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Abstract

Basing of fieldworks geomorphologic and geologic setting of 14 raised marine beaches in northern Hornsund Region was presented. Their age is approximated by radiocarbon and thermoluminescence datings of sediments. The latter indicated that the four highest but mostly questionable marine beaches (220—230,200—205,180—190 and 100—120 m a.s.l.) should be referred to the Wedel Jarlsberg Land (Saalian) Glaciation. The four lower beaches (80—95, 70—75, 50—60 and 40—46 m a.s.1.) are connected with the Bogstranda (Eemian) Interglacial and the pre-maximum part of the Sorkapp Land (Vistulian) Glaciation. The post-maximum part of this glaciation, including Lisbetdalen Stage (50—40 ka) and Slaklidalen Stage (30—20 ka), was the time when the three still lower marine beaches (32—35, 22—25,16—18 m a.s.l.) were formed. Three lowermost marine beaches (8—12,4.5—6,2 m a.s.l.) are of the Holocene age.

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Authors and Affiliations

Leszek Lindner
Leszek Marks
Waldemar Roszczynko
Julia Semil
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Abstract

The coastal regions of southwest India which falls in the tropical regime, have witnessed many transgression-regression events and climatic extremes in the Quaternary Period. A core, 15 m long, was recovered from the floodplains associated with a typical backwater body (lake) in the southwestern coast of India. The granulometric analysis proved dominance of sand and silt fractions and extremely high energy conditions over the entire core. The TOC/TN ratio indicated a domination of the C4-type over the C3-type plants in the lower half of the core, suggesting a warm climate. The C3-type plants prevail in the upper part of the core, thus reflecting cool and wet environments. Extremely low values of TOC/TN ratio (0.33% to 10%) of the core indicate short periods of very high rainfall events and the rapid influx of nutrients to the basin and the eutrophication of the basin. The presence of slightly brackish, brackish/marine and marine benthic foraminifers at 12.5–9 m depth indicates episodes of transgression and regression. The derived AMS radiocarbon dates suggest the Marine Isotope Stage 3 for the lower part of the core.
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Authors and Affiliations

Divya Murali
1
Rajesh Reghunath
1
Pranav Prakash
1
Ravi Bhushan
2
K. Anoop Krishnan
3
Sruthy Rose Baby
1

  1. Department of Geology, University of Kerala, Karyavattom Campus, Trivandrum, Kerala-695581, India
  2. Geosciences Division, Physical Research Laboratory, Navrangpura, Ahmedabad 380009, Gujarat, India
  3. Biogeochemistry Group, National Centre for Earth Science Studies, Akkulam, Trivandrum, Kerala, India
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Abstract

Results of a geomorphologic study as well as radiocarbon and pollen analyses of sediments in small basins of the Jasło-Sanok Depression (Western Carpathians) are summarised. Floors of these basins, carved in soft shale-sandstone Krosno Beds, are covered with channel fluvial deposits and oxbow-lake sediments with lake chalk and peat accumulated in the Late Vistulian and Holocene. Since the early Atlantic Phase (ca 8,400–7,900 BP) the apparent acceleration of overbank (flood) deposition intermitting the peat accumulation is observed. The plant succession includes the Late Glacial (pre-Allerød, Allerød and Younger Dryas) with coniferous park forests, through mixed deciduous forests of the Holocene with elm, hazel, oak and lime as well as spruce-elm forests with alder in wetlands, up to present-day hornbeam forests (Tilio-Carpinetum of various types) and extra-zonal Carpathian beech forests (Dentario-Glandulosae- Fagetum). Abies alba (fir) is frequent in both these association types. First evidences of synanthropic plants that prove presence of prehistoric man appeared in the Subboreal Phase. The oldest radiocarbon date 13,550±100 BP (Gd-7355) [16,710–16,085 b2k], from a bottom part of the Humniska section is probably overestimated. This is indicated by palynological data, which suggest attribution of this section to the older Allerød. Small thickness of gravel blanket from the Plenivistulian termination and the beginning of the Late Vistulian, as well as large areas devoid of weathering and solifluction covers indicate that during the Plenivistulian weathering processes and removal of silt-clay material predominated in the basins. In that time the deflation was among important processes, which is proved by deflation troughs, faceted cobbles and thick covers of the Carpathian type of loess. The Besko Basin has pre-Vistulian tectonic foundation, while landforms of its floor are of erosion-degradation origin and formed during the last Scandinavian glaciation. In the Holocene the basin floors were overbuilt with fluvial deposits up to 8 m thick.

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Authors and Affiliations

Tadeusz Gerlach
Piotr Gębica
Kazimierz Szczepanek
Dorota Nalepka
Adam Walanus

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