Stratigraphy of the Bandelier Tuff in the Pajarito Plateau. Applications to waste management
Stratigraphy of the Bandelier Tuff in the Pajarito Plateau. Applications to waste management
复制标题
帕杰里托高原班德利尔凝灰岩的地层学。
DOI：
--
复制
发表时间：
1978
期刊：
影响因子：
--
通讯作者：
M. Bevier
中科院分区：
文献类型：
--
作者：
B. Crowe;G. Linn;G. Heiken;M. Bevier
Pajarito高原内的Bandelier凝灰岩由下部的气降和灰流沉积层（Otowi段）不整合覆盖上部的气降和灰流沉积层（Tshirege段）组成。Tshirege段的火山灰流序列由三个冷却单元组成，遍布帕加里托高原的大部分地区。下部冷却单元由3至6个火山碎屑流单元组成；中间和上部冷却单元各由至少三个火山碎屑流单元组成。下、中冷却单元之间的接触与火山碎屑流单元的接触一致。该层位是策日格段远段地层的重要标志。采用中子活化、延迟中子活化和延迟中子活化技术测定了班德列尔凝灰岩未变样和变样样品的主要元素和微量元素分析。测定了Bandelier凝灰岩的岩石学、粒度学和形态特征，为凝灰岩作为放射性废物处置介质的适用性提供了背景资料。班德列尔凝灰岩的水文特征主要受凝灰岩的次级特征（冷却带）控制。这些特征随侵位温度和凝灰岩输运距离的变化而变化。原生沉积特征对凝灰岩远端剖面的输运路径提供了二级控制。«少
The Bandelier Tuff within the Pajarito Plateau consists of a lower sequence of air-fall and ash-flow deposits (Otowi Member) disconformably overlain by an upper sequence of air-fall and ash-flow deposits (Tshirege Member). The ash-flow sequence of the Tshirege Member consists of three cooling units throughout much of the Pajarito Plateau. The lower cooling unit is formed by three to as many as six pyroclastic flow units; the middle and upper cooling units each consist of at least three pyroclastic flow units. The contact between the lower and middle cooling unit coincides with a pyroclastic flow unit contact. This horizon is a prominent stratigraphic marker within distal sections of the Tshirege Member. Major and trace element analyses of unaltered and altered samples of the Bandelier Tuff were determined by neutron activation and delayed neutron activation and delayed neutron activation techniques. Petrographic, granulometric and morphologic characteristics of the Bandelier Tuff were determined to provide background information on the suitability of the Tuff as a medium for radioactive waste disposal. The hydrologic characteristics of the Bandelier Tuff are controlled primarily by secondary features of the Tuff (cooling zones). These features vary with emplacement temperature and transport distance of the Tuff. Primary depositional featuresmore » provide second order control on transport pathways in distal sections of the Tuff.« less