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岩石磁学是古地磁学和环境磁学研究的基础,是鉴定岩石和沉积物中磁性矿物种类、粒度和含量的有效途径。对黄土高原东南部三门峡盆地的水沟—会兴沟旧石器遗址会兴沟剖面黄土—古土壤序列(S_0~S_8)进行系统的岩石磁学研究表明:本剖面沉积物的主要载磁矿物为磁铁矿、磁赤铁矿和赤铁矿,显示准单畴(PSD)磁性颗粒特征。所有磁学参数曲线均表现出基本一致的变化特征,与深海氧同位素曲线能够很好的对应,反映了第四纪以来的冰期—间冰期旋回中,东亚季风影响下的风尘黄土堆积中磁性矿物种类、粒度和含量的周期性变化特征。黄土中高矫顽力磁性矿物的相对含量要高于古土壤中的,而随着成土作用的加强,在古土壤中细粒的低矫顽力磁性矿物显著增加的同时,其中高矫顽力磁性矿物的绝对含量也相应增加。质量磁化率(χ)与非磁滞剩磁磁化率(χ_(ARM))和饱和等温剩磁(SIRM)及磁粒度参数χ_(ARM)/SIRM和χ_(ARM)/χ均呈明显的正相关关系,表明由成土作用产生的单畴(SD)颗粒和较小PSD颗粒对磁化率增强有显著的贡献。
Rock magnetism is the basis of palaeomagnetic and environmental magnetism studies and an effective way to identify the types, sizes and contents of magnetic minerals in rocks and sediments. Systematic rock magnetism studies on the Loess-Huixinggou Paleolithic loess-paleosol sequence (S_0 ~ S_8) in the Sanmenxia Basin in the southeastern part of the Loess Plateau show that the main magnetite-bearing minerals in this section are Magnetite, maghemite and hematite, showing quasi-single domain (PSD) magnetic particle features. All the curves of magnetic parameters show a consistent change, which is in good agreement with that of the deep-sea oxygen isotope curve. It reflects that in the glacial-interglacial cycles since the Quaternary, magnetic minerals Type, size and content of the cyclical changes in characteristics. The relative content of high coercivity magnetic minerals in loess is higher than that in paleosol, while with the increase of soil compaction, the low coercivity magnetic minerals of fine particles in ancient soils are significantly increased, while the high coercivity The absolute content of magnetic minerals also increased accordingly. The mass susceptibility (χ) and the nonhysteresis remanence (χ ARM) and the saturation isothermal remanence (SIRM) as well as the magnetic particle size parameters χ ARM / SIRM and χ ARM / χ were significantly positive The correlation shows that the single domain (SD) particles and the smaller PSD particles produced by the soil-forming effect have a significant contribution to the enhancement of magnetic susceptibility.