The North China Craton is the oldest continental block,and has suffered from large-scale lithospheric thinning and destruction,which in turn led to gold deposits in northern China.The decratonic gold deposits in the N...The North China Craton is the oldest continental block,and has suffered from large-scale lithospheric thinning and destruction,which in turn led to gold deposits in northern China.The decratonic gold deposits in the North China Craton became the most important gold deposits in China,and geophysical methods are key means to detect and discover gold deposits there.In this paper,based on the geological and petrophysical characteristics of the North China Craton,the geological model of the decratonic gold deposits is transformed into a geophysical model.At present,two methods of geophysical exploration of decratonic gold deposits are in use:rapid and efficient exploration on the scale of the ore concentration area,and large depth exploration on the scale of the deposit area.In detail,the airborne electromagnetic,magnetic and gravity methods are used to detect the shallow(1,500 m)anomaly area on the scale of the ore concentration area.Through the ground-controlled source electromagnetic and ground magnetotelluric methods,explorations for targets at significant depth(5,000 m)are carried out in the mining area.Then,taking the Liaodong ore concentration area as an example,geophysical methods are used to discover two prospecting areas around the Jianshanzi Fault in the Qingchengzi ore concentration area,Baiyun-Xiaotongjiapuzi deep prospecting area,and Qingchengzi deep prospecting area.Next,three prospecting areas are delineated around the Jixingou Fault in the Wulong mining area,Wulong deep prospecting area,Weishagou deep prospecting area,and Chang’an deep prospecting area.The anomalies in the ore concentration area and mining area are revealed by means of three-dimensional exploration methods,thereby providing technical support for the exploration of metal minerals such as decratonic gold deposits.展开更多
The Paleoproterozoic boron deposits in east Liaoning occur in Mg-rich marble of Li’eryu Formation of Liaohe group. The mineralization was controlled by stratigraphic lithology. The volcano-sedimentation is the materi...The Paleoproterozoic boron deposits in east Liaoning occur in Mg-rich marble of Li’eryu Formation of Liaohe group. The mineralization was controlled by stratigraphic lithology. The volcano-sedimentation is the material base of ore- formation. Boron mainly derived from volcanic source. Boron in Li’ eryu formation was activated and transferred by mignati- zation and then deposited into ore when metasomatism occurrs in Mg-rich marble. Structural deformation reconstructed the boron ore bodies. Meanwhile, ore-bearing hydrothermal solution produced by structural deformation and remetasomated the host-ore rocks or filled in fissure of ore. Boron deposit is a stratabound deposit, which formed by mignatization and structu- ral deformation mineralization.展开更多
基金supported by the National Key Research and Development Program“Deep Earth Resources Exploration and Exploitation”(Grant No.2016YFC0600101)the Beijing Science and Technology Program“Deep Earth Exploration Technology Research and Development”Special Funding(Grant No.Z181100005718001)the National Natural Science Foundation Key Project(Grant No.42030106)。
文摘The North China Craton is the oldest continental block,and has suffered from large-scale lithospheric thinning and destruction,which in turn led to gold deposits in northern China.The decratonic gold deposits in the North China Craton became the most important gold deposits in China,and geophysical methods are key means to detect and discover gold deposits there.In this paper,based on the geological and petrophysical characteristics of the North China Craton,the geological model of the decratonic gold deposits is transformed into a geophysical model.At present,two methods of geophysical exploration of decratonic gold deposits are in use:rapid and efficient exploration on the scale of the ore concentration area,and large depth exploration on the scale of the deposit area.In detail,the airborne electromagnetic,magnetic and gravity methods are used to detect the shallow(1,500 m)anomaly area on the scale of the ore concentration area.Through the ground-controlled source electromagnetic and ground magnetotelluric methods,explorations for targets at significant depth(5,000 m)are carried out in the mining area.Then,taking the Liaodong ore concentration area as an example,geophysical methods are used to discover two prospecting areas around the Jianshanzi Fault in the Qingchengzi ore concentration area,Baiyun-Xiaotongjiapuzi deep prospecting area,and Qingchengzi deep prospecting area.Next,three prospecting areas are delineated around the Jixingou Fault in the Wulong mining area,Wulong deep prospecting area,Weishagou deep prospecting area,and Chang’an deep prospecting area.The anomalies in the ore concentration area and mining area are revealed by means of three-dimensional exploration methods,thereby providing technical support for the exploration of metal minerals such as decratonic gold deposits.
文摘The Paleoproterozoic boron deposits in east Liaoning occur in Mg-rich marble of Li’eryu Formation of Liaohe group. The mineralization was controlled by stratigraphic lithology. The volcano-sedimentation is the material base of ore- formation. Boron mainly derived from volcanic source. Boron in Li’ eryu formation was activated and transferred by mignati- zation and then deposited into ore when metasomatism occurrs in Mg-rich marble. Structural deformation reconstructed the boron ore bodies. Meanwhile, ore-bearing hydrothermal solution produced by structural deformation and remetasomated the host-ore rocks or filled in fissure of ore. Boron deposit is a stratabound deposit, which formed by mignatization and structu- ral deformation mineralization.
