Title :

Luminescence chronology of the northeastern Bulgarian loess-paleosol sequences (Viatovo and Kaolinovo)

Author(s) :

Balescu, Sanda [Auteur correspondant]
Histoire, Archéologie et Littérature des Mondes Anciens - UMR 8164 [HALMA]
Jordanova, Diana [Auteur]
National Institute of Geophysics, Geodesy and Geography [NIGGG]
Forget Brisson, Laurence [Auteur]
Université du Québec à Montréal = University of Québec in Montréal [UQAM]
Hardy, Francois [Auteur]
Université du Québec à Montréal = University of Québec in Montréal [UQAM]
Huot, Sebastien [Auteur]
Illinois State Geological Survey
Lamothe, Michel [Auteur]
Université du Québec à Montréal = University of Québec in Montréal [UQAM]

Journal title :

Quaternary International

Pages :

15-24

Publisher :

Elsevier

Publication date :

2020

ISSN :

1040-6182

English keyword(s) :

Loess
Pleistocene
IRSL dating
K-feldspars
Bulgaria
Romania

English abstract : [en]

The key reference loess sequence of Viatovo in NE Bulgaria, lying within the lower Danube basin, recordsclimatic and environmental changes over the last 800 ka. This 20m thick loess sequence consists of seven loessunits ...
Show more >The key reference loess sequence of Viatovo in NE Bulgaria, lying within the lower Danube basin, recordsclimatic and environmental changes over the last 800 ka. This 20m thick loess sequence consists of seven loessunits (L1 to L7) intercalated by six paleosols (S1 to S6) below the modern soil (S0). The Matuyama-Brunhespalaeomagnetic boundary has been identified in the lowest loess unit (L7). This reference loess sequence remains so far undated by radiometric techniques. Its chronostratigraphy relies only on pedostratigraphic and magnetostratigraphic evidence. This contrasts with the adjacent reference loess sequences of SE Romania (Tuzla,Mostistea, Mircea Vodă) whose luminescence chronology is now securely established up to MIS 8.The aim of this study is to validate the chronostratigraphic framework of the Viatovo loess sequence using theluminescence dating method. For this purpose, the luminescence method is applied to the three upper loess units (L1, L2, L3) from two adjacent sites: the reference site of Viatovo and the nearby site of Kaolinovo, both located in the Ludogorie region (NE Bulgaria) and showing the same superposition of loess (L1 to L7) and interbedded paleosols. Luminescence dating (Infrared stimulated luminescence; IRSL) was carried out using the feldspar fine sand-size grain fraction (60–80 μm), applying the IRSL50 and the pIRIR290 dating techniques. For the equivalent dose (De) determination we used both the SAR post-infrared infrared (pIRIR290) protocol on single aliquots and the multiple-aliquot additive dose (MAAD IRSL50) protocol. The pIRIR290 ages and the fading corrected MAADIRSL50 ages are self-consistent. It demonstrates for the first time, that the three upper loess layers (L1, L2, L3) at Viatovo and Kaolinovo were deposited during the marine isotope stages (MIS) 2–4, 6 and 8, thus constraining the youngest well-developed paleosol (S1, a chernozem) to the Last Interglacial. These IRSL50 and pIRIR290 ages are in good agreement with the luminescence ages obtained for (1) the two upper loess layers (L1, L2) from the Harletz sequence in NW Bulgaria and (2) the three upper loess units (L1, L2, L3) from the adjacent SE Romanian loess sequences. The luminescence chronology of the loess sequences is presented along with the pedogenic and magnetic property data. The pedostratigraphic records of the NE Bulgarian and SE Romanian loess sequences show the same palaeoclimatic trends, with progressive aridification during interglacial periods (from S6 to S0).Show less >

Language :

Anglais

Popular science :

Non

Collections :

• Histoire Archéologie Littératures des Mondes Anciens (HALMA) - UMR 8164

Source :

Harvested from HAL