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自从1968年以来,晚白垩纪——新生代地磁反转年代表的绝对年令已被测定出来,测定方法是假定每一时距内的扩张速度是恒定的,后在一个海洋磁异常综合剖面中的固定两个或更多的标准点的年令,而在这些点之外用内插法或用外插法求得绝对年令。以前,所用标准点不超过四个,而现在测定一百万年以内的数据,使用11个标准点。这种改进是根据意大利深海石灰岩的磁性地层学的研究做出的;这些研究把地磁倒转次序与有孔虫、颗石藻分带紧密地联系在一起。标准点的绝对年令是用一些阶的界面上的最精确的年令确定的。而界面又是根据生物地层分带确定的。与以前的表相比,最大的变化是晚古新世——早始新世,新的年令较LaBrecgue等人1977年表的年令新300万年,比Ness等人1980年表的年令新180万年。
The absolute year of the Late Cretaceous-Cenozoic geomagnetic inversion has been measured since 1968 by assuming that the rate of expansion at each time-distance is constant, and in an integrated marine magnetic anomaly profile The year or two of the standard two or more points are fixed, and the absolute year is determined by interpolation or extrapolation at these points. In the past, no more than four standard points were used, and the data for one million years is now measured using 11 standard points. This improvement is based on the study of magnetic stratigraphy in deep-sea limestone in Italy; these studies closely linked the order of geomagnetic inversion with the foraminifera and coccolithophytic zonation. The absolute number of years of standard points is determined by the most accurate year of the order. The interface is determined by the biological strata. Compared with the previous table, the biggest change is the Late Paleocene-Early Eocene. The New Year’s order is three million years more than the annual order of LaBrecgue et al.’s 1977 table, compared with the Ness et al. 1980 table year Make the new 180 million years.