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赤道太平洋岩芯R C11—209的第四纪碳酸盐记录的离散几乎是同一地区DSDP158孔晚中新世岩芯记录离散的两倍。碳酸盐时序的频谱分析表明,中新世的碳酸盐记录主要由频率极低的组分组成,其离散密集在相当于周期大约400千年的频率上,第四纪记录也以低频组分为主,但其离散密集在周期相当于100千年和40千年的频率上。互频谱分析表明,两种记录都与计算出的地球轨道偏心率的变化相关,并且表明,第四纪记录与计算出的地轴斜度记录相关。因而地球轨道参数的这些离散可以用来“调准”这两项记录的时标。根据400千年周期附近的两种记录中的离散的相似性以及观测到的碳酸盐波动与全球冰川体积变化之间的联系(如氧同位素测定所指出的)认为,占优势的400千年周期自从中新世形成时起就与北极冰帽的长期变动直接或间接地联系在一起。第四纪碳酸盐频谱的主要差别在于与100千年周期有关的频率处的离散值明显增大,这一增大被认为与北半球冰帽的冰期和间冰期变动直接或间接有关。
Quaternary carbonate records of the equatorial Pacific core R C11-209 are almost twice as discrete as the Late Miocene core records of the DSDP 158 holes in the same area. Carbonate timing spectrum analysis shows that the carbonate records of the Miocene are mainly composed of very low frequency components, which are densely distributed at frequencies corresponding to a period of about 400 years. Quaternary records also use low frequency components Predominant, but discretely concentrated at frequencies equivalent to 100 and 40 years. Cross-spectrum analysis shows that both records are related to the calculated change in eccentricity of the Earth’s orbit and indicate that Quaternary records correlate with the calculated geosynchronous slope records. These discrete orbits of Earth orbit parameters can therefore be used to “align” the time scales of the two records. Based on the discrete similarities in the two records around the 400-year cycle and the link between the observed fluctuations in carbonate and global glacial volume (as indicated by the oxygen isotope measurements), the dominant 400-thousand-year period, since The formation of the Miocene has been directly or indirectly linked with the long-term changes in the Arctic ice cap. The main difference in the Quaternary carbonate spectrum is the noticeable increase in the discrete values at the frequency associated with the 100-year cycle, which is thought to be directly or indirectly related to the glacial and interglacial changes in the ice caps in the northern hemisphere.