North American APW during the Jurassic: An Answer from the Black Hills

北美洲在中生代经历了东西两个边缘的构造作用，古地磁数据有助于计算过去的相对板块位置和相对运动。然而，准确重建所依赖的北美明显的极地魔杖路径，对于中侏罗世和上侏罗世基本上是悬而未决的。来自新英格兰的数据表明，APWP位于高纬度，但来自科罗拉多高原的数据表明，APWP的纬度要低得多。这一差异很重要，但仍未得到解决，因为这两个数据集都存在缺陷。该项目将试图通过对怀俄明州和南达科他州黑山的圣丹斯和莫里森地层的研究，确定北美这一时间段的APWP，这些地层可能逃脱了影响其他地区的旋转和叠印。这些结果将有助于确定北美克拉通地区中、上侏罗世的磁极，以便更好地解决几个构造问题。

0073891Housen North America experienced tectonism on both east and west margins during the Mesozoic, and paleomagnetic data have been instrumental in working out past relative plate positions and relative motion. However, the apparent polar wunder path for North America, on which accurate reconstruction rely, is basically unresolved for the middle and upper Jurassic. Data from New England suggests that the APWP lies at high latitudes, but data from the Colorado Plateau indicates a significantly lower latitude APWP. This discrepancy is important, and remains unresolved because flaws exist in both data sets. This project will attempt to define the APWP for this time interval for North America by study of the Sundance and Morrison formations in the Black Hills of Wyoming and South Dakota that may have escaped the rotations and overprints affecting other regions. Results will help anchor poles of middle to upper Jurassic age for cratonic North America so that several tectonic questions can be better addressed.