Rothman Daniel H
Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Proc Natl Acad Sci U S A. 2002 Apr 2;99(7):4167-71. doi: 10.1073/pnas.022055499. Epub 2002 Mar 19.
The last 500 million years of the strontium-isotope record are shown to correlate significantly with the concurrent record of isotopic fractionation between inorganic and organic carbon after the effects of recycled sediment are removed from the strontium signal. The correlation is shown to result from the common dependence of both signals on weathering and magmatic processes. Because the long-term evolution of carbon dioxide levels depends similarly on weathering and magmatism, the relative fluctuations of CO2 levels are inferred from the shared fluctuations of the isotopic records. The resulting CO2 signal exhibits no systematic correspondence with the geologic record of climatic variations at tectonic time scales.
在去除锶信号中再循环沉积物的影响之后，锶同位素记录的最后5亿年显示出与无机碳和有机碳之间同位素分馏的同期记录显著相关。这种相关性表明是由于两个信号对风化作用和岩浆作用的共同依赖性所致。由于二氧化碳水平的长期演变同样依赖于风化作用和岩浆活动，因此从同位素记录的共同波动中推断出二氧化碳水平的相对波动情况。由此产生的二氧化碳信号在构造时间尺度上与气候变化的地质记录并无系统的对应关系。
