Evidence of the spreading culmination in the Eastern Tethyan Repno oceanic domain, assessed by the petrology and geochemistry of N-MORB extrusive rocks from the Mt. Medvednica ophiolite mélange (NW Croatia)
<p>Eastern Tethyan Repno oceanic domain (ROD) from Zagorje-Mid-Transdanubian Shear Zone bounds Meliata-Maliak and Dinaric-Vardar oceanic systems. The domain lacks ophiolite complexes and oceanic rocks are restricted into Early Callovian to Late Valanginian four ophiolite mélanges in...
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| Format: | Article |
| Language: | English |
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Croatian Geological Survey
2012-10-01
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| Series: | Geologia Croatica |
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| Online Access: | http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/570 |
| _version_ | 1819227050198695936 |
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| author | Damir Slovenec Boško Lugović |
| author_facet | Damir Slovenec Boško Lugović |
| author_sort | Damir Slovenec |
| collection | DOAJ |
| description | <p>Eastern Tethyan Repno oceanic domain (ROD) from Zagorje-Mid-Transdanubian Shear Zone bounds Meliata-Maliak and Dinaric-Vardar oceanic systems. The domain lacks ophiolite complexes and oceanic rocks are restricted into Early Callovian to Late Valanginian four ophiolite mélanges integrated in Kalnik Unit. Previous researchs on ophiolitic rocks from Kalnik Unit provided high-resolution tectonomagmatic evolution of crust formation at different settings from Late Anisian to Cretaceous. N-MORB-type crust with peculiar suprasubduction signatures formed on spreading ridge from Late Carnian to Late Pliensbachian and first intraoceanic subduction rocks were dated to Late Bathonian. The newly discovered basaltic rocks in coherent slices with Latest Bajocian-Early Bathonian radiolarian cherts from Mt. Medvednica ophiolite mélange sector completed the Late Pliensbachian-Late Bathonian chemostratigraphic gap in the domain. The analyzed unfractionated extrusive rocks lack any influence of a subduction related component [(Nb/La)<sub>n</sub> = 1.16-1.34; Th/Ta = 0.99-1.05] and are akin to proper N-MORB compositions [(Nd/Lu)<sub>N-MORB</sub> ~ 1.1; (La/Lu)<sub>cn </sub>= 0.82-0.92] that were derived from slightly depleted mantle source [ε<sub>Nd(T=170 Ma) </sub>= +6.21 to +6.27; (<sup>87</sup>Sr/<sup>86</sup>Sr)<sub>i</sub> = 0.703365 to 0.703511]. The rocks are interpreted as vestiges of the middle ocean ridge crust formed during culmination stage of spreading in the ROD.</p> |
| first_indexed | 2024-12-23T10:35:13Z |
| format | Article |
| id | doaj.art-f7e269374bbe4d298623498140c59782 |
| institution | Directory Open Access Journal |
| issn | 1330-030X 1333-4875 |
| language | English |
| last_indexed | 2024-12-23T10:35:13Z |
| publishDate | 2012-10-01 |
| publisher | Croatian Geological Survey |
| record_format | Article |
| series | Geologia Croatica |
| spelling | doaj.art-f7e269374bbe4d298623498140c597822022-12-21T17:50:18ZengCroatian Geological SurveyGeologia Croatica1330-030X1333-48752012-10-0165343544610.4154/GC.2012.32437Evidence of the spreading culmination in the Eastern Tethyan Repno oceanic domain, assessed by the petrology and geochemistry of N-MORB extrusive rocks from the Mt. Medvednica ophiolite mélange (NW Croatia)Damir Slovenec0Boško Lugović1Croatian Geological SurveyInstitute of Mineralogy, Petrology and Mineral Deposits, Faculty of Mining, Geology, and Petroleum Engineering, University of Zagreb<p>Eastern Tethyan Repno oceanic domain (ROD) from Zagorje-Mid-Transdanubian Shear Zone bounds Meliata-Maliak and Dinaric-Vardar oceanic systems. The domain lacks ophiolite complexes and oceanic rocks are restricted into Early Callovian to Late Valanginian four ophiolite mélanges integrated in Kalnik Unit. Previous researchs on ophiolitic rocks from Kalnik Unit provided high-resolution tectonomagmatic evolution of crust formation at different settings from Late Anisian to Cretaceous. N-MORB-type crust with peculiar suprasubduction signatures formed on spreading ridge from Late Carnian to Late Pliensbachian and first intraoceanic subduction rocks were dated to Late Bathonian. The newly discovered basaltic rocks in coherent slices with Latest Bajocian-Early Bathonian radiolarian cherts from Mt. Medvednica ophiolite mélange sector completed the Late Pliensbachian-Late Bathonian chemostratigraphic gap in the domain. The analyzed unfractionated extrusive rocks lack any influence of a subduction related component [(Nb/La)<sub>n</sub> = 1.16-1.34; Th/Ta = 0.99-1.05] and are akin to proper N-MORB compositions [(Nd/Lu)<sub>N-MORB</sub> ~ 1.1; (La/Lu)<sub>cn </sub>= 0.82-0.92] that were derived from slightly depleted mantle source [ε<sub>Nd(T=170 Ma) </sub>= +6.21 to +6.27; (<sup>87</sup>Sr/<sup>86</sup>Sr)<sub>i</sub> = 0.703365 to 0.703511]. The rocks are interpreted as vestiges of the middle ocean ridge crust formed during culmination stage of spreading in the ROD.</p>http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/570petrology, geochemistry, N-MORB extrusives, ophiolite mélange, Bajocian-Bathonian , Zagorje-Mid-Transdanubian Zone, Mt. Medvednica, Croatia |
| spellingShingle | Damir Slovenec Boško Lugović Evidence of the spreading culmination in the Eastern Tethyan Repno oceanic domain, assessed by the petrology and geochemistry of N-MORB extrusive rocks from the Mt. Medvednica ophiolite mélange (NW Croatia) Geologia Croatica petrology, geochemistry, N-MORB extrusives, ophiolite mélange, Bajocian-Bathonian , Zagorje-Mid-Transdanubian Zone, Mt. Medvednica, Croatia |
| title | Evidence of the spreading culmination in the Eastern Tethyan Repno oceanic domain, assessed by the petrology and geochemistry of N-MORB extrusive rocks from the Mt. Medvednica ophiolite mélange (NW Croatia) |
| title_full | Evidence of the spreading culmination in the Eastern Tethyan Repno oceanic domain, assessed by the petrology and geochemistry of N-MORB extrusive rocks from the Mt. Medvednica ophiolite mélange (NW Croatia) |
| title_fullStr | Evidence of the spreading culmination in the Eastern Tethyan Repno oceanic domain, assessed by the petrology and geochemistry of N-MORB extrusive rocks from the Mt. Medvednica ophiolite mélange (NW Croatia) |
| title_full_unstemmed | Evidence of the spreading culmination in the Eastern Tethyan Repno oceanic domain, assessed by the petrology and geochemistry of N-MORB extrusive rocks from the Mt. Medvednica ophiolite mélange (NW Croatia) |
| title_short | Evidence of the spreading culmination in the Eastern Tethyan Repno oceanic domain, assessed by the petrology and geochemistry of N-MORB extrusive rocks from the Mt. Medvednica ophiolite mélange (NW Croatia) |
| title_sort | evidence of the spreading culmination in the eastern tethyan repno oceanic domain assessed by the petrology and geochemistry of n morb extrusive rocks from the mt medvednica ophiolite melange nw croatia |
| topic | petrology, geochemistry, N-MORB extrusives, ophiolite mélange, Bajocian-Bathonian , Zagorje-Mid-Transdanubian Zone, Mt. Medvednica, Croatia |
| url | http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/570 |
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