Geochemical facets of the Inikan Formation as indicators of stratification and hydrochemistry of the Cambrian paleobasin
Geochemical facets of the Inikan Formation as indicators of stratification and hydrochemistry of the Cambrian paleobasin
Russian Geology and Geophysics (September 2023) 65 (2): 251-271
- anaerobic environment
- Asia
- black shale
- Cambrian
- carbonaceous composition
- carbonate rocks
- chemical composition
- clastic rocks
- Commonwealth of Independent States
- EDS spectra
- electron microscopy data
- geochemistry
- lithogeochemistry
- major elements
- marine environment
- marker beds
- mineral composition
- mudstone
- organic compounds
- paleoenvironment
- Paleozoic
- petrography
- Russian Federation
- sedimentary rocks
- SEM data
- spectra
- total organic carbon
- trace elements
- X-ray diffraction data
- X-ray spectra
- Yakutia Russian Federation
- Inikan Formation
- Malaya Kuonamka beds
-Geochemical studies of Inikan Formation rocks from the coastal outcrops of the Yudoma River were carried out. All analyzed lithological varieties are characterized by significant enrichment in B, Ni, Mo, Ag, Sb, U (redox-sensitive trace metals and elements associated with biodeposition). The source of the elements was sea water that leached them from the eolian material. It was found that the deposits accumulated in anoxic environments with periods of both euxinic (probably, in the bottom water mass) and suboxic conditions. Such anoxic and euxinic conditions developed due to the stable stratification of the ocean that existed in the early-middle Cambrian in this part of the basin. In addition, the long-term accumulation of organic-rich sediment under conditions of anoxia, periodic euxinia, and stable stratification indicates the presence of a geomorphologically isolated depression in this part of the basin. CIA-Kcorr ranges from 68 to 95. The low values of the CIA may be related to the height of the relief in the sedimentary source area.
