Heavy mineral analysis of Ice Complex sediments on Muostakh Island (NE Siberia)

• Main Author: Manthey, Christoph
• Format: Thesis
• Language: unknown
• Published: 2015
• Subjects: laptev; Laptev Sea; lena river; Siberia
• Online Access: https://epic.awi.de/id/eprint/39009/; https://epic.awi.de/id/eprint/39009/1/Bachelorarbeit_Christoph_Manthey.pdf; https://hdl.handle.net/10013/epic.46242; https://hdl.handle.net/10013/epic.46242.d001

This Bachelor's thesis focuses on the heavy mineral analysis of sediment samples taken in 2012 by an expedition team lead by Hanno Meyer from the Ice Complex formation on Muostakh Island in the Laptev Sea (NE Siberia). The heavy mineral analysis was used to investigate the provenance and transportation and sedimentation processes of the settled material. As influencing effects on the heavy mineral composition the origin of the material, further transportation energy and chemical weathering could be identified, which was also confirmed by a principal component analysis in combination with grain-size distribution data, provided by Hanno Meyer. The heavy mineral composition is dominated by amphibole, followed by pyroxene, garnet and opaque minerals. The origin indicating mineral leucoxene, appearing regional augmented, could not be identified. As provenance the Lena river could be identified by the use of comparative heavy mineral data. The sedimentation occurred in three phases. Between the first and second phase a hiatus in the stratigraphic record exist. 14C-dating (Meyer (unpublished)) confirm this indicating a gap between ca. 41.6 kyr BP and ca. 19.7 kyr BP. This disconformity is caused by an erosional event. After this event chemical weathering took place at the top of the deposited layers of the first phase producing significant red aggregates. The second phase is characterized by higher transportation energy compared to the first and third phase, which is reflected by the appearing of rutile almost just in the corresponding unit and a more coarse grain-size distribution.