Abstract The Gold King mine water release that occurred on 5 August 2015 near the historical mining community of Silverton, Colorado, highlights the environmental legacy that abandoned mines have on the environment. During reclamation efforts, a breach of collapsed workings at the Gold King mine sent 3 million gallons of acidic and metal-rich mine water into the upper Animas River, a tributary to the Colorado River basin. The Gold King mine is located in the scenic, western San Juan Mountains, a region renowned for its volcano-tectonic and gold-silver-base metal mineralization history. Prior to mining, acidic drainage from hydrothermally altered areas was a major source of metals and acidity to streams, and it continues to be so. In addition to abandoned hard rock metal mines, uranium mine waste poses a long-term storage and immobilization challenge in this area. Uranium resources are mined in the Colorado Plateau, which borders the San Juan Mountains on the west. Uranium processing and repository sites along the Animas River near Durango, Colorado, are a prime example of how the legacy of mining must be managed for the health and well-being of future generations. The San Juan Mountains are part of a geoenvironmental nexus where geology, mining, agriculture, recreation, and community issues converge. This trip will explore the geology, mining, and mine cleanup history in which a community-driven, watershed-based stakeholder process is an integral part. Research tools and historical data useful for understanding complex watersheds impacted by natural sources of metals and acidity overprinted by mining will also be discussed.

Abstract The recent detection of plumes of methane venting into the Martian atmosphere indicates the probable presence of a substantial subsurface hydrocarbon reservoir. Whatever the immediate source of this methane, its production(whether by biogenic or abiogenic process) almost certainly occurred in association with the presence of liquid water in the deep (>5+ km [>3+ mi]) subsurface, where geothermal heating is thought to be sufficient to raise crustal temperatures above the freezing point of water. Indeed, a geologicevidence that the planet once possessed vast reservoirs of subpermafrost groundwater that may persist to the present day exists. If so, then methanegeneration has likely spanned a similar period of time, extending over a considerable part of the geologic history of Mars. As on Earth, the ventingof natural gas on Mars indicates that substantial amounts of gas are likely present, either dissolved in groundwater or as pockets of pore–filling free gas beneath the depth where the pressure–temperature conditions permitthe formation of gas hydrate. Hydrate formation requires the presence of either liquid water or ice. The amount of water on Mars is unknown; however,the present best geologic estimates suggest that the equivalent of a global layer of water 0.5–1 km (0.3–0.6 mi) deep may be stored as ground ice and groundwater beneath the surface. The detection of methane establishes the subsurface of Mars as a hydrocarbon province, at least in the vicinity of the plumes. Hydrocarbon system analysis indicates that methane gas and hydrate deposits may occur in the subsurface to depths ranging from approximately 10 m (~30 ft) to 20 km (10 mi). The shallow methane deposits may constitute a critical potential resource that could make Mars an enabling.stepping stone for the sustainable exploration of the solar system. They provide the basis for constructing facilities and machines from local Martian resources and for making higher energy–density chemical rocket fuels for both return journeys to Earth and for more distant exploration.

Abstract The simplest models of passive margins would suggest that they are characterized by tectonic quiescence as they experienced gentle thermal subsidence following the extensional events that originally formed them. Analysis of newly acquired and pre-existing 2D seismic data from the Rockall Plateau to the Faroe Shelf, however, has confirmed that the NE Atlantic Margin was the site of significant active deformation. Seismic data have revealed the presence of numerous compression-related Cenozoic folds, such as the Hatton Bank, Alpin, Ymir Ridge and Wyville–Thomson Ridge Anticlines. The distribution, timing of formation and nature of these structures have provided new insights into the controls and effects of contractional deformation in the region. Growth of these compressional features occurred in five main phases: Thanetian, late Ypresian, late Lutetian, Late Eocene (C30) and Early Oligocene. Compression has been linked to hotspot-influenced ridge push, far-field Alpine and Pyrenean compression, asthenospheric upwelling and associated depth-dependent stretching. Regional studies make it clear that compression can have a profound effect on seabed bathymetry and consequent bottom-water current activity. Bottom-water currents have directly formed the early Late Oligocene, late Early Miocene (C20), Late Miocene–Early Pliocene, and late Early Pliocene (C10) unconformities. The present-day Norwegian Sea Overflow (NSO) from the Faroe–Shetland Channel into the Rockall Trough is restricted by the Wyville–Ymir Ridge Complex, and takes place via the syncline (Auðhumla Basin) between the two ridges. The Auðhumla Basin Syncline is now thought to have controlled the path of the NSO into the Rockall Trough and the resulting unconformity formation and sedimentation therein, no later than the Mid Miocene.

Abstract The ‘Unconventional oil and gas resources and the geological storage of carbon dioxide’ section of the Proceedings is designed to provide new insights from recent research and exploitation within these major growth areas in applied geology. Research and innovation on unconventional oil and gas have been driven by market needs – specifically concerns over oil and gas supply – as well as technological development. A cross-section of this work is highlighted in the current set of papers, covering ultra-heavy oil, shale oil, shale gas, basin-centred gas, tight gas and clathrates. Unsurprisingly, much of this research has been pioneered in North America. This work is complemented herein by some initial studies from Europe. Similarly, the geological storage of CO 2 is not simply a story of technological advance but also a response to an urgent societal imperative. Carbon dioxide sequestration is recognized as an important method for reducing greenhouse gas emissions in the near future, and is expected to have growing relevance to the oil and gas industry and the energy sector. Recent findings from current commercial carbon capture and storage projects in the North Sea and North Africa are presented and are complemented by an overview of major research programmes established in North America.

Abstract The San Juan volcanic field comprises 25,000 km 2 of intermediate composition mid-Tertiary volcanic rocks and dacitic to rhyolitic calderas including the San Juan-Uncompahgre and La Garita caldera-forming super-volcanoes. The region is famous for the geological, ecological, hydrological, archeological, and climatological diversity. These characteristics supported ancestral Puebloan populations. The area is also important for its mineral wealth that once fueled local economic vitality. Today, mitigating and/or investigating the impacts of mining and establishing the region as a climate base station are the focuses of ongoing research. Studies include advanced water treatment, the acid neutralizing capacity (ANC) of propylitic bedrock for use in mine-lands cleanup, and the use of soil amendments including biochar from beetle-kill pines. Biochar aids soil productivity and revegetation by incorporation into soils to improve moisture retention, reduce erosion, and support the natural terrestrial carbon sequestration (NTS) potential of volcanic soils to help offset atmospheric CO 2 emissions. This field trip will examine the volcano-tectonic and cultural history of the San Juan volcanic field as well as its geologic structures, economic mineral deposits and impacts, recent mitigation measures, and associated climate research. Field trip stops will include a visit to (1) the Summitville Superfund site to explore quartz alunite-Au mineralization, and associated alteration and new water-quality mitigation strategies; (2) the historic Creede epithermal-polymetallic-vein district with remarkably preserved resurgent calderas, keystone-graben, and moat sediments; (3) the historic mining town of Silverton located in the nested San Juan-Silverton caldera complex that exhibits base-metal Au-Ag mineralization; and (4) the site of ANC and NTS studies. En route back to Denver, we will traverse Grand Mesa, a high NTS area with Neogene basalt-derived soils and will enjoy a soak in the geothermal waters of the Aspen anomaly at Glenwood Springs.

Abstract Resource estimates for gas hydrate that have been reported during the past 30 years have pointed to a truly vast potential, but one that has persistently remained just over the horizon due to technical and economic hurdles. It is only in the last 10 years that commercial development of gas hydrate has been considered in the context of a petroleum system. The new focus is on components such as source, migration, traps, seals, and reservoir lithology. The petroleum system model, combined with recent drilling efforts, has led to revised resource estimates and viable production scenarios. Most of the world’s gas hydrate occurs in low concentrations in impermeable shales (comprising 3% to 5% of the sediment volume) or as isolated veins that cannot be commercially developed. In contrast, sands within the hydrate-stability zone typically have high hydrate saturations within the pore volume, exceeding 80% saturation in some locations. Although the gas hydrate reservoirs having commercial potential are only a small fraction of the global hydrate volume, they still have resource potential in the thousands of trillion cubic feet (Tcf). Although it is unrealistic to consider the global potential of gas hydrate to be in the hundreds of thousands of Tcf, there is a strong potential in the hundreds of Tcf or thousands of Tcf. The U.S. Minerals Management Service (MMS) estimates a total gas hydrate volume for the Gulf of Mexico of between 11,112 and 34,423 Tcf, and a mean estimate of 6,717 Tcf in place in sandstone reservoirs. A United States Geological Survey (USGS) assessment for the North Slope of Alaska reports a mean estimate of 85.4 Tcf technically recoverable from hydrate. Gas has been produced from hydrate-bearing reservoirs on a very limited scale through short-term production tests in the Canadian Arctic and on the North Slope of Alaska. A long-term, industry-scale production test is planned for the North Slope in the summer of 2010 and the potential for hydrate development for local use following soon after. Production testing for hydrate in the Gulf of Mexico will follow within a few years. Japan is planning an offshore hydrate production test in 2011. Hydrate development programs are also in progress in India and South Korea.

Abstract A strong upward trend exists for the consumption of all energy sources as people throughout the world strive for a higher standard of living. Someday, possibly soon, the earth's store of easily accessed hydrocarbons will no longer satisfy our growing economies and populations. By then, an unfamiliar but kindred hydrocarbon resource called natural gas hydrate may become a significant source of energy. Approximately 35 years ago, Russian scientists made what was then a bold assertion that gas hydrates, a crystalline solid of water and natural gas and a historical curiosity to physical chemists, should occur in abundance in the natural environment. Since this early start, the scientific foundation has been built for the realization that gas hydrates are a global phenomenon, occurring in permafrost regions of the arctic and in deep-water parts of most continental margins worldwide. The amount of natural gas contained in the world's gas-hydrate accumulations is enormous, but these estimates remain highly speculative. Researchers have long speculated that gas hydrates could eventually be a commercial producible energy resource, yet technical and economic hurdles have historically made gas-hydrate development a distant goal instead of a near-term possibility. This view began to change in recent years with the realization that this unconventional resource could possibly be developed with the existing conventional oil and gas production technology. The pace of gas-hydrate energy assessment projects has significantly accelerated over the past several years, but many critical gas-hydrate exploration and development questions still remain. The exploitation and potential development of gas-hydrate resources is a complex technological problem. However, humans have successfully dealt with such complicated problems in the past to satisf your energy needs; technical innovations have been key to our historical successes.

Abstract A regional three-dimensional model has been constructed for the lithospheric structure of the NE Atlantic margin. Starting from the known bathymetry and an initial sediment thickness estimate and making allowance for thermal effects, the geometry of the crystalline crust was predicted using isostatic and flexural principles. Optimization methods were then used to modify the base sediment and Moho interfaces to improve the fit between observed and calculated gravity anomalies. The method provides new insights into basin morphology and into variations in the thickness of both crystalline continental crust and igneous oceanic crust. When combined with imaging of the gravity and magnetic fields, the model highlights the importance of broadly NW-trending lineaments on the development of post-Caledonian basin architecture. In some cases these lineaments are interpreted as pre-Caledonian structures that were reactivated as transfer zones during phases of Mesozoic extension. Some of the lineaments appear to have influenced the early evolution of the oceanic crust by providing the precursors to transform offsets and possibly also by affecting the pattern of asthenospheric flow. The crustal thickening of the Faroe-Iceland Ridge is clearly imaged and its geometry is interpreted to reflect temporal variations in the enhanced oceanic crustal production rate responsible for this feature, including a Late Eocene minimum which can be correlated with plate reorganization in the north Atlantic region. There is some evidence of Cenozoic deformation linked to transpressive reactivation of the lineaments. However, a deflection in the axis of the North Hatton Anticline across the NW-trending Anton Dohrn lineament is more likely to have been inherited from an offset in an underlying, reactivated basement structure than to have resulted from strike-slip movements at the time of folding.

Abstract The nature and age of the Cenozoic compressional/transpressional deformation within the NE Faroe–Shetland Basin, the Wyville–Thomson Ridge and Hatton Bank areas have been investigated, primarily using seismic reflection data. In all three areas, the folds reach approximately 2 to 4 km in amplitude and 40 km in wavelength. Early and mid-Eocene compressional/transpressional deformation affected the Hatton Bank and Wyville–Thomson Ridge areas, and folding was locally active even earlier, during Paleocene/Cretaceous times. However, the main Cenozoic compressional/transpressional tectonism that affected the Hatton Bank area was coeval with development of the regional Late Eocene Unconformity (C30), and with changes in spreading geometries and a phase of accelerated subsidence in the Rockall Basin. Within the NE Atlantic margin, WNW- to NW-trending lineaments/transfer zones and associated oceanic fracture zones facilitate significant structural segmentation. Offsets in the continent–ocean boundary along Hatton Bank probably reflect inherited basin architecture, and many Cenozoic folds in the Hatton Bank, Wyville–Thomson Ridge and NE Faroe–Shetland Basin areas are considered to mainly reflect compressional buttressing against pre-existing structures. However, relatively small lateral displacements probably occurred along some reactivated transfer zones following continental break-up. Paleocene–Eocene compressional/transpressional deformation may have affected parts of the Faroe–Shetland Basin, but seismic resolution of this is largely masked by pervasive polygonal faulting. Significant, early to mid-Miocene compressional/transpressional deformation is recorded in the NE Faroe–Shetland Basin, and may also have exerted a major influence on the Wyville–Thomson Ridge and surrounding area. In particular, mid-Miocene growth of the Faroe Bank Channel syncline may have resulted in major changes in northern hemisphere deep-ocean circulation with associated impact on global climate. Compressional/transpressional deformation appears to have continued into Pliocene– ?Recent times and resulted in the development of features such as the Pilot Whale Anticline and associated mud volcanoes/diapirs.

Abstract The Porcupine Basin is characterized by a large central free air gravity anomaly high (+55 mGal) flanked by local lows. In contrast, the Porcupine Seabight Basin has low-amplitude anomalies in its centre, flanked by edge anomalies. Two transects, one in each of these basins, have been modelled using satellite gravity data; the upper parts of the transects are constrained by interpretation of recent commercial seismic reflection data and two wells. Results from the modelling suggest that the Porcupine Basin is not in isostatic equilibrium. In contrast, the essentially zero free air anomaly over the centre of the Porcupine Seabight Basin suggests that this basin is isostatically compensated. The difference in isostatic compensation between the two basins may reflect a fundamental contrast between the strength of the crust; the crust underlying the Porcupine Basin possesses the greater strength. The Clare Lineament may represent a fundamental boundary within the ‘Avalonian Terrane’ that juxtaposes basement blocks of differing rheologies.