河北省丰宁地区两类碱长花岗质岩石

Two Types of Granites of the Fengning District, Hebei Province

冀北丰宁地区的小坝子潜流纹岩、黑山咀流纹斑岩、老虎沟门花岗岩和窟窿山花岗岩是空间上紧密共生,生成时间相近和矿物组成相似的碱长花岗质岩石,也是华北地区中生代晚期岩浆作用的代表性产物。本文报导了这些岩石的地质学、岩相学和岩石地球化学资料,比较了它们的异同,探讨了物质来源问题,提出它们可以划分成为两种成因类型,即一类来源于较浅部的、以火成表壳岩为主的变质物质、另一类为较深部的火成物质的观点。

The subvolcanic rhyolilc, rhyolitic porphyry, Laohugoumeu granite and Kulongshau granite in the Fengning district, Hebei Province are four alkali-feldspar granitic rocks which have associated relationship in occurrence, near on forming-period and similar on forming-rock minerals and petrochemistry. Data of geology, petrology, petrochemistry and geochemistry for them are reported and are used to compare difference between them and discuss derived-material of these rocks. Two types of granitic rocks have been distinguished and considered of two derived-materials, e. g. one is derived from weathered and metamorphic igneous rock similar to igneous supracrustal rock and another from deep igneous material which is unweathered.