Magnetostratigraphy of the lower Cretaceous strata in Tlayua Quarry, Tepexi de Rodriguez, State of Puebla, Mexico
Magnetostratigraphy of the lower Cretaceous strata in Tlayua Quarry, Tepexi de Rodriguez, State of Puebla, Mexico
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DOI：
10.1186/bf03352624
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发表时间：
2006-01-01
影响因子：
3
通讯作者：
Urrutia-Fucugauchi, Jaime
中科院分区：
文献类型：
--
作者：
Benammi, Mouloud;Alvarado-Ortega, Jesus;Urrutia-Fucugauchi, Jaime
在普埃布拉州Tepexi de Rodriguez的Tlayua采石场的早白垩世沉积地层中，识别出由9个磁性带组成的磁极反转地层序列。结合明显属于Albian的菊石的生物地层年龄划分，地磁极性序列可与白垩纪长正常间隔C34 n中段（C34 n. ln-C34 n.2n时，年龄为1亿~ 1亿500万年）进行对比。软、硬磁性矿物的磁性和特征剩磁分别占主导地位。岩石磁性和正反转测试表明，剩磁是主要的。该部分显示反向和正极性，平均方向分别为：D=344.9度，I=32.4度，k=21，a95=4.2度和D=149.4度，I=-36.6度，k=17，a95=8.7度。与北美视极移路径的比较表明，自白垩纪以来，该地区的构造稳定。
A stratigraphic sequence of magnetic polarity reversals consisting of nine magnetozones is recognized in Early Cretaceous sedimentary strata in the Tlayua Quarry of Tepexi de Rodriguez, state of Puebla. Combined with biostratigraphic age assignments using ammonites that apparently belonging to the Albian, the geomagnetic polarity sequence can be correlated with the middle part of chron C34n (C34n.ln-C34n.2n chrons, with an age of 100-105 Myr), the Cretaceous long normal interval. The magnetic properties and characteristic remanence of magnetization are dominated by soft and hard coercivity magnetic minerals. Rock-magnetic properties and a positive reversal test suggest that remanence is primary. The section displays both reverse and normal polarities with mean directions: D=344.9 degrees, I=32.4 degrees, k=21, a95=4.2 degrees and D=149.4 degrees, I=-36.6 degrees, k=17, a95=8.7 degrees, respectively. Comparison with the North American apparent polar wander path indicates tectonic stability of the region since the Cretaceous.