Strategic metallic ores are very important to economic development. China's demand to and dependence on metal minerals keep increasing due to its rapid urbanization and industrialization in the last 2-3 decades. Import is an important source of mineral resources for a country. Identifying and evaluating the effect of strategic ores is of great practical significance to ensure their supply security. However, there is no standard method to evaluate the significance of strategic minerals so far. To analyze the supply security challenges and protective measures of the strategic metal ores, this paper evaluates the supply security of 13 strategic metal minerals between 1994 and 2016 in China from two dimensions: the degree of domestic supply security and the degree of supply security for imported resources. The degree of domestic supply security is an index to combine the estimated depletion time and the relative mineral scarcity index based on economic mineable reserves. The degree of supply security for imported resources is an index that is used for evaluating the import safety degree of mineral ores by combing net import reliance and market concentration. Results showed that: 1) the supply security is poor for Cr, Fe, Co and Ni ores. These ores should be paid more attention because the domestic supply of these ores are in short, while the degree of supply security are also poor; 2) the supply security is relatively poor for Sn ores. The domestic supply of this ore is relatively abundant but the degree of supply security has been declining in recent years; 3) the supply security is relatively good for Al, Cu, Zr and Au ores. The domestic supply of these ores are in short but the degree of supply security is relatively good; 4) the supply security is good for Mo, Sb, W and REE ores. The domestic supply of these ores are relatively abundant and the degree of supply security scarcity is relatively good. This paper presents suggestions on limiting export of strategic metallic ores, encouraging import, looking for global cooperation, boosting internal exploration, increasing inputs on mining and processing technologies, producing high added\|value products, improving recycling recovery at each steps, and balancing import sources. This method also applies to other materials, which can provide references for China to evaluate supply security of strategic metallic ores.

Compared with those countries who completely depend on imported potash fertilizer in the global potash fertilizer market, China has specific reserve and production capacity in potash at about 40% dependence on imported since 2013. This paper uses static market balance theory to discuss the influence of domestic potash fertilizer on imported potash fertilizer's price and studies the conducting path of domestic and global potash fertilizer prices by means of spatial price conducting theory. China rises its production by 1%, the prices in the major markets will drop 12.6% to 21.0%, which is outstanding at the 1% statistic level. A co-integrated relation exists between China's domestic and global potash fertilizer prices with domestic price as weak exogenous order and global as endogenous order, meaning a one-way conducting mechanism between domestic and global potash fertilizer prices. This paper suggests China continue to boost potash resource exploration, fully use the conducting mechanism and market linkage of domestic potash fertilizer to global to guarantee the domestic potash fertilizer supply, and increases China's competitiveness in global potash fertilizer market. 

This paper, based on the grain size data of drilling cores in Kunming basin, analyzes the grain size trend curve, grain size parameters, possibility accumulative curve, discusses the evolution of the Quaternary sedimentary environment in Kunming basin. The work reveals that the early Pleistocene is fluvial facies—lake facies, the middle Pleistocene is lake facies—shallow lake facies—lake facies—fluvial facies, and since the late Pleistocene is fluvial facies—lake facies—shallow lake facies—lake facies—fluvial facies.