Publication details
CHROMIUM-RICH ILLITE/SMECTITE IN THE BASAL BALINKA CONGLOMERATE OF THE UPPER CARBONIFEROUS-PERMIAN BOSKOVICE BASIN (BOHEMIAN MASSIF)
| Authors | |
|---|---|
| Year of publication | 2023 |
| Type | Article in Periodical |
| Magazine / Source | Annales Societatis Geologorum Poloniae |
| MU Faculty or unit | |
| Citation | |
| web | https://doi.org/10.14241/asgp.2023.05 |
| Doi | http://dx.doi.org/10.14241/asgp.2023.05 |
| Keywords | Chromium illite-smectite; Cr-rich spinelides; Balinka Conglomerate; diagenetic alteration; Upper Carboniferous; Boskovice Basin; Bohemian Massif |
| Description | The Upper Carboniferous polymictic Balinka Conglomerate was deposited along the western margin of the Boskovice Basin (eastern part of the Bohemian Massif). Angular aggregates of deep-green chromium-rich interstratified clay mineral R1-illite(0.8)/smectite (I/S) are present exclusively in the basal part of this unit. The textural position of chromium-bearing I/S (0.77–2.88 wt.% Cr2O3; 0.040–0.153 apfu Cr) in the conglomerate matrix indicates a genetic link with the highly altered chromium spinel, which is preserved in the relics. The source of Cr-rich spinelides was serpentinized peridotites in the adjacent Moldanubicum (Gföhl Unit). The formation of I/S is related to diagenetic processes in the conglomerate matrix. The fluids would have relatively high fugacity of CO2 and activity of K+. K/Ar ages of 284.1 ± 7.7 and 276.3 ± 7.4 Ma (lower Permian – Kungurian/Artinskian age) confirmed the diagenetic origin of this I/S. |