地质通报
地質通報
지질통보
GEOLOGICAL BULLETIN OF CHINA
2014年
11期
1793-1803
,共11页
徐建鑫%李才%范建军%巴桑玉珍%徐梦婧
徐建鑫%李纔%範建軍%巴桑玉珍%徐夢婧
서건흠%리재%범건군%파상옥진%서몽청
班公湖-怒江缝合带%那东洋岛%侏罗纪%岩石学%地球化学
班公湖-怒江縫閤帶%那東洋島%侏囉紀%巖石學%地毬化學
반공호-노강봉합대%나동양도%주라기%암석학%지구화학
Banggong Co-Nujiang River suture zone%Nadong oceanic island%Jurassic%petrology%geochemistry
那东洋岛位于班公湖-怒江板块缝合带的中西段,前人已对其进行了初步报道,但未进行详细的研究。对那东洋岛的岩石组合进行岩石学、地球化学的研究,显示那东洋岛具典型的洋岛型岩石组合,其玄武岩和辉长岩的稀土元素配分曲线和微量元素蛛网图与典型OIB相似。通过对洋岛灰岩中珊瑚化石的鉴定,结合洋岛岩石组合与木嘎岗日岩组的野外接触关系,初步认为那东洋岛的时代为中侏罗世,这一时期班公湖-怒江带特提斯洋正处于大洋演化阶段。那东洋岛的发现对揭示班公湖-怒江洋在侏罗纪的演化历史具有重要意义。
那東洋島位于班公湖-怒江闆塊縫閤帶的中西段,前人已對其進行瞭初步報道,但未進行詳細的研究。對那東洋島的巖石組閤進行巖石學、地毬化學的研究,顯示那東洋島具典型的洋島型巖石組閤,其玄武巖和輝長巖的稀土元素配分麯線和微量元素蛛網圖與典型OIB相似。通過對洋島灰巖中珊瑚化石的鑒定,結閤洋島巖石組閤與木嘎崗日巖組的野外接觸關繫,初步認為那東洋島的時代為中侏囉世,這一時期班公湖-怒江帶特提斯洋正處于大洋縯化階段。那東洋島的髮現對揭示班公湖-怒江洋在侏囉紀的縯化歷史具有重要意義。
나동양도위우반공호-노강판괴봉합대적중서단,전인이대기진행료초보보도,단미진행상세적연구。대나동양도적암석조합진행암석학、지구화학적연구,현시나동양도구전형적양도형암석조합,기현무암화휘장암적희토원소배분곡선화미량원소주망도여전형OIB상사。통과대양도회암중산호화석적감정,결합양도암석조합여목알강일암조적야외접촉관계,초보인위나동양도적시대위중주라세,저일시기반공호-노강대특제사양정처우대양연화계단。나동양도적발현대게시반공호-노강양재주라기적연화역사구유중요의의。
Nadong oceanic island in the middle and western part of the Bangong Co-Nujiang River suture zone has already been preliminarily reported by previous researchers. The authors conducted detailed research on the petrology and geochemistry of Nadong oceanic island, and the results indicate that Nadong oceanic island is a typical oceanic island-type rock association. The basalt and gabbro in the REE patterns and spider diagrams are similar to features of typical OIB. Based on the identification of coral fossils in oceanic limestone and the observation of the contact relationship between the island rock association and the Mugakangri rock group, the authors believe that Nadong oceanic island was formed in the Middle Jurassic. During this period, a Jurassic ocean basin existed in the Bangong Co-Nujiang River suture zone. The discovery of the Nadong oceanic island plays a key role in revealing the evolutionary history of the Bangong Co-Nujiang River Ocean during the Jurassic.