Field and laboratory investigations into remagnetizations and remanence acquisition

对重磁化和剩磁采集的现场和实验室研究

• 批准号: 229648-2009
• 负责人: Cioppa, Maria
• 金额: $ 1.6万
• 依托单位: University of Windsor
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=496896
• 关键词: Field; laboratory; investigations; into; remagnetizations

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.

沉积盆地的古地磁学和岩石磁学研究已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、反转时标的发展和过去的气候变化。因此，了解在盆地内产生、改变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过分。 申请人先前的古地磁和岩石磁学研究集中在北美中部威利斯顿盆地的奥陶纪-密西西比纪碳酸盐岩。 这些碳酸盐岩提供了重要的信息;然而，它们通常具有弱的自然磁化，并带有一个或多个可能与特定成岩事件相关或不相关的二次磁化。使问题更加复杂的是，如果二次磁化不能被识别，我们对盆地中发生的过程的理解可能会受到影响。 所提出的研究旨在减少和限制这些并发症，即使他们继续检查传统的假设在沉积岩中的再磁化的起源，调查剩磁采集机制，并评估一些额外的可能因素在再磁化。提出了三种实现长期目标的新方法：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（白垩纪维京海盗地层和等效地层），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研究;并将对特定成岩事件对磁化的影响进行仔细检查。 这些研究将允许继续建设一个大陆规模的合成和数据库的分布在威利斯顿和加拿大西部沉积盆地，旨在评估控制因素的沉积盆地的再磁化和剩磁收购的再磁化。