(桂林工學(xué)院資源與環(huán)境工程系， 桂林 541004)
摘 要: 與大多數(shù)含銅斑巖產(chǎn)于陸相火山巖區(qū)不同，甘肅公婆泉含銅斑巖(即英安斑巖和花崗閃長斑巖)在空間和成因上與中-晚志留世淺海相火山巖系關(guān)系密切。這兩類含銅斑巖均侵入于石英粗面巖中，斑晶礦物成分、 斜長石牌號(hào)、 巖石化學(xué)成分、鐵族及成礦元素的豐度等相近， 均屬鈣堿性巖系(里特曼指數(shù)為1.69～2.75)， 具富K(K2O為2.80%～4.77%)、 低A l(Al2O3為14.46%～16.01%)、 低Ca(CaO為2.49%～4.63%)及成礦元素含量較高的特點(diǎn)。 與花崗閃長斑巖相比較， 英安斑巖的斑晶含量較低而晶屑含量較高、 鉀化蝕變較強(qiáng)烈、 Fe2O3 /FeO值和K2O含量較高、CaO含量較低。 兩類斑巖是同源巖漿的淺成-超淺成侵入體， 英安斑巖的侵位深度相對(duì)較淺。
關(guān)鍵字: 關(guān)鍵詞: 斑巖銅礦 斑巖 甘肅公婆泉
（Department of Resources and Environment Engineering,Guilin Institute of Technology, Guilin 541004, P. R. China）
Abstract:In the world, most of the bearing-copper porphyries occur at the zone of the continental volcanic rocks, but the situation is very different in the Gongpoquan copper ore field: the porphyries(dacite porphyry and granodiorite porphyry)occur at the area of the marine volcanic rocks. These two sorts of porphyries invaded into the S2-3 quartz trachyte, and they are similar in the mineral composition of porphyritic crystal, number of feldspar, chemical composition of rock, and element abundance(V, Cr, Mn, Co, Ni, Zn, Mo, Sn, W, As, etc). In addition, the por phyries belong to the lime-alkali series(δ=1.69~2.75) and are characterized by higher K2O(2.80%~4.77%), lower Al2O3(14.46%~16.01%), lower CaO(2. 49%~4.63%), and higher minerogenetic element abundance. On the other hand, comparing with the granodiorite porphyry, the dacite porphyry holds the following different charaters: less quantity of porphyritic crystal and more quantity of crystalloclastic, more intensive K-alternation, higher Fe2O3/FeO and K2O, and lower CaO. Accordingly, these porphyries are shallow invasive body from the same magma chamber, and the invasive depth of the dacite porphyry is more shallow than the invasive depth of the granodiorite.
Key words: porphyry copper porphyry Gongpoquan Gangsu
