地球历史的“开”、“合”节律与古地磁变化

地球历史的节律突出表现为“开”与“合”有规律的组合。“开”、“合”节律应根据地质、地球化学、地球物理、生物等各种信息综合分析而建立，一般可分为全球性、区域性、地区性、露头和微观五个级别的“开”、“合”旋回或韵律。文中综合各方面资料编制了全球“开”、“合”旋回演化简图。古地磁场强度、古地磁场极性倒转比例、古地磁场极性倒转频率和真极移速率在地史上均呈周期变化，与开合构造关系密切，同受全球性因素制约。因此，用“开”、“合”观点研究古地磁可以揭示古地磁的本质特征。通过古地磁的研究有助于确定“开”、“合”环境，恢复“开”、“合”历史，探索“开”、“合”机制。

CORRELATIVE RHYTHMS OF “OPENING” AND “CLOSING” AND PALAEOMAGNETIC VARIATIONS IN THE EVOLUTION OF THE EARTH

The rhythm of the Earth′s history is prominently shown by the regular combination of “opening” and “closing”. The rhythm of “opening” and “closing” is established basically on the comprehensive analyses of the various information such as geology, geochemistry, geophysics, biology etc. In this paper, the authors synthesize all kinds of materials and draw up the schematic evolution diagram to illustrate the cycles of “opening” and “closing” on a global scale. The intensity of palaeomagnetic field, the proportion and frequency of palaeomagnetic polarity reversal, and the rate of true polar wandering may display the periodic changes in the geological history and are closely related to the “opening” and “closing”, and may be restricted to the global factors. Therefore, applying the viewpoint of “opening” and “closing” to the palaeomagnetic study, we can reveal the essence of palaeomagnetic phenomena. So the palaeomagnetic study will contribute to determine the environments of “opening” and “closing” and to recover the history of them as well as to probe into the mechanism of them.