Middle and Upper Triassic radiolarite components from the Kcira-Dushi-Komani ophiolitic mélange and their provenance (Mirdita Zone, Albania)

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• 作者：Hans-Jü ; rgen Gawlick^a ; ^{gawlick@unileoben.ac.at} ; &Scaron ; pela Goričan^b ; Sigrid Missoni^a ; Paulian Dumitrica^c ; Richard Lein^d ; Wolfgang Frisch^e ; Lirim Hoxha^f
• 关键词：Eastern Mediterranean ; Western Tethys ; Biostratigraphy ; Distal passive margin and oceanic deposition ; Diagenesis
• 刊名：Revue de Micropaléontologie
• 出版年：2016
• 出版时间：October-December 2016
• 年：2016
• 卷：59
• 期：4
• 页码：359-380
• 全文大小：17641 K
• 卷排序：59

文摘

The Middle Jurassic Kcira-Dushi-Komani Mélange in the northwestern Mirdita Ophiolite Zone contains blocks of Triassic oceanic crust, radiolarites and open marine limestones. We describe the microfacies and present biostratigraphic data from radiolarite clasts and blocks and from basalt-radiolarite blocks with preserved autochthonous sedimentary cover. The radiolarians yield Middle to Late Triassic (Late Anisian to Late Norian) ages for the oceanic realm from which the ophiolite and radiolarite blocks and clasts derived. Together with limestone blocks, the provenance areas of the components in the Kcira-Dushi-Komani Mélange are determined as the distal shelf and the ocean floor of the Neotethys. In the course of ophiolite obduction, the components were transported by mass movements into newly formed trench-like basins in front of the westward propagating nappe stack. These basins were later incorporated in the nappe stack forming the typical features of a syntectonic mélange. Our radiolarian biostratigraphic data confirm Late Anisian formation of the Neotethys Ocean, parts of which became closed in the Middle Jurassic. The data clearly speak in favour of one Neotethys Ocean to the east, from which the Mirdita ophiolites derived as far-travelled nappes.