Pregled bibliografske jedinice broj: 35604
Illitization of smecites in paleosols from Istria, Croatia
Illitization of smecites in paleosols from Istria, Croatia // Conference of the European Clay Groups Association, Program with abstracts
Krakov: Pracownia AA, 1999. str. 119-119 (poster, međunarodna recenzija, sažetak, znanstveni)
CROSBI ID: 35604 Za ispravke kontaktirajte CROSBI podršku putem web obrasca
Naslov
Illitization of smecites in paleosols from Istria, Croatia
Autori
Ottner, Franz ; Durn, Goran ; Schwaighofer, Bernd ; Fröschl, H. ; Tišljar, Josip
Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni
Izvornik
Conference of the European Clay Groups Association, Program with abstracts
/ - Krakov : Pracownia AA, 1999, 119-119
Skup
Conference of the European Clay Groups Association
Mjesto i datum
Kraków, Poljska, 05.09.1999. - 09.09.1999
Vrsta sudjelovanja
Poster
Vrsta recenzije
Međunarodna recenzija
Ključne riječi
illitization of smectites; paleosols; Istria; Croatia
Sažetak
Greenish clays often occur as thin layers in Early Cretaceous shallow-
water carbonate sediments of Istria where they mark the top of
shallowing upwards sequences. When they show evidence of
subaerial exposure and pedogenesis they are considered paleosols.
Paleosols bear important information on material supply, climate,
relief, and duration of subaerial exposure phases
Clay minerals in <2m and <0.2 m fractions were analyzed
using XRD and FTIR. Chemical composition (main and trace
elements) was employed using XRF and ICP-MS.
The clay mineralogical composition is as follows: (1) illitic material,
(2) randomly oriented I/S mixed layer, (3) regularly oriented I/S
mixed layer, (4) kaolinite and (5) chlorite.
In the Selina profile the clay mineral distribution shows a clear trend.
The main clay mineral in the upper part is illitic material up to 78
wt.%. In the lower part of the profile illite values are below 50 wt.
%. The second main clay mineral group are ordered and irregularly oriented illite/smectite mixed layer minerals respectively.
Mineralogical as well as chemical data point out, that a
transformation of smectite (from the mixed-layer minerals) to illite
must have occurred. Wetting and drying experiments and layer
charge measurements support that theory.
K-fixation necessary for illitization of smectites could have been achieved at
surface temperatures by repeated wetting and drying. The K+
might have been provided by plants, marine waters, volcanic rocks or other various sources.
Izvorni jezik
Engleski
Znanstvena područja
Geologija
