Karst Research Group, School of Geosciences, University of South Florida, 4202 E. Fowler Ave., NES 107, Tampa, FL, 33620, USA.
Biology and Paleo Environment Division, Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY, 10964, USA.
Sci Rep. 2021 Jan 21;11(1):261. doi: 10.1038/s41598-020-80025-6.
Sea-level reconstructions are important for understanding past ice sheet variability and its response to past and future warming. Here we present Neogene and Quaternary sea-level snapshots using phreatic overgrowths on speleothems (POS) from caves on Mallorca, Spain. POS are excellent sea level index points because of their clear relationship to sea level and precise U-Pb chronology. We find that local sea-level before and at the onset of the Messinian Salinity Crisis was at 33.3 ± 0.25 m (6.54 ± 0.37 Ma) and 31.8 ± 0.25 m (5.86 ± 0.60 Ma) above present levels, respectively. We further present global mean sea level (GMSL) estimates, i.e. local sea level corrected for glacial isostatic adjustment and long-term uplift, for three other POS. The results show that GMSL during the Pliocene-Pleistocene Transition was 6.4 m (- 2.0-8.8 m) at 2.63 ± 0.11 Ma and during the beginning and the end of the Mid-Pleistocene Transition was - 1.1 m (- 5.6-2.4 m) and 5 m (1.5-8.1 m), respectively. These estimates provide important constraints for the past evolution of sea level and show that local sea level prior to the MSC was similar to the highest stand during the Pliocene, with markedly lower position afterwards.
海平面重建对于了解过去冰盖的变化及其对过去和未来变暖的响应非常重要。在这里,我们使用西班牙马略卡岛上洞穴中的石笋(speleothems)上的准饱和带生长(phreatic overgrowths on speleothems,POS)来呈现中新世和第四纪的海平面快照。POS 是出色的海平面指标点,因为它们与海平面有明确的关系,且具有精确的 U-Pb 年代。我们发现,在 Messinian 盐度危机之前和开始时,当地海平面分别比现在高出 33.3 ± 0.25 米(6.54 ± 0.37 百万年前)和 31.8 ± 0.25 米(5.86 ± 0.60 百万年前)。我们进一步呈现了另外三个 POS 的全球平均海平面(GMSL)估计值,即经过冰川均衡调整和长期隆起校正后的当地海平面。结果表明,在中新世-更新世过渡期,2.63 ± 0.11 百万年前的 GMSL 为 6.4 米(-2.0-8.8 米),在中更新世过渡期开始和结束时,GMSL 分别为-1.1 米(-5.6-2.4 米)和 5 米(1.5-8.1 米)。这些估计值为过去海平面的演化提供了重要的约束,并表明 MSC 之前的当地海平面与上新世的最高位相似,之后的位置明显较低。