What can be learned from the K-Ar ages of illite from Rotliegend sandstones of the Fore-Sudetic Monocline, SW Poland?

Julita BIERNACKA
2014 Geological Quarterly  
Biernacka, J., 2015. What can be learned from the K-Ar ages of illite from Rotliegend sand stones of the Fore-Sudetic Monocline, SW Po land? Geo log i cal Quar terly, 59 (2): 257-270, doi: 10.7306/gq.1210 The avail able K-Ar ages of authigenic illite from Rotliegend ae olian sand stones of the Fore-Sudetic Monocline, SW Po land, in clud ing those from six sam ples ex am ined in the pres ent study, are crit i cally re viewed in terms of their geo log i cal mean ing and com pared with the K-Ar
more » ... ed with the K-Ar ages of illite from the re main ing part of the South ern Perm ian Ba sin in Europe. The ma jor ity of ages fall in the range be tween 195 and 150 Ma, i.e. they cor re spond to Ju ras sic times. The re sults may be grouped in sev eral time in ter vals, which are al most iden ti cal to those iden ti fied for Rotliegend sand stones of Cen tral and West ern Eu rope, and which are ten ta tively in ter preted as pulses of in tense illite growth. Short-last ing illitisation is re corded only at places. More often, illitisation pro ceeded as a multi-stage pro cess, which in the north ern part of the Fore-Sudetic Monocline might have lasted un til the Cre ta ceous. The K-Ar ages of authigenic illite gen er ally co in cide with the mod elled time of gas gen er a tion from Car bon if er ous rocks and the fill ing of res er voirs in the area of the Fore-Sudetic Monocline. Pos si bly, the same un der lying pro cesses trig gered illitisation and hy dro car bon ex pul sion, or hy dro car bon mi gra tions trig gered fluid flows and illite crystallisation. Fig. 1A -localization of boreholes mentioned in the text against the background of palaeogeography at the end of Rotliegend deposition in SW Poland (according to Gast et al., 2010; Kiersnowski et al., 2010b) B -the extent of Rotliegend deposits in Europe after Glennie (1990) and Karnkowski (1999)
doi:10.7306/gq.1210 fatcat:o5h3mcufsfcw5d3ay7xodnacbq