成岩成矿深度:主要影响因素与压力估算方法

The diagenetic and metallogenic depth: main constriants and the estimation methods

成岩成矿深度是金属矿床成矿地质体的重要空间参数,受到地质构造、岩浆岩、围岩等诸多因素的影响。初步讨论了成矿深度的主要影响因素:岩浆因素和构造因素。内生矿床,特别是岩浆热液矿床的形成深度与岩浆作用的深度有关,岩浆侵位深度限定了矿床形成深度的下限,而岩浆上升和侵位过程中分异出的热液的深度直接决定了成矿深度。构造变形直接控制了多孔介质的渗透率,渗透率制约了流体的流动,成矿流体运移和就位则直接与成矿深度相关联。还阐述了成岩成矿深度(压力)的估算方法,以流体包裹体温压计为主,结合其它矿物地质温度计和压力计,并综合考虑成矿地质构造、岩浆岩、围岩等因素,才能获得合理和符合地质实际的成矿深度,为找矿勘查提供经得起检验的深度参数。

Rock-forming and metallogenic depth are the important spatial parameters for mineralized geologic bodies of metallic ore deposit,and affected by many factors including geological structures,magmatic rock and wall rock.The major influencing factors on metallogenic depth are discussed preliminarily,including magma and structure factors.The depth of endogenic mineralization,especially the formation depth of magmatic-hydrothermal mineral deposits,is related to the depth of magmatism and magma emplacement.The depth of magmatic emplacement restricts the lower limit of the formation depth of mineral deposits,while the depth of magmatic hydrothermal fluid exsolved from ascending magma and intrusion directly determines metallogenic depth.Structural deformation directly controls the permeability of porous medium,and permeability restricts fluid flow,while ore-forming fluid migration and accumulation are directly associated with metallogenic depth.Estimation methods for diagenetic and metallogenic depth（or pressure） are also discussed.Finally,the author indicated that the reasonable metallogenic depth which corresponds to geologic facts could be acquired based on thermobarometer of fluid inclusion,combined with other mineral geologic thermometer and manometer,and metallogenic geological structure,magmatic rock and wall rock considered comprehensively,which also provides depth parameter withstand the test for mineral prospecting and make a contribution to deep ore exploration.