Origin of clayey materials deposited during Aptian/Albian emersion in Istria, Croatia

Scientific paper - Abstract

• Author: Marta Mileusnić https://orcid.org/0000-0003-3776-3661
• Author: Goran Durn
• Author: Franz Ottner
• Author: Josip Tišljar
• Author: Dunja Aljinović
• Author: Uroš Barudžija https://orcid.org/0000-0002-1617-9362
• Editor: Katarzyna Górniak
• Author's institution: University of Zagreb; Faculty of Mining, Geology and Petroleum Engineering; (Department of Mineralogy, Petrology and Mineral Resources)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geology

Abstract (english)

The subject of this study are clayey materials deposited during Late Aptian / Early
Albian long-lasting emersion phase in Istria (period of 11-19 million years). When they
show indication of subaerial exposure and pedogenesis they are considered paleosols. The
goal was to estimate the provenance of clayey materials. Investigations were based on
detailed sedimentological, geochemical, and mineralogical analyses of clayey materials and
undissolved limestone residue from the bottom of clayey horizons. Considering isolation of
Adriatic carbonate platform during Aptian/Albian, there are three possible sources of
material forming investigated clayey materials: (1) undissolved limestone residue; (2)
volcanic material; and (3) aeolian material. Signs of vadose zone (geopetal structure, crystal
silt) and small depths of palaeokarstification in limestone, as well as, low weight content of
indissoluble limestone residue indicate small contribution of undissolved limestone residue
in formation of investigated clayey materials. There are signs (immobile chemical elements
proportions; negative europium anomaly; fragments of pyroclasts with altered volcanic
glass; zircon, feldspars, pyroxene and amphibole grains in sand fraction; smectite in
undissolved limestone residue) of volcanic material contribution in formation of clayey
materials. Volcanic material probably came after resedimentation because during Aptian
and Albian there is no known calcium-alkaline volcanism in neighbouring areas. Irregular
and rounded forms of volcanic minerals in clayey materials are also in favour of
resedimentation. Aeolian dust is probably the most important component of source
material. Significant atmospheric circulation and accumulation of great amount of aeolian
material during Aptian and Albian due to arid climate on the land; domination of smectite
(formed by alteration of great amount of volcanic material widespread due to strong
volcanic activity and formed by authigenesis in soils as a consequence of hot climate with
contrasted seasons); very fine grain size of investigated clayey matrix which could enable
long transport; and presence of metamorphous minerals (tourmaline, garnet) are indications
of aeolian origin.

• Language: english
• Publication type: Scientific paper - Abstract
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Publication title: Abstracts / 4th Mid-European Clay Conference 2008
• Series title: Mineralogia. Special papers
• Numbering: vol. 33, p. 115
• p-ISSN: 1896-2203
• URN:NBN: urn:nbn:hr:169:747957
• Publication: 2008
• Conference: Title: 4th Mid-European Clay Conference 2008; Acronym: MECC'08; Location: Zakopane, Poland; Organizer: Mineralogical Society of Poland - Polish Clay Group; Organizer: Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology; Organizer: Stanisław Staszic Scientific Association; Start date: 2008-09-22; End date: 2008-09-27; Assembly type: Lecture
• Document URL: http://www.ptmin.agh.edu.pl/mpsp30/mpsp33.pdf
• Type of resource: Text
• Publisher: Mineralogical Society of Poland
• Publishing place: Kraków
• Access conditions: Open access
• Created on: 2020-08-24 09:59:19