A discontinuous climatic record from 187 to 74 ka from a speleothem of the Clamouse Cave (south of France)
Introduction
A detailed knowledge of the timing of past climatic changes in continental records is essential for a comparison with the marine [1], [2] or ice [3], [4] core records because of their close relationships, and for global reconstructions of climate variability. Speleothems provide reliable paleoenvironmental records as numerous climatic proxies may be investigated such as oxygen and carbon stable isotope ratios, petrographic analyses, fluorescence banding, trace elements concentrations or EPR (Einstein–Podolsky–Rosen) spectrometry and reflectance [5], [6], [7], [8], [9], [10]. Speleothems are barely affected by erosion or other post-depositional processes, and they will also complement the continental record based on lake sediments or pollen sequences. Moreover, because of the generally closed system conditions for the U–Th system, they can be precisely dated back to ca. 500 ka by the 230Th/234U disequilibrium method [11] with thermal ionization mass spectrometry (TIMS).
We investigate the patterns of growth and of the stable carbon and oxygen isotope changes of the Cla4 stalagmite (Clamouse Cave, south of France). The present-day isotopic compositions of rain, seepage water and calcite were measured in order to determine the isotopic equilibrium state of the modern chemical system, which will be compared to the past isotopic changes in the Cla4 speleothem. The climatic changes in Cla4 during the glacial marine isotope stage (MIS) 6.4 will be particularly discussed. The Cla4 climatic record will be compared to North Atlantic and Mediterranean marine records, and to their continental margins [12], [13].
Section snippets
Site and speleothem description
The studied stalagmite (Cla4) was collected from Clamouse Cave, near the Mediterranean Sea (Fig. 1). The Clamouse area is close to the southern province of the Larzac Plateau, a large karstic plateau elevated 700–900 m asl.
The cave is a complex karstic system, developed in upper Jurassic dolomites and limestones. The 3500 m long explored galleries are arranged in three major levels in relation to the deepening of the Herault River [14]. The lowest level (35–60 m asl) is still active with a
Sampling strategy
The stalagmite was cut longitudinally and one half was used for sampling. Pieces of 20×3×5 mm were cut parallel to growth layers to provide samples for Th/U dating. When visible, a hiatus is characterized by a thin white or colored clay layer separating two zones of calcite more or less colored or with different crystal fabrics. Fifteen samples were preferentially cut on both sides of visible growth hiatuses in order to precisely determine their duration (Fig. 2). Additional samples (83) from
U–Th dating
Table 1 gives analytical results, U contents, age estimates and measured 234U/238U activity ratios for each of the 15 samples collected above and below the visible hiatuses. Correction for detrital contamination was not required because the 230Th/232Th activity ratios are greater than 400 for all samples. The deposition of this stalagmite started before 189.00 ka and ended after 74.54 ka (Table 1). The lack of age inversion for all samples (within the 2σ error for the growth phase of ∼189 ka)
Discussion
The Cla4 stalagmite grew discontinuously over the 190–75 ka interval that encompassed MIS 5, 6 and the end of MIS 7 [2]. The Cla4 growth phases will be first compared to the precisely U/Th-dated high sea stands [31], [32], [33], [34], [35], [36], [37] and to reconstructed sea levels from the orbitally tuned marine isotopic records [1], [2]. Then, the Cla4 paleodata will be compared: (1) to Mediterranean continental [32] and marine [33] records, and (2) to the North Atlantic marine records [34],
Conclusion
The U/Th dating of stalagmite Cla4 from the Clamouse Cave in southern France shows that the Cla4 stalagmite grew discontinuously during the warm and humid phases (MIS 5.1, 5.3, 5.5 and 7), as well as during a brief period during the glacial stage MIS 6. During MIS 5, the temperature oscillated with an amplitude of ∼4°C, and could have decreased by ∼6°C at the end of sub-stage 5.5. The growth rates of Cla4 vary by a factor of ∼100 independently of these warmer/colder climatic conditions, and
Acknowledgements
This study was supported by the Centre National de la Recherche Scientifique et le Commissariat à l’Energie Atomique, UMR 1572. The Cla4 stalagmite from Clamouse Cave was collected with the permission and the help of P. Dubois. We wish to thank C. Vertonghen, M. Bakalowicz and S. Van-Exter for their active collaboration in the field. Thanks also to M. Stievenard and O. Cattani for the stable isotope measurements on water. Thanks are also due to L. Turpin for his helpful discussions, as well as
References (64)
- et al.
Age dating and the orbital theory of the ice ages: development of a high resolution 0 to 300,000-year chronostratigraphy
Quat. Res.
(1987) - et al.
Controls on trace element (Sr-Mg) compositions of carbonate cave waters: implications for speleothem climatic records
Chem. Geol.
(2000) - et al.
Mg, Sr and Sr isotope geochemistry of a Belgian Holocene speleothem: implications for paleoclimate reconstructions
Chem. Geol.
(2000) - et al.
Comparative study of a stalagmite sample by stratigraphy, laser induced fluorescence spectroscopy, EPR spectrometry and reflectance imaging
Chem. Geol.
(2000) - et al.
Paleoclimatic record of a long deep sea core from the Eastern Mediterranean
Quat. Res
(1977) - et al.
Paleoclimatic record of speleothems in a tropical region: study of laminated sequences from a Holocene stalagmite in Central-West Brazil
Quat. Int.
(2002) - et al.
Holocene climate variability in Europe: evidence from δ18O, textural and extension-rate variations in three speleothems
Quat. Sci. Rev.
(1999) - et al.
U–Th isotope systematics from the Soreq cave, Israel and climatic correlations
Earth Planet. Sci. Lett.
(1998) - et al.
A detailed 31,000-year record of climate and vegetation change, from the isotope geochemistry of two New Zealand speleothems
Quat. Res.
(1998) - et al.
231Pa and 230Th contamination at zero age: a possible limitation on U/Th series dating of speleothem material
Chem. Geol.
(1999)
Timing and duration of the Last Interglacial inferred from high resolution U-series chronology of stalagmite growth in Southern Hemisphere
Earth Planet. Sci. Lett.
Equilibrium and non-equilibrium oxygen isotope effects in synthetic carbonates
Geochim. Cosmochim. Acta
The isotopic geochemistry of speleothems. I. The calculation of the effects of different modes of formation on the isotopic composition of speleothems and their applicability as palaeoclimatic indicators
Geochim. Cosmochim. Acta
Timing and hydrological conditions of Sapropel events in the Eastern Mediterranean, as evident from speleothems, Soreq cave, Israel
Chem. Geol.
Mediterranean pluvial periods and sapropel formation over the last 200000 years
Palaeogeogr. Palaeoclimatol. Palaeoecol.
The kinetics of calcite precipitation from thin films of calcareous solutions and the growth of speleothems: revisited
Chem. Geol.
The kinetics of calcite solution and precipitation in geologically relevant situations of karst areas. 1. Open system
Chem. Geol.
Northwest European palaeo-climate as indicated by growth frequency variations of secondary calcite deposits
Palaeogeogr. Palaeoclimatol. Palaeoecol.
Mediterranean Quaternary sapropels as immediate response of the African Monsoon to variation of insolation
Palaeogeogr. Palaeoclimatol. Palaeoecol.
Astronomical calibration of Gauss to Matuyama sapropels in the Mediterranean and implication for the geomagnetic polarity time scale
Earth Planet. Sci. Lett.
Continental oxygen isotopic record of the last 170,000 years in Jerusalem
Quat. Res.
The Holocene and upper Pleistocene pollen record from padul (Granada, Spain): a new study
Palaeogeogr. Palaeoclimatol. Palaeoecol.
A long pollen record from lac du Bouchet, Massif Central, France: for the period ca. 325 to 100 ka BP (OIS 9c to OIS 5e)
Quat. Sci. Rev.
TIMS U-series dating and stable isotopes of the last interglacial event in Papua New Guinea
Geochim. Cosmochim. Acta
High-precision U-series dating of corals from Western Australia and implications for the timing and duration of the last interglacial
Earth Planet. Sci. Lett.
Reconciliation of late Quaternary sea levels derived from coral terraces at Huon peninsula with deep sea oxygen isotope records
Earth Planet. Sci. Lett.
Extending the Vostok ice core record of paleoclimate to the penultimate glacial period
Nature
Oxygen 18/16 variability in Greenland snow and ice with 10−3 to 105-year time resolution
J. Geophys. Res.
Climate and vegetation history of the midcontinent from 75 to 25 ka: a speleothem record from Crevice cave, Missouri, USA
Science
Microzonality of luminescence of cave flowstones as a new indirect index of solar activity
C.R. Acad. Bulg. Sci.
Cited by (60)
Strong coupling of the East Asian summer monsoon and hydroclimate footprints during 53–47 ka
2022, Palaeogeography, Palaeoclimatology, PalaeoecologyCitation Excerpt :And it may be a pervasive hydroclimate phenomenon which can be interpreted reasonably at various timescales (Ding et al., 2008; Dai et al., 2021). For the inverse directions between the δ13C and δ18O values of Hulu Cave on millennial-centennial scales, the previously interpreted as “damping model” due to the short residence time of precipitation in soil, led to an isotopic non-equilibrium between the water and the soil CO2 (Kong et al., 2005), which is reasonable and is also exemplified by other studies (Bar-Matthews et al., 2000; Plagnes et al., 2002). While the question is how to explain these co-variant characteristics of trace element with that of δ13C, but opposite to the δ18O.
Influences on Asian summer monsoon during Dansgaard-Oeschger events 19 to 25 (70–115 kyr B.P.)
2022, Palaeogeography, Palaeoclimatology, Palaeoecology