摘要
红岩黄铁矿经详细勘探查明,为一矿体集中、埋藏较浅、品位中等、可供工业利用的大型黄铁矿矿床。矿床产于“粤北山字型构造”前弧西翼的英德盆地西缘之中泥盆统东岗岭组礁后泻湖相碳酸盐岩中,受北西向、东西向构造及层间裂隙控制,为沉积-改造-再造式的层控矿床,具有典型意义。
The Hongyan pyrite deposit is located at the western edge of the Yinde basin. Detailed exploration shows that it is a large-sized economic deposit with concentrated orebodies, small buried depth and moderate grade. The ore district lies on the western limb of frontal arc of the 'Northern Guangdong epsilon-type structural system', the ore deposit occurs in backreef lagoon facies carbonate rocks of Middle Devonian Donggangling Formation and is controlled by NW- and EW- trending structures and interformational fissures, being a sedimentary-reworked-transformed stratabound deposit with typical significance. From southwest to northeast, the strata in the ore district consists in turn of clastic rocks of Middle Devonian Guitou Formation and carbonate rocks of Middle Devonian Donggangling Formation, Upper Devonian Tianziling Formation and Lower Carboniferous Menggongao Formation. The sedimentary environment from Late Guitou to Early Tianziling experienced on the whole three stages, i. e., platform shallow water sedimentation, formation of bioherm along the platform margin and bottom flow sedimentation in the basin. The ore district is composed of 20 orebodies with a controlled length of 2200m, which generally occur along the stratification. The weathered orebodies can be generally divided into top limonite zone, upper powdery pyrite zone and middle-lower massive pyrite zone. The primary ores mainly have radiating, spherical strawberry metasomatic relic and cataclastic textures. In texture, they are mainly characterized by massive and disseminated ones and next by banded and brecciated ones. Pyrite has four modes of occurrence, dark yellow anhedral granular, yellowish colloidal, light yellow medium-coarse granular, and fine-grained (powdery) aggregates. The orebodies are controlled by certain horizons and occur along the stratification in the stratoid and lenticular forms. From the lower part upward, there appear three ore-bearing stratigraphic horizons, top part of Guitou Formation, Donggangling Formation (major ore bearing bed) and bottom of Tianziling Formation. The early-sedimentary pyrite was controlled by tidal flatlagoon facies, whereas the late stage transformation and reworking stages were mainly governed by structural and exogenic processes. According to S, Pb isotopic determinations, K-Ar and U-Pb dating for rocks and ores, and decrepitation temperature measurements for pyrite, it is considered that the ore deposit was formed in a special sedimentary environment and later became richer in grade and concentrated quite a few orebodies as a result of the superimposition of late-stage transformation and reworking process. It is therefore called 'sedimentary-reworked-transformed' type stratabound deposit.
出处
《矿床地质》
CAS
CSCD
北大核心
1989年第2期81-90,共10页
Mineral Deposits
