%0 Journal Article
%T Nd isotope as the tracer of seawater evolution of early Miocene in the eastern Pacific Ocean
%A Jihua Liu
%A Lirong Chen
%A Yingxi Wang
%A Jianxiu Han
%J Chinese Science Bulletin
%@ 1861-9541
%D 2003
%I 
%R 10.1007/BF02900948
%X Fiftysix samples of nannofossil ooze were collected from Core PC5794 in the northern equatorial Pacific at 5 cm intervals. With the methods of mass spectrometer (VG354) and ICP, the Nd isotopic compositions (ŠĆNd(t)), Mn contents and Mg/Sr ratios of carbonate phase have been analyzed. CaCO3 contents of bulk sediments were obtained by dissolution of 0.5 mol/L HCl. Based on these data, the high-resolution ŠĆNd(t) profile of seawater in early Miocene with core depth(or time) have been established. The values of ŠĆNd(t) range from -6.2 to -2.97 and 4 fluctuation cycles existed during 24.06-22.02 Ma. 4 low ŠĆNd(t) values (about-6.4) correspond to high CaCO3 contents, which implicates that there were 4 cold epochs or 4 times of Antarctic Bottom Water activity. They occurred at the time of 24.06 Ma, 23.85 Ma, 22.88 Ma and 22.26 Ma, respectively. High ŠĆNd(t) values correspond to the high Mn contents and high values of Mg/Sr ratio, which indicates the existence of 4 intense hydrothermal activity periods during 24.06-22 Ma, the durations of them are 4.05-23.98 Ma, 23.69-23.15 Ma, 22.74-22.37 Ma and 22.06-22.02 Ma, respectively.
%K Nd isotope
%K seawater evolution
%K eastern Pacific Ocean
%U http://link.springer.com/article/10.1007/BF02900948