Analysis Of Time Distribution Patterns Of Au,Cu And Fe Deposits In China From A Recycling Perspective

In this paper,the population dynamics model is used to analyze the deposit data under the scale of the geological time.According to the relationship between the deposit and age,the cumulative reserves-age distribution pattern and the metallogenic type-age distribution model of gold,copper and iron deposits in China are tentatively analyzed and studied,and the metallogenic regularities of the three minerals are summarized.The following findings and understandings are obtained:(1)By analysis gold resources of China reserve-cumulative age distribution patterns,we summarize gold reserves concentrating mainly on Mesozoic and Cenozoic.The fitting curves of China and global gold deposits-age index function show that the half-lives of the two deposits are 324.96 Ma and 1760.16 Ma,respectively,and the recycling rate of Chinese gold deposits is significantly faster than the global.By analysis of gold metallogenic type-cumulative age distribution patterns,hydrothermal type gold deposit of China distribute in the Phanerozoic.The main metallogenic epoch of skarn type gold deposits mainly concentrated in the late phase of the Yanshan.The metallogenic epoch of metamorphic gold deposits is mainly concentrated in Mesozoic and Palaeozoic era.(2)The fitting curves of China and global copper deposits-age index function show that the half-lives of the two deposits are 316.51 Ma and 382.96 Ma,respectively.The recycling rate of Chinese copper deposits is similar to that of the whole world,but it is faster than the global since the Paleozoic,reflecting the relative complexity of China's regional structure since this time.By analyse Cu metallogenic type-cumulative age distribution patterns,the relationship of Chinese metallogenic epoch and the main copper deposits are obvious.Precambrian mainly formed magmatic copper nickel sulfide deposit,sedimentary metamorphic deposit.The Paleozoic Era mainly formed marine volcanic rock type deposit.The Mesozoic and Cenozoic Era mainly formed porphyry and skarn type deposits.(3)By analyse Fe resources of China reserve-cumulative age distribution patterns,the time range of iron ore formation in China is basically the same as that inthe world,mainly formed in the Archean-Palaeoproterozoic.The fitting curves of China and global iron deposits-age index function show that the half-lives of the two regions are 821.26 Ma and 760.03 Ma,respectively.Iron ore-type-cumulative age distribution pattern analysis shows that iron ore in different ages has obvious characteristics: the Archean-Paleozoic is the main formation period of China's iron ore,basically all sedimentary metamorphism;the Neoproterozoic is the type of iron ore increased;Late Paleozoic and Mesozoic are another important period of iron ore mineralization in China;Quaternary formed a modern weathered sedimentary deposit.