敖瑙达巴斑岩型锡多金属矿床地质特征

敖瑙达巴矿床是我国北方地区首次发现的斑岩型锡多金属矿床。该矿床产于距晚侏罗世火山岩盆地4km的中生代断隆区,含矿斑岩以花岗斑岩为主(148×10~6a,I_(Sr)=0.708)。钾硅酸盐化核、绢英岩带、黄玉云英岩带、青磐岩带及角岩化带构成了矿床中大致对称的前进中心式蚀变分带,岩体上部—顶部—边部(接触带附近)分别赋存着锡—锡银—铜工业矿体。研究表明,敖瑙达巴矿床属高位陆上环境的潜火山-斑岩型锡多金属矿床,它既不同于斑岩铜矿床,也与广东的银岩斑岩锡矿床有较大的差别。

Geological Characteristics Of The Aonaqdaba Porphyry Tin-Polymetallic Deposit

The Aonaodaba ore deposit occurring in the Mesozoic faulted upwarping area l km from the Late Jurassic volcanic basin is a tin-silver-copper porphyry deposit discovered for the first time in North China. The ore porphyry is mainly granite porphyry (148 Ma, Isr=0.708 ). The potassic-silicate alteration core, phyllic zone, topaz greisen zone, propylite zone and hornfels zone constitute an approximately symmetrical progressive and central type alteration zoning in this deposit. Economic tin, tin-silver and copper orebodies are seen respectively in the upper part, the top and the margin (near the contact zone) of the porphyry body. Studies show that the Aonaodaba deposit is a subvolcanic-porphyry tin-polymetallic deposit formed in a high-level continental environment. Genetically, it is different not only from porphyry copper deposits but from the Yinyan porphyry tin deposit of Guangdong Province as well.