British Geological Survey

About: British Geological Survey is a government organization based out in Nottingham, United Kingdom. It is known for research contribution in the topics: Groundwater & Aquifer. The organization has 2561 authors who have published 7326 publications receiving 241944 citations.

Sr isotope evidence for population movement within the Hebridean Norse community of NW Scotland.

Abstract: The excavation at Cnip, Isle of Lewis, Scotland, of the largest, and only known family cemetery from the early Norse period in the Hebrides, provided a unique opportunity to use Sr isotope analysis to examine the origins of people who may have been Norwegian Vikings. Sr isotope analysis permits direct investigation of a person9s place of origin rather than indirectly through acquired cultural and artefactual affiliations. Sr isotope data suggest that the Norse group at Cnip was of mixed origins. The majority were consistent with indigenous origins but two individuals, of middle-age and different sex, were immigrants. They were, however, not from Norway but were raised separately, most probably on Tertiary volcanic rocks (e.g. the Inner Hebrides or NE Ireland) or, for the female, on marine carbonate rocks.

Carbon dioxide capture and geological storage

Abstract: Carbon dioxide capture and geological storage is a technology that could be used to reduce carbon dioxide emissions to the atmosphere from large industrial installations such as fossil fuel-fired power stations by 80-90%. It involves the capture of carbon dioxide at a large industrial plant, its transport to a geological storage site and its long- term isolation in a geological storage reservoir. The technology has aroused considerable interest because it can help reduce emissions from fossil fuels which are likely to remain the dominant source of primary energy for decades to come. The main issues for the technology are cost and its implications for financing new or retrofitted plants, and the security of underground storage.

The geochemistry of the Plenus Marls at Dover, England: evidence of fluctuating oceanographic conditions and of glacial control during the development of the Cenomanian–Turonian δ13C anomaly

Abstract: The sediments and organic calcite geochemistry (Fe2+, Mn2+, Sr, Mg, δ18O, δ13C) of the Plenus Marls at Dover (southeast England) reflect the changing oceanographic conditions associated with the development of the late Cenomanian-early Turonian S1SC excursion.The Plenus Marls of Dover consist of five marl-chalk couplets with a total thickness of up to 3 m. The sediments were deposited in an increasingly shallowing sea during a major regressional phase of the Chalk Sea over Europe. Each marl horizon was deposited in slightly cooler water of lower productivity and higher energy level than the overlying chalk, and represents a phase of enhanced regression. Inoceramus prisms and shell fragments from the marls have enhanced Mg values, whereas all the biogenic calcite from the chalks is enriched in Fe2+. The high clay content of the Plenus Marls probably originated from the post-depositional argillization of unstable silicate detritus (possibly of volcanoclastic origin) introduced into the regressing sea by rejuvenated river systems. The δ18O values of individual planktic and benthic foraminifera species have been lightened by diagenetic reaction; however they demonstrate (1) the presence of a constant temperature gradient in the water column with warmer surface waters relative to the bottom waters, and (2) the association of a marked temperature drop with the appearance of Jefferies' cold water occidental fauna and the development of a Mn2+ anomaly (Bed 5) in the average calcite skeletons of all particle size fractions. The δ13C values of individual planktic and benthic foraminifera species show that a normal oceanic gradient existed except at two levels (Beds 3, 5), where this is reversed with heavier values shown by the benthic forms. The normal δ13C gradient steepened rapidly as the water shallowed and the δ13C excursion reached maximum values. Dysaerobic and anaerobic water conditions were completely absent and the level of oxygenation (macrofaunal diversity) increased in parallel with the shallowing and the enhanced δ13C excursion.Comparison with the Plenus Marls section at Flixton (east Yorkshire), which shows evidence of restricted faunas and deposition under anoxic conditions (black bands rich in terrestrial organic matter), demonstrates that between these two localities there is unequivocal correlation of the δ13C excursion and the temperature drop associated with Jefferies' cold water occidental fauna. Anomalous geochemical features of the Dover Plenus Marls are explained by the redeposition of Flixton-type coccolith-rich chalk (very low Fe2+ content) and by the occasional introduction of cold northern bottom waters enriched in 13C.The status of the Cenomanian-Turonian oceanic anoxic event and its supporting evidence is discussed and is considered to be untenable on present evidence. An alternative hypothesis based upon a glacial mechanism is put forward; this is supported by evidence of widespread regression, restricted ocean circulation, lower ocean temperatures, enhanced input of terrestrial organic matter, and the presence of dropstones.