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hydrocarbon reservoirs Contact Kea Giles for additional information or assistance. Long term origination rates are reset only at mass extinctions Andrew Z. Krug and David Jablonski, Dept. of Geophysical Sciences, University of Chicago,fake oakleys, 5734 South Ellis Avenue, Chicago, Illinois 60637, USA. Posted online 15 June 2012; doi: 10.1130/G33091.1. Diversification during recovery intervals is rapid relative to background rates, but the impact of recovery dynamics on long term evolutionary patterns is poorly understood. Age distributions for cohorts of marine bivalves show that intrinsic origination rates tend to remain constant,burberry factory outlet, shifting only during intervals of high biotic turnover, particularly mass extinction events. Genera originating in high turnover intervals have longer stratigraphic durations than genera arising at other intervals, and drive the magnitude of the shift following the Cretaceous Paleogene extinction. Species richness and geographic range promote survivorship and potentially control rates through ecospace utilization, and both richness and range have been observed to expand more rapidly in recovery versus background states. Post Paleozoic origination rates, then, are directly tied to recovery dynamics following each mass extinction event. Canyon morphology on a modern carbonate slope of the Bahamas: Evidence of regional tectonic tilting T. Mulder et al.,ray bans, Universit de Bordeaux, UMR 5805 EPOC, 33405 Talence cedex, France. Posted online 29 June 2012; doi: 10.1130/G33327.1. New high quality bathymetry data collected in November 2010 during an international cruise led by the University of Bordeaux on the French Oceanographic research vessel Le Surot depict the morphology of the northern slope of the Little Bahama Bank (North of Gran Bahama). The survey reveals the details of large and small scale morphologies, including slope failure scars and canyons. The slope shows true turbidite systems extending over approx. 40 km and built by mass flow events and turbidity currents. Slope failures show sinuous head scarps, most of them being filled with recent sediment. Canyons have amphitheater shaped heads resulting from these coalescing slump scars. Canyons rapidly open on a short channel and a depositional lobe. Detailed analyses of bathymetric data show that the canyon and failure scar morphology and geometry vary following a W E trend along the bank slope, consistently with a westward tectonic tilt of the bank during the Cenozoic. The study of such carbonate turbidite systems could lead of the discovery of new types of rock bearing hydrocarbon reservoirs in similar systems located in ancient carbonate dominated depositional systems. New Zealand and UK Holocene flooding demonstrates interhemispheric climate asynchrony Mark G. Macklin et al.,katespade, Institute of Geography and Earth Sciences,coach factlet outlet online, Aberystwyth University, Ceredigion SY23 3DB, UK. Posted online 29 June 2012; doi: 10.1130/G33364.1. More than 1,000 radiocarbon ages sourced from floodplains in the UK and New Zealand have been used to detect the timing of large scale flooding during the past 10,000 years in these temperate maritime regions of the Northern and Southern Hemispheres. Probability and statistical analyses of these datasets shows that flood rich centuries in New Zealand and the UK were largely asynchronous during this time period. Since these major periods of flooding, or "wet centuries," are controlled by large scale shifts in atmospheric circulation, these findings demonstrate that short term climate change was out of phase in the temperate maritime regions of the Northern and Southern Hemispheres. This supports recent research that has suggested that Holocene climate changes may have been antiphased between the polar regions, possibly related to variation in the strength of deep water formation. Reconstructing and interrogating flood histories in the UK and New Zealand provides a novel means of addressing one of the grand challenges in Holocene paleoclimate research, namely establishing whether centennial scale climate change between the Hemispheres has been synchronous. These data strongly suggest climatic asynchrony. Evans et al.,marc jacobs outlet, School of Applied Geology, Curtin University, GPO Box 1987,ray ban, WA 6845, Australia. Posted online 29 June 2012; doi: 10.1130/G33037.1. Ocean crust forms from mantle derived magmas at mid ocean ridges, travels across the ocean floor as Earth's tectonic plates move, and descends down subduction zones to be recycled into the Earth. This cycling of material from Earth's interior to exterior and back again forms one of the planet's primary geochemical cycles. Oceanic crust reacts chemically with the ocean, and this process changes the composition of that crust. Thus, when oceanic crust is recycled back into the interior of the Earth, it adds components that were not present when it was first formed. One of the most interesting and least well known changes in the composition of ocean crust is its oxidation by the ocean. It has been proposed that subduction of this oxidized ocean crust, and release of the oxidized components within the Earth, cause portions of Earth's mantle to oxidize, and that this oxidation is a necessary prerequisite to the formation of some types of ore deposits that include copper, gold, and molybdenum. However, this conclusion is controversial. Evans and colleagues used new analyses of mantle derived material in oceanic crust and model calculations to explore the plausibility of different proposed fates for subducted oxidized material. The offshore export of sand during exceptional discharge from California rivers Jonathan A. Warrick and Patrick L. Geological Survey, Pacific Coastal and Marine Science Center, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA. Posted online 29 June 2012; doi: 10.1130/G33115.1. Having an accurate accounting of how much sand is available to build beaches is important for understanding and dealing with coastal erosion. west coast are the primary sources of sand to this region's popular beaches,vans pas cher, and the majority of this sand is discharged during floods on these rivers. Warrick and Barnard found that rivers with high rates of sediment discharge, like the Santa Clara River of southern California,louboutin, discharge sand far offshore of the littoral cell the nearshore area that provides sand for beaches. Thus,hogan outlet, a significant amount of the sand discharged by rivers such as these is deposited on the inner continental shelf, beyond the reach of waves that would otherwise move it up onto beaches. This suggests that a portion of the sand supplied to the southern California coastal regions by rivers will not resupply sand budgets of the coastal littoral cells. Langridge, Dept. of Geological Sciences, University of Canterbury, Private Bag 4800,asics running, Christchurch, New Zealand. Posted online 29 June 2012; doi: 10.1130/G33363.1. The Alpine fault is the major onshore plate boundary structure between the Australian and Pacific plates on the South Island of New Zealand. No previous study of the central portion of the high uplift central segment has provided on fault evidence for the most recent earthquake (MRE). Landridge discovered the main trace of the fault in the rainforest north of Gaunt Creek (Westland) as a north trending fault a major deviation from the generally northeast trending fault. 1717 earthquake. By comparing other records for the 1717 earthquake with recent research along the fault, De Pascale and Landridge calculate a moment magnitude (Mw) of between Mw 8.0 to 8.2 in 1717,tory burch, a great earthquake that is larger than any previous estimate. Because the Alpine fault has not ruptured for 300 years, it is likely approaching the end of its seismic cycle and poses a significant seismic hazard to New Zealand. Disequilibrium dihedral angles in dolerite sills: A new proxy for cooling rate Marian B. Holness et al., Department of Earth Sciences, University of Cambridge, Downing Street,lululemon, Cambridge CB2 3EQ, UK. Posted online 29 June 2012; doi: 10.1130/G33119.1. Working out how long bodies of magma take to solidify is important if we want to understand how volcanoes behave. Until now this has been done using theoretical cooling models or by looking at how big the individual crystals are (the bigger the crystals the longer time they had to grow). Here we show that the way the grain fit together gives us an accurate picture of how long magma took to solidify: the geometry of three grain junctions is a highly sensitive speedometer for crystallization times between 10 and 1000 years,ghd hair. Gravity fluctuations induced by magma convection at Kilauea volcano, Hawai'i Daniele Carbone and Michael P. Poland, Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Osservatorio Etneo,polo shirts, Catania 95125, Italy. Posted online 29 June 2012; doi: 10.1130/G33060.1. This paper reports on the first continuous gravity measurements accomplished at Kilauea volcano in Hawai'i. Daniele Carbone and Michael Poland recorded the shortest period gravity oscillations related to volcanic activity that have ever been detected, which they associate with convection in a shallow magma chamber. Rapid magma convection has long been hypothesized at persistently active volcanoes based on numerical simulations, but supporting data are largely absent from the literature. Carbone and Poland interpret their gravity data to be the first geophysical fingerprint of convection occurring over a time scale on the order of minutes in a shallow magma reservoir. The implications of the paper are twofold: (1) the results provide a new perspective on how magma circulates at Kilauea and other persistently active volcanoes, which can impact the understanding of gas emissions, seismic activity, and eruptions; and (2) Carbone and Poland highlight the great potential of a continuous gravity, a relatively new technique, as a tool to study (and monitor) active volcanoes. 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