摘要
野外地质、岩石学、元素地球化学研究表明，以往被认为是钙碱性系列岩石的浙江梧村地区西山头组火山岩、潜火山岩与沐尘岩体应为典型的钾玄质岩石。这套岩石富碱（w（Na2O＋K2O）=7．80％～11．48％）、高钾（w（K2O）／w（Na2O）=1．10—1．67）、贫钛（w（TiO2）=0．22％-0．88％）、低铁（w（FeO＋Fe2O3）=2．91％-6．36％）、铝含量较高（w（Al2O3）=15．39％～18．24％）、SiO2含量中等（w（SiO2）=56．96％-69．02％），富集大离子亲石元素和轻稀土元素，且w（Ce）／w（Yb）（27．29—38．19）、w（Ta）／w（Yb）（0．32—0．74）和w（Th）／w（Yb）（4．76—7．72）比值高，具有钾玄质系列的岩石地球化学特征。梧村地区矿产资源丰富，矿床在时间和空间上与钾玄质岩浆岩密切共生，钾玄质岩浆岩为成矿母岩，是重要的找矿岩石学标志。
Field geological, petrological and elementary geochemical studies reveal that the volcanic rocks, subvolcanic rocks and Muchen pluton of Xishantou Formation in the Wucun area in Zhejiang Province, which were formerly identified as calcicolous alkaline series rocks, should be typical shoshonitic rocks. These rocks are rich in alkali（ Na2O ＋ K2O = 7.80% - 11.48% ） and kalium （ K2O/Na2O = 1. 10 - 1.67 ）, and poor in titanium （TiO2 =0. 22% -0. 88% ） and ferrum（FeO ＋ Fe2O3 =2. 91% -6. 36% ）, also they have a relatively high content of aluminum （ 15.39% - 18.24% ）, a moderate content of SiO2 （56. 96% -69.02% ）, and high ratios of Ce/Yb （27.29 -38. 19）, Ta/Yb（0. 32 -0. 74） and Th/Yb （4. 76 -7. 72）. Besides, they abound in macroion lithopile element and light rare earth element. All these are petrological geochemical features of shoshonitic rock series. The Wucun area is rich in mineral resources, its mineral deposit symbioses closely with shoshonitic magma rocks both in time and in space, and the shoshonitic magma rocks are its rock-forming matrix. These are important signs for ore-seeking petrology.
出处
《现代地质》
CAS
CSCD
北大核心
2007年第3期443-450,共8页
Geoscience
基金
中国地质调查局地质大调查项目(200413000021)
关键词
钾玄质岩石
元素地球化学
西山头组火山岩
潜火山岩
沐尘岩体
梧村地区
浙江
shoshonitic rock
elemental geochemistry
Xishantou Formation volcanic rock
subvolcanic rock
Muchen pluton
the Wucun area
Zhejiang
