The Hunsrück Slate Konservat‐Lagerstätte

This is the final version. Available on open access from Wiley via the DOI in this record. The Lover Devonian Hunsrück Slate in western Germany is world-famous for its exceptionally preserved and beautiful fossils. What makes this KonservatLagerstätte so fascinating is its unique style of pyritization that has perfectly captured an entire ecosystem, from delicate echinoderms with preserved soft tissues to the Lovecraftian Mimetaster

Cumberland Bay (South Georgia) glacial evolution during the Holocene

This is the final version. Available via the link in this recordToday, South Georgia is heavily glaciated with glaciers often terminating into the ocean via steep-sided bay and U-shaped valleys. However, due to a low number of well-dated climate records from the island, there is uncertainty about how glaciers responded to Holocene climate variability. Here, we reconstruct the glacial evolution of Cumberland Bay, one of the most dynamic glacial systems in the world, from marine sediment core GC673 (ca. 9.7 cal. Kyr BP to Present; ca. 6 m from the nearest land). We used benthic foraminiferal and diatom assemblages, biogenic silica, alkenones and pXRF to infer Holocene glacial evolution in Cumberland Bay. The relative abundance of the benthic foraminifera Fursenkoina fusiformis is interpreted as a proxy for more intense diatom blooms resulting from increased terrestrial runoff associated with the spring-summer melting of glaciers. The F. fusiformis abundance correlates well with diatom concentration accumulation rates and peaks in both proxies correspond to elevated (but low) abundance of sea ice diatom taxa. A sequence of several glacial advancement events can be recognized. The high productivity of the early Holocene is associated with melt associated with the retreat of glaciers into the inner fjord during the early Holocene warm period. Subsequent advancements seem to have two different causes. The first mid-Holocene advancement corresponds to a decrease in alkenone-derived palaeotemperatures from GC673. The two advancements from the late Holocene correspond to increases in published LOI data suggested as indicating increased strength of the South Westerly Winds (SWW) at the latitude of South Georgia which would have increased winter snowfall aiding the growth of glaciers. Our proxies are aligned with and build upon published glacial trends previously constrained with plant macrofossil and pollen evidence from nearby peat bogs and dated glacial moraines. We conclude that the primary driver of productivity at site GC673 were diatom blooms associated with spring/summer melt of glaciers whose growth is partially associated with strengthened SSW

South Georgia marine productivity over the past 15 ka and implications for glacial evolution

This is the final version. Available from Copernicus Publications via the DOI in this record. Data availability: Raw radiocarbon dates with calibrations are available in Table 2 and dataset used and analysed are included in the Supplement.The subantarctic islands of South Georgia are located in the Southern Ocean, and they may be sensitive to future climate warming. However, due to a lack of well-dated subantarctic palaeoclimate archives, there is still uncertainty about South Georgia's response to past climate change. Here, we reconstruct primary productivity changes and infer Holocene glacial evolution by analysing two marine gravity cores: one near Cumberland Bay on the inner South Georgia shelf (GC673: ca. 9.5 to 0.3 cal. kyr BP) and one offshore of Royal Bay on the mid-shelf (GC666: ca. 15.2 cal. kyr BP to present). We identify three distinct benthic foraminiferal assemblages characterised by the dominance of Miliammina earlandi, Fursenkoina fusiformis, and Cassidulinoides parkerianus that are considered alongside foraminiferal stable isotopes and the organic carbon and biogenic silica accumulation rates of the host sediment. The M. earlandi assemblage is prevalent during intervals of dissolution in GC666 and reduced productivity in GC673. The F. fusiformis assemblage coincides with enhanced productivity in both cores. Our multiproxy analysis provides evidence that the latest Pleistocene to earliest Holocene (ca. 15.2 to 10.5 cal. kyr BP) was a period of high productivity associated with increased glacial meltwater discharge. The mid–late Holocene (ca. 8 to 1 cal. kyr BP), coinciding with a fall in sedimentation rates and lower productivity, was likely a period of reduced glacial extent but with several short-lived episodes of increased productivity from minor glacial readvances. The latest Holocene (from ca. 1 cal. kyr BP) saw an increase in productivity and glacial advance associated with cooling temperatures and increased precipitation which may have been influenced by changes in the southwesterly winds over South Georgia. We interpret the elevated relative abundance of F. fusiformis as a proxy for increased primary productivity which, at proximal site GC673, was forced by terrestrial runoff associated with the spring–summer melting of glaciers in Cumberland Bay. Our study refines the glacial history of South Georgia and provides a more complete record of mid–late Holocene glacial readvances with robust chronology. Our results suggest that South Georgia glaciers were sensitive to modest climate changes within the Holocene.Leverhulme TrustNatural Environment Research Council (NERC)Natural Environment Research Council (NERC