PRBLIMINARY DISCUSSION ON THE PROBLEMS OF MINEROGENETIC SERIES OF MINERAL DEPOSITS
Cheng Yuqi;Chen Yuchuan;Zhao Yiming
Having briefly reviewed problems sush as the classification of mineral deposits, mineralzoning and others, and based on minerogenetic analyses of some examples of various kinds ofminerals deposits, the authors are of the poinion that the concept of the minerogenetic series ofthe iron deposits put forward earlier could also be applied to the study of mineral deposits ofvarious compositions formed in different geological settings. The investigation of the problemsof minerogenetic series has just began. Future researches of this subject will perhaps furtherincrease the validity of the prognostic effect, so to say, of the study of mineral deposits, andwill also be beneficial to the promotion of the efficiency and effect of the regional mineroge-netic analysis and mineral prognostic works. The division of minerogenetic series is based on synthetic studies of the characteristics ofregional geology and mineralization and their historical development of the mineral depositsconcerned. Every minerogenetic series is composed of two or more genetic types of mineraldeposits or compositional types of ores, each of which contains certain common and/or respe-ctive useful minerals and elements, found in three-diamensionally different parts of a certaingeological unit. Although the said types are formed under somewhat different geological settings,yet under the influence of similar salient geological conditions, chiefly in the same or differentstages of a certain minerogenetic epoch, and furthermore, being ioterrelated in the light of theevolution of the minerogenetic regions as an entity. The various types of each series wouldthus often condition each other as ore-finding indicators of certain mining district or a regionof greater extension. Fundamentally, each of the types concerned is nothing but a special faciesof a certain magmatic. sedimentary or metamorphic formation of certain geological age in acertain region. At the moment, the nature of the minerogenetic series of the magmatogenic mineral depo-sits, examples of which form the main subject of description and discusson of the present paper,is somewhat better known. They may be preliminarily classified into different series accordingto the source, composition, evolution, mode of occurrence and other geological characteristics ofthe magmatic rocks concerned. Based on the data so far obtained. of which most are Chinesedeposits, twelve such series have been provisionally suggested. As to those related to the processof sedimentation, and also of diagenesis, it seems that they may be grouped on the basis of somecommon yet rather important mineral-bearing formations, of which seven series are recomma-nded, and only one example of one series is being described in this paper. For mineraldeposits of the metamorphic terrains, the factors to be considered in the establishment of mine-rogenetic series are generally the nature and degree of metamorphism, including migmatism, aswell as characters of the pre-metamorphic formations and other geological features. Examplesof two of such series are very briefly mentioned in this paper.