Palaeomagnetism of the Guaniguanico Cordillera, western Cuba: a pilot study
Palaeomagnetism of the Guaniguanico Cordillera, western Cuba: a pilot study
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古巴西部瓜尼瓜尼科山脉的古地磁学：一项试点研究
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
C. Rosales
中科院分区：
文献类型：
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作者：
L. Alva;A. Goguitchaichvili;J. Cobiella;J. Urrutia‐Fucugauchi;M. Fundora;J. M. Grajales;C. Rosales
Abstract A palaeo- and rock-magnetic study was carried out on the Jurassic–Cretaceous Guaniguanico Cordillera (15 sites, 112 oriented cores) in order to define a preliminary magnetostratigraphy and to obtain some constraints on the tectonic evolution of western Cuba. Rock-magnetic experiments indicate Ti-poor titanomagnetites as principal remanence carriers. Two magnetic phases seem to be present in a few samples: some spinels, which saturate at moderate magnetic fields and goethite, with higher coercivity. The presence of hematite (or mixture of spinels and hematite) is apparent in two units. In most cases the characteristic palaeodirections could be determined above 300°C. Eleven sites yield normal magnetic polarity and four reverse. The polarity zones can be tentatively correlated to chrons CM29–C24 in the reference geomagnetic polarity time scale. The mean palaeodirection calculated from all sites is Dm=335.7°, Im=43.1°, k=11, α 95 =12.3 and N=15. The corresponding palaeopole is Plat=66.4°, Plong=205.8°, K=13, and A 95 =11.1. This pole is not significantly different from North American Jurassic–Cretaceous poles. This suggests that no major latitudinal displacements and deformation have occurred since the Jurassic, in contrast to some previously proposed tectonic models.
