https://research-information.bris.ac.uk/files/56550030/1_s2.0_S1871101415300662_main_1_.pdf

Rapid uranium-series age screening of carbonates by laser ablation mass spectrometry

Uranium–thorium dating method and Palaeolithic rock art

New data from offshore and onshore regions confirm the view that the Quaternary uplift of Britain and subsidence beneath the North Sea are coupled, mediated by lower-crustal flow induced by the lateral pressure gradient caused by climate-driven surface processes. Most measured onshore uplift rates, in both upland and lowland localities, are only applicable since the Mid-Pleistocene Revolution; beforehand, generally lower rates prevailed. Earlier (?Oligocene–Pliocene) phases of uplift and subsidence had typically even lower rates; furthermore, the western margin of the North Sea depocentre was ∼200 km farther from the modern coastline of north-east England. In the earliest Cenozoic, complex isostatic adjustments occurred in response to the magmatism associated with the Iceland mantle plume; the contemporaneous land surface (relative to the present-day rock column) in northern England was typically ∼1500 m OD. However, this activity died out during the Palaeogene; the main effect of these events on the modern isostatic configuration was via the emplacement of thick mafic underplating, which now constricts the mobile lower-crustal layer, explaining the Late Cenozoic ultra-stability of Ireland. The evidence enables interpretations of the present-day topography of Britain as static, caused by the Iceland mantle plume, or actively developing in response to plate motions or plate boundary forces, to be excluded.

Isostatic compensation of Quaternary vertical crustal motions: coupling between uplift of Britain and subsidence beneath the North Sea

The Brassington Formation of the Pennines is the most extensive onshore Miocene succession in the UK It is preserved as outliers in Lower Carboniferous Limestone During the Cenozoic, central England underwent uplift, with erosion of post-Mississippian strata from the Pennine axis in the Peak District The Brassington Formation is hence significant in reconstructing Cenozoic geological history It is non-marine, derived from Triassic sandstone and of Mid–Late Miocene age The c 60 outliers occur in three clusters over c 220 km2 They are remnants of a sedimentary prism at least 75 m thick and with a volume of c 10 km3 Suffosion of bedrock, conditioned by aggressive precursor fluids of hypogenic origin, was the major control on subsidence The calculated volume of the fills in the Bees Nest and Green Clay outliers is 37–50 × 106 m3 Referenced to a sub-Miocene surface at c 450 m OD in pre-subsidence times, the original volume of this subsidence complex was c 218 × 106 m3 and the aggregated volume of the Late Neogene White Peak palaeokarst was at least 066 km3 Subsidence was concomitant with Pliocene uplift of the Pennine Axis, suggesting suffosion accommodation of 3 × 106 m3 per km2 or 244 m3 per annum

A reassessment of the Brassington Formation (Miocene) of Derbyshire, UK and a review of related hypogene karst suffosion processes

Book Review: Caves and Karst of the Yorkshire Dales

The British Isles have been affected by as many as 30 glaciations during the Quaternary. However, the evidence for pre-Devensian glaciations in upland regions is scarce. Understanding the extent and timing of earlier upland glaciations is essential for modelling the long-term evolution and sensitivity of the British Ice Sheet. Caves, being protected from surface erosion and weathering, can preserve evidence of earlier glaciations in the form of speleothem and sediment archives. The ∼70-km-long Ogof Draenen cave system in South Wales, UK, contains multiple cave levels related to changes in the surface topography and drainage during the past 0.5 Ma. The cave contains evidence of massive influxes of sediment that were sufficient to choke the cave and alter the underground drainage. Analysis of the cave sediments, passage morphology and geometry suggests the cave once acted as a subterranean glacial spill-way before being overridden by ice. Speleothem U-series data demonstrate that this sediment influx occurred before Marine Isotope State (MIS) 9, probably during the Anglian glaciation (MIS 12). Evidence from Ogof Draenen indicates the impact of subsequent glaciations on the landscape evolution of the region was minimal and that much of the surface topography dates from the Anglian.

/pdf/speleogenetic-evidence-from-ogof-draenen-for-a-pre-devensian-44rucxahm6.pdf

Speleogenetic evidence from Ogof Draenen for a pre-Devensian glaciation in the Brecon Beacons, South Wales, UK

The Gunung Mulu National Park, Sarawak, Malaysia has been a focus of scientific research and exploration for several decades. Previous work investigated the relationship between fluvial incision into the limestone massif and the chronological evolution of the 500m-deep network of cave passages. This study involved analyses of newly available speleothem material using state-of-the-art U-Th dating methods and assessment of the potential for extension of the chronological record using U-Pb dating techniques.

Christopher J. M. Smith

Papers

Speleogenetic evidence from Ogof Draenen for a pre-Devensian glaciation in the Brecon Beacons, South Wales, UK

U-Th dating of speleothems to investigate the evolution of limestone caves in the Gunung Mulu National Park, Sarawak, Malaysia