The August 2007 expedition to the Black Sea continued a multiyear project designed to locate and study ancient shipwrecks in deep water. The expedition revisited and investigated two shipwrecks, Sinop D (at 325 m depth off Sinop, Turkey) and Chersonesos A (at 135 m depth off Sevastopol, Ukraine). These wreck sites are good case studies for our research because they are located in different parts of the Black Sea, in anoxic and suboxic waters, respectively. Preliminary data reported here are from seawater samples taken from around the wrecks and a year-long collection of temperature, salinity, and pressure data. Trace-element data from the seawater samples are consistent with reported processes and values for the Black Sea. The oceanographic sensor data confirm the stagnant nature of the anoxic water layer that has allowed for the high level of preservation of the Sinop D wreck site. We also discuss the design and placement of two sets of experiments left in situ to characterize the decay rates of common materials found on ancient shipwrecks, including wood and metal. By providing ways to understand the chemical and physical processes that characterize different parts of the Black Sea water column, these wrecks are important sites for (1) determining the preservation potentials of cultural materials in deep water, and (2) informing the design of methodologies necessary to conserve them.

Abstract The Otway Basin is a large, multi-phase rift basin located on the Australian southern margin. Oil and gas recovered from the Otway Basin belong to the Austral petroleum supersystem and are predominately derived from Mesozoic fluvio-lacustrine source rocks. Based on the results of geohistory modeling and oil and gas family analysis, two main petroleum systems are identified in the basin, the Early Cretaceous Crayfish(!) petroleum system and the Early-Late Cretaceous Eumeralla-Shipwreck(!) petroleum system. Both of these petroleum systems are classified as “known”. The symbol (!) represents the level of certainty, in this case “known,” meaning that the hydrocarbons in the named source rock and the named primary reservoir unit have been geochemically examined and found to be genetically related. The Crayfish(!) petroleum system is mostly restricted to a series of syn-rift half grabens in the western Otway Basin. The stratigraphic and areal location of potential source and reservoirs rocks in the Crayfish(!) petroleum system is strongly controlled by growth on major half graben faults. Multiple episodes of hydrocarbon charge characterize the Crayfish(!) petroleum system, with oil and gas emplaced during the Early Cretaceous, and a dry gas charge during the Tertiary. Hydrocarbons from the Eumeralla-Shipwreck(!) petroleum system are sourced from coaly facies developed during the regionally extensive fluvio-lacustrine sag sequence that followed the first rifting phase. The reservoir is a fluvio-deltaic lowstand sequence that was deposited during initiation of the second rift phase. The major factors influencing the distribution of the Eumeralla-Shipwreck(!) petroleum system are Late Cretaceous deltaic loading and Oligocene-Miocene carbonate deposition. Favorable conditions for a recent expulsion phase occur in the eastern Otway Basin, where a thick Oligocene-Miocene prograding carbonate succession overlies the relatively thin Late Cretaceous succession.

Abstract Mudflows on the Mississippi River Delta Front (MRDF) are recognized hazards to oil and gas infrastructure in the shallow (20–300 m water depth) Gulf of Mexico. Preconditioning of the seafloor for failure results from high sedimentation rates coupled with slope over-steepening, under-consolidation and abundant biogenic gas production. Catastrophic failure of production platforms and pipelines due to seafloor displacement during infrequent large hurricanes such as Camille in 1969 and Ivan in 2004, point to cyclical loading of the seafloor by waves as a primary movement trigger. Due to data limitations, the role of smaller storms and background oceanographic processes in driving seafloor movement has remained largely unconstrained but these are thought to contribute to significant seafloor change. With the aid of new high-resolution multibeam mapping and seismic reflection profiling across sections of the MRDF, several moving features within the deforming delta-front environment are investigated and potential hazards to infrastructure installed and adjacent to the region are discussed. Via repeat mapping surveys of selected areas and records of changing shipwreck locations, we highlight significant seafloor displacement across annual to decadal timescales. For example, individual blocks mapped within mudflow gullies adjacent to Southwest Pass show downslope transport of more than 80 m in a single year, while the SS Virginia , a 153 m-long oil tanker sunk in 1942, has been relocated and found to have moved downslope more than 400 m in 14 years, without a major hurricane (>Category 2) passing through the region.