湖北清江榨洞石笋双波长反射光谱特征及其古气候意义

本文提出一种表征洞穴石笋纹层颜色的新方法———双波长分光光度法,用于研究湖北清江榨洞2号石笋的反射光谱特征并探讨其古气候的替代意义。双波长分光光度法能消除因样品表面性质等差异而引起的测量误差,提高分析测试的精密度和准确性,有利于真实反映石笋沉积纹层的颜色特征并揭示其内在机制。研究结果表明,石笋纹层450nm/700nm的反射光谱特征能较好地反映洞穴碳酸盐中痕量铁。由于铁是气候控制下地球表层各种作用的产物,可灵敏指示气候条件,因而石笋纹层的反射光谱是一个潜在的高分辨率古气候替代指标

STALAGMITES FROM ZHA CAVE,QINGJIANG,HUBEI PROVINCE: DOUBLE WAVELENGTH REFLECTANCE SPECTRUMS AND THEIR PALEOCLIMATIC SIGNIFICANCE

Double wavelength spectrophotometry as a new method is proposed to determine lamination colour in stalagmites from Zha Cave, Qingjiang, Hubei province, China. The method can eliminated the measurement error due to the surface difference of samples, and help studying relationships between the color and composition of samples and hence between speleothem color and climate. Our results show that the reflectances of 450nm/700nm for stalagmite laminations can better reflect the change of trace iron. As iron is a product of climate-controlled geochemical processes, it is considerably sensitive to weather conditions. Therefore, the double wavelength reflectance spectrums of stalagmite laminations are a potential proxy for high-resolution paleoclimate reconstruction index.