ALBERT

Description: 〈span〉〈div〉Abstract〈/div〉At the 2015 United Nations International Climate Change Conference in Paris (COP21), 197 national parties committed to limit global warming to well below 2°C. But current plans and pace of progress are still far from sufficient to achieve this objective. Here we review the role that geoscience and the subsurface could play in decarbonizing electricity production, industry, transport and heating to meet UK and international climate change targets, based on contributions to the 2019 Bryan Lovell meeting held at the Geological Society of London. Technologies discussed at the meeting involved decarbonization of electricity production via renewable sources of power generation, substitution of domestic heating using geothermal energy, use of carbon capture and storage (CCS), and more ambitious technologies such as bioenergy and carbon capture and storage (BECCS) that target negative emissions. It was noted also that growth in renewable energy supply will lead to increased demand for geological materials to sustain the electrification of the vehicle fleet and other low-carbon technologies. The overall conclusion reached at the 2019 Bryan Lovell meeting was that geoscience is critical to decarbonization, but that the geoscience community must influence decision-makers so that the value of the subsurface to decarbonization is understood.〈/span〉

Description: Though climate models exhibit broadly similar agreement on key long-term trends, they have significant temporal and spatial differences due to inter-model variability. Such variability should be considered when using climate models to project the future marine Arctic. Here we present multiple scenarios of 21 st -century Arctic marine access as driven by sea ice output from 10 CMIP5 models known to represent well the historical trend and climatology of Arctic sea ice. Optimal vessel transits from North America and Europe to the Bering Strait are estimated for two periods representing early-century (2011–2035) and mid-century (2036–2060) conditions under two forcing scenarios (RCP 4.5/8.5), assuming Polar Class 6 and open-water vessels with medium and no ice-breaking capability, respectively. Results illustrate that projected shipping viability of the Northern Sea Route (NSR) and Northwest Passage (NWP) depends critically on model choice. The eastern Arctic will remain the most reliably accessible marine space for trans-Arctic shipping by mid-century, while outcomes for the NWP are particularly model-dependent. Omitting three models (GFDL-CM3, MIROC-ESM-CHEM, MPI-ESM-MR), our results would indicate minimal NWP potential even for routes from North America. Furthermore, the relative importance of the NSR will diminish over time as the number of viable central Arctic routes increases gradually toward mid-century. Compared to vessel class, climate forcing plays a minor role. These findings reveal the importance of model choice in devising projections for strategic planning by governments, environmental agencies, and the global maritime industry.

Description: The Carboniferous Bowland Shale of northern England has drawn considerable attention because it has been estimated to have 1329 trillion cubic feet hydrocarbons in-place (gas and liquids) resource potential (Andrews 2013). Here we report on the oil and gas generation characteristics of three selected Bowland Shale whole-rock samples taken from cores and their respective kerogen concentrates. Compositional kinetics and phase properties of the primary and secondary fluids were calculated through the PhaseKinetics and GOR-Fit approaches and PVT modelling software. The three Bowland Shale samples contain immature, marine type II kerogen. Pyrolysate compositions imply primary generation of paraffinic–naphthenic–aromatic (PNA) oil with low contents of wax and sulphur. Bulk kinetic parameters have many similarities to those of productive American Palaeozoic marine shale plays. The secondary gas generation potential of Bowland Shale is greater than the primary gas potential although it requires a 10 kcal mol –1 higher activation energy to achieve peak production. Primary oil, primary gas and secondary gas reach their maximum generation at 137, 150 and 200°C respectively for a 3°C Ma –1 heating rate. Different driving forces of expulsion including the generation of hydrocarbon and overpressure caused by phase separation during sequential periods of subsidence and uplift could be inferred.

Description: The Greater Caucasus and southern Crimean Mountains form part of a fold–thrust belt located on the northern margin of the Black Sea, south of the Precambrian craton of eastern Europe. Its southern limit is approximated by the Main Caucasus Thrust, which runs to the west from onshore Russia and Georgia along the whole of the northern margin of the Black Sea. The Main Caucasus Thrust is related to a zone of present-day seismicity along the southern Crimea–Caucasus coast of the Black Sea called the Crimea–Caucasus Seismic Zone. Thick continental crust north of the Main Caucasus Thrust lies adjacent to the thin ‘suboceanic' or transitional crust of the Black Sea Basin. A local seismic tomography study of this area in the vicinity of the Kerch and Taman peninsulas, which lie between the Azov Sea and the Black Sea, has been carried out based on 195 weak (m b ≤3) earthquakes occurring from 1975 to 2010 and recorded at four permanent and three temporary seismological stations on the Kerch and Taman peninsulas. The results, for a volume of about 200 x 100 km (east–west and north–south, respectively) and a depth of about 40 km, provide evidence for significant heterogeneity in the P-wave and S-wave velocities. Velocities inferred in the northern part of the model suggest that the continental crust underlying the Crimea–Azov region north of the Main Caucasus Thrust is of different tectonic affinity (cratonic) than that underlying the northeastern part of the Black Sea, south of the Main Caucasus Thrust (Neoproterozoic–Palaeozoic accretionary domain). In the southern part of the model, at depths of 25–40 km, the uppermost mantle below the thin quasi-oceanic crust of the Black Sea has anomalous low P-wave velocities with high P- to S-wave velocity ratios. This is tentatively interpreted as representing serpentinized upper mantle of continental lithosphere exhumed during Cretaceous rifting and lithospheric hyperextension of the eastern Black Sea. The transition between the continental domains and the crust underlain by anomalous upper mantle is closely related to the Crimea–Caucasus Seismic Zone, where earthquake foci deepen northwards, suggesting that the latter is being thrust under the former in this intra-plate setting.

Description: The DOBRE-2 wide-angle reflection and refraction profile was acquired in June 2007 as a direct, southwestwards prolongation of the 1999 DOBREfraction'99 that crossed the Donbas Foldbelt in eastern Ukraine. It crosses the Azov Massif of the East European Craton, the Azov Sea, the Kerch Peninsula (the easternmost part of Crimea) and the northern East Black Sea Basin, thus traversing the entire Crimea–Caucasus compressional zone centred on the Kerch Peninsula. The DOBRE-2 profile recorded a mix of onshore explosive sources as well as airguns at sea. A variety of single-component recorders were used on land and ocean bottom instruments were deployed offshore and recovered by ship. The DOBRE-2 datasets were degraded by a lack of shot-point reversal at the southwestern terminus and by some poor signal registration elsewhere, in particular in the Black Sea. Nevertheless, they allowed a robust velocity model of the upper crust to be constructed along the entire profile as well as through the entire crust beneath the Azov Massif. A less well constrained model was constructed for much of the crust beneath the Azov Sea and the Kerch Peninsula. The results showed that there is a significant change in the upper crustal lithology in the northern Azov Sea, expressed in the near surface as the Main Azov Fault; this boundary can be taken as the boundary between the East European Craton and the Scythian Platform. The upper crustal rocks of the Scythian Platform in this area probably consist of metasedimentary rocks. A narrow unit as shallow as about 5 km and characterized by velocities typical of the crystalline basement bounds the metasedimentary succession on its southern margin and also marks the northern margin of the northern foredeep and the underlying successions of the Crimea–Caucasus compressional zone in the southern part of the Azov Sea. A broader and somewhat deeper basement unit (about 11 km) with an antiformal shape lies beneath the northern East Black Sea Basin and forms the southern margin of the Crimea–Caucasus compressional zone. The depth of the underlying Moho discontinuity increases from 40 km beneath the Azov Massif to 47 km beneath the Crimea–Caucasus compressional zone.

Description: 〈span〉〈div〉Abstract〈/div〉At the 2015 United Nations international climate change conference in Paris (COP21), 197 national parties committed to limit global warming to well below 2°C. But current plans and pace of progress are still far from sufficient to achieve this objective. Here we review the role that geoscience and the subsurface could play in decarbonising electricity production, industry, transport, and heating, to meet UK and international climate change targets, based on contributions to the 2019 Bryan Lovell meeting held at the Geological Society of London. Technologies discussed at the meeting involved decarbonisation of electricity production via renewable sources of power generation, substitution of domestic heating using geothermal energy, use of carbon capture and storage (CCS), and more ambitious technologies such as bioenergy and carbon capture and storage (BECCS) that target negative emissions. It was noted also that growth in renewable energy supply will lead to increased demand for geological materials to sustain the electrification of the vehicle fleet and other low-carbon technologies. The overall conclusion reached at the 2019 Bryan Lovell meeting was that geoscience is critical to decarbonisation, but that the geoscience community must influence decision makers so that the value of the subsurface to decarbonisation is understood.〈/span〉

Description: 〈p〉This review of the role of the mantle lithosphere in plate tectonic processes collates a wide range of recent studies from seismology and numerical modelling. A continually growing catalogue of deep geophysical imaging has illuminated the mantle lithosphere and generated new interpretations of how the lithosphere evolves. We review current ideas about the role of continental mantle lithosphere in plate tectonic processes. Evidence seems to be growing that scarring in the continental mantle lithosphere is ubiquitous, which implies a reassessment of the widely held view that it is the inheritance of crustal structure only (rather than the lithosphere as a whole) that is most important in the conventional theory of plate tectonics (e.g. the Wilson cycle). Recent studies have interpreted mantle lithosphere heterogeneities to be pre-existing structures and, as such, linked to the Wilson cycle and inheritance. We consider the current fundamental questions in the role of the mantle lithosphere in causing tectonic deformation, reviewing recent results and highlighting the potential of the deep lithosphere in infiltrating every aspect of plate tectonics processes.〈/p〉

Description: The margin of the northeastern Black Sea is formed by the Crimea and Kerch peninsulas, which separate it from the Azov Sea to the north. The age and architecture of the sedimentary successions in this area are described from exploration reflection seismic profiling acquired in the area, in addition to the regional DOBRE-2 CDP profile acquired in 2007. The sediments range in age from Mesozoic to Quaternary and can be divided into five seismo-stratigraphic complexes linked to the tectono-sedimentological evolution of the area. The present regional basin architecture consists of a series of basement structural highs separating a series of sedimentary depocentres and is mainly a consequence of the compressional tectonic regime affecting the area since the Eocene. This has focused shortening deformation and uplift along the axis of the Crimea–Caucasus Inversion Zone on the Kerch Peninsula and Kerch Shelf of the Black Sea. Two major sedimentary basins that mainly formed during this time – the Sorokin Trough in the Black Sea and the Indolo-Kuban Trough to the north of the Kerch Peninsula in the Azov Sea – formed as marginal troughs to the main inversion zone.

Description: The Carboniferous Bowland Shale of northern England has drawn considerable attention because it has been estimated to have 1329 trillion cubic feet hydrocarbons in-place (gas and liquids) resource potential (Andrews 2013). Here we report on the oil and gas generation characteristics of three selected Bowland Shale whole-rock samples taken from cores and their respective kerogen concentrates. Compositional kinetics and phase properties of the primary and secondary fluids were calculated through the PhaseKinetics and GOR-Fit approaches and PVT modelling software. The three Bowland Shale samples contain immature, marine type II kerogen. Pyrolysate compositions imply primary generation of paraffinic–naphthenic–aromatic (PNA) oil with low contents of wax and sulphur. Bulk kinetic parameters have many similarities to those of productive American Palaeozoic marine shale plays. The secondary gas generation potential of Bowland Shale is greater than the primary gas potential although it requires a 10 kcal mol –1 higher activation energy to achieve peak production. Primary oil, primary gas and secondary gas reach their maximum generation at 137, 150 and 200°C respectively for a 3°C Ma –1 heating rate. Different driving forces of expulsion including the generation of hydrocarbon and overpressure caused by phase separation during sequential periods of subsidence and uplift could be inferred.

Description: New deep seismological data from Ellesmere Island and the adjacent Arctic continental margin provide new information about the crustal structure of the region. These data were not available for previous regional crustal models. This paper combines and redisplays previously published results – a gravity-derived Moho map and seismological results –to produce new maps of the Moho depth, the depth to basement and the crystalline crustal thickness of Ellesmere Island and contiguous parts of the Arctic Ocean, Greenland and Axel Heiberg Island. Northern Ellesmere Island is underlain by a thick crustal block (Moho at 41 km, c. 35 km crust). This block is separated from the Canada–Greenland craton in the south by a WSW–ENE-trending channel of thinned crystalline crust (Moho at 30–35 km, 〈20 km thick crust), which is overlain by a thick succession of metasedimentary and younger sedimentary rocks (15–20 km). The Sverdrup Basin in the west and the Lincoln Sea in the east interrupt the crustal architecture of central Ellesmere Island, which is interpreted to be more representative of its initial post-Ellesmerian Orogen structure, but with a later Sverdrup Basin and Eurekan overprint.