Paleomagnetic and paleointensity study of an Oligocene-Miocene lava sequence from the Hannuoba Basalts in northern China
文献类型：期刊论文
| 作者 | Pan, YX; Hill, MJ; Zhu, RX |
| 刊名 | PHYSICS OF THE EARTH AND PLANETARY INTERIORS
 |
| 出版日期 | 2005-07-15 |
| 卷号 | 151期号:1-2页码:21-35 |
| 关键词 | Absolute Paleointensity Paleomagnetic Direction K-ar Dating Oligocene-miocene Hannuoba Basalts North China Block |
| ISSN号 | 0031-9201 |
| DOI | 10.1016/j.pepi.2004.12.004 |
| 文献子类 | Article |
| 英文摘要 | A combined geochronologic, paleomagnetic and paleointensity investigation has been performed on a lava sequence from the Hannuoba Basalts in northern China. Potassium-argon (K-Ar) dating indicates that the lava sequence is of late Oligocene to middle Miocene age (similar to 24-15 Ma). Rock magnetic measurements of thermomagnetic curves, hysteresis properties, saturation isothermal remanent magnetization (SIRM) and back-field demagnetization on representative samples from each lava flow in conjunction with reflected light microscopy observations show the primary carriers of remanence to be fine-grained pseudo-single domain titanomagnetite with various titanium contents. Stepwise thermal and alternating field demagnetization successfully isolated stable characteristic remanent magnetization from 40 out of the 43 lava flows, which record 24 paleomagnetically independent directions. Data (excluding directions regarded as abnormal/transitional) yield a mean direction of DII= 6.8 degrees/56.3 degrees, with alpha(95) = 5.2 degrees and kappa = 51.6, corresponding to a paleomagnetic pole at 232.3 degrees E, 83.7 degrees N with dp = 5.4 degrees and dm = 7.5 degrees, consistent with previously published paleomagnetic poles for the North China Block. The modified Thellier method with systematic partial thermoremanent magnetization (pTRM) checks and pTRM-tail checks was conducted on 72 selected samples. Reliable paleointensity estimates from four lava flows yield a mean virtual dipole moment of (5.6 +/- 1.6) x 10(22) A m(2), suggesting moderately low intensity of the geomagnetic field. This is in good accord with reliable paleointensity datasets for the late Oligocene to middle Miocene (30-15 Ma), but lower than the average for middle Miocene to Pliocene age (15-2 Ma). It thus appears that at some point in the mid-Miocene there was a transition where the field intensity changes between these two states. although many more data are needed to confirm this. (c) 2005 Elsevier B.V. All rights reserved. |
| WOS关键词 | GEOMAGNETIC-FIELD STRENGTH ; EARTHS MAGNETIC-FIELD ; CRETACEOUS NORMAL SUPERCHRON ; LONG-TERM VARIATIONS ; ABSOLUTE PALEOINTENSITY ; PALEOSECULAR VARIATION ; INNER-MONGOLIA ; POLAR WANDER ; SOUTH CHINA ; INTENSITY |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000229670200002 |
| 出版者 | ELSEVIER SCIENCE BV |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/65713]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Pan, YX |
| 作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, Paleomagnetism Lab SKL LTE, Beijing, Peoples R China 2.Univ Liverpool, Dept Earth & Ocean Sci, Geomagnetism Lab, Liverpool L69 7ZE, Merseyside, England |
| 推荐引用方式 GB/T 7714 | Pan, YX,Hill, MJ,Zhu, RX. Paleomagnetic and paleointensity study of an Oligocene-Miocene lava sequence from the Hannuoba Basalts in northern China[J]. PHYSICS OF THE EARTH AND PLANETARY INTERIORS,2005,151(1-2):21-35. |
| APA | Pan, YX,Hill, MJ,&Zhu, RX.(2005).Paleomagnetic and paleointensity study of an Oligocene-Miocene lava sequence from the Hannuoba Basalts in northern China.PHYSICS OF THE EARTH AND PLANETARY INTERIORS,151(1-2),21-35. |
| MLA | Pan, YX,et al."Paleomagnetic and paleointensity study of an Oligocene-Miocene lava sequence from the Hannuoba Basalts in northern China".PHYSICS OF THE EARTH AND PLANETARY INTERIORS 151.1-2(2005):21-35. |
入库方式： OAI收割
来源：地质与地球物理研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。