北冰洋-欧亚大陆-太平洋地学断面东南段岩石圈有效弹性厚度

袁炳强; Poudjom DjomaniYvette H.; 王平; 袁学诚; 左愚

北冰洋-欧亚大陆-太平洋地学断面东南段岩石圈有效弹性厚度

1.
西北大学地质学系, 陕西西安 710069
2.
GEMOC National Key Center, Department of Earth and Planetary Science, Macquarie University, NSW, Australia
3.
中国地质调查局, 北京 100083
4.
国土资源部区域重力调查方法技术中心, 陕西西安 710016

基金项目: 澳大利亚Macquarie大学地球化学演化与大陆成矿研究中心项目

详细信息

作者简介:
袁炳强(1957-), 男, 高级工程师, 1982年毕业于西安地质学院, 西北大学博士生, 主要从事地球物理资料应用研究

中图分类号: P311
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出版历程
- 收稿日期: 2002-03-09
- 刊出日期: 2002-07-25

Effective Lithospheric Elastic Thickness of Southeastern Part of Arctic Ocean-Eurasia Continent-Pacific Ocean Geoscience Transect

1.
Department of Geology, Northwest University, Xi'an 710069, China
2.
GEMOC National Key Centre, Department of Earth and Planetary Science, Macquarie University, NSW 2109, Australia
3.
China Geological Survey, Beijing 100083, China
4.
Centre for Regional Gravity S tudies, the Ministry of Land and Resources, Xi'an 710016, China

摘要

摘要: 大陆岩石圈有效弹性厚度(T_e) 是表示岩石圈强度的参数, 计算该参数对研究岩石圈大规模构造, 分析大陆板块内的均衡补偿机制有一定意义.利用Forsyth提出的相关技术计算了北冰洋-欧亚大陆-太平洋地学断面东南段自黑水到泉州的T_e值.并分析了重力和地形波长的相关性特征, 初步认为: 计算T_e值所选的每个数据块在短波长(6.6~ 10 0km) 内岩石圈板块的强度足以平衡地形负载, 重力和地形不相关; 在长波长(10 0~ 2 5 0km) 内, 地形及地下负载由弯曲模型补偿, 岩石圈板块在地形及地下负载作用下而挠曲.断面通过地段具有较低热流密度值的四川陆核有较高的T_e值, 具有较高热流密度值的宁化、大田地区有较低的T_e值, 反映了较高的热流密度值对应较低的T_e值; 较低的热流密度值对应较高T_e值的关系.T_e可分为南东低值段和北西高值段.地壳厚度大体上与T_e值呈正相关关系.
- 有效弹性厚度 /
- 相关技术 /
- 北冰洋-欧亚大陆-太平洋地学断面
Abstract: The effective lithospheric elastic thickness of the continent is an important parameter to examine the large scale structure and analyze the mechanism of isostatic compensation within the plate, and is a parameter standing for the strength of the lithosphere. The T_e values along Quanzhou Heishui, the southeast section of the Arctic Ocean Eurasian continent Pacific Ocean geoscience transect, are estimated by using the coherence technique developed by Forsthy. Studies of the feature of the coherence between gravity and topography suggest that at short wavelengths (6.6-100 km) for each data box that is used to estimate T_e, the plate is strong enough to support topographic loads and gravity and topography are uncorrelated; at long wavelengths where the plate is deflected by surface and subsurface loads which are compensated by the flexure model. The high T_e values of Sichuan land stone with low heat flow values and the low T_e values in Ninghua, Datian with high heat flow values reflect a correlation, with low heat flow values corresponding to high T_e values and with high heat flow values corresponding to low T_e values. T_e values can be divided into two sections: northwest high section and southeast low section. There is roughly a positive correlation between crustal thickness and effective elastic thickness of the lithosphere.
- effective elastic thickness /
- coherence technique /
- Arctic Ocean Eurasian continent Pacific Ocean geoscience transect

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图 1 布格重力异常

(等值线间隔10×10^-5 m/s²)

Fig. 1. Bouguer gravity anomaly contoured at intervals of 10×10^-5 m/s²

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图 2 岩石圈地球物理格架

1.区带走廊; 2.薄岩石圈分布地区(岩石圈厚度 < 80 km); 3.岩石圈正常厚度分布地区(岩石圈厚度为80~120 km); 4.厚岩石圈分布区(岩石圈厚度 > 120 km); 5.地热流值(mW/m²); 6.陆核区; 7.地壳厚度陡变带; 8.巨型断裂; 9.缝合带

Fig. 2. Geophysical structural framework of lithosphere

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图 3 T_e值与大地热流的对比

图中横座标L为黑水-泉州地学断面在东西方向上的投影长度(图 4相同)

Fig. 3. Comparison between T_e and heat flow

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图 4 T_e值与地壳厚度的对比

Fig. 4. Comparison between T_e and crustal thickness

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表 1 计算T_e应用物理参数

Table 1. Physical parameters used for estimation of T_e

表 2 20个数据块的T_e及D值

Table 2. T_e and D values of 20 subgrids

参考文献(11)

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