Naslov
Diagenesis of pelitic sediments in the Sava Depression (Croatia)

Autori
Grizelj Anita ; Španić Darko ; Tibljaš, Darko ; Kovačić, Marijan

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
MINERALOGIA, SPECIAL PAPERS Vol.33 / Gorniak, Katarzyna ; Szydlak, Tadusz - Zakopane : Mineralogical Society of Poland -Polish Clay Group, 2008, 63-63

Skup
4th Mid-European Clay Conference 2008,

Mjesto i datum
Zakopane, Poljska, 22.09.2008. - 27.09.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
illit-smektit; minerali glina; miocen; Savska potolina; pelitni sedimenti; rendgenska difrakcija;
(illite-smectite; clay minerals; Miocen; Sava depression; pelitic sediments; X-ray diffraction)

Sažetak
Mineralogical investigations of the Miocene pelitic sediments were performed on samples from six wells from the Sava Depression (sub-basin in the SW part of the Pannonian Basin System). The main goal was determination of mineral composition including determination of smectite content in illite-smectite and illite and chlorite crystallinity indices. Paleotemperatures were estimated from vitrinite reflectance and Thermal Alteration Index (TAI) measurements on eighteen samples. The main components of the pelitic sediments are carbonate minerals and clay minerals together with ubiquitous quartz. In certain samples, smaller amounts of feldspars, pyrite, opal CT and hematite were found. In greater depths, smectite and illite-smectite content in <2 &#956; m fraction decrease, simultaneously with illite and chlorite content increase. It has been established, that smectite illitisation is primarily influenced by temperature and depth increase, mineral composition of the rocks (potassium availability) and exposure time. Based on X-ray diffraction investigations of pelitic sediments from the Sava Depression, three stages of diagenesis have been revealed: 1) Early stage of diagenesis is characteristic for rocks from depths <1, 8 km. In those rocks smectite, illite-smectite of the randomly interstratified (R0) type and detritic illite are present. 2) Intermediate stage of diagenesis, marked with the appearance of ordered type of illite-smectite was recorded at the depths >1, 8 km and temperature higher than 80°C. 3) At depths > 4, 6 km coresponding to temperatures &#8805; 190°C, late stage of diagenesis, characterised by appearance of illite-smectite with <10% smectite, has been established. Transformation of randomly interstratified R0 type of illite-smectite into R1 type, as well as transformation of R1 into ordered R3 type fit to catagenesis of organic matter.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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