Field and laboratory investigations into remagnetizations and remanence acquisition

沉积盆地的古地磁和岩石磁学研究已被证明是各种主题的重要信息来源，这些主题包括矿床的起源、逆转时间尺度的发展和过去的气候变化。因此，了解在盆地内产生、修改和破坏特定磁化成分的地质和环境过程的重要性怎么强调都不为过。申请人之前的古地磁和岩石磁学研究主要集中在北美中部威利斯顿盆地的奥陶系-密西西比碳酸盐岩。这种碳酸盐提供了重要的信息；然而，它们通常具有弱的自然磁化作用，并携带一种或多种次生磁化作用，可能与特定的成岩事件有关，也可能与之无关。更复杂的是，如果二次磁化不被识别，我们对盆地中发生的过程的理解可能会受到影响。建议的研究旨在减少和限制这些复杂性，尽管他们继续检验关于沉积岩中再磁化起源的传统假说，研究剩磁获取机制，并评估一些额外的可能的再磁化因素。正在提议对长期目标采取三种新的办法：过去对威利斯顿和加拿大西部沉积盆地的古地磁研究将扩展到较年轻的碎屑岩(白垩纪Viking组及相当物)，将对流体/温度相互作用对剩磁获取和潜在再磁化的潜在影响进行实验调查；将仔细研究特定成岩事件对磁化的影响。这些研究将允许继续建立大陆规模的威利斯顿和加拿大西部沉积盆地中的重磁化分布的综合和数据库，旨在评估沉积盆地中的重磁化和剩磁获取的控制因素。

Paleomagnetic and rock magnetic studies of sedimentary basins have proven to be significant sources of information on subjects as diverse as the origin of ore deposits, the development of reversal time scales and past climate variation. As such, the importance of understanding the geologic and environmental processes that have created, modified and destroyed specific magnetization components within a basin cannot be overstated. The applicant's previous paleomagnetic and rock magnetic studies have focused on Ordovician- Mississippian carbonates of the Williston Basin in central North America. Such carbonates have provided significant information; however, they typically have weak natural magnetizations, and carry one or more secondary magnetizations that may or may not be associated with specific diagenetic events. To complicate matters even further, if the secondary magnetization is unrecognized, our understanding of the processes that occur in the basins may be affected. The studies proposed are aimed at reducing and constraining these complications, even as they continue to examine the traditional hypotheses on the origins of remagnetizations in sedimentary rocks, investigate remanence acquisition mechanisms, and evaluate some additional possible factors in remagnetization. Three new approaches to the long term objectives are being proposed: the past paleomagnetic studies of the Williston and Western Canada Sedimentary Basins will be extended to younger, clastic rocks (Cretaceous Viking Formation and equivalents), experimental investigations on the potential for fluid / temperature interaction effects on remanence acquistion and potentially remagnetization will be conducted; and a close examination of the impact of specific diagenetic events on magnetization will be performed. These studies will allow continued construction of a continental-scale synthesis and database of the distribution of remagnetizations in the Williston and Western Canada Sedimentary Basins that aims to evaulate the controlling factors on remagnetization and remanence acquisition in sedimentary basins.