- 责任者：Du Yunkong (Key Laboratory of Marginal Sea Geology ; South China Sea Institute of Oceanology ; Chinese Academy of Sciences ; Guangzhou 510301 ; China) ; Liu Hailing
- 刊名：Marine Geology & Quaternary Geology
- 出版年：2013
- 卷期：33(6)
- 关键词：古地磁 ; paleomagnetism ; 构造演化 ; structural evolution ; 海南 ; Hainan Province
- 页码：p.93-103
- 图表：7 illus., 4 tables, 36 refs.
- 分类号：0400
- issnNo：ISSN0256-1492
- isbnNo：CN37-1117/P
In order to study the movement of the Qiongzhong and Sanya blocks of Hainan Island since Late Paleozoic, 143 drilling core samples were collected from 18 sites. Samples were tested with Schonstedt TSD-1 demagnetizer, Model-600 alternating demagnetizer and 2G-755R rock superconducting magnetome- ter in the paleomagnetic laboratory of South China Sea Institute of Oceanology, Chinese Academy of Sci- ences. For most of the samples, characteristic remanence component could be separated. Data Indicate that the Early-Middle Carboniferous geomagnetic field was in a direction of D=34.0 , I=46.9°,k= 55.9,ags = 5.2°, while the Middle Triassic direction was D=359.8°,I=31.1°,k=154.2,a95 =3.3°, and the Early Cretaceous direction D= 3.0°, I=43.7° ,k=34.7 ,a95 =4.4°, which are different from the modern geomag- netic field direction（D=358.6°,I=26.1°）. The paleo-latitude of Hainan Island was 28. I°N for Early-Mid- dle Carboniferous, 16.8°N for Middle Triassic and 25.5°N for Early Cretaceous. Referring to precious pal- eomagnetic data, the paleo-latitude of the Qiongzhong block was at 28. 1°N in Early-Middle Carboniferous, 16.5°N in the Early Triassic, and 28.6°N in the Early Cretaceous; but the paleo-latitude of the Sanya block was at 16.8°N in Middle Triassic, and 26.4°N in Early Cretaceous. Comparing with the Cretaceous mag- netic reference pole of the South China Block, the magnetic paleopole of Hainan Island calculated from our data shows no significant tilting movement since the Mesozoic granites of Hainan Island formed. According to the movement process of the blocks reflected by the paleomagnetism and the regional geological setting, it can be deduced that collision and suture between the Sanya and Qiongzhong blocks began in Mid-Trias- sic, which resulted in the formation of the ＂Qiongnan suture zone＂.