DOI: 10.25921/gm02-r698
title: NOAA/WDS Paleoclimatology - Manita peć Cave Geochemical Data from 105900 to 5300 Cal Yr BP

description: We present stable carbon (δ13C) and oxygen (δ18O) isotope records from two partially coeval speleothems from Manita peć Cave, Croatia. The cave is located close to the Adriatic coast (3.7 km) at an elevation of 570 m a.s.l. The site experienced competing Mediterranean and continental climate influences throughout the last glacial cycle and was situated close to the ice limit during the glacial phases. U-Th dating constrains the growth history from Marine Isotope Stage (MIS) 5 to MIS 3 and the transition from MIS 2 to MIS 1. 14C dating was used to estimate the age of the youngest part of one stalagmite found to be rich in detrital thorium and thus undatable by U-Th. On a millennial scale, δ18O variations partly mimic the Dansgaard–Oeschger interstadials recorded in Greenland ice cores (Greenland Interstadials, GI) from GI 22 to GI 13. We interpret our δ18O record as a proxy for variations in precipitation amount and/or moisture sources, and the δ13C record is interpreted as a proxy for changes in soil bioproductivity. The latter indicates a generally reduced vegetation cover towards MIS 3–MIS 4, with shifts of ~8‰ and approaching values close to those of the host rock. However, even during the coldest phases, when a periglacial setting and enhanced aridity sustained long-residence-time groundwater, carbonic-acid dissolution remains the driving force of the karstification processes. Speleothem morphology follows changes in environmental conditions and complements regional results of submerged speleothems findings. Specifically, narrow sections of light porous spelaean calcite precipitated during the glacial/stadial sea-level lowstands, while the warmer and wetter conditions were marked with compact calcite and hiatuses in submerged speleothems due to sea-level highstands. Presumably, the transformation of this littoral site to a continental one with somewhat higher amounts of orographic precipitation was a site-specific effect that masked regional environmental changes.
description: Data contributed as part of SISAL v3 Global Speleothem Isotope and Trace Element Database (https://doi.org/10.25921/jajq-qg60). Notes from the SISAL database: The second age–depth model spanned the 110 ka to 45 ka time period, and it is partially presented by both speleothems MP-2 and MP-3 (SISAL entity_id = 815, 816). In order to produce a single age–depth model, the chronology data from both speleothems was merged. In the tuning protocol, the MP-2 dataset was used as the main record because it covered the longer time span compared to the MP-3 speleothem. Eight tie points were selected in MP-3, i.e., the MP-2 δ18O depth profiles, to transpose δ18O and δ13C as well as the corresponding U-Th data of the MP-3 speleothem onto the MP-2 depth scale. Tuning and tie point selection was performed based on visual similarity between the two δ18O depth series. Linear interpolation was performed in between tie points to transpose all MP-3 data onto the MP2 depth scale. Original depth uncertainty of the MP-3 U-Th samples was increased for at least 25% to account for an extra error introduced by this tuning protocol and this increased uncertainty was then applied in the age–depth modelling procedure. All accepted ages are in stratigraphic order as presented in Figure 3b.