对汉中盆地城固县军王村(JWC)剖面的色度参数进行分析,并结合磁化率、烧失量、氧化铁进行主控因素的研究.结果表明:亮度(${L^*}$)含量的变化与有机质含量密切相关,红度(${a^*}$)的变化与氧化铁含量密不可分;色度参数曲线与磁化率曲线具有同步的变化趋势,其中${L^*}$、${a^*}$、${a^*}$/${b^*}$对气候响应敏感,能作为较好的气候替代指标,记录了该区的气候和成壤环境变化;各色度参数的变化趋势反映了晚更新世末期气候冷干全新世初期气候开始转向暖湿全新世中期气候湿热全新世晚期气候暖湿降低,但晚更新世末期的气候并不是持续稳定的,在38.8~25.6 ka BP期间出现了短暂的相对温暖湿润的阶段.
英文摘要:
The chroma and its major controlling factors of the Junwangcun loess-paleosol profile in the Hanzhong basin have been studied. The results show that the lightness is strongly linked to the organic matter. By contrast, the redness is strongly linked to the types and concentrations of iron oxides. The curves of chroma present a similar pattern to the curves of magnetic susceptibility. ${L^*}$ , ${a^*}$ , ${a^*}$/${b^*}$ are sensitive to climate response,which can be used as a good alternative climate index to record the changes in climate and pedogenic environment. The change of chroma indicates a cold and dry climate during the late Pleistocene (55.5 ~ 11.5 ka BP) , a climate shift from cold-dry to warm-humid during the early Holocene (between 11.5 ~ 8.5 ka BP),a warm and humid climate during the mid-Holocene (between 8.5-3.0 ka BP) , and a cooler and drier climate during the late Holocene (since 3.0 ka BP). The climate is not persistently steady during the late Pleistocene, with a short-term warm and wet climate in the glacial period (38.8 ~25.6 ka BP).