ZOBODAT - www.zobodat.at Zoologisch-Botanische Datenbank/Zoological-Botanical Database Digitale Literatur/Digital Literature Zeitschrift/Journal: Austrian Journal of Earth Sciences Jahr/Year: 2017 Band/Volume: 110_1 Autor(en)/Author(s): Barrett Samuel, Schmidmair Daniela, Spötl Christoph Artikel/Article: Mineralogical composition of the Baumkirchen lacustrine sequence (Würmian, Inn Valley, Tyrol): provenance and palaeogeographical implications 43-56 Austrian Journal of Earth Sciences Vienna 2017 Volume 110/1 43 - 56 DOI: 10.17738/ajes.2017.0004 Mineralogical composition of the Baumkirchen lacustrine sequence (Würmian, Inn Valley, Tyrol): provenance and palaeogeographical implications Samuel BARRETT1)*), Daniela SCHMIDMAIR2) & Christoph SPÖTL1) 1) Institute of Geology, University of Innsbruck, Innrain 52, A-6020 Innsbruck, Austria; 2) Institute of Mineralogy and Petrography, University of Innsbruck, Innrain 52, A-6020 Innsbruck, Austria; *) Corresponding author,
[email protected] KEYWORDS Würmian; Alps; provenance; palaeogeography; Pleistocene; palaeolake Abstract The Baumkirchen palaeolake sequence east of Innsbruck, Tyrol, is a well-known and studied Late Pleistocene sequence of key im- portance for Alpine Quaternary stratigraphy. Recent luminescence dating and geochemical analysis revealed that the sequence is made up of two compositionally slightly different phases representing sedimentation during Marine Isotope Stages (MIS) 3 and 4 separated by a ca. 7-15 ka-long hiatus. We investigated the bulk mineralogical composition of the sediment to better characterise the compositional differences, and analysed modern stream sediments to constrain the provenance from different catchments. The modern stream sediments closely match expectations based on catchment geology besides an overrepresentation of dolomite in several catchments, likely attributable to the greater sediment generation potential of dolostone based on its physical and petro- graphic properties.