Naslov
Terra Rossa profile near Rovinj, its mineralogy and geochemistry

Autori
Durn, Goran

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

Izvornik
Abstracts / Velić, Ivo ; Vlahović, Igor - Zagreb : Hrvatski geološki institut, 1991, 100-100

Skup
Second International Symposium on Adriatic Carbonate Platform

Mjesto i datum
Zadar, Hrvatska, 12.05.1991. - 18.05.1991

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
terra rossa ; profile ; Rovinj ; mineralogy ; geochemistry

Sažetak
The terra rossa soil (sediment) profile (16 samples different by means of structure and colour from the sufrace to the contact with underlying rocks) near Rovinj, Istra, was subjected to (1) granulometric analysis by sieving and gravity sedimentation (2) mineralogical analysis of the clay and silt fraction by X-ray diffraction and DTA (3) Quantitative determinations of microelements and iron by AAS and XRF. The profile is approximately 850 cm thick and lies directly on the underlying dolomite of Cretaceous age. The contact between terra rossa and dolomite is Sharp. The amount of the clay fraction (<2µm) in the upper section of the profile has an icreasing trend with depth (from 41, 1% to 71, 6%). This regularity is observed to the depth of 345 cm. From this depth on (lower section of the profile), the amount of the clay fraction shows a slight decrease and small variation (59, 9%-66, 4%). The silt fraction (2-63µm) shows a reverse trend in the upper part of the profile while in the lower part it increases and varies slightly. The amount of the sand fraction (>63µm) is small (0, 05-1, 1%) and is randomly distributed. The X-ray diffractograms indicate that the clay fraction (<2µm) consists of ilite, kaolinite, quartz, goethite, hematite and abundant amount of amorphous and mica (ilite). The lower part of the profile is characterized by the presence of interstratified minerals, not present in the upper part of the profile. Distribution of microelements and iron through the profile is not uniform. Enrichment in zirconium and cadmium is abvous in the lower section of th profile. Granulometric, mineralogical and microelement analysis indicate that possibly the contribution of various parent Materials was not uniform with depth. Possible parent Materials were flysch sediments, eolian sediments and carbonate rock residual Products. Erosion of clastic rocks, transport and their deposition on carbonate bedrocks and only minor deposition of carbonate residua is the likely mechanism explaining the origine of the terra rossa soil (sediment) profile near Rovinj.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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