Reconstructions of past surface ocean conditi...

Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclose...

In this paper we describe CO2-PENS, a comprehensive system-level computational model for performance assessment of geologic sequestration of CO2. CO2-PENS is designed to perform probabilistic simulations of CO2 capture, transport and injection in different geologic reservoirs. Additionally, the long-term fate of CO2 injected in geologic formations, including

Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m/s. Critical velocities in large rivers can be of the order of 1-10 m/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. The importance of the low chara...

Concerns about potential liquefaction and resulting flowslide type failures at Wickiup Dam in Central Oregon prompted geophysical studies of the left wing dike, studies which included a high resolution seismic reflection survey. High resolution seismic reflection data effectively delineated structures and correlated lithologies to shallow borehole data above the surface of the dipping, basalt b...