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1、第26卷第2期吳海權(quán):浙江天目山超單元的地球化學(xué)特征及其成因機(jī)制探討839.2O%一11.60%12%一9.25%,表征,礦物成分含量變化表現(xiàn)出結(jié)晶巖石化學(xué)參數(shù)見表2。從中可現(xiàn)出結(jié)構(gòu)變化者遞增或持平,但總分異作用的特征??闯觯河芍芗覇卧缓未鍐卧w有所減少。這些特征顯示天目山2巖石化學(xué)特征一亭子山單元一÷白水I51單元,超單元具有結(jié)構(gòu)和成分雙重演化特主量元素分析結(jié)果和主要--*63.89%--*64.05%--*64.49%,總表2天目山超單元巖石化學(xué)成分及有關(guān)參數(shù)Table2PetrochemicalcompositionsandrelevantparametersoftheTianmus
2、hansuperunitSi0.68.8964.0563.8956.54Ti0,0_31O.6l0.660.81A120315.49l6.4216.1817.52Fe2O30.881.391.421.42FeO1.8O2.792.995.97MnO0.070.090.1O0.17MgO0_381.291.563.2l氧化物含量(%)CaO0.982.722.995.99N04.193.843.713_36K,O5.975.004.932-31P2O50.070.210.210.34H,0O.610.94O.861.43Loss0.420.750.470.91∑100.081O0.O999.9
3、899.96NKA0.860.720.710.46ACNK1.O20.990.960.93K2O+N2o1O.178.858.645.670/Na2O1.431.311.35O.72有關(guān)參數(shù)4.O33.743.612.41AR4-282.752.651.64SI2.858.941O.6719.67DI88.8975.9773.8249.78注:樣品由安徽省地質(zhì)實(shí)驗(yàn)研究所測試體遞增但不明顯,(KO+Na0)5.表3天目山超單元微量元素含量及有關(guān)數(shù)值(×10。。)Table3Traceelementcontentsandrelevantvalues(X10)0fthe67%_8.64%---*8
4、.85%_10.17%.Tianmushansuperunit(K2o/o)0.72_1.35_1.311.43,總體遞增,其余氧化物幾乎都為Li21.O729.76362318.71Be3_392.421.9l1.14總體遞減趨勢。隨著硅、堿質(zhì)的Sc8.5710.64126313.19V97555.O844.75175.14增高,它們的分異指數(shù)(DI)CrlO_8l19.0716.4339.23Co1.686.466.222O.5549.78—73.8275.97—88.89和里特Ni3.667.616_3616.28Cu238148.0454.53128-36曼指數(shù))2.413.61—3
5、.744.03,Gal7.89l8.4616.O818.39Rb145.37l51.O7l29.1667.86總體逐漸增加,固結(jié)指數(shù)(sI)Sr80.09284.85374.33596.57Zr366.9337l_26460.25174.2719.6710.67_8.94—2.85,總體Nb216514.991O.981O.19Me2.931.160.971-34Sn2.402.711_321.27逐漸減小。含鋁指數(shù)(ANKC)為Cs4.264r3O6.684.27Ba478.47l51923199O.551087_360.93一O.96O.99_1.02,總體略有Hf6.647.187.O
6、73.60Ta1.09O.96O.550.6O增高,屬于正?!^鋁質(zhì)類型。W1.781.741.65O.85Pbl6.1724.8l14.O59.1l天目山超單元總體表現(xiàn)為中性Th11.081O.958.193.97U3.072.751.571.23巖類一酸性巖類演化,屬富堿、高66.5049_3261.4326.8ORb/Sr1.93O.610-350.12鉀的鈣堿性一堿性系列巖石。Ba/Sr6.295.O55I321.96Sr/Y1.23l0.1l6.O925-363巖石地球化學(xué)特征Yh1.231.030.770_37Zr1.O31.95242O.92微量元素分析則顯示(見表Hf1.93
7、1.24l_220.62Nb1.15O.6O0.44O.413),各單元以Ba、Sr含量最高,TaO.860.440.25O.27RbO.501.351.150.61Zr、Rb含量較高為特征,其中Ba最Cs1_301.161.811.16Sr1.150.821.071.71BaO.232.763.621.98高可達(dá)1990.55×10‘6o各單元的大Y0.872.242.791.22離子親石元素一般均富集,以