Late Coniacian- Early Campanian planktonic foraminiferal bioevents and biostratigraphy of the northern Tunisia
<p>Planktonic foraminifera were quantitatively analyzed across the Upper Coniacian - Lower Campanian succession at Jebel Ennahli and Ettout sections, northern Tunisia. This succession is characterized by hemipelagic facies domainated by a continuous sedimentary succession, al...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Croatian Geological Survey
2014-06-01
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| Series: | Geologia Croatica |
| Subjects: | |
| Online Access: | http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/628 |
| Summary: | <p>Planktonic foraminifera were quantitatively analyzed across the Upper Coniacian - Lower Campanian succession at Jebel Ennahli and Ettout sections, northern Tunisia. This succession is characterized by hemipelagic facies domainated by a continuous sedimentary succession, allowing a good biostratigraphic correlation for this time interval. 55 planktonic foraminiferal species have been identified belonging to 13 genera. The distribution pattern of 17 heterohelicids and 38 trochospiral forms reveals to the identification of12<strong> </strong>major bio-events and establishing three zones based on heterohelicids and five zones based on trochospiral forms. The trochospiral based zones are from base to top: <em>Dicarinella primitiva</em> Interval Zone, <em>Dicarinella concavata</em> Interval Zone, <em>Dicarinella asymetrica</em> Total Range Zone, and <em>Globotruncanita elevata/Globotruncana arca</em> Concurrent Range Zone, <em>Globotruncana ventricosa</em> Interval Zone; while the three heterohelicid based planktonic foraminiferal biozones are: <em>Pseudotextularia nuttalli</em> Interval Zone, <em>Sigalia carpatica<strong> </strong></em>Interval Zone, <em>Ventilabrella eggeri/Planoglobulina manuelensis</em>Concurrent Range Zone. The bioevents and planktonic foraminiferal zones were correlated with the previously published works especially in Tunisia and other palaeolatitude provinces.</p> <p>There are no significant planktonic foraminiferal datums recorded across the Coniacian/Santonian boundary (CSB) except the lowest occurrence (LO) of <em>Dicarinella asymetrica</em>, which<em> </em>was recorded slightly below the LO of inoceramid <em>Platyceramus cycloides cycloides</em> representing a good proxy for the CSB. The Santonian/Campanian boundary of the studied sections are characterized by a major turnover represented by the highest occurrence of <em>Sigalia</em>, <em>Dicarinella</em> and <em>Whiteinella</em> genera; in addition to the lowest occurrence of <em>Ventilabrella </em>and <em>Planoglobulina </em>genera and above slightly the LO <em>Globotruncana</em> and <em>Globotruncanita</em>.</p> |
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| ISSN: | 1330-030X 1333-4875 |