"Sedimentary phosphorite, fertilizer ore, and the evolving phosphorus cycle: an integrated approach"

“沉积磷矿、化肥矿石和不断演变的磷循环：综合方法”

• 批准号: 327174-2012
• 负责人: Pufahl, Peir
• 金额: $ 2.77万
• 依托单位: Acadia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571940
• 关键词: Sedimentary; phosphorite; fertilizer; ore; evolving

Phosphorite is a marine chemical sediment rich in phosphorus and a non-renewable fertilizer ore. Phosphorus is a bioessential element that forms skeletons and DNA, is essential for cellular energy transfer, and limits biologic productivity over geologic timescales. Since its precipitation is so closely tied to biology, phosphorite is not simply a recorder of geologic processes, but intimately involved in the evolution of life and ocean-atmosphere development. Research is focused on the Neoproterozoic-Paleozoic phosphogenic episode, Earth's second major period of phosphorite deposition. Four major episodes of phosphorite deposition are recognized that correspond to significant reorganizations of the Earth system. Studies are located in Cambrian and Ordovician strata of eastern and western Canada, and in Neoproterozoic, Silurian, and Devonian rocks of Brazil. These deposits are part of a system of P cycling prior to, during, and after the final stages of ocean-atmosphere oxygenation related to the emergence and diversification of animals. Precise causes remain unclear, but speculation about variations in the P cycle have been attributed to dramatic climate fluctuations, biologic evolution, supercontinent amalgamation and breakup, as well as changing ocean-atmosphere composition and circulation. Understanding the relationship between bioavailable P, ocean redox state, and the Ediacaran and Cambrian radiations is a primary focus. This will be done using an integrated approach combining sedimentology, sequence stratigraphy, and geochemistry to constrain the depositional and postdepositional context of phosphorites. Most recent studies are based on geochemical proxies, which are interpreted outside the sedimentologic, oceanographic, diagenetic, and metamorphic aspects of hosting sedimentary rocks. Significant to Canada is that this unique approach will enhance our nation's ability to acquire a stable and secure source of phosphorite by developing expertise on poorly understood deposits in New Brunswick, Quebec, and British Columbia.

磷矿是一种富含磷的海洋化学沉积物，是一种不可再生的肥料矿石。磷是形成骨骼和DNA的生物必需元素，对细胞能量转移至关重要，并在地质时间尺度上限制生物生产力。由于磷块岩的沉淀与生物学密切相关，它不仅是地质过程的记录者，而且与生命的进化和海洋-大气的发展密切相关。研究的重点是新元古代-古生代的磷事件，地球上的第二个主要时期的磷沉积。磷块岩沉积的四个主要事件被认为对应于地球系统的重大重组。研究位于加拿大东部和西部的寒武纪和奥陶纪地层，以及巴西的新元古代、志留纪和泥盆纪岩石。这些存款的P循环系统的一部分之前，期间和之后的海洋-大气氧化的最后阶段有关的出现和多样化的动物。确切的原因尚不清楚，但对P循环变化的猜测归因于剧烈的气候波动，生物进化，超大陆合并和分裂，以及海洋-大气成分和环流的变化。了解生物有效磷，海洋氧化还原状态，埃迪卡拉和寒武纪辐射之间的关系是一个主要的焦点。这将使用一个综合的方法相结合的沉积学，层序地层学和地球化学，以限制沉积和沉积后的背景下的磷块岩。最近的研究是基于地球化学指标，这是解释以外的沉积学，海洋学，成岩，变质方面的托管沉积岩。对加拿大来说，重要的是，这种独特的方法将通过开发对新玩法、魁北克和不列颠哥伦比亚省鲜为人知的矿床的专门知识，提高我国获得稳定和安全的磷矿石来源的能力。