TY - JOUR
T1 - Pleistocene volcanism and the geomorphological record of the Hrazdan Valley, central Armenia: linking landscape dynamics and the Palaeolithic record
AU - Sherriff, Jenni
AU - Wilkinson, Keith
AU - Adler, Daniel
AU - Arakelyan, Dmitri
AU - Beverly, Emily
AU - Blockley, Simon
AU - Gasparyan, Boris
AU - Mark, Darren
AU - Meliksetian, Khachatur
AU - Nahapetyan, Samvel
AU - Preece, Katie
AU - Timms, Rhys
PY - 2019/12/15
Y1 - 2019/12/15
N2 - The Southern Caucasus lies at the intersection of Africa, the Levant and Eurasia, and is thus a region of considerable interest in the study of Pleistocene hominin population dynamics and behaviour. While Palaeolithic archaeological sites in the region such as Dmanisi and Nor Geghi 1 attest to such palaeogeographic significance, a greater understanding of the chronology and nature of climatic and geomorphic changes in the region is needed to fully understand hominin settlement dynamics. The Hrazdan river valley, central Armenia, has the potential to offer such insights given its rich Palaeolithic record and complex history of Pleistocene infill as a result of alluvial, lacustrine, aeolian, and volcanic processes. We therefore present a stratigraphic framework for basin infill and hominin activity during the Pleistocene, based on extensive geomorphological and geological mapping, published chronometric results (40Ar/39Ar and K-Ar), and archaeological survey. We demonstrate that the onset of Pleistocene volcanism in the Gegham Range to the immediate east of the Hrazdan valley occurred around 700 ka BP, after which there were several phases of effusive eruption lasting until 200 ka. Interbedded with lava emplaced by these eruptions are alluvial and lacustrine sequences, some with evidence of pedogenesis and several of which have yielded Palaeolithic artefacts. Taken together these sequences suggest a cyclical model of infill whereby lava flow along the valley resulted in the blockage of the palaeo-Hrazdan river and lake formation in the lea of the lava dams. Breaching of these dams resulted in a shift to predominately fluvial deposition, and the consequent development of floodplain soils. Hominin populations exploited the floodplains at times when the last of these phases coincided with interglacial and interstadial climates, but they also occupied the surrounding valley sides during the same warm, humid phases.
AB - The Southern Caucasus lies at the intersection of Africa, the Levant and Eurasia, and is thus a region of considerable interest in the study of Pleistocene hominin population dynamics and behaviour. While Palaeolithic archaeological sites in the region such as Dmanisi and Nor Geghi 1 attest to such palaeogeographic significance, a greater understanding of the chronology and nature of climatic and geomorphic changes in the region is needed to fully understand hominin settlement dynamics. The Hrazdan river valley, central Armenia, has the potential to offer such insights given its rich Palaeolithic record and complex history of Pleistocene infill as a result of alluvial, lacustrine, aeolian, and volcanic processes. We therefore present a stratigraphic framework for basin infill and hominin activity during the Pleistocene, based on extensive geomorphological and geological mapping, published chronometric results (40Ar/39Ar and K-Ar), and archaeological survey. We demonstrate that the onset of Pleistocene volcanism in the Gegham Range to the immediate east of the Hrazdan valley occurred around 700 ka BP, after which there were several phases of effusive eruption lasting until 200 ka. Interbedded with lava emplaced by these eruptions are alluvial and lacustrine sequences, some with evidence of pedogenesis and several of which have yielded Palaeolithic artefacts. Taken together these sequences suggest a cyclical model of infill whereby lava flow along the valley resulted in the blockage of the palaeo-Hrazdan river and lake formation in the lea of the lava dams. Breaching of these dams resulted in a shift to predominately fluvial deposition, and the consequent development of floodplain soils. Hominin populations exploited the floodplains at times when the last of these phases coincided with interglacial and interstadial climates, but they also occupied the surrounding valley sides during the same warm, humid phases.
KW - Pleistocene
KW - palaeogeography
KW - volcanism
KW - geomorphology
KW - Palaeolithic
KW - Gegham Range
KW - tectonism
KW - 40Ar/39Ar chronology
KW - Southern Caucasus
KW - 2020
U2 - 10.1016/j.quascirev.2019.105994
DO - 10.1016/j.quascirev.2019.105994
M3 - Article
VL - 226
SP - 105994
JO - Quaternary Science Reviews
JF - Quaternary Science Reviews
SN - 0277-3791
ER -