渤海曹妃甸沙坝—泻湖海岸现代沉积的磁化率与粒度、矿物的关系

Sedimentary Characteristics of Caofeidian Sand Bar-Lagoon System

根据实测数据，对曹妃甸沙坝－泻湖海岸现代沉积的磁化率、频率磁化率与粒度、矿物的关系进行了探讨。曹妃甸海区沉积类型较为复杂，可划分为深水区、潮滩区、沙坝区、潮汐汊道区。磁化率、频率磁化率同粒度分布一样，各分区各具特点，表现了不同地貌部位与水动力环境的差异，显示出很强的分异现象。磁化率同金属矿物及磁铁矿具有较高的相关性，相关系数分别为０．６１３、０７３１。用磁化率分异度表征各分区沉积物的特点，深水区沉积物磁化率分异度ＤＤ：－０２＜ＤＤ＜０．２；沙坝区沉积物磁化率分异度ＤＢ： ０５＜ＤＢ＜２．１；潮汐汊道区沉积物磁化率分异度ＤＯ：－０１＜ＤＯ＜－０．２。不同潮滩沉积物磁化率分异度各有差异，南堡湖滩区沉积物磁化率分异度ＤＳＴ：－０．７＜ＤＳＴ＜０．１：而泻湖东北部潮滩区沉积物磁化率分异度ＤＮＥＴ：－０．１＜ＤＮＥＴ＜１．４。

The relationships between susceptibility, frequency dependent susceptibility, grain-size and heavy mineral components of sediments of Caofeidian sand bar-lagoon system are studied based on the measurement of susceptibility of high frequency and low frequency, and the analyses of mineral components and grain-size. The area can be subdivided into four geomorphologic zones: tidal flat zone, deep Water zone, sand bar zone and tidal inlet zone. Susceptibility and frequency dependent susceptibility are different in different zones, similar to the grain-size distribution of sediments. Coefficients of correlation between susceptibility, metal minerals and magnetite are 0. 613 and 0.731. Susceptibility diversification are varies in different zones: -0.2<DD<0.2 in deep water zone, 0.5<DB<2.1 in sand bar zone, -0.8<DO<-0.2 in tidal inlet zone, -0.7<DS<0.1 in Nanbao tidal fiat zone, -0.1<DNET<1.4 in the flat of northwest of Caofeidian lagoon.