The Red Bed Paleomagnetic Inclination Correction and the Accuracy of the Late Paleozoic North American Apparent Polar Wander Path

该计划的工作将调查PI最近的磁各向异性研究如何影响晚古生代北美视极漂移路径的准确性，这些研究表明，含赤铁矿的红色沉积岩可以承受高达30度的倾角变浅。在北美晚古生代至中中生代的视极移路径中，红层古极主导并控制着这一区域的位置，因此，红层剩余物的不准确性将极大地影响基于这一区域的古地理。PI之前由nsf资助的研究表明，等温剩余物各向异性和磁化率各向异性的组合可以用来识别和校正含赤铁矿的红色沉积岩的倾斜浅。通过热退磁和化学退磁，可以分离出特征带剩磁颗粒的磁性结构。这对于精确的倾角校正至关重要。尽管对这些修正的准确性的初步测试支持了它们的有效性，但考虑到红层对晚古生代北美地表极移路径的重要性，PI建议进一步测试他为石炭纪Mauch块体地层确定的修正倾角的准确性。火成岩古地极可能是检验修正后的倾角的最佳方法，但北美洲石炭纪的火成岩结果很少，而且很分散。因此，他的策略是收集和修正与Mauch块体年龄相同的其他红层单元和含磁铁矿沉积岩的倾角。如果磁各向异性确实控制了剩余物的精度，那么校正后的古磁极应该是一致的。宾夕法尼亚的Brush Creek石灰岩和Buffalo粉砂岩的含磁铁矿校正倾角将特别重要，因为PI已经通过比较古新世Nacimiento组的校正结果与同期火成岩结果建立了磁铁矿校正的准确性。他将校正来自加拿大新不伦瑞克省的Maringouin组、Shepody组和Enrage组红色层和来自纽芬兰西部的Deer Lake组岩石的红层对比的倾角。这些岩石提供了北美洲石炭纪古地磁结果。最后，尽管北美石炭纪火成岩的结果是分散的，但PI计划重新研究新不伦瑞克火山的遗迹，因为它们与他提议研究的其他新不伦瑞克火山单元很接近。他希望检查新不伦瑞克火山遗迹的准确性和年龄，以确保它们提供石炭纪油田的可靠记录。拟议的工作将在三年内进行，包括三个实地季节，并将支持一名研究生在利哈伊大学的博士论文工作。

The proposed work will investigate how the PI's recent magnetic anisotropy studies, showing that hematite-bearing red sedimentary rocks can suffer up to 30 degrees of inclination shallowing, impact the accuracy of the Late Paleozoic North American apparent polar wander path. Red bed paleopoles dominate and control the position of the Late Paleozoic to mid-Mesozoic portion of North America's apparent polar wander path, thus inaccuracies in red bed remanence would greatly affect any paleogeographies based on this part of the pole path. the PI's previous NSF-funded study has shown that a combination of isothermal remanence anisotropy and anisotropy of magnetic susceptibility can be used to identify and correct inclination shallowing in red, hematite-bearing sedimentary rocks. By using thermal demagnetization and chemical demagnetization, the magnetic fabric of the characteristic remanence-carrying grains can be isolated. This is critical for an accurate inclination correction. Though initial tests of the accuracy of these corrections support their validity, given the importance of red beds to the Late Paleozoic North American apparent polar wander path, the PI proposes to further test the accuracy of the corrected inclination he has determined for the Carboniferous Mauch Chunk Formation. Igneous paleopoles would be the best way to test the corrected inclination, but igneous results for Carboniferous North America are few and scattered. Therefore, his strategy is to collect and correct the inclinations of other red bed units, and magnetite-bearing sedimentary rocks, of the same age as the Mauch Chunk. If magnetic anisotropy does truly control the accuracy of remanence, the corrected paleopoles should agree with each other. The corrected magnetite-bearing inclinations from the Brush Creek Limestone and Buffalo Siltstone in Pennsylvania will be particularly important since the PI has established the accuracy of the magnetite correction from a comparison of corrected results from the Paleocene Nacimiento Formation to coeval igneous results. He will correct the inclinations of the Maringouin, Shepody, and Enrage Formation red beds from New Brunswick, Canada and the Deer Lake Group rocks from western Newfoundland for the red bed part of the comparison. These rocks have given excellent Carboniferous age paleomagnetic results for North America. Finally, although Carboniferous North American igneous results are scattered, the PI plans to restudy the remanence of the New Brunswick Volcanics, given their proximity to the other New Brunswick units he proposes to study. He wishes to check the accuracy and age of the New Brunswick Volcanics remanence to make sure they provide a reliable record of the Carboniferous field. The proposed work will be conducted over three years, including three field seasons, and will support a graduate student's PhD dissertation work at Lehigh University.