1 : 27 1 F ig11d istribution of Oph io lite Belts in Beishan area g 1 22 : 1, 1, 1 ; g 1 2 : 1, 1 ; g 1 22 : 1, 1, 1, 1, βκ1, βλ1 ; g 1 2 : βµ1 2, 131

: 100926248 (2010) 0120026211 1, 2, 1, 1, 1, 1, 1, 1 (11, 710054; 21, 710054) : 4, : 22,, 2,, 22 2, 222, : ; ; ; ; : P588 : A, 2,, 22 22 22,, (, 1990, 1996;, 2000;, 2001;, 2002 ;, 2003 ; 2002, 2005;, 2008), 1 111, 4 (1) : (g ) 22 ; (g ) 2; (g ) 22; (g ) 2 112 (2009), (1) 222 ; 22 ; 22 22; 2 22 : 2009206223; : 2009210213 : (1212010531602, 1212010630904) (1212010813036) : (19532),,, E2m ail: xayhequn@ 1261com

1 : 27 1 F ig11d istribution of Oph io lite Belts in Beishan area g 1 22 : 1, 1, 1 ; g 1 2 : 1, 1 ; g 1 22 : 1, 1, 1, 1, βκ1, βλ1 ; g 1 2 : βµ1 2, 131 1 T ab11d ivision of tectonic units of Beishan area (after Yang H equn, et al. 2009) g 21 22 g 22 22 g 2 g 23 2 2 g 24 22 22 g 21 22 g g 22 22 g 23 :, 2009 2 211 22 22,, 6, (2005), :,,,,,,,,,, :,,,,,,, 2, :,,

28 N OR T H W ES T ERN GEOL OGY 2010,,,,,,, (2001) R b2sr, 46318M a; R b2sr 48618M a, :, ;, ;, ;,, :,,,,,,,, :,,, 2 2,,,,, 2122, (2005) :,,,,, 2,, :,, ;,, 2 213 22,,,,,,,,,,,,,,,,,, 214 2, 300 km 2, 20,, 7, :,,

1 : 29,, :,,,, :, 215,,,,,,,, (2), 2, 2 2 T ab12t he contrast of sequence in rock associations of oph io lite 2 2 1 2A ; 2B ; 2 ; () 3A ; 3B 4 2 2, 3 311 2 (1),, M go 30172% 48181%, m gf> 6, m gf 61415154; m gf 8177 11182; m gf 61469144; m gf 71599102, m gf 61927135; m gf 1219426119, m gf 912310128; m g f 915210100; m gf 12113; m gf 11115; m g f 61869175; () m g f 8187; m gf 7109; m gf 7123 (2) 2 ; m gf< 6 312 2 22 222 (3), (2, 3, 4, 5, 6),,, 2, 22 2 2 2,,,, 2

30 N OR T H W ES T ERN GEOL OGY 2010 2 2 F ig12chodrie2no rm alized R EE diagram s fo r oph io lites from Hongliuhe2N iu juanzi belt 1016201 ; 15181 ; 111314171 ; 12212223241 2 3 2 F ig13chodrie2no rm alized R EE diagram s fo r oph io lites from Bai yunshan2x ichangjing belt 11 ; 31 ; 25671, 2,,, 2, 222 2, 2 2, 4, (Cypuru s ) 411 22, ; 2 42 F ig14chodrie2no rm alized R EE diagram s fo r oph io lites from J ijitaizi yunshan2x iao2 huangshan belt 2526301 ; 2728291

1 : 31 5 2 F ig15chodrie2no rm alized R EE diagram s fo r oph io lites from Hong sh ishan2q ing hekou belt 31323539401 ; 411 ; 2 2 ; 2 (),, 2 222, 412 22, 1g20, 8 km, ( ),, 12,, 5 6 2 F ig16chodrie2no rm alized R EE diagram s fo r oph io lites from H ui tongshan2zhang fangshan belt 441 ; 451 ; 46471, 3,, ( ) 511, 22 2 222, : (1990) ; (2002) 2222 ; (2002 )

32 N OR T H W ES T ERN GEOL OGY 2010 22 2?,, : R b2sr 46318M a,, 3 R EE T ab13r EE compo sitions and m ain param eter of oph io lite belts in beishan area L a Ce P r N d Sm Eu Gd T b D y Ho E r Tm Yb L u Y (L agyb) N Eu 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 g g g 4155 5150 1140 5106 1140 0177 1195 0130 2160 0143 1140 0116 1130 0120 2136 1142 2175 6120 0193 5100 1195 0193 2130 0150 3112 0169 1190 0123 1152 0121 1122 1134 0131 1113 1107 0141 0117 0109 0137 0101 0157 1108 80160 17150 89190 1313 4114 1119 1193 0126 28119 1107 3142 8132 6191 2144 1100 0164 2163 0141 0188 1105 4198 11160 10100 4136 1163 1104 4173 0167 0171 1101 2197 7197 6164 1192 0170 0152 2125 0134 0189 0196 9192 25100 4100 15170 3197 0193 3100 0148 2186 0163 1162 0127 1175 0129 1413 3183 0179 0169 3115 1147 3175 1198 0123 0156 0111 0183 0121 0162 0113 0126 0108 2132 1179 0151 0194 2114 1175 0168 0130 0119 0177 0111 0182 1110 4133 9183 8155 3160 1135 0194 3196 0158 0174 0199 37190 80130 35120 8112 1176 1122 4117 0161 6113 0173 7191 18180 12140 3135 1114 0179 2149 0135 2114 0194 5137 12140 8175 2169 0197 0163 2156 0139 1142 0199 21140 45140 24190 5178 1156 1102 3158 0150 4103 0184 0140 0189 0187 0135 0115 0110 0157 0109 0147 1107 13110 28170 20190 5193 2105 1120 3183 0157 2131 0199 8197 15170 8152 2127 0170 0143 1135 0120 4148 0191 9117 19180 13130 4123 1110 0189 0138 0156 16129 0178 0158 1122 0172 0122 0116 0105 0125 0104 1157 1169 32110 71120 32100 6118 0196 0199 4139 0164 4194 0155 34190 76140 32110 6167 1129 1110 4155 0171 5118 0165 22170 46110 26150 5150 1177 0190 2159 0131 5192 0198 20150 42190 24130 5163 1184 0193 2175 0141 5103 0199 0131 0185 0145 0112 0105 0104 0124 0103 0187 0197 0116 0186 0182 0127 0109 0105 0122 0104 0149 1101 6103 11140 7186 2137 0197 0158 2156 0138 1159 1107 12180 27110 18140 4124 1132 0187 3141 0152 2153 0191 51150 10610 46140 7185 2110 0171 1161 0126 21159 0194 0130 1115 0199 0133 0107 0108 0128 0104 0172 0163

1 : 33 3 L a Ce P r N d Sm Eu Gd T b D y Ho E r Tm Yb L u Y (L agyb) N Eu 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 g g 2133 5170 3100 0190 0130 0111 0140 0105 3193 1107 2112 5130 3100 0160 0112 0111 0140 0104 3158 0165 0180 1190 1140 0140 0116 0111 0125 0104 2116 1102 0119 0140 0120 0106 0108 0105 0110 0102 1128 1160 0132 0159 0140 0115 0108 0104 0111 0101 1196 1127 0145 1110 0150 1100 0109 0104 0118 0102 1169 0140 2138 3190 2100 0160 0130 0115 0150 0104 3121 1124 0175 1160 0180 0125 0110 0105 0117 0104 2198 1111 0113 0174 0194 0153 0118 0113 0170 0111 0113 0192 0135 1112 0193 0132 0112 0106 0116 0102 1110 0164 1110 1118 0154 0125 0120 1104 0117 0142 1103 14110 31170 18180 4152 1150 0176 2154 0142 3175 1100 17140 38160 21150 5129 1180 1102 2185 0144 4112 0199 9150 20150 3116 11140 3113 0157 1188 0132 1196 0144 1120 0120 1118 0124 8152 5143 0167 47120 86130 11100 40120 7167 1181 7131 1115 6145 1140 3183 3148 0150 3515 9115 0173 6165 16110 13160 4130 1153 1110 3152 0155 1128 0195 8110 22160 17190 5185 2116 1134 5189 0187 0193 1101 : : 128931384445 (1995) ; 37103039434647 (1999) (, 2001) (, 1996;, 2005), R b2sr 42011M a 2,,,,,,,,,,, (2008) (2008) 22 512 22 2,,, 513 ( 1) 22 22 22,, (JxK ) (ChX ), (A r2p t1b c ),, (C 1x ) (C 1ym ) (C 1g d )(C 1l) (C 1bs) (, 2008)(1990, 1996),, X ia L in2qi (2005 ) 1, 19951

34 N OR T H W ES T ERN GEOL OGY 2010,, 6 Sm 2N d, 32210413M a (, 2005), 2 2,, U 2Pb 2743M a (, 2006) ;, 2 2, R b2sr 27016730170M a (, 2002), U 2Pb 2848M a (, 2005) 22,,, (2) 2 2 22, (Q bd )(Jxp )(ChG) (A r2p t1bc),, 6 4,, 22,, 2,, 2 2 2, 22 2, :,! (R eferences) : ; ;, 1 2 [J ] 1, 2005, 24 (2): 502561 N ie Fengjun, J iang Sihong, L iu Yan, et al1 Sm 2N d iso top ic dating of apatite separates from H eiyingshan h igh2grade iron depo sit, Inner M ongo lia [J ] 1 M ineral D epo sits, 2005, 24 ( 2 ): 502561 ( in Ch inese w ith English (P 3f ), (P 2j t), (P 1-2 s), (C 2sb), (C 2g ), (C 2sb), (C 2jj ), (C 1h l) ;, R b2sr 333197188M a, R b2sr 275168 8140M a (, 1996) (),, abstract) 1,,, 1 [M ] 1 :, 20021 N ie Fengjun, J iang Sihong, Bai D am ing, et al1 M etallogenic Studies and O re P ro specting in the Con junction A rea of Inner M ongo lia A u tonom ou s R egion, Gansu P rovince and X injiang U ygur A utonomous R egion (Beishan M t1), N o rthw est Ch ina [M ] 1Geo logical Publish ing House, Beijing, 2002 ( in Ch inese w ith English abstract) 1 1, 19951

1 : 35,,, 1 [J ] 1, 2003, 36 (1): 112171 Gong Q uansheng, L IU M ingqiang, L iang M inghong, et al1 T he tecton ic facies and tecton ic evo lu tion of Beishan o rogenic belt, Gansu [ J ] 1 N o rthw estern Geo logy, 2003, 36 ( 1 ): 11217 ( in Ch inese w ith English ab stract) 1,,, 1 [J ] 1, 2002, 35 (4): 302401 H e Sh ip ing, R en B ingshen, Yao W enguang, et al1 T he division of tectonic units of Beishan area, Gansu2Inner M ongo lia [J ] 1 N o rthw estern Geo logy, 2002, 35 (4): 302401 (in Ch inese w ith English abstract) 1,,, 1 [J ] 1, 2005, 38 (3): 62151 H e Sh ip ing, Zhou H uiw u, R en B ingchen, et al1 C rustal evo lution of Palaeozo ic in Beishan area, Gansu and Inner M ongo lia, Ch ina [J ] 1 N o rthw estern Geo logy, 2005, 38 ( 3 ): 62151 ( in Ch inese w ith English ab stract) 1,,, 1 [J ] 1, 2004, 20 (2): 35723591 L i Songlin, L i W enqian, Feng X inchang, et al1 A ge of Fo rm ation of W eiya Com p O site Stock s in Eastern T ianshan M ountains [J ] 1 X injiang Geo logy, 2004, 20 (2): 35723591 (in Ch inese w ith English abstract) 1,,, 1 U 2Pb [J ] 1, 2004, 23 (12): 1215212201 L i X iangm in, X ia L inqi, X ia Zuchun, et al1 Zircon U 2Pb geoch rono logy of vo lcanic rock s of the Q i eshan Group in the East T ianshan M ountains [J ] 1 R egional Geo logy of Ch ina, 2004, 23 (12): 1215212201 (in Ch inese w ith English abstract) 1,,, 1 - [J ] 1, 2001, 34 (2): 212271 R en B ingchen H e Sh ip ing, Yao W enguang, et al1r b2sr iso tope age of N iuquanzi oph io lite and its tectonic significance in Beishan district, Gansu [ J ] 1 N o rthw estern Geo logy, 2001, 34 (2): 21227 (in Ch inese w ith English abstract) 1,,, 1 [J ] 1, 2005, 79 (4): 49825021 W u H ua, L i H uaqin, M o X inhua, et al1 A ge of the Baish iqun M afic2u ltram afic Comp lex, H am i, X injiang and Its Geo logical Significance [ J ] 1 A cta Geo logica Sinica, 2005, 79 (4): 49825021 (in Ch inese w ith English abstract) 1,,, 1 [M ] 1 :, 20081 Xu Xueyi, H e Sh ip ing, W ang Hongliang, et al1 Geo logical generality of in N o rth2w est Ch ina [M ] 1 Beijing: Science P ress, 2008 (in Ch inese) 1,,, 1 [J ],, 2008, 41 (1): 222281 Yang H equn, L i Y ing, L i W enm ing, et al1 General D iscussion on M etallogenitic T ectonic Setting of Beis2 han mountain, no rthw estern Ch ina [J ] 1N o rthw estern Geo logy, 2008, 41 (1): 22228 (in Ch inese w ith English abstract) 1,,, 1 - - [J ] 1, 2009, 42 (4) 1 Yang H equn, L i Y ing, Zhao Guobin, et al1stratigraph ic Co rrelation and its Significance of X injiang2gansu2 Inner mongo lia jo in area [J ] 1 N o rthw estern Geo logy, 2009, 42 (4) (in Ch inese w ith English abstract) 1,,, 1 [M ] 1 :, 19901 Zuo Guochao, H e Guoqi, L i Hongcheng, et al1p lante T ectonics and M etalloogenic R egulaties in Beishan R egion [M ] 1Pek ing U niversity Publication, Beijing, 19901, 1 [M ] 1 :, 19961 Zuo Guochao, L im ao song1fo rm ation and Evo lution of the

36 N OR T H W ES T ERN GEOL OGY 2010 Early Paleozo ic L itho sphere in the Beishan A rea, Gansu2Inner M onggu, Ch ina [M ] 1Gansu Science and T echno logy Publication, L angzhou, 19961 iso top ic constraints[j ]1 Geoch im ica, 2000, 29 (2): 1082 119 (in Ch inese w ith English abstract) 1 X ia L inqi, X ia Zuchun, Xu Xueyi, et al1 R elationsh ip s,, 1 betw een Basic and Silicic M agm atism in Continental : Sm 2N d [J ] 1, 2000, 29 (2): 10821191 Zhou Guoqing, Zhao J ianxin, L i X ianhua1 Characteristics of the Yueyashan oph io lite from w estern Inner M ongo lia R ift Settings: A Petrogeochem ical Study of Carboniferous Po st2co llisional R ift Silicic V o lcanics in T ianshan, NW Ch ina [J ] 1 A cta Geo logica Sinica, 2005, V o l179, N o15, 63326531 and its tectonic setting: Geochem istry and Sm 2N d Character and Structural A ttr ibute of the Be ishan Oph iolite YAN G H e2qun 1, L I Y ing 2, ZHAO Guo2b in 1, L IW en2yuan 1, W AN G X iao2hong 1, J IAN G H an2b ing 1, TAN W en2juan 1, SU N N an2yi 1 (1. X i an Institu te of Geology and M inera l R esou rces, X i an 710054, Ch ina; 21 Chang an U n iversity, X i an 710054, Ch ina) Abstract: T h is paper summ arizes the assem b lege of rock types and geochem ical characteristics of fou r oph io lite belts in Beishan region, and analyzes the the regional geo logical background condition s. T he resu lt show s that the Hongliuhe2N iu juanzi2x ichangjing oph io lite belt w as fo rm ed in Early Palaeozo ic and is part of the ocean ic basin type and qu ite sim ilar to the p resen t ocean ic oph io lite in characteristic. T h is op h io lite belt ind ica tes the su tu reline of the no rth2sou th p la tes becau se the Gongpoquan2dongqiyishan vo lcan ic rock s in the no rth belongs to the in land vo lcan ic rock series w ith active con tinen tal m argin environm en t and the shallow sub2sea P2V 2M n2u 2bearing sedim en tary strata of the Cam b rian in the sou th rep resen t ing the ex tended tecton ic befo re the p la te becom ing d ivergen t. T he J ijita izi2x iaohuang shan oph io litic belt, fo rm ed in the Early Paleozo ic back2arc basin environm en t, is distribu ted betw een X ingx ingx ia2h an shan p la te and Gongpoquan2Dongqiyishan a rc belt. T he Hong sh ishan2b a iheshan2 B engp eshan op h io lit ic belt and H u itong shan2zhangfang shan op h io lit ic belt a re sim ila r to R ed Sea in environm en t, w h ich w as fo rm ed from the stage w ith the m ax im um ex ten sional rift to the in itial stage of fo rm ing the sm all ocean basin in late Paleozo ic. Key words: op h io lite; ocean ic ba sin; back2a rc ba sin; rift; beishan