000147764 001__ 147764
000147764 005__ 20250107140859.0
000147764 0247_ $$2doi$$a10.1007/s00531-021-02091-z
000147764 0248_ $$2sideral$$a125460
000147764 037__ $$aART-2021-125460
000147764 041__ $$aeng
000147764 100__ $$aBrlek, Mihovil
000147764 245__ $$aKarst bauxite formation during Miocene Climatic Optimum (central Dalmatia, Croatia): mineralogical, compositional and geochronological perspectives
000147764 260__ $$c2021
000147764 5060_ $$aAccess copy available to the general public$$fUnrestricted
000147764 5203_ $$aThe Miocene Climatic Optimum (MCO) represents a global warm period (approximately 17‚Äì14.7¬†Ma) interrupting a long-term period of Cenozoic cooling. To elucidate if bauxitization took place in southeastern European mid-latitude areas during the MCO, we studied a section of undated massive karst bauxite (Crveni Klanac, CK) in central Dalmatia, Croatia, hosted in Upper Cretaceous limestones and overlain by Miocene Sinj Basin lacustrine deposits. Integrated mineralogical, morphological and geochemical analyses indicate the predominant mineral phases of the homogenous bauxite matrix are authigenic, subhedral to euhedral kaolinite and gibbsite. The in-situ mineralization was a consequence of pedogenic processes, indicating the CK bauxites formed autochthonously. In situ U‚ÄìPb zircon ages of the lower, middle and upper parts of the CK bauxite are very similar, dominated by Miocene and Oligocene ages, indicating that they all share similar protolith(s). Subsequent high-precision chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) analyses indicate a maximum depositional age (MDA) for the pre-bauxitic material of 16.9576 ¬± 0.021¬†Ma (2œÉ uncertainty, incorporating decay constant uncertainty). This MDA, a maximum age of autochthonous bauxitization, coincides with the onset of the MCO. Based on currently available geochronological constraints, the maximum timeframe for CK bauxitization was less than ~ 700¬†ka, which matches the records of the MCO in paleo-mid-latitude Europe. The potential imprint of pre-17¬†Ma bauxitization and contribution of older (i.e., Upper Paleogene) bauxite deposits resedimented to the CK profile, as well as degree of potential parautochthonous origin of the CK bauxites, is yet to be investigated. More than simply aligning with regional and local reconstructions of continental climatic conditions during the onset and the early stages of the MCO, the high degree of autochthony of the CK bauxites provide a precise climatic constraint. For in-situ bauxitization to occur in the southeastern parts of mid-latitude continental Europe, paleoclimatic and paleoenvironmental conditions must have had mean annual temperature greater than 17‚Äì22¬†¬8C and mean annual precipitation of more than 1100‚Äì1200¬†mm.
000147764 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/
000147764 590__ $$a2.698$$b2021
000147764 591__ $$aGEOSCIENCES, MULTIDISCIPLINARY$$b114 / 202 = 0.564$$c2021$$dQ3$$eT2
000147764 592__ $$a0.859$$b2021
000147764 593__ $$aEarth and Planetary Sciences (miscellaneous)$$c2021$$dQ1
000147764 594__ $$a4.6$$b2021
000147764 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000147764 700__ $$aGaynor, Sean P.
000147764 700__ $$aMongelli, Giovanni
000147764 700__ $$0(orcid)0000-0002-4970-6333$$aBauluz, Blanca$$uUniversidad de Zaragoza
000147764 700__ $$aSinisi, Rosa
000147764 700__ $$aBrcic, Vlatko
000147764 700__ $$aPeytcheva, Irena
000147764 700__ $$aMišur, Ivan
000147764 700__ $$aTapster, Simon
000147764 700__ $$aTrinajstic, Nina
000147764 700__ $$aLaita, Elisa
000147764 700__ $$0(orcid)0000-0002-2169-4561$$aYuste, Alfonso$$uUniversidad de Zaragoza
000147764 700__ $$aŠuica, Sanja
000147764 700__ $$aGrizelj, Anita
000147764 700__ $$aKukoc, Duje
000147764 700__ $$aSchaltegger, Urs
000147764 700__ $$0(orcid)0000-0002-1954-6180$$aLaita, Elisa$$uUniversidad de Zaragoza
000147764 7102_ $$12000$$2120$$aUniversidad de Zaragoza$$bDpto. Ciencias de la Tierra$$cÁrea Cristalografía Mineralog.
000147764 773__ $$g110, 8 (2021), 2899-2922$$pInt. j. earth sci.$$tInternational Journal of Earth Sciences$$x1437-3254
000147764 8564_ $$s1354492$$uhttps://zaguan.unizar.es/record/147764/files/texto_completo.pdf$$yVersión publicada
000147764 8564_ $$s1672348$$uhttps://zaguan.unizar.es/record/147764/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000147764 909CO $$ooai:zaguan.unizar.es:147764$$particulos$$pdriver
000147764 951__ $$a2025-01-07-14:07:07
000147764 980__ $$aARTICLE