甘肃灵台新近纪红粘土磁组构特征的沉积学意义

对第四纪典型风成马兰黄土、受成壤作用影响较大的第五层古土壤、新近纪红粘土、埋藏化石的红粘土围岩层的磁组构分析表明:新近纪红粘土的磁组构参数P、F值界于马兰黄土—第五层古土壤与经流水改造的化石围岩之间，L均值与风成黄土相当， Q均值接近于水成红粘土化石围岩，而在事件性沉积方面又类似于风成马兰黄土、第五层古土壤；磁组构参数F-L、P-Q组合图位于马兰黄土—第五层古土壤与经流水改造的化石围岩过渡带。反映红粘土沉积物既具有风成原地堆积物的磁组构参数特征，又有经历了后期流水改造的化石围岩的特点，是风成原地堆积与风动力搬运而来的母质颗粒经后期流水改造共同作用的产物。

Sedimentological Significance of the Magnetic Fabric of the Neogene Red Clay in Lingtai, Gansu Province

The analysis of magnetic fabric of the Malan loess, the fifth layer of paleosol which is well known for its intensity of weathering and pedogenesis, red clay and matrix indicates that the magnetic fabric parameters P, F of Neogene Red Clay are between Malan loess the fifth layer of paleosol and matrix with the overlapping boundary as the equation "F=1.01". The average value of L is equal to that of the eolian loess while the average value of Q, which is similar to that of the eolian Malan loess from the aspect of event deposition, approximately corresponds with that of the matrix red clay of hydraulic genesis and is in the transition area when it is in the assembled diagram of magnetic fabric parameters. All above show that the red clay deposits have the similar characters of magnetic fabric values resembling those of eolian deposits without experiencing transportation and also the features of shrouding rock of the fossils undergoing the hydraulic reconstruction thus the conclusion can be reached that red clay is the product of the primary aeolian particles which go through the post depositional hydraulic process.