Last glacial climate oscillations and sudden environmental changes investigated in stalagmites from southwest Sulawesi, western Pacific

İbrahim Tonguç UYSAL,Emma ST PIERRE,Jian-Xin ZHAO,James SHULMEISTER,Ezgi ÜNAL İMER

doi:10.3906/yer-1905-20

Abstract

We investigated two stalagmites from the Saripa Cave and Bumi Cave in southern Sulawesi, Indonesia, using high-precision U-series dating and high-resolution trace element and C-O-Sr isotope analysis. The growth record (from 10.4 ± 0.1 ka to 77.4 ± 0.9 ka) of the Saripa Cave stalagmite (SR04-ST3) is fragmented with two major (at the top: 10.4-11.6 ka and middle: 43.8-44.7 ka sections of the stalagmite) and some short (middle and bottom sections) growth phases, interrupted by long-lasting growth hiatuses. Both the timing of the growth phases and the δ18O values for different growth phases are correlated with those of cold/dry (~22 ka and 43.8-44.7 ka) and wet/warm periods (e.g., Greenland Interstadials 12, 14, and 21) in the northern hemisphere speleothem records, displaying both anti-phase and in-phase relationships with the northern hemisphere records. This observation is unique in the Western Pacific tropical region, mostly likely because the Saripa Cave is located within the region of the latitudinally migrating Intertropical Convergence Zone (ITCZ), whereby the rainfall seasons may have changed through time depending on the mean latitude of the ITCZ. The Saripa Cave stalagmite contains textural laminae, which are here interpreted as a record of rapid environmental changes, possibly caused by volcanic eruptions at around 22.55 ka and 44.73 ka BP. The Bumi Cave record (stalagmite BC-09-3-C), on the other hand, presents very little variation in stable isotope and trace element compositions between 26.8 ka and 18.5 ka and does not seem to be influenced by any possible volcanic activity. More detailed future studies investigating millimeter- to submillimeter-scale geochemical time-series constrained by accurate ages in speleothems can be useful in unfolding the effects of eruptions and provide parallel records of climate and sudden environmental changes.

Highlights

IntroductionKnown as speleothems, provide a unique opportunity to reconstruct climate changes, human evolution, recurrence patterns of paleoseismic events, and volcanic eruptions (e.g., Wang et al, 2001; Zhao et al, 2001; Fleitmann et al, 2004, 2009; Kagan et al, 2005; Tuccimei et al, 2006; Frisia et al, 2008; Wynn et al, 2008; Siklosy et al, 2009; Badertscher et al, 2014; Jamieson et al, 2015)
U-series dating U-series age data are presented in Table 1 and the locations of samples with their U-series ages on two stalagmites are shown in Figures 3 and 5
Our results suggest that rainfall seasons in Southwest Sulawesi may have changed dramatically, resulting in both in-phase and anti-phase relationships with the northern hemisphere (NH) records in different times depending on the mean location of the Intertropical Convergence Zone (ITCZ)

Summary

Introduction

Known as speleothems, provide a unique opportunity to reconstruct climate changes, human evolution, recurrence patterns of paleoseismic events, and volcanic eruptions (e.g., Wang et al, 2001; Zhao et al, 2001; Fleitmann et al, 2004, 2009; Kagan et al, 2005; Tuccimei et al, 2006; Frisia et al, 2008; Wynn et al, 2008; Siklosy et al, 2009; Badertscher et al, 2014; Jamieson et al, 2015). High-precision U-series dating and high-resolution geochemical analyses of speleothems have the potential to provide parallel records of climate and environmental change, and offer insights into the complex interplay of tectonics and hydroclimatological processes. Indonesia is a apt location to test the interplay of volcanism and hydroclimatological processes.

Results

Discussion

Conclusion