| Summary: | This study analyses the active geomorphic processes and the geological events recorded the landscape around Kongressvatnet, an arctic, meromictic lake located in western Spitsbergen (the largest island in Svalbard). This geomorphic analysis is in collaboration with a short core analysis of sediments from the lake. The interpretation and comparison of the lacustrine sediment record and the surficial geology record of Kongressvatnet will draw conclusions about past climate variation in western Spitsbergen during the Holocene. The surficial geology map and structural geology map of the Kongressvatnet catchment was complied from field observations (July and August 2006) and detailed aerial photographic interpretation. This study used lichenometry, pebble counts, GPS and altimeter elevations and topographic profiles to collect morphologic and temporal data. Units were classified based on the morphology, grain size, sorting, rounding, sedimentary structures, lithological content, vegetation cover, and the slope of each deposit. Temporal variance was determined by lichen long axis length (using Rhyzocarpum geographica, based on Werner, 1990), vegetation cover (relative difference), presence of periglacial features and relative surface elevation (specifically for fluvial surfaces). Well defined shoreline terraces are found at 5m above modern lake level (104-105m a.s.l.), at 10m above modern lake level (109-110m a.s.l.), and indicate that lake levels were at least 10m higher in the past. If the modern outlet was not incised (threshold at ~110m) and the large inactive colluvial fan in the channel like wind gap (NW of Kongressvatnet) was not present (threshold at ~110m) it is possible that Kongressvatnet drained into Linnedalen. A raised marine delta at 65m a.s.l. (11,000 yrs BP (referenced in Mangerud and Svendsen, 1990)) and large alluvial fan is present along the proposed wind gap outlet route. It is possible that these features were formed when (and if) a Kongressvatnet outlet flowed into Linnedalen. To the north of Kongressbreen, distinct trim lines, moraine-like mounds, weathering differences, and beheaded drainages indicate that ice extended beyond LIA limit in the form of a valley glacier. These features may be expressions of a Younger Dryas glacial advance or Late Weichselian deglaciation.
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