Paleomagnetism and counterclockwise tectonic rotation of the Upper Oligocene Sooke Formation, southern Vancouver Island, British Columbia
Paleomagnetism and counterclockwise tectonic rotation of the Upper Oligocene Sooke Formation, southern Vancouver Island, British Columbia
复制标题
不列颠哥伦比亚省温哥华岛南部上渐新统苏克组的古地磁作用和逆时针构造旋转
DOI：
10.1139/e08-012
复制
发表时间：
2008
影响因子：
1.4
通讯作者：
E. A. Nesbitt
中科院分区：
文献类型：
--
作者：
D. Prothero;Elizabeth Draus;T. Cockburn;E. A. Nesbitt
位于加拿大不列颠哥伦比亚省温哥华岛南部海岸的苏克组的时代长期以来一直存在争议。先前的古地磁研究已经在下面的始新世火山基底岩石上产生了令人困惑的逆时针构造旋转，并且对Sooke地层本身没有结论性的结果。我们采取了21个样品在四个网站的苏克湾以西的苏克组的含油气部分，从缪尔河口的沙切河口。Sooke地层在交变磁场（AF）和热退磁后产生单分量剩磁，大部分保持在磁铁矿中，完全反转，逆时针旋转35° ± 12°。这与早期的结果是一致的，并表明旋转是真实的，而不是由于构造倾斜，因为该地区的Sooke组几乎没有倾角。这种旋转特征也与从港口奥林匹克半岛东北端获得的逆时针旋转一致..
The age of the Sooke Formation on the southern coast of Vancouver Island, British Columbia, Canada, has long been controversial. Prior paleomagnetic studies have produced a puzzling counterclockwise tectonic rotation on the underlying Eocene volcanic basement rocks, and no conclusive results on the Sooke Formation itself. We took 21 samples in four sites in the fossiliferous portion of the Sooke Formation west of Sooke Bay from the mouth of Muir Creek to the mouth of Sandcut Creek. After both alternating field (AF) and thermal demagnetization, the Sooke Formation produces a single-component remanence, held largely in magnetite, which is entirely reversed and rotated counterclockwise by 35° ± 12°. This is consistent with earlier results and shows that the rotation is real and not due to tectonic tilting, since the Sooke Formation in this region has almost no dip. This rotational signature is also consistent with counterclockwise rotations obtained from the northeast tip of the Olympic Peninsula in the Port...