Origin and internal architecture of an offshore mudstone belt

近海泥岩带的成因和内部构造

• 批准号: 238532-2008
• 负责人: Pattison, Simon
• 金额: $ 1.82万
• 依托单位: Brandon University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=393962
• 关键词: Origin; internal; architecture; offshore; mudstone

Mudrocks are relatively understudied and are mostly ignored despite the fact that they comprise over 50 % of all sedimentary rocks in the geologic record. There has been a renewed interest in mudrocks over the past few years partly in response to the economic potential of shale gas and basin center gas. The focus of this research will be the Cretaceous Mancos Shale mudstone belt in Utah. The Cretaceous was a naturally occurring greenhouse period in Earth's history when the dinosaurs reigned supreme and the Western Interior of North America from Arctic Canada to the Gulf of Mexico was flooded with sea water. Global sea level was up to 250 m higher than present day. The Cretaceous Western Interior Seaway (CWIS) dissected the North American continent into two parts: a mountainous western half and a lower-lying eastern half. The western half was tectonically active with only a narrow coastal plain separating the mountains from the sea. Small- to moderate-sized, fast-flowing rivers drained the eastern part of the mountains and transported a significant volume of sediments into the CWIS, depositing a thick succession of sands, silts and clays. Following deposition and lithification, these sedimentary rocks were slowly uplifted to form the magnificent scenery in the western interior of the United States. One of the most spectacular regions is the Canyonlands-area of east-central Utah which is home to one of the longest continuous cliff-lines in the world, the 300-km-long Book Cliffs. The main objective of this research is to add fundamental new knowledge regarding the origin and internal architecture of offshore mudstone belts. Long-term goals for this research are to unravel the sediment delivery mechanisms and dominant direction of sediment transport on the shelf, and to develop appropriate models for shelf mudstones. Unravelling the origin and internal architecture of the Mancos Shale mud belt will lead to a better understanding of shallow marine sedimentation patterns, sea level change (i.e. rate, magnitude, cyclicity), basin history and environmental change through time. The latter is essential for placing our modern "early stage" greenhouse conditions into their proper historical perspective.

相对而言，泥岩的研究较少，尽管它们占地质记录中所有沉积岩的50%以上，但大多数情况下都被忽视。 在过去几年中，人们对泥岩重新产生了兴趣，部分原因是页岩气和盆地中心天然气的经济潜力。 本次研究的重点将是犹他州的白垩纪曼科斯页岩泥岩带。 白垩纪是地球历史上一个自然发生的温室时期，恐龙统治着地球，北美西部内陆从加拿大北极到墨西哥湾都被海水淹没。 全球海平面比现在高出250米。 白垩纪的西部内陆海道（CWIS）将北美大陆分成两部分：多山的西半部和地势较低的东半部。 西半部是构造活跃的，只有一个狭窄的沿海平原将山脉与海洋分开。 小型到中型，快速流动的河流排出了山脉的东部，并将大量沉积物运送到CWIS，沉积了厚厚的砂，粉砂和粘土。 这些沉积岩经过沉积和岩化作用，慢慢地被抬升，形成了美国西部内陆的壮丽景色。 最壮观的地区之一是犹他州中东部的波特兰地区，这里有世界上最长的连续悬崖之一，300公里长的书崖。 本研究的主要目标是增加有关海上泥岩带起源和内部结构的基础新知识。 这项研究的长期目标是解开沉积物输送机制和沉积物输运的主要方向在货架上，并制定适当的模式，货架泥岩。 揭示Mancos页岩泥带的起源和内部结构将有助于更好地了解浅海沉积模式，海平面变化（即速率，幅度，周期性），盆地历史和环境变化。 后者对于将我们现代的“早期”温室条件纳入其适当的历史视角至关重要。