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REGIONAL TECTONIC INTERPRETATION OF IMAGE ENHANCED GRAVITY AND MAGNETIC DATA COVERING THE MID-NORWEGIAN SHELF AND ADJACENT MAINLAND

Abstract Gravity and magnetic field data covering mid-Norway and the Norwegian Sea were processed in order to enhance tectonic features on various scales. The local features were subjected to an unconventional processing technique involving a non-linear, adaptive Wallis filter designed to enhance the smallest wave lengths. When compared with recent structural information derived from seismic data, the processed gravity and magnetic maps show the main structural trends, major fault zones and basin boundaries, thus proving their worth for regional tectonic mapping. Previously undetected NW–SE-trending offshore crustal lineaments are revealed. A landward prolongation of the Bivrost Lineament appears to continue subparallel towards Proterozoic shear zones below the Caledonian nappes in the Rana area, either along the western margin of the Transscandinavian Granite–Porphyry Belt or the NW–SE-trending Mala–Skelleftea Tectonic Zone. A large lineament is also observed as a landward prolongation of the Surt Lineament indicating a relationship with the Storsjon–Edsbyn Deformation Zone, a major, deep, crustal shear zone in the Precambrian of Sweden. A slightly increased seismic activity, which is possibly related to the present ridge push force, is observed along parts of the previously unknown transfer zones. Combined gravity and magnetic modelling indicates a low crustal thickness in the northwesternmost part of the Voring Basin, between the Surt and the Jan Mayen Lineaments. The lack of correlation between the gravity and the magnetic patterns observed on the residual field maps suggests the presence of a shallow Curie isotherm situated above or within the uppermost basement.

Continuation of the Caledonides north of Norway: seismic reflectors within the basement beneath the southern Barents Sea

Abstract The offshore continuation of the Caledonides to the north of Norway is poorly understood, and the seismic signature of these rocks is unknown. Indeed, the seismic signature of basement rocks is in general poorly documented from conventional seismic data. This paper discusses an area in the southern Barents Sea — the ‘Gjesvaer low’ — where inferred Caledonian basement rocks have been studied from conventional seismic data. The Gjesvaer low, which has not been described previously as a separate structural element, is defined on image-processed gravity data. The main processing steps were directional filtering and principal component analysis. The interpretation of the low as a feature within the inferred basement rocks is based on well data, the calculated depth to magnetic basement, seismic signature and velocities. In addition, two-dimensional gravity modelling shows that density variations within the basement rocks may explain the observed gravity anomaly. Although the following model may be simplistic, distinct seismic reflectors within the low may be interpreted as originating from tectonic boundaries within a thrust system. In the most likely evolutionary scenario, the Gjesvaer low and the south-western part of the Nordkapp Basin are interpreted as having been formed as continuous Caledonian structures whose continuity has survived until the present. Subsequent Late Palaeozoic erosion may have removed more than 10 km of Caledonian rocks in the area of the low. Carboniferous rifting reactivated the Caledonian structures and the south-western Nordkapp Basin was formed. The Nordkapp Basin, which was decoupled from the Gjesvaer low in Carboniferous times, subsided while the low was again eroded.

Chapopote Asphalt Volcano may have been generated by supercritical water

Asphalt volcanoes and lava-like flows of solidified asphalt on the seafloor (Figure 1) were first discovered and described by MacDonald et al. [2004]. The flows covered more than one square kilometer of a dissected salt dome at abyssal depths (∼3000 m) in the southern Gulf of Mexico. “Chapopote” (93°26′W, 21°54′N) was one of two asphalt volcanoes they discovered. MacDonald et al. determined that the apparently fresh asphalt must initially have flowed in a hot state, and subsequently chilled, contracted, and solidified, much in the same way as normal lava does on the surface of the Earth. The two asphalt-volcanoes discovered occur at the apex of salt domes that pierce through the seafloor. These “piercement salt domes,” known as the Campeche Knolls, are pertinent features of the deep Campeche Sedimentary Basin, which has a sediment thickness of about 10 km. According to conventional theory [Vendeville and Jackson, 1992], piercement salt domes represent “salt diapirs” that have risen up, due partly to density contrasts between salt and clay/sand from the “mother salt” located between 7 and 10 km below seafloor. A salt diapir is a vertical body of sub-surface salt, which is most often circular in cross section, is one to several kilometers in diameter, and can be 8–10 km high.

Red Sea Salt Formations—A Result of Hydrothermal Processes

A new conceptual model, called ‘the hydrothermal salt model’, predicts that salt may accumulate in the marine sub-surface from the hydrothermal circulation of sea water. The hypothesis is based on the physicochemical behaviour of supercritical sea water; when sea water is driven into its supercritical high-temperature and high-pressure domain (407 °C, 298 bars), it loses its solubility for the common sea salts (chlorides and sulphates). Consequently, a spontaneous precipitation of salts takes place in the water-filled pore spaces. The same process may occur when porous rocks containing saline pore water are exposed to sufficiently high temperature and pressure, for example in the subduction of oceanic crust. Salts will also precipitate sub-surface or sub-marine during boiling, in contact with high heat flow sources, such as magma intrusions. Large accumulations of salt are found within the central trough and along both sides of the Red Sea rift. Many of the associated accumulation features are difficult to explain in terms of the conventional ‘evaporite’ model for salt deposits. The features are as follows: (1) several kilometre thick salt deposits on both flanks of the Red Sea, (2) thick (~3 km) salt deposits inside the central graben, (3) dense, hot brines inside some of the central graben deeps (Atlantis II Deep, Conrad Deep, etc.), (4) up to 40-km-long walls and ridges of exposed salt on the northern Red Sea seafloor, (5) tall walls of salt adjacent to the Conrad Deep central graben, and (6) large flows of salt in the Thetis Deep. Furthermore, these huge accumulations of salt took place in a relatively short geological period of time. On the basis of these pertinent structures and features, it is concluded that accumulation, deformation, and transportation of salts may have several drivers and origins, including a process closely associated with hydrothermal activity. Whereas hydrothermally produced salts are lost directly to sea water in mid-ocean spreading hydrothermal systems, they are protected by sediments and ponded high-density brines on the seafloor in deep-spreading centres like that of the Red Sea. Because the Red Sea is the closest active analogue to the rifting and rupturing of ‘Atlantic-type’ continental lithosphere, it may also be the key to understanding the accumulations of huge underground salt deposits and salt-related structures in some of the world’s ancient deep-water rifted margins.

Remote sensing methods in offshore exploration

Abstract The aim of modern remote sensing methods is to enhance variations in digital data sets by applying various numerical filtering techniques and statistical calculations in order to enhance features of interest in the available data. However, a necessary condition for this approach is the availability of an advanced and user-friendly remote sensing system with the possibility to perform interactive processing and “on-the-screen” interpretation. In the present work, a remote sensing system from International Imaging Systems (I2S) was used to interpret geophysical data sets from the Barents Sea region (both offshore and onshore). Features interpreted from the data sets are integrated with other data sets in order to obtain information about the co-variation of features having geological significance. These gravimetric data were used to identify Palaeozoic structural elements in the Barents Sea. Gravity data based on satellite altimetry is also presented and compared with conventional gravity data. The present results indicate that main structural elements can be defined more precisely from the processed data than from ordinary gravity contour maps. An additional benefit of such processing is the detection of subtle trends in the gravimetric field.

Role of supercritical water ingeological processes; e.g., salt accumulation, petroleum migration, and volcanism

This study produces an attempt to estimate the cost of future global energy supplies. The approach chosen to address this concern relies on a comparative static exercise of estimating the cost of three energy scenarios representing different energy futures. The first scenario, the business as usual scenario, predicts the future energy-mix based on the energy plans held by major countries. The second scenario is the renewable energy scenario, where as much of the primary energy supply as possible is replaced by renewable energy by 2050. The cost of the renewable energy generating technologies and their theoretical potential are taken into account in order to create a plausible scenario. The third scenario, the nuclear case, is based on the use of nuclear and renewable energy to replace fossil-fuels by 2050. Endogenous learning rates for each technology are modeled using an innovative approach where learning rates are diminishing overtime. It results from the analysis that going fully renewable would cost between -0.4 and 1.5% of the global cumulated GDP over the period 2009-2050 compared to a business as usual strategy. An extensive use of nuclear power can greatly reduce this gap in costs.The Miocene alkali basaltic rocks cover the northeastern part of Jordan, within Harrat Al-Shaam plateau. The volcanic concentrated along the Dead Sea boundary and spread around the north east of Jordan area, and was considered as interplat volcanic field in Jordan. The volcanic basalt is associated with xenoliths fragmental rocks or xenocryst minerals. Nine samples were collected from the study area and analyzed for XRD, XRF and SEM. These samples presented the xenoliths rocks and minerals existing in the study area. This study is focused on the garnet and pyroxene xenoliths minerals in Tulayl Al-Hasna area within Ufayhim Formation. Hand samples are characterized by coarse aggregates of garnets up to (2 cm in diameter) with dark brown to red color, and highly fresh fractures. Also, the pyroxene (<1.5 cm) with gray to dark green color, and the olivine (range 3 4 mm) are pale green to dark green and pale yellowish color. In thin sections, plagioclase phenocryst in the garnet presented corona texture. In addition, garnet surrounded by orthopyroxene refers to kelyphite texture. There are two types of kelyphite texture fibers and radial as shown in Scanning Electron Microscope photomicrograph. The mineralogical analyses of garnet for X-Ray Diffraction are composed of almandine, pyrope and majorite. The existence of minerals reflects the high pressure and temperature of the upper mantle origin. The chemical analysis showed the average composition of garnet as follow (Alm 42.78, Pyro 41.04, Gross 16.18), pyroxene (Wo 16.90, Fs 20.37, En 62.73). This referred to presentation of the following elements Mg, Fe and Ca in the garnet. As a result, the basaltic garnet xenoliths were from shallow lithosphere mantle origin.Context and objectives Fast Sodium Reactor (FSR) is one of the most promis ing nuclear reactor concept (“Generation IV systems”) to be issued in the next decades [1]. Thi s technology is intended to be much safer, to have a significantly better yield and to produce less wa stes with a lower nocivity. Liquid sodium is used as the thermal fluid in direct contact with the nuc lear core. Ideally, the heat extracted should be transferred between sodium and water in steam gener ators. BUT when sodium is brought in contact with liquid water, a highly exothermal chemical rea ction ensues which is believed to be explosive in certain situations [2]. Such a contact may happen i n a number of instances (repairs, decommissioning,..) and not only during major accid ents. This is thus a significant safety issue which may significantly handicap the development of this technology. Unfortunately the reasons for which the mixing of s dium with water may lead to an explosion, generating blast waves like an explosive material, do not seem to have been clarified so far not even deeply studied. The primary objective of this PhD w ork is thus to identify the details of the phenomenology, to isolate the leading mechanisms an d to propose a modelling approach.W examine the implications of increased unconventional crude oil production in North America. This production increase has been made possible by the existence of alternative oil-recovery technologies and persistently elevated oil prices that make these technologies commercially viable. We first discuss the factors that have enabled the United States to expand production so rapidly and the glut of oil inventory that has accumulated in the Midwest as a result of logistical challenges and export restrictions. Next, we assess the extent to which the increase in U.S. domestic production will affect global supply conditions and whether the U.S. experience can be repeated in other countries with unconventional oil sources. The evidence suggests that even in the bestcase scenario, the increase in U.S. oil production is unlikely to have a large effect on the global oil market’s demand–supply balance, so its effect on the price of oil is expected to be limited. Furthermore, the United States enjoys unique infrastructural and technological advantages that make it unlikely that rapid increases in unconventional production can be achieved elsewhere.T reactions of sunflower, rapeseed, corn and cameline oils in supercritical (sc) methanol were studied in a flow tubular reactor over a wide range of methanol (ether)/oil ratio, pressure, temperature, and residence time. Special attention was focused on the studies of the product distribution and how it varies upon variation of the above reaction parameters. Reaction conditions to enable high selectivity and conversion of vegetable oils transesterification were determined. Advantages of the reaction in supercritical alcohols and ethers over similar reaction in the presence homogeneous catalysts were demonstrated. It was found that the oil type produced insignificant effect on the product composition (fatty acid esters) and oil conversion value. The reaction conditions provided the selectivity and high conversion of the oils were selected.ID-215 INFLUENCE OF SILICA NANOPARTICLES ON THE TOUGHNESS OF FUSION BONDED EPOXY Patrícia Saliba, Herman Mansur UFMG, Brazil patalvessaliba@gmail.com, hmansur@demet.ufmg.brT Niger Delta is the hub of oil and gas production in Nigeria, and is one of the world’s most severely oil spill impacted areas. The exploration and exploitation of oil interfere with ecological and biodiversity integrity of ecosystems arising from flaring of associated gases, oil spills, use of drilling chemicals, etc. These processes can release heavy metals into coastal waters. Heavy metals are associated with crude oil in variable concentrations depending on the geologic background. Nigeria’s dominant and internationally preferred crude petroleum, Bonny Light, has associated with it metals, the main metals occurring in the order nickel>vanadium>cadmium>copper, lead. Recent pollution studies have revealed elevated levels of Zn, Cu, Pb, Cr, Ni, and V, in Niger Delta water, sediments and food species, thereby, compromising safety of the user population. Oil spills in the Niger Delta impact tremendously on the region’s flora and fauna which serve as the main livelihood support structures of the inhabitants. A recent UNEP study on a section of the Niger Delta revealed widespread oil contamination of land, groundwater and surface waters. Drinking water from wells in one community had benzene, a known carcinogen, 900 times above WHO permissible limit. The UNEP study concludes that restoration of the investigated area would take minimum of 30 years. This paper discusses the incidents of oil pollution, and prospect and challenges of ecosystem restoration of Niger Delta oil degraded environments.