Stratigraphic and Tectonic Analysis of Neogene Coal-Bearing Basins Along the Alaska Range Suture Zone

阿拉斯加山脉缝合带新近纪含煤盆地地层与构造分析

• 批准号: 9725587
• 负责人: Kenneth Ridgway
• 金额: $ 13.31万
• 依托单位: Purdue Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-06-01 至 2002-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9725587&HistoricalAwards=false
• 关键词: Stratigraphic; Tectonic; Analysis; Neogene; Coal

9725587 Ridgway This proposal seeks funding for a three-year investigation of Neogene sedimentary basins located along the north-central flank of the Alaska Range. These basins contain the record of basin development along an ancient suture zone, the uplift history of the highest mountain range in North America, extensive low-sulfur coal reserves, and potential petroleum reservoirs. The east-west trending basins were filled by fluvial and lacustrine deposits and consist of the Miocene Usibelli Group (~ 600 m thick) and the Pliocene Nenana Gravel (~ 1000 m thick). The general questions to be addressed include: (1) How do basins form within the interior of collisional/accretionary orogenic settings? Can a conceptual model be developed for basin formation along former suture zones? (2) What can the synorogenic deposits contained within these basins teach us about the Neogene uplift of the Alaska Range? Does the detrital record contain information on how deformation and uplift changed along strike and through time for this orogenic belt? What was the influence of paleoclimate on detrital composition during unroofing of the Alaska Range? (3) Coal from the Usibelli Group is becoming an increasingly important energy source for Alaska and for export to Pacific Rim countries. What were the depositional, tectonic, and climatic controls on coal deposition in these basins? A regionally integrated stratigraphic, paleogeographic and tectonic framework for all the Neogene basins will be needed to answer these questions. A database will be established by reconstructing the depositional systems for each basin; construction of a series of cross sections through the central Alaska Range; and compositional analysis of sandstone's and conglomerates. Major contributions of the proposed research include documentation of the long term evolution of sedimentary basins along a suture zone; delineation of along strike variations in the uplift history of the Alaska Range; and analysis of the distribution of potentially commercial coals for future exploration.

9725587里奇韦该提案寻求资金，用于对阿拉斯加山脉中北部侧翼的新近系沉积盆地进行为期三年的调查。这些盆地包括沿古老缝合带的盆地发展记录、北美最高峰山脉的隆升历史、广泛的低硫煤储量和潜在的石油储集层。东西走向的盆地充填河流和湖泊沉积，由中新世乌西贝利群(厚约600m)和上新世涅纳砾岩(厚约1000m)组成。要解决的一般问题包括：(1)盆地是如何在碰撞/增生造山环境内部形成的？沿着以前的缝合带，能否建立一个盆地形成的概念性模型？(2)这些盆地中的同造山沉积能为我们提供什么关于阿拉斯加山脉新近纪隆起的信息？碎屑记录是否包含有关该造山带的变形和隆升如何随走向和时间变化的信息？在阿拉斯加山脉去顶过程中，古气候对碎屑组分的影响是什么？(3)乌西贝利集团的煤正成为阿拉斯加和太平洋沿岸国家日益重要的能源来源。这些盆地的沉积、构造和气候对煤沉积的控制是什么？要回答这些问题，需要一个针对所有新近系盆地的区域综合地层、古地理和构造格架。将通过重建每个盆地的沉积系统、建立穿过阿拉斯加中部山脉的一系列横断面以及分析砂岩和砾岩的成分来建立一个数据库。拟议研究的主要贡献包括记录沿缝合带的沉积盆地的长期演化；描绘阿拉斯加山脉隆起历史上沿走向的变化；以及分析未来勘探的潜在商业煤的分布。