沉积矿床多因素多阶段成矿论

沉积矿床不是海水直接沉淀的产物,而是多因素多阶段复杂过程的产物,工业矿床是最后阶段物理富集的产物。沉积成矿受沉积环境及地质背景的制约,它们左右着矿床的时空展布规律。造山、造陆特别是造海运动左右着成矿域、带的展布和结构,导致不同的成矿过程和成矿模式。在浪基面以上形成具碎屑结构的层状矿床,在浪基面以下,经深埋成岩作用形成成岩矿床和由变热了的承压的含矿地层水入侵而形成的层控矿床。

COMPOSITE-PROCESS AND POLY-EPISODIC ASPECT OF THE CHINESE SEDIMENTARY MINERAL DEPOSITS

Genesis of sedimentary mineral deposits can not be derived directly by any kind of simple chemical reactions, but were products of a complex procedure through composite-process and poly-episodic generations. The procedure were not just evolutionary, but also revolutionary in nature. Metallogenic process is really constrained collectively through materialistic process, sedimentary environment, and geological background. The going-on of the whole procedure were governed by both effects of sedimentary, geochemical, biogeochemical, organic geochemical, paleo-climatical, geologic-physical as well as properties of the relevant earth crust segment, their structural making up and tectonic mobility.Sedimentary mineral deposit is nothing but a special kind of sedimentary facies, of a definite sedimentary assemblage, Different genetic types of mineral deposits and different ore associations charaterize different sedimentary assemblages, different ore-forming belt or territory.Crustal movement, including orogenic movement, epeirogenic movement, as well as eustatic movement, controls the formation and distribution of all kinds of sedimentary mineral deposits. Epeirogenic movement of local occurrence usually deviate the general distribution pattern of the mineral deposits. The influence of eustatic movement is likely more sensitively effective. Most kinds of sedimentary mineral deposits occur preominantly within the transgression frontal belt and lower part of marine transgressive sedimentary series.Mineral deposits can not be precipitated directly from sea water, but were products of terrestrial imbibition, biological enrichment and pore water concentration instead. Above the wave base, in the inner continental shelf, where the dynamic condition of the sea water is strong, mineral deposits that were formed under the recycling sedimentary regime up there, are predominantly clastic in texture and well bedded in structure. They are largely huge industrial deposits. Where as below the wave base, in the outer continental shelf environment, the situation is apparently oxygen deficient and dynamically more or less stagnant, and the resulted industrial mineral deposits are mostly of the deagenetic or stata-bound type, formed under the process of deep-burying diagenesis through the action of pieizometric heated fromation water.Thus, it can be seen, in the investigation of the genesis and rule of distribution of mineral deposits, we can never rely only on the deciphering of their relevant "process", but must also had a good understanding of their genetic "sedimentary environment" and "geologic background" condition as well. Otherwise, any "model" or "rule" that might be got, can only of local meaning at most.The theory of multi-process and poly-episodic metallogenisis composed of three -constituent items, i. e., the procedure of the genetic process, the sedimentary environment, and the geological background. The investigation of "genetic process", "genetic procedure", and the "origin of the ore forming elements" gives us the "sedimentary markers" of the existing mineral deposits. Whereas, investigations of "sedimentary environment" tell us the rule of spacial distribution of the mineral deposits, and the analysis of "geological background" help us to the understanding of metallogenic epoches.