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Fig. 1
Sample locations: A – Orlova Chuka Cave location; B – Sketch of the Orlova Chuka Cave basing on material from official cave web page www.dvemogili.bg; C – Cross section of the Orlova Tchuka Cave sediments; D – Ocz-6 sample.
Fig. 2
Locations of identified calcite types in ocz-6 stalagmite. A, B, C, D, E localization of five different types of calcite distinguished in ocz-6 stalagmite 1 – The zone with disturbed U-series ages; 2 – Positions of thin sections; 3 – Stalagmite growth axis scale in mm.
Fig. 3
Microscopic photos of ocz-6 calcite types. A, B – photos from thin section I, in which the observed columnar compact fabric is dominant, with narrow overlays of columnar open fabric; C, D – photos from thin section II, in which observed fabrics are mainly alternating columnar open and columnar compact fabrics, and higher contents of detrital material were observed; E, F – photos from thin section III, exhibiting a very strongly porous zone; the dominant fabric is columnar open fabric, and in some pores, the presence of opaque minerals and traces of secondary mineralization are noticeable; G – photo from thin section VI; similar to photos A and B, the dominant fabric is columnar compact fabric; H – photo from thin section VI, documenting the transition zone between the columnar compact fabric and what is classified as columnar elongated fabric, where much thinner calcite crystals occur and the incomplete coalescence of crystals and a few impurity-rich layers were also observed.
Fig. 4
Results of U-series dating. A – Age-depth model; B – Linear approximation of deposition stages; C – Ocz-6 stalagmite growth rate; 1, 2, 3, 4, 5 – Distinguished phases of stalagmite deposition with corresponding growth rate estimations.
Fig. 5
δ18O (black line) and δ13C (gray line) records from the ocz-6 stalagmite. 1, 2, 3, 4, 5 –Distinguished phases of stalagmite deposition.
Fig. 6
Trace element profiles from thin – sections I, III, IV, V description in the text.
Fig. 7
Comparison of ocz-6 isotopic records with other LIG speleothem records: A – δ18O records from the Mediterranean region; B – δ13C records from the Mediterranean region (Bar-Matthews et al., 2003; Drysdale et al., 2005; Zumbühl, 2010; Nehme et al., 2015); C – δ18O records from Western and Central Europe; D – δ13C records from Western and Central Europe (Couchoud et al., 2009; Vansteenberge et al., 2016; Demeny et al., 2017); E – δ18O records from the Alps; F – δ13C records from the Alps (Holzkamper et al., 2004; Meyer et al., 2008; Moseley et al., 2015).
Fig. 8
Comparison of ocz-6 isotopic records with global proxies: A – δ18O and δ13C records from ocz-6 stalagmite; B – δ18O record from GRIP core (Chappellaz et al., 1997); C – Summer insolation for 45 N (Davis and Brewer, 2008); D – Global sea level (Dutton and Lambeck, 2012).
Results of the U-series dating of stalagmite from Orlova Chuka Cave. Reported errors are 2σ.