"Chevrons". Litorale Ablagerungen ungeklärter Genese - exemplarische Studie an Küsten von Südbrasilien und Zentralchile
Final Report Abstract
Although strong tsunamis are common along the Chilean coast, our research did not result in any evidence for a tsunamigenic influence on the formation of chevron structures, both in Chile and Brazil. All investigated forms and deposits associated to the sedimentary chevron structures have been formed by aeolian dynamics. In all cases, intercalated clasts and coarse shells can clearly be related to former anthropogenic influence (shell middens in most cases). “Floating” boulders found in blowouts and deflation depressions in interdunal situations reflect the origin from bedrock as weathering residuals or corestones in all of our studied cases. Disturbance of stratification inside the sand bodies can also be explained by wet avalanching in a (partly) humid climate. As a consequence, positive indicators for a waterborne formation of the investigated “chevron”-shaped features could not be elaborated along the central coast of Chile and the southeastern coast of Brazil. However, particular outcomes going beyond the original scope of this project comprise (i) detailed studies of coastal changes and their relation to palaeoseismicity in central Chile; (ii) the detection of anthropogenic shell accumulations and related IRSL chronostratigraphies; (iii) new chronological OSL data on late Pleistocene and Holocene dune generations and coastal evolution in SE Brazil; (iv) the attempt to date Pleistocene marine terraces in central Chile with cosmogenic nuclides (10Be).
Publications
- 11–14 Oct 2012: 14th International German Ostracodologists' Meeting 2012, Cologne: Microfaunal investigation of the Quebrada Pachingo coastal swamp (Bahia Tongoy, northern central Chile) – Late Holocene environmental changes and their potential causes
J. Scheder, S.M. May, A. Pint, H. Brückner, D. Kelletat, G. Rixhon
- 26–30 Aug 2012: 32nd International Geographical Congress, Cologne: A shell midden in the Longotoma dune complex (central Chile) – geochronological data and palaeoenvironmental context
S.M. May, H. Brückner, A. Hilgers, D. Kelletat, S. Poetsch, G. Rixhon, A. Zander
- 26–30 Aug 2012: 32nd International Geographical Congress, Cologne: Microfaunal investigation of the Quebrada Pachingo coastal swamp (Bahia Tongoy, northern central Chile) – Late Holocene environmental changes and their potential causes
J. Scheder, S.M. May, A. Pint, H. Brückner, D. Kelletat, G. Rixhon
- 27–31 Aug 2013: 8th IAG International Conference on Geomorphology, Paris: Investigations on anthropogenic shell accumulations in the Longotoma dune complex (central Chile) – geochronological data and palaeoenvironmental context
S.M. May, H. Brückner, A. Hilgers, D. Kelletat, S. Poetsch, G. Rixhon, A. Zander
