地球科学与环境学报
地毬科學與環境學報
지구과학여배경학보
JOURNAL OF EARTH SCIENCES AND ENVIRONMENT
2009年
4期
331-343
,共13页
绝对板块运动%热点%热点参考架%无净旋转参考架%岩石圈的净旋转
絕對闆塊運動%熱點%熱點參攷架%無淨鏇轉參攷架%巖石圈的淨鏇轉
절대판괴운동%열점%열점삼고가%무정선전삼고가%암석권적정선전
absolute plate motion%hotspots%hotspot reference frame%no-net-rotation reference frame%net rotation of the lithosphere
根据热点假设,热点对于中间层是固定的.相对热点的板块运动叫做绝对板块运动.绝对板块运动模型可以通过反演火山链传播的速率和走向数据以确定相对板块运动在角速度空间的原点来得到.利用一组近来(0～7.8 Ma)全球分布的热点的迁移速率和走向数据,结合板块运动模型NNR-NUVEL1A,已研制出一个叫做APM2的现今绝对板块运动模型.按照该模型,太平洋板块围绕60.063°S、102.210°E处的极以(0.833 0°±0.013 3°)/Ma的速率运动,非洲板块围绕46.849°N、44.372°W的极以(0.101 5°±0.013 4°)/Ma的速率运动,南极板块的运动则以46.871°N、146.942°E为极,速率为(0.084 6°±0.017 7°)/Ma,欧亚板块的运动更慢,极为27.291°N、171.925°W,速率为(0.065 5°±0.020 6°)/Ma.这一模型表明,岩石圈相对深部地幔有一个以49.423°S、90.625°E为极,速率为(0.198 3°±0.013 5°)/Ma的净旋转.表明太平洋热点同印度-大西洋热点不一致,显示太平洋热点的运动也不一致.为了分析和比较,还给出了仅用全球分布的热点的走向数据和仅用印度-大西洋热点的走向数据得到的板块绝对运动的角速度.
根據熱點假設,熱點對于中間層是固定的.相對熱點的闆塊運動叫做絕對闆塊運動.絕對闆塊運動模型可以通過反縯火山鏈傳播的速率和走嚮數據以確定相對闆塊運動在角速度空間的原點來得到.利用一組近來(0～7.8 Ma)全毬分佈的熱點的遷移速率和走嚮數據,結閤闆塊運動模型NNR-NUVEL1A,已研製齣一箇叫做APM2的現今絕對闆塊運動模型.按照該模型,太平洋闆塊圍繞60.063°S、102.210°E處的極以(0.833 0°±0.013 3°)/Ma的速率運動,非洲闆塊圍繞46.849°N、44.372°W的極以(0.101 5°±0.013 4°)/Ma的速率運動,南極闆塊的運動則以46.871°N、146.942°E為極,速率為(0.084 6°±0.017 7°)/Ma,歐亞闆塊的運動更慢,極為27.291°N、171.925°W,速率為(0.065 5°±0.020 6°)/Ma.這一模型錶明,巖石圈相對深部地幔有一箇以49.423°S、90.625°E為極,速率為(0.198 3°±0.013 5°)/Ma的淨鏇轉.錶明太平洋熱點同印度-大西洋熱點不一緻,顯示太平洋熱點的運動也不一緻.為瞭分析和比較,還給齣瞭僅用全毬分佈的熱點的走嚮數據和僅用印度-大西洋熱點的走嚮數據得到的闆塊絕對運動的角速度.
근거열점가설,열점대우중간층시고정적.상대열점적판괴운동규주절대판괴운동.절대판괴운동모형가이통과반연화산련전파적속솔화주향수거이학정상대판괴운동재각속도공간적원점래득도.이용일조근래(0～7.8 Ma)전구분포적열점적천이속솔화주향수거,결합판괴운동모형NNR-NUVEL1A,이연제출일개규주APM2적현금절대판괴운동모형.안조해모형,태평양판괴위요60.063°S、102.210°E처적겁이(0.833 0°±0.013 3°)/Ma적속솔운동,비주판괴위요46.849°N、44.372°W적겁이(0.101 5°±0.013 4°)/Ma적속솔운동,남겁판괴적운동칙이46.871°N、146.942°E위겁,속솔위(0.084 6°±0.017 7°)/Ma,구아판괴적운동경만,겁위27.291°N、171.925°W,속솔위(0.065 5°±0.020 6°)/Ma.저일모형표명,암석권상대심부지만유일개이49.423°S、90.625°E위겁,속솔위(0.198 3°±0.013 5°)/Ma적정선전.표명태평양열점동인도-대서양열점불일치,현시태평양열점적운동야불일치.위료분석화비교,환급출료부용전구분포적열점적주향수거화부용인도-대서양열점적주향수거득도적판괴절대운동적각속도.
The plate motions with respect to the hotspots, which are fixed relative to the mesosphere according to the hotspot hypothesis, are called absolute. The absolute plate motion model can be achieved by inverting the data set of the propagation rates and/or trends of volcanic chains to determine the origin in the angular space for the relative plate motion.A current absolute plate motion model designated as APM2 has been developed using a data set of migration rates and trends of recent (0～7.8 Ma) globally distributed hotspots tracks in conjunction with the plate motion model NNR-NUVEL1A. According to this model, the Pacific plate is moving at a rate of (0.833 0°±0.013 3°)/Ma about a pole at 60.063°S, 102.210°E;Africa has a motion of (0.101 5°±0.013 4°)/Ma about 46.849°N, 44.372°W;Antarctic has a motion of (0.084 6°±0.017 7°)/Ma about 46.871°N, 146.942°E;Eurasia has an even slower motion of (0.0655°±0.0206°)/Ma about 27.291°N, 171.925°W. The model shows that the lithosphere has a net rotation of (0.198 3°±0.013 5°)/Ma about 49.423°S,90.625°E with respect to the deep mantle. It is demonstrated that the Pacific hotspots are inconsistent with the Indo-Atlantic hotspots.Also, it is shown that the Pacific hotspots involved appear do not have a coherent motion. For analysis and comparison, this paper also gives the angular velocities of absolute plate motions obtained from only trend data for global distributed hotspots and from only trend data for only Indo-Atlantic hotspots.
