Abstract
This study presents results from a multi-proxy analysis of cores taken in a crater-lake sequence from Eski Acigol in central Turkey which cover the period from pre-c. 16000 cal. yr BP to the present. The sediments comprise an upper unit of generally non-laminated, banded to massive silts and peats of mid- to late-Holocene age, overlying a laminated unit of late-Pleistocene to early/mid-Holocene age. The laminae, comprising mainly aragonite, amorphous silica (diatom frustules) and organic matter were formed in a relatively deep, dilute, meromictic lake. Pollen data indicate an abrupt replacement of Artemisia-chenopod steppe by grass-oak-terebinth parkland during the period of laminae deposition, marking the start of the Holocene. A gradual increase in tree pollen during the early Holocene came to an end c. 6500 cal. yr BP (U-series and adjusted C-14 timescale), when mesic deciduous taxa declined at the same time as lake levels fell. Human impact on regional vegetation is inferred from a sharp decline in oak around 4500-4000 cal. yr BP. Diatom, isotopic and mineralogical data indicate that during the second half of the Holocene the lake became relatively shallow and oscillated between fresh and brackish/evaporated water conditions. The contrast between wetter early- and drier late-Holocene climatic conditions is matched by other eastern and central Mediterranean proxy climate data. While the Eski Acigol sequence resembles Holocene hydroclimatic changes in the Saharo-Arabian zone and was also apparently linked to orbital forcing, it is unlikely to have had the same direct cause, i.e., an expansion and subsequent retreat of monsoon rainfall.
Original language | English |
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Pages (from-to) | 721-736 |
Number of pages | 16 |
Journal | The Holocene |
Volume | 11 |
Issue number | 6 |
Publication status | Published - 2001 |
Keywords
- isotopes
- diatoms
- pollen
- crater lake
- mineralogy
- hydrothermalism
- Mediterranean
- Turkey
- Holocene
- TOTAL-SAMPLE DISSOLUTION
- CENTRAL ANATOLIA
- DI-MONTICCHIO
- SAPROPEL S1
- KONYA BASIN
- RECONSTRUCTION
- RECORD
- LACUSTRINE
- VEGETATION
- DIATOMS