On October 22, 2020, the first 3000 m scientific deep drill for the solid mineral exploration area of the Qinghai-Tibet Plateau funded by the Ministry of Science and Technology was successfully completed in the Jiama copper polymetallic mining area (Fig. 1). The deep drill is the core task of a special project for Deep Resources Exploration and Mining(DREAM) in the framework of the National Key Research and Development Program (NKRDP), which named as “Deep exploration technology, exploration and reserve increases demonstration of the metallogenic system of the important mineral resource base in the Qinghai-Tibetan Plateau”. The project was undertaken by the Institute of Mineral Resources of China Geological Survey and Chengdu Center of China Geological Survey. The Shandong Provincial Third Geological and Mineral Exploration Institute is responsible for the deep drill construction. Since the start of construction on June 22, 2019, the construction team has overcome the effects of high cold and hypoxia and the Covid-19 epidemic,and completed on October 21, 2020, which lasted 488 days.The drilling footage of deep drilling is 3003.33 m, achieving a breakthrough of 3000 m deep drilling in the field of solid mineral exploration on the Qinghai-Tibet Plateau.

The establishment of Jiama Scientific Deep Drill is aimed at the major needs of China for deep resource exploration and mining and technical equipment research and development. It aims to realize the demonstration of increasing reserves for deep resource exploration of porphyry copper-polymetallic deposits in the Tibet Plateau and reveal the fine structure of the rock mineralization system under the continent-continent collisional orogenic background. It aims to achieve the goal of mineralization theoretical innovation, improve exploration models, and demonstration of resource reserves.

At present, the Jiama Scientific Deep Drill has revealed a 234.34 m thick hornfels-type copper-molybdenum ore body and a skarn-type copper-molybdenum-gold-silver orebody with a thickness of more than 298 m. Among them, the thickness of copper-rich skarn ore body with a copper grade greater than 0.70%, is 44.12 m and the average grade of copper is 1.17%, the average grade of molybdenum is 0.04%,the average grade of associated gold is 0.63 g/t, and the average grade of associated silver is 20.12 g/t. Encouraged by this achievement, China National Gold Group Tibet Huatailong Mining Development Co., Ltd. has matched the exploration and research funding of more than 75×106RMB.A total of 30 drilling holes have been constructed in the Jiama mining area. The cumulative drilling footage is 45000 m, and the mine drilling rate has reached 100%.

Although the relevant grade analysis data of the porphyry ore body has not yet been obtained, the discovery of the thick skarn copper polymetallic ore body has already highlighted the demonstration effect of exploration and reserve increase.In addition, the science and technology research team led by chief scientist Ju-xing Tang discovered that the “multi-center”porphyry-skarn compound mineralization is the key factor controlling the formation of thick copper-rich molybdenum ore bodies, and preliminarily reveal a continuous evolution and transition relationship between the porphyry copper oreforming porphyry body and its deep secondary magma chamber under the continental-continent collisional orogenic background. This understanding is significantly different from the understanding of the emplacement process of the porphyry body in the traditional porphyry copper mineralization theory.It laid a solid foundation for perfecting the exploration model of porphyry copper deposit and the innovation of mineralization theory under the background of continentalcontinent collision orogen.

The completion ceremony of scientific deep drilling was held on the drilling platform in the Jiama mining area. On October 22, 2020, the chief scientist of the project, Ju-xing Tang, announced the successful completion of the Jiama Scientific Deep Drill. Some expert and government officials from the Department of Science and Technology Development of Ministry of Natural Resources (MNR),Department of Science and Technology of Tibet Autonomous Region, Department of Natural Resources and Bureau of Geology and Mineral Exploration of Tibet Autonomous Region, Chengdu Center of China Geological Survey, China National Gold Group Huatailong Co., Ltd., Geological and Mineral Exploration of Shandong Province attended the completion ceremony and congratulated the successful implementation of the Jiama 3000 m Scientific Deep Drill. At the same time, the attending experts at the meeting highly evaluated the demonstration effect of deep exploration and reserve increase of Jiama Scientific Deep Drilling and the innovation of prospecting theory and technology and believed that it was the integration of deep resource exploration technology for the formation of “full chain design and integrated implementation ” of porphyry mineralization system. The system is of strategic significance, and it is also full of confidence and expectations for the follow-up scientific research results of scientific deep drilling and the innovation of mineralization theory.

Source from https://www.cgs.gov.cn/gzdt/zsdw/202010/t20201026_657519.html

Compiled by Li-qiong Jia and Xi-jie Chen

Contact: No. 45 Fuwai Street, Xicheng District, Beijing 100037, P.R. China Tel: +86-10-58584239 Email: xijiechen 2020＠163.com (Xi-jie Chen)

Fig. 1. Construction site of Jiama 3000 m Scientific Deep Drill on the Qinghai-Tibet Plateau.