کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4736641 1640907 2011 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
40Ar/39Ar dating and phytolith analysis of the Early Pleistocene sequence of Kvemo-Orozmani (Republic of Georgia): chronological and palaeoecological implications for the hominin site of Dmanisi
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
40Ar/39Ar dating and phytolith analysis of the Early Pleistocene sequence of Kvemo-Orozmani (Republic of Georgia): chronological and palaeoecological implications for the hominin site of Dmanisi
چکیده انگلیسی

The Kvemo-Orozmani locality contains a 15 m thick Early Pleistocene fluvio-lacustrine sequence bracketed by two lava flows. Located 13 km up the Masavera River Valley (west) from the Dmanisi Site, Kvemo-Orozmani is therefore of prime interest to improve the paleoecological framework as well as dating Dmanisi. 40Ar/39Ar ages obtained on the two lava flows indicate that Kvemo-Orozmani sequence brackets the Dmanisi sediments between 1.825 ± 0.021 Ma and 1.765 ± 0.021 Ma. Phytolith assemblages found at the bottom of the sequence indicate a warm and humid climate while the assemblages found at the top suggest dryer-colder climatic conditions. The shift in phytolith assemblages observed at Kvemo-Orozmani is similar to the one already described in Dmanisi and occurs near the end of the Oluduvai subchron. The new palaeoecological and chronological data confirm the hypothesis made in Dmanisi about the palaeoenvironmental context during the hominin occupation that suggests a temperate climate becoming drier. The age we obtained on the overlying lava flow establishes a minimum age for the climatic transition at both Kvemo-Orozmani and the Dmanisi Site of 1.765 ± 0.021 Ma.


► We investigate the Early Pleistocene sequence of Orozmani (Lesser Caucasus).
► We obtain two 40Ar/39Ar ages on lava flows bracketing this sequence.
► Phytoliths as well as ages show that Orozmani is contemporaneous with the Dmanisi site.
► The temporal and environmental frameworks of Dmanisi are improved using Orozmani data.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Quaternary Science Reviews - Volume 30, Issues 21–22, October 2011, Pages 3099–3108
نویسندگان
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