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Results of shore-based micropaleontological analysis, summarizing planktonic foraminifera biostratigraphy at Site U1559A. IODP Hole U1559A located in the central South Atlantic (30°15.6335′S, 15°2.0942′W). Collected data allowed to identify slumped interval of older material present within much younger upper part of the local sedimentary sequence.
Volcanic Whole Rock Dataset from Tajogaite eruption sequence, La Palma 2021 (NERC Grant NE/W007673/1)
Major and trace element data of lava and tephra samples from the 2021 Tajogaite eruption. Major and select trace element collected by XRF, trace elements collected by ICPMS, both at the University of Granada. Data collected as part of NERC Urgency Grant led by K Chamberlain (Liverpool), in collaboration with M Pankhurst (INVOLCAN), J Scarrow (Granada), D Morgan (Leeds), J Hickey (Exeter), D Neave (Manchester), for understanding how eruptions begin, evolve and end. Samples analysed span the entire September - December 2021 eruptive sequence of Tajogaite, and data were collected between December 2021 and August 2022.
This data set contains micromagnetic simulation results of magnetosome chains with different bending or collapse degrees, including finite element models and various magnetic parameters (hysteresis loops, isothermal remanent magnetism curves, and first-order reversal curves and energy barriers). Published in Pei et al. (2022; doi: 10.1029/2021JB023447)
The effect of clay content on the dilatancy and frictional properties of fault gouge (NERC Grant NE/L002469/1)
This information details the method of calculating dilatancy from pore volumometry measurements. In the velocity step tests, an initial shear enhanced compaction phase drastically reduces the sample pore volume until the sample yields. After the sample yields, the pore volume continues to decrease but at a lower rate of decrease. The imposed velocity steps cause compaction or dilation of the sample material that is superimposed on this overall compaction trend. Pore pressure is held at a set point in all tests and any volume changes in the control system are assumed to correspond directly to changes in pore volume in the sample. The method here is aimed at producing quantitative, reproducible values for dilatancy from experimental data. The script fits a polynomial function to all the volume data to give the overall trend of the shear enhanced compaction. The data position of the start of the velocity step of interest is entered manually into the function. When dilatancy occurs on a step change in velocity, this is not immediately recorded using volumometry, as the permeability of the sample will produce a transient response as pore fluid pressure equilibrates between the sample and the pore fluid pressure system. To discount time effects, every velocity step was processed with a ‘time_dep’ phase for the first 100µm of displacement after the imposed velocity step change. Using the values for ‘vel_step’ and ‘time_dep’, the volumometry data are split into separate matrices incorporating time and volume preceding and following the velocity step change. A linear regression model fits a polynomial curve to the pore volumometry data and returns the coefficient of determination (R2) for the fit of the model. The shear enhanced compaction phase prior to yield is included in the fit. The code incrementally adds the value entered for ‘step’ to the data in the velocity step of interest. This ‘step’ value is a positive or negative value depending on whether the velocity has increased or decreased, respectively. A new linear regression model is then fitted to the whole dataset and if the R2 value has increased, the code will continue to loop to add the value of ‘step’ to the pore volume data. It concludes when the R2 value reaches a peak and begins to decrease, as the fit is no longer improving. We assume at this point that the effect of the dilatancy due to the velocity step has been removed, and the cumulative sum of the ‘step’ values is equivalent to the dilatancy. As the loop goes one iteration past the optimum R2 value, the code reverts to the previous set of values with the best R2 value. In experiments with multiple velocity step changes, the code needs to retain the previous corrections of the data. The function ‘pf_correct’ is used to correct the velocity steps that have been previously processed. The values for ‘vel_step’, ‘time_dep’ and the returned value of ‘offset’ need to be given in the inputs for ‘pf_correct’.
Radiocarbon measurements on foraminifera from sediment cores in the North Atlantic (NERC Grant NE/M004619/1, NE/M003434/1)
Radiocarbon measurements on planktic and benthic foraminifera from sediment cores in the North Atlantic: Ocean Drilling Program (ODP) 983, SU90-44, MD04-2829, MD01-2461, and EW9302-2JPC Site 983 is located on the Bjorn Drift in approximately 1650 m water depth on the eastern flank of the Reykjanes Ridge. Hole 983A Position: 60°24.200'N, 23°38.437'W. Sediment core SU90-44 collected from the north-eastern Atlantic basin, near the top of a small abyssal hill, southeast of the Rockall plateau, 50°01'N, 17°06'W, 4279 m. Sediment core MD04-2829 collected from Rosemary Bank in the Northern Rockall Trough 58º 56.93’ N; 09º 34.30’ W; 1743 m water depth. Sediment core MD01-2461 was collected from the north-western flank of the Porcupine Seabight approximately 550 km to the southwest, 51°45’N, 12°55’W; 1153 m water depth, recovered in 2001. Core EW9302-2JPC recovered from the Rockall Plateau and East Flank of Reykjanes Ridge from the Flemish Cap in the south- eastern Labrador Sea, 48°47.70′N, 45°05.09′W, taken at water depth 1251m.
Uranium and Thorium activity data in sediment cores in the North Atlantic Ocean (NERC Grant NE/M004619/1)
Activity (dpm/g) of Uranium and thorium isotopes from 3 sediment cores in the North Atlantic: ODP980, ODP983, EW9302-2JPC. Ocean Drilling Program (ODP) Site 980 was drilled in July 1995 in the North Atlantic Ocean, on the Feni Drift, off the eastern edge of the Rockall Plateau at 55.49°N, 14.70°W. Hole 980A Position: 55°29.087'N, 14°42.134'W. Hole 980B Position: 55°29.094'N, 14°42.137'W. ODP Site 983 was drilled was drilled in July 1995 and is located on the Bjorn Drift in approximately 1650 m water depth on the eastern flank of the Reykjanes Ridge. Hole 983A Position: 60°24.200'N, 23°38.437'W. Site EW9302-2JPC, an ODP Site Survey in 1993, of Rockall Plateau and East Flank of Reykjanes Ridge from the Flemish Cap in the south- eastern Labrador Sea (Figure 1). EW9302-2JPC Position: 4847.700 N, 4505.090 W, taken at water depth 1251m.
Radiocarbon data from benthic and planktic foraminifera in core EW9302-2JPC Northwest Atlantic Ocean (NERC Grant NE/M004619/1)
Radiocarbon ages of planktic and benthic foraminifera from sediment core EW9302-2JPC in the Northwest Atlantic from 0 to 30,000 years ago. Picked monospecific planktic foraminifera (G. bulloides and N. pachyderma) and mixed planospiral benthic formanifera (Cibicidoides, Melonis, Elphidium) were prepared to graphite at the NERC Radiocarbon Facility - East Kilbride and passed to the Keck Carbon Cycle AMS Facility, University of California, Irvine, USA for 14C analysis.
Mean sortable silt versus depth data in sediment core from Ocean Drilling Program (ODP) site 980 (NERC Grant NE/M004619/1)
Mean grain size data in the sortable silt fraction (10-63 um) from 0- 8 meters composite depth in Ocean Drilling Program (ODP) site 980. Ocean Drilling Program (ODP) Site 980 was drilled in July 1995 in the North Atlantic Ocean, on the Feni Drift, off the eastern edge of the Rockall Plateau at 55.49°N, 14.70°W. Hole 980A Position: 55°29.087'N, 14°42.134'W. Hole 980B Position: 55°29.094'N, 14°42.137'W.
Gas concentration, methane stable isotopes, and noble gas data of groundwater and deep gas samples from the Vale of Pickering, Yorkshire (NERC Grant NE/R018049/1)
Groundwater and gas samples collected from sites in the Vale of Pickering and analysed for major gas concentrations, methane stable isotopes, and noble gas compositions.
African Legacy Geoscience Data for Geothermal Exploration - East Africa, Djibouti, Ethiopia and Kenya (NERC Grant NE/X006255/1)
Digitized GIS geological and geochemical datasets taken from maps and reports as part of BGS Overseas Development Research in 1980-90s.