Geophysical and Petrological Study of the Northern Chile Ridge: Investigating Thermal Effects of Transform Offsets onRidge Axis Morphology, Crustal Thickness and Magmatism

智利北部海脊的地球物理和岩石学研究：研究变换偏移对脊轴形态、地壳厚度和岩浆作用的热效应

• 批准号: 9618401
• 负责人: Fernando Martinez
• 金额: $ 52.57万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-11-15 至 2003-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9618401&HistoricalAwards=false
• 关键词: Geophysical; Petrological; Study; Northern; Chile

Abstract OCE 96-18401 (University of Hawaii: J. Karsten/F. Martinez) OCE 96-18736 (Duke University: E. Klein) This combined program will conduct a detailed geophysical and geochemical study of the Northern Chile Ridge and Valdivia Fracture Zone intra-transform spreading centers. A 40-day field program will use SeaBeam 2000, magnetics, and gravity to map the detailed geomorphology of the axial region out to the Brunhes-Matuyama magnetic reversal boundary. The neo-volcanic zone will be sampled at ~125 sites by dredging and wax coring; lavas recovered will be analyzed by electron microprobe, ICP-MS, DCP, and mass spectrometry for major element, trace element, and Pb-Nd-Sr isotopic characteristics. The combined data set for the Northern Chile Ridge will be used to investigate the relationship of axial depth, crustal structure and lava composition with thermal effects associated with large offset transform faults. The Valdivia F.Z. data set will be used to further investigate the extent and variability of anomalous geochemical features of the Southeast Pacific discovered in previous studies of the Southern Chile Ridge (i.e., DUPAL isotopic signatures and MORB with subduction zone trace element characteristics) and to extend on-going studies of relationships between Pacific mid-ocean ridge basalt chemistry and axial depth to deeper ridge segments.

摘要OCE 96-18401（夏威夷大学：J. Karsten/F.马丁内斯）OCE 96-18736（杜克大学：E。Klein）这一联合项目将对北方智利海脊和瓦尔迪维亚断裂带内转换扩张中心进行详细的地球物理和地球化学研究。 一个为期40天的实地项目将使用SeaBeam 2000、磁力学和重力来绘制轴向区域的详细地貌图 去布伦斯-松山磁场 反转边界 新火山区将在约125个地点通过疏浚和蜡取芯取样;回收的熔岩将通过电子微探针、ICP-MS、DCP和质谱法分析主要元素、微量元素和Pb-Nd-Sr同位素特征。 将利用智利海脊北方的综合数据集调查轴向深度、地壳结构和熔岩成分与大偏移转换断层相关的热效应之间的关系。 瓦尔迪维亚足球俱乐部数据集将被用于进一步调查在以前的南智利海脊研究中发现的东南太平洋异常地球化学特征的程度和变化（即， DUPAL同位素特征和具有俯冲带微量元素特征的MORB），并将正在进行的太平洋洋中脊玄武岩化学与轴向深度之间关系的研究扩展到更深的脊段。