Petrological-Geochemical Characteristics of Volcanic Ash Sediments in Yanchang Formation in Ordos Basin
详细信息
- 责任者：Qiu Xinwei (State Key Laboratory of Continental Dynamics ; Institute of Petroliferous Basin ; Northwest University ; Xi’an 710069 ; China) ; Liu Chiyang
- 刊名：Earth Science
- 出版年：2011
- 卷期：36(1)
- 关键词：火山灰 ; volcanic ash ; 沉积物 ; sediments ; 鄂尔多斯盆地 ; Ordos Basin
- 页码：p.139-150
- 图表：7 illus., 1 table, 47 refs.
- 分类号：0801
- issnNo：ISSN1000-2383
- isbnNo：CN42-1233/P
摘要
Volcanic ash sediment is widely distributed in Yanchang Formation in Ordos Basin, in order to study lithogeochemistry characteristics and formational mechanism of volcanic ashes sediment, the paper use many analysis methods, such as observe the cores, microscope, XRF, ICP-MS, SEM et al.. The results indicate volcanic ash sediment containing much crystal and shard fragments, including tuff and bentonite, the illite and andreattite can be seen under the SEM; SiO2 content between 50.29%~79.82%, rich potassium, K2O+Na2O at 3.20%~7.88%, the negative correlation present in relationship of SiO2 with Al2O3, TFe2O3 and MgO; ∑REE=99.82×10-6~550.15×10-6, and rich in LREE, deplete in HREE, the curve rightward incline , Eu negative abnormity and the δEu between 0.147~0.837, there is no evidently Ce abnormity, and K, Rb, Ba, Th are of positive abnormity.