摘要
在湖北省京山县雁门口地区栖霞组上部的含泥灰岩中存在丰富的节房虫科底栖有孔虫化石,主要有节房虫属、厚壁虫属和郎格虫属,壳体均被草莓状黄铁矿充填。对其系统的显微镜、扫描电镜观察和黄铁矿的能谱分析结果发现,黄铁矿草莓体直径最大为15μm,平均约10μm,硫铁原子比值(S/Fe)为1.90±0.10,表明在黄铁矿形成过程中,有孔虫壳体空腔内呈轻度-中度贫氧的微环境。在分析该类黄铁矿成因的基础上,认为有孔虫壳体内的黄铁矿在指示沉积环境和保存环境方面具有局限性。
Abundant benthic foraminiferas, identified mainly as Nodosaria, Pachyphloia and Langella, were discovered in the muddy limestone of the Qixia Formation in Yanmenkou area, Jingshan County, Hubei Province. Most of the foraminiferas chamber were filled by pyrite framboids. Systematic microscopic, scanning electron microscopic observations and energy spectrum analysis of pyrite were catTied out. The maximum diameter of pyrite framboids is 15 μm, and the average is about 10 μm. The sulfur to iron atom ratio （S/Fe） is 1.90 ±0.10. All these features indicate that these chamber were formed under a weak to moderate dysoxic micro-environments. Based on the discussion of the formation mechanisms of pyrite framboids, it is thought that these pyrite framboids in foraminiferas chamber have restricted significance in the study of deposition and diagenesis environment.
出处
《高校地质学报》
CAS
CSCD
北大核心
2009年第4期470-476,共7页
Geological Journal of China Universities
基金
国家重点基础研究发展计划(2007CB815603)
国家自然科学基金项目(40839910)联合资助
关键词
草莓状黄铁矿
底栖有孔虫
微环境
雁门口
栖霞组
S/Fe
framboids of pyrite
benthic foraminifera
micro-environment
S/Fe ratio
Yanmenkou
Qixia Formation
