Journal
BASIN RESEARCH
Volume 33, Issue 1, Pages 570-593Publisher
WILEY
DOI: 10.1111/bre.12485
Keywords
biomarkers; diagenesis; illite-smectite; K-Ar; maximum palaeotemperatures; porosity
Categories
Funding
- Narodowe Centrum Nauki [2013/10/A/ST10/00050]
Ask authors/readers for more resources
The study examined the diagenetic history of Ediacaran sedimentary rocks in the East European Craton using XRD characterization, K-Ar dating, mudstone porosity measurements, and organic geochemistry investigations. The results revealed differences in burial depth and diagenetic advancement between the cratonic core and margin, with older ages generally observed in the north. The findings suggest short-lasting pulses of potassium-bearing hot fluids influenced illitization in porous rocks without altering organic matter, leading to unique diagenetic patterns in the region.
The diagenetic history of the Ediacaran sedimentary rocks in the East European Craton (EEC) over the area extending from Arkhangelsk (Russia) in the north to Podolia (Ukraine) in the south was revealed by means of the XRD characterization and K-Ar dating of clay fractions, mudstone porosity measurements and organic geochemistry investigations. Mudstone porosity measurements produced direct evidence of shallow maximum burial of the Ediacaran sediments on the craton (Russia, Lithuania, Belarus, Volyn), not exceeding 1.5 km, and much deeper burial at the cratonic margin, in Podolia and Poland. In general, illitization of smectite and biomarker indices indicates more advanced diagenesis at the cratonic margin. K-Ar dating of authigenic illite-smectite and aluminoceladonite revealed the Palaeozoic age of mineral diagenesis (ca. 450-300 Ma) both on the craton and its margin, with older ages generally observed in the north. When the maximum palaeotemperatures were evaluated from illite-smectite and biomarkers, based on the calibrations from the conventional burial diagenetic sections, a major mismatch was detected for the cratonic area: 100 degrees C-130 degrees C from illite--smectite and tens of(o)C lower from the lipid biomarkers. This diagenetic pattern was interpreted as the result of short-lasting (in ky scale) pulses of potassium-bearing hot fluids migrating from the Caledonian and Variscan orogens deep in the craton interior, effectively promoting illitization in porous rocks without altering the organic matter. Analogous short pulses of fluids were responsible for numerous diagenetic phenomena, including Mississippi Valley-Type ore deposits, in the American Midwest, in front of the Appalachians. K-Ar dating indicates that the entire Proterozoic sedimentary cover of the Great Unconformity on the EEC remained untouched by measureable post-sedimentary changes until the early Palaeozoic, thus for over 1000 My, which is an unprecedented finding.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available