Coniacian – Maastrichtian calcareous nannofossil biostratigraphy and carbon-isotope stratigraphy in the Zagros Basin (Iran): consequences for the correlation of Late Cretaceous Stage Boundaries between the Tethyan and Boreal realms
Coniacian – Maastrichtian calcareous nannofossil biostratigraphy and carbon-isotope stratigraphy in the Zagros Basin (Iran): consequences for the correlation of Late Cretaceous Stage Boundaries between the Tethyan and Boreal realms
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DOI：
10.1127/0078-0421/2014/0045
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发表时间：
2014-06
影响因子：
2.2
通讯作者：
Mohammad Javad Razmjooei;N. Thibault;A. Kani;A. Mahanipour;M. Boussaha;C. Korte
中科院分区：
文献类型：
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作者：
Mohammad Javad Razmjooei;N. Thibault;A. Kani;A. Mahanipour;M. Boussaha;C. Korte
对伊朗扎格罗斯盆地古尔皮组Shahneshin剖面的钙质超微化石进行了生物地层学和稳定同位素地层学研究。结果表明，古尔皮组的时代为早科尼亚世晚期至塔内阶晚期。年龄模型表明，Shahneshin部分跨越Coniacian中期Campanian具有良好的连续性，而冷凝突出在晚期Campanian，跨Campanian/Maastrichtian边界和晚期Maastrichtian。极端的冷凝记录后，完全没有Danian，Selandian和下Thanetian被包括在Gurpi组的顶部只有6米。碳同位素剖面与其他参考曲线的相关性允许识别Shahneshin剖面的几个晚白垩世偏移，如Beeding、白色瀑布、Kingsdown、Michel Dean、Haven Brow、马蹄湾、Buckle、Hawks Brow、Santonian/Campanian边界（SCBE）和Campanian/Maastrichtian边界（CMBE）事件。与最近提出的晚白垩世全球δ 13 C叠加的相关性表明，该汇编与Santonian-early Campanian间隔的磁性地层学存在重大不匹配。在钙质超微化石生物地层学的支持下，δ 13 C对比揭示了：（1）科尼亚阶/桑托阶、桑托阶/坎帕阶和坎帕阶/马斯特里赫特阶界线相对于碳同位素地层学和钙质超微化石生物层位的位置;（2）特提斯界和北方界的对比。
Calcareous nannofossil biostratigraphy and stable isotope stratigraphy have been investigated in the Shahneshin section of the Gurpi Formation from the Zagros Basin (Iran). The results show that the Gurpi Formation spans the late early Coniacian to late Thanetian. The age-model shows that the Shahneshin section spans the Coniacian to mid-Campanian with a good continuity whereas condensation is highlighted in the late Campanian, across the Campanian/Maastrichtian boundary and in the late Maastrichtian. Extreme condensation is recorded after the Cretaceous-Paleogene boundary with the complete absence of the Danian, and the Selandian and lower Thanetian being comprised in only 6 m at the top of the Gurpi Formation. Correlation of the carbon-isotope profile with other reference curves allows the recognition of several Late Cretaceous excursions at the Shahneshin section such as the Beeding, White Fall, Kingsdown, Michel Dean, Haven Brow, Horseshoe Bay, Buckle, Hawks Brow, Santonian/Campanian boundary (SCBE) and Campanian/Maastrichtian boundary (CMBE) events. Correlation to a recently proposed global δ13C stack for the Late Cretaceous points to a major mismatch of this compilation with magnetostratigraphy in the Santonian–early Campanian interval. The δ13C correlation, supported by calcareous nannofossil biostratigraphy, brings insights into: (1) the position of the Coniacian/Santonian, Santonian/Campanian and Campanian/Maastrichtian boundaries with respect to carbon-isotope stratigraphy and calcareous nannofossil bio-horizons, and (2) their correlation between the Tethyan and Boreal realms.