中文摘要：

胶南岚山头地区花岗质片麻岩的化学成分表现为SiO2含量普遍高，为68．4％～78．26％，Al2O3含量为11．34％～15．84％，而TiO2、Fe2O3、FeO、MnO和MgO的含量明显偏低，其中Fe2O3为0．69％～2．12％，FeO为0．18％～1．56％，MgO为0．05％～1．53％；岩石明显富含Na2O、K2O强烈贫CaO，其中Na2O＋K2O的含量为8．32％～10．33％，K2O的含量为3．87％～5．24％，CaO的含量为0．19％～1．27％。稀土元素配分模式显示轻稀土明显富集、重稀土相对平坦，具较强的轻、重稀土元素分馏和强烈-中等的负Eu异常。具强烈富集大离子亲石元素（K、Rb、Ba、Th）的特点，高场强元素Ti、Nb和Ta显示明显负异常，且所有样品均具明显负P异常。花岗片麻岩的原岩为A型花岗岩，指示其形成于拉张作用下的陆缘火山弧构造环境，原岩可能为新元古代下地壳富钾的变质玄武岩部分熔融而成，形成压力为0．8～1．0GPa，部分熔融程度小于10％。胶南A型花岗质片麻岩的原岩形成于新元古代，与扬子板块北缘新元古代陆缘火山活动有关，可能是Rodinia超大陆裂解事件在苏鲁地区的强烈反响。

英文摘要：

Chemical components of Jiaonan granitic gneiss indicate that SiOz and Al2O3 contents of the samples range from 68.4% to 78.2% and from 11.34% to 15.84%, respectively. TiOz, Fe2O3, FeO, MnO and MgO contents are obviously low; Fe2O3 ： 0.69 % - 2.12 %, FeO = 0.18 % - 1.56 % and MgO = 0.05 % - 1.53 %. Na2O, K2O contents of the rock are high and CaO is evidently low, with Na2O＋ K2O being 8.32 % - 10.33 %, K2O 3.87% -5.24%, and CaO 0.19% - 1.27%. The REE patterns are characterized by obvious enrichment of light rare earth elements, clear deficiency of heavy rare earth elements, and medium-intense negative Eu anomalies. In the MORB normalized multi-element variation diagram, multi-element variations show the relative concentration of K, Rb, Ba and Th, evident depletion of Ti, Nb and Ta, and clear negative P anomalies. The protolith of granitic gneiss in Jiaonan belongs to A-type granite formed in volcanic arc tectonic surroundings under the action of tensional force. The source rock of A-type granite might have been derived from partial melting of the lower crust K-rich metabasalt formed in Neoproterozoic. It was formed at the temperature up to 1 000℃, pressure from 0.8 GPa to 1.0 GPa, and partial melting degree lower than 10 %. The formation of A-tyPe granite might have been related to the volcanic arc activity on the northeast margin of the Yangtze block in Neoproterozoic, which is supposed to be the reflection of the Neoprotorozoic Rodinia supercontinent breakup event in Sulu area.