The Arctic is warming faster than any other region on Earth. As sea ice diminishes, the surface boundary conditions, such as roughness and air–sea coupling, change and open‐water fetch increases. This may enhance wind forcing on Arctic coasts. Lake sediments can record these changes through the deposition of wind‐blown grains and elements, offering insights into past wind and climate dynamics. We reconstruct c . 8200 years of wind and climate variability using laminated sediments from a closed‐basin lake in central Spitsbergen, Svalbard archipelago, High Arctic. By integrating geochemical, visual and granulometric fingerprints within a multiproxy geostatistical framework, we link aeolian minerogenic input to specific catchment sources. Our findings show that iron (Fe)‐rich coarse silt‐sized clasts originate from distinct dolerite outcrops west and northwest of the lake, upwind of the dominant summer westerlies. This reveals a locally filtered westerly input that aligns with valley‐fjord channelling. We identify four phases of enhanced aeolian activity during the Mid‐ and Late Holocene, which occurred when local boundary conditions were favourable for entraining and transporting sediment into the basin. Major shifts in sediment sources and depositional conditions coincide with the end of the Holocene Thermal Maximum and the gradual onset of the Neoglacial. However, the reconstructed wind signal demonstrates a comparatively stable long‐term behaviour, with no clear correspondence to regional palaeoclimate records.
We have investigated fine‐grained marine sediments buried under delta sediments and multiple till beds in a tributary valley in western Norway. The marine bed contains bivalves, foraminifera and terrestrial plant material. The fauna and flora are rather poor, but the presence of molluscan species Mytilus edulis and Arctica islandica suggests that Atlantic waters reached the coastal areas at the time of deposition. The age range of radiocarbon dates from about 25 to 50 ka BP conflicts with previous studies from the area and is considered as minimum ages only. This conclusion is supported by amino acid epimerization values in molluscs from the radiocarbon‐dated unit, indicating that it should be correlated with an Early Weichselian, MIS 5c interstadial. The marine unit and overlying delta succession are situated on the outer coast up to 56 m above present sea level, suggesting that they were deposited during a high sea‐level stand following retreat of an extensive MIS 5d glaciation. A compiled Weichselian glaciation curve shows five major glacial advances extending to the outermost coast or beyond. These advances seem to correspond to periods with North Atlantic sea surface cooling. Three till units on top of the delta are interpreted to represent glacier advance prior to the Last Glacial Maximum (LGM) and during the subsequent deglaciation. Clast fabrics in the lower till and orientation of clastic dikes show an upvalley component opposite to LGM maximum ice‐flow direction. This indicates that initial glacier advance was by fjord glaciers extending to the outer coast while there was limited glacier extent in coastal mountain areas. This interpretation favours fast ice flow along the fjords and major supply of ice from interior mountain areas. Glacier growth in coastal mountains led to merging with fjord glaciers, reorientation of the ice‐flow direction and ultimately maximum glacier extent. Empirical data on ice‐sheet growth are extremely rare and may have been overlooked in many stratigraphic records. Such data are vital for understanding behaviour of ice sheets and in a wider sense, the climate system.
The postglacial evolution of High Arctic coastal environments is recorded in the rich fossiliferous archives of raised marine terraces. This study employs a multi‐proxy approach combining molluscan community analysis, taphonomy and sedimentology to reconstruct the Early to Mid‐Holocene environmental dynamics of the Mimerdalen embayment in the Billefjorden area of central Svalbard. Our results indicate that local benthic succession was driven by a complex interplay of glacio‐isostatic rebound and fluctuating sediment supply rather than simple climatic warming. We identify a four‐stage evolutionary trajectory: (1) an initial glaciomarine, brackish‐water phase dominated by the pioneer taxa Mya truncata and Hiatella arctica ; (2) a transition to fully marine conditions that facilitated the expansion of thermophilous species ( Mytilus edulis and Arctica islandica ); (3) a return to restricted brackish conditions due to forced regression and basin shallowing; and (4) a transition towards modern open‐fjord equilibrium, as slower glacio‐isostatic uplift and Mid‐Holocene Neoglacial cooling led to the disappearance of the thermally demanding taxa. Although not directly radiocarbon dated, valves of Arctica islandica and Zirfaea crispata are stratigraphically associated with dated M. truncata , suggesting their presence as early as ~10.4 cal. ka BP. This potentially advances their known regional arrival by up to 600 and 300 years, respectively, with A. islandica persisting until ~7.7 cal. ka BP. Comparisons with the Kapp Ekholm reference section demonstrate that local geomorphological stability and ephemeral disturbances, such as hyperpycnal deltaic input, were critical drivers of biodiversity, enabling the establishment of thermally demanding species. Ultimately, our findings confirm that Early Holocene sea temperatures significantly exceeded modern values, while emphasizing the overwhelming importance of salinity and seabed stability in shaping molluscan ecological structure. This study underscores the crucial role of local environmental heterogeneity in modulating the biological response to regional Holocene climate forcing in the High Arctic.
End moraines are formed at glacier ice margins and show the extent of former glaciations. Here in this review article, we use a fourfold genetic classification of end moraines (dump moraines, push moraines, lodge moraines and hummocky end moraines) to highlight the importance of lodge moraines, which are end moraines composed primarily of subglacial till deposited submarginally at and near the ice margin. Such end moraines were named ‘lodge moraines’ by Chamberlin (1894) in the same article that defined push moraines and dump moraines. We review the use of the term but emphasize that many end moraines are made in this manner without having received a genetic name. Lodge moraines are among the largest moraines in the world, some more than 10 km wide. They are especially common at the former margins of the lobes that drained the southern Laurentide Ice Sheet but have also been described in Iceland and Scandinavia. They are typically asymmetric with a steeper distal side. Because of their size, relatively few lodge moraines have received extensive sedimentological analysis, and an interpretation as a lodge moraine here is based largely on geomorphology and boreholes that reveal thick, uniform subglacial till similar to the till in up‐ice till plains. These large lodge moraines are thought to form by advection of subglacial till to a somewhat stationary margin forming a wedge over time. However, smaller end moraines that fit the definition of lodge moraines are found in Iceland and Norway where frozen‐on slabs of subglacial till are stacked at the margin during seasonal oscillations. Part of our rationale for this paper is pedagogical, in that a review shows that six of the most widely used glacial geology textbooks neither mention lodge moraines nor describe the till advection, wedge‐forming process that makes the large lodge moraines. We conclude that lodge moraines are common and of equal importance for understanding end‐moraine genesis as push, dump and hummocky end moraines.
The glacierized Valle Frías in Northern Patagonia is one of the best‐studied valleys in South America and includes varved sediments from Lago Frías. We complement this lacustrine record with a high‐resolution documentation of varve counts and their composition. Geochemical and grain size analyses support their interpretation as proglacial varves attributed to over‐ and interflows resulting from snow‐ and glacier melt. Integration of radiometric, tephra and historic ages with microfacies analyses and semi‐automatic varve counting utilizing high‐resolution images obtained by computed tomography provides a calendar‐year chronology consisting of an upper (1960–2019 CE) and a floating lower varve chronology (1803–1893 CE). Intercalated between both varved sections are two event layers: a tephra resulting from the eruption of Volcán Calbuco (1893 CE) directly followed by an erosive mass‐wasting deposit associated with the Great Chilean Earthquake (1960 CE). Statistical comparison of varve‐thickness measurements with instrumental temperature data and dendroclimatological summer‐temperature reconstruction on an annual basis indicates only a weak temperature control on varve thickness. However, analysis of decadal means documents that the occurrence of thicker varves in the 21st century coincides with warmer summers.
