CAJ | 학술논문

在龙木错-双湖-澜沧江板块缝合带中段的冈玛错-日湾茶卡地区，近东西向展布着一条富含暖水型生物化石的早石炭世地层日湾茶卡组（C1r）。对日湾茶卡组砂岩中的碎屑锆石进行LA-ICP-MS U-Pb定年，分析结果显示存在325~400Ma、400~500Ma、500~600Ma、950~1100Ma、1400~1800Ma和大于1800Ma六个年龄区间；最年轻的碎屑锆石年龄为325 Ma，时代为早石炭世维宪期；碎屑锆石中362 Ma和454Ma的年龄峰值最明显，为龙木错-双湖-澜沧江洋岛弧消减事件和加里东运动的年龄记录，表明碎屑岩的物源区主要来自于扬子大陆周缘。结合古生物化石资料可知，日湾茶卡组属于欧亚大陆扬子型石炭纪沉积地层，为岛弧环境下的一套浅水台型沉积。
재룡목착-쌍호-란창강판괴봉합대중단적강마착-일만다잡지구，근동서향전포착일조부함난수형생물화석적조석탄세지층일만다잡조（C1r）。대일만다잡조사암중적쇄설고석진행LA-ICP-MS U-Pb정년，분석결과현시존재325~400Ma、400~500Ma、500~600Ma、950~1100Ma、1400~1800Ma화대우1800Ma륙개년령구간；최년경적쇄설고석년령위325 Ma，시대위조석탄세유헌기；쇄설고석중362 Ma화454Ma적년령봉치최명현，위룡목착-쌍호-란창강양도호소감사건화가리동운동적년령기록，표명쇄설암적물원구주요래자우양자대륙주연。결합고생물화석자료가지，일만다잡조속우구아대륙양자형석탄기침적지층，위도호배경하적일투천수태형침적。
The Riwanchaka Formation (C1r), a set of carbonate and clastic early Carboniferous strata rich in warm-water fossils, is spread in the Gangmar Co-Riwanchaka area along the central Lungmu Co-Shuanghu-Lancang River suture zone nearly in east-west direction. An analysis of 120 age data of sandstone samples from the Riwanchaka Formation indicates that detrital zircon has six age ranges, which are 325~400Ma, 400~500Ma, 500~600Ma, 950~1100Ma, 1400~1800Ma and>1800Ma, and that the youngest detrital zircon age is 325Ma, which confirms its age of Early Carboniferous. Among these ages, peak ages of 362Ma and 454Ma are the most obvious. They reflect the tectonic magmatic events of the initial arc reduction stage in the Lungmu Co-Shuanghu-Lancang River Ocean and the Caledonian orogeny, implying that the provenance of the clastic rocks was probably the Yangtze Continent. In combination with the information of fossils, the authors hold that the Riwanchaka Formation (C 1r) should be Carboniferous sedimentary strata of Eurasia Yangtze type, belonging to the shallow water deposition in an island arc envir onment.