Fig 1
(A) Location of the study site in Slovenia; (B) cave map and profile location (marked with a red circle) (modified from Zupan Hajna et al., 2008); (C) studied profile scheme: grey shading — flowstones; brown shading — clays; diagonal shading (light blue) — collapsed limestone blocks; yellow crosshatching — younger speleothem cover; red line — principal disconformity; F1 — faunal position; USp — position of Ursus speleus sp (cave bear) bone fragments; RP — sampling profile for C and O isotope analyses; and (D) magnetostratigraphic log according Pruner et al., (2009) correlated with the GPTS (Cande and Kent, 1995); black — normal polarity, white — reverse polarity, grey — transitional polarity, wavy line — disconformity. GPTS, Geomagnetic polarity time scale.
Table 1
Detailed data of benchmarks used for OIS.
| No. | Age (Ma) | Age uncertainty | Depth in RP profile (mm) | Depth uncertainty (mm) | δ18O [‰] | δ13C [‰] | Type of benchmark |
|---|---|---|---|---|---|---|---|
| 1 | 0.12 | 0.02 | 65 | 2.5 | −4.90 | −6.84 | U-series age |
| 2 | 0.495 | 0.015 | 210 | 2.5 | −5.32 | −9.20 | Age at model* |
| 3 | 0.78 | 0.0117 | 280 | 2.5 | −5.45 | −9.22 | Paleomagnetic |
| 4 | 0.80 | 0.02 | 295 | 2.5 | −5.39 | −9.72 | Age at model* |
| 5 | 2.58 | 0.0387 | 1572.5 | 2.5 | – | – | Paleomagnetic |
| 6 | 3.2 | 0.048 | 1860 | 2.5 | −5.28 | −7.75 | Paleomagnetic |
OIS, Oxygen isotope stratigraphy.
* Ages obtained from borders of the RP66 flowstone (on Fig. 1) made by Hercman et al., submitted.
Fig 2
Stable oxygen (A) and carbon (B) isotope compositions in the RP profile. Vertical red lines — principal disconformity; vertical, dotted, and brown lines — main clay layers.
Table 2
Results of U-series dating of the RP profile.
| Lab. no. | Sample | U cont. (ppm) | 234U/238U AR | 230Th/234U AR | 230Th/232Th AR | Age (ka) | *Corrected age (ka) |
|---|---|---|---|---|---|---|---|
| 1537 | RP 1 | 0.1236 ± 0.0061 | 1.117 ± 0.067 | 0.698 ± 0.045 | 14 ± 3 | 120 ± 20 | |
| 1538 | RP66 | 0.1239 ± 0.0049 | 1.239 ± 0.059 | 1.068 ± 0.051 | 1.184 ± 0.052 | >450 |
The reported errors are 2s.
Calculations use the decay constant of Jaffey et al., 1971 (238U), Cheng et al., 2013 (234U and 230Th) and Holden, 1990 (232Th). Ages do not include uncertainties associated with decay constants. Reported errors are equal to 2s.
AR, Activity ratio.
* Age adjusted for detrital contamination, indicated by the presence of 232Th, using the typical silicate activity ratio 230Th/232Th = 0.83 ± 0.42, derived from the following activity ratios: 232Th/238U = 1.21 ± 0.6, 230Th/238U = 1.0 ± 0.1, and 234U/238U = 1.0 ± 0.1 (e.g., Cruz et al., 2005).
Fig 3
Comparison of similarity indicators in the Medi and LR04 records to the RP oxygen isotope composition (calculation in Gen-Corr by Pawlak and Hercman, 2016); (A) boxplots for the upper part of the RP profile and (B) boxplots for the lower part of the RP profile; the vertical axis represents the 2s uncertainty of the similarity indicator.
Fig 4
Correlation results of the RP oxygen isotope record with the LR04 and Medi records. All data presented were normalised and the marine d18O data were inverted. (A) RP curve (blue line) for the upper segment of the profile correlated with the LR04 curve (black line); (B) RP curve (blue line) for the lower segment of the profile correlated with the Medi curve (black line); (C) age-depth model for the upper segment of the profile; and (D) age-depth model for the lower segment of the profile; red lines — confidence intervals; grey boxes — hiatuses; red boxes —principal disconformity.
Fig 5
The final set of stable carbon and oxygen isotope records of the RP profile; (A) MIS scale (warm — red; cold — blue) (Lisiecki and Raymo, 2005); (B) stable oxygen isotope record (smoothed data — blue; raw data — grey); and (C) stable carbon isotope record (smoothed data — black; raw data — grey); grey boxes — hiatuses; red box — principal disconformity; green boxes — episodes where the R2 value is significantly greater, R2 = 0.4538, R2 = 0.4944, and R2 = 0.6065. MIS, Marine isotope stage.
Fig 6
Correlation of d13C and d18O values from the entire RP profile (p < 0.05).