Tagasi otsingusse
Kiipli, E. et al., 2008

Hydrodynamic control of sedimentation in the Ordovician (Arenig-Caradoc) Baltic Basin

Kiipli, E., Kallaste, T., Kiipli, T.
DOI
DOI10.1111/j.1502-3931.2008.00112.x
Aasta2008
AjakiriLethaia
Köide41
Number2
Leheküljed127-137
Tüüpartikkel ajakirjas
Eesti autor
Keelinglise
Id5057

Abstrakt

Changes in mineralogy, geochemistry and grain size in a deep shelf succession from the Ordovician Baltic Basin are used to determine shifts in marine current direction and sea-level fluctuations. The analyses show a long-term, relatively stable interval in the Arenig–Llanvirn followed by shorter periods of perturbations and rearrangements in the early Caradoc. The Arenig deposits of the Aizpute-41 core have a high 2–10 µm terrigenous component. During the Llanvirn the proportion of this size fraction diminished. The grain size change was accompanied by mineralogical changes. In the early Caradoc the kaolinite disappeared, the muscovite content decreased, and quartz and albite increased. This and several geochemical indicators point to an input of considerable part of sediment from different sources than in the Arenig–Llanvirn. Two currents, a southwesterly for the Arenig and a westerly for the early Caradoc, are proposed. A red facies belt in the deep shelf marks the pathway of the Arenig–Llanvirn current. Smaller shifts in SiO2/Al2O3 ratio in the Aizpute-41 section are interpreted as reflecting transgressions and regressions corresponding to regional stage boundaries.

Viimati muudetud: 5.3.2024
KIKNATARCSARVTÜ Loodusmuuseumi geokogudEesti Loodusmuuseumi geoloogia osakond
Leheküljel leiduvad materjalid on enamasti kasutamiseks CC BY-SA litsensi alusel, kui pole teisiti määratud.
Portaal on osaks teadustaristust ning infosüsteemist SARV, majutab TalTech.
Open Book ikooni autor Icons8.