Authigenic carbonate sedimentation in Eravnoe group lakes (Western Transbaikalia; response to Holocene climate change
Authigenic carbonate sedimentation in Eravnoe group lakes (Western Transbaikalia; response to Holocene climate change
Russian Geology and Geophysics (November 2017) 58 (11): 1390-1400
- Asia
- authigenic minerals
- Buryat Russian Federation
- C-13/C-12
- carbon
- carbonates
- Cenozoic
- climate change
- Commonwealth of Independent States
- dolomite
- Holocene
- infrared spectra
- isotope ratios
- isotopes
- lacustrine environment
- lake sediments
- O-18/O-16
- oxygen
- paleoclimatology
- Quaternary
- Russian Federation
- sedimentation
- sediments
- Siberia
- spectra
- stable isotopes
- upper Holocene
- Vitim Plateau
- Western Transbaikalia
- X-ray diffraction data
- Yeravnoye Lakes
- Lake Dolgoye
Sediments of intracontinental closed lakes are unique natural archives that store climate history records. We study Late Holocene carbonate-bearing sediments of Lake Dolgoe, a small saline lake in the Eravnoe basin on the Vitim Plateau (western Transbaikalia). Sediment samples have been analyzed by several methods: X-ray powder diffraction, infrared spectroscopy, stable isotope ( (super 18) O and (super 13) C) determination, laser diffraction particle size analysis, XRF elemental analysis, etc. The mineral phases of bottom sediments include clastic and carbonate components and hydromagnesite at the section top; carbonates are authigenic varieties of the calcite-dolomite series. Modeling of complex XRD profiles reveal Mg-calcite with various Mg contents and excess-Ca dolomites, which are mixed-structure crystals compositionally close to stoichiometric dolomite. The crystal structure and relative percentages of carbonates from the dated sedimentary section controlled by climate and lake level changes allow reconstructing the Holocene history of Lake Dolgoe.