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Distinguishing diamictons using till macrofabric and grain size analysis: A case study in the northern Serra do Gêres Mountains, NW Iberian Peninsula
Geological Society of America Abstracts with Programs (2019)
  • João A. Santos, San Jose State University
  • Javier Santos-González, University of Leon
  • José Maria Redondo-Vega, University of León
  • Jeffrey R. Irwin, South Dakota State University
Abstract
Till macrofabric and grain size analysis of glacial diamictons present in several valleys of the Northern Serra do Gerês Mountains in the Iberian Peninsula northwest were used to interpret till types and to reconstruct the glacial paleoprocess history of this mountainous region. Slope deposits, subglacial deformation and supraglacial melt-out tills are dominant in the northern portion of this range. Supraglacial melt-out tills, representative of periods of glacial stability followed by recession, present weaker fabric data and coarser, poorly sorted sediments. Slope deposits, representative of postglacial mass wasting activity, present weaker to strong fabric data and coarser, poorly sorted sediments. Subglacial deformation tills, representative of glacial readvance stages followed by stability, present poorly sorted fine sediments, folding, and striated clasts. These diamictons are of importance in the reconstruction of the glacial dynamics and history of the Northern Serra do Gerês Mountains due to poor preservation of glacial landforms related to the Last Glacial Maximum in several glaciated valleys.
Keywords
  • Glacial geomorphology,
  • Till macrofabric analysis,
  • Serra do Gerês Mountains,
  • NW Iberian Peninsula
Disciplines
Publication Date
Spring May, 2019
DOI
10.1130/abs/2019CD-328883
Citation Information
João A. Santos, Javier Santos-González, José Maria Redondo-Vega and Jeffrey R. Irwin. "Distinguishing diamictons using till macrofabric and grain size analysis: A case study in the northern Serra do Gêres Mountains, NW Iberian Peninsula" Geological Society of America Abstracts with Programs Vol. 51 Iss. 4 (2019) ISSN: ISSN 0016-7592
Available at: http://works.bepress.com/joao-santos/32/