沉积物化学

CHAPTER 5 MARINE SEDIMENTATION Section 5 Sedimentary Chemistry

(一) Eh,Fe3+/Fe2+,pH 沉积物的Eh,Fe3+/Fe2+,PH为采样现场表层沉积物的测定值。在本区其变化范围:Eh为-213—436mV;Fe3+/F2+为0.29—14.67;PH为6.75—8.99。Eh的分布特征:河口区高,西港区低。如九龙江河口湾及浔江内,Eh值都在100mV以上。尤其是九龙江河口湾水道内Eh值都在200mV以上。西港等内港区Eh值普遍较低,一般都在60mV以下。Eh值分布与沉积物关系密切。

The ranges of main chemical contents in surface sediment in Xiamen Harbour are: Eh:-213-436mV, Fe3+/Fe2+: 0.29-14.67, PH:6.75-8.99, organic matter: ND-3.05%, total nitrogen: 0.002-0.194%, Fe2O3:0.67-10.7%, Al2O3: 3.59-21.92%, TiO2: ND-0.99%, carbonate: ND-24.73%, CaO: ND-12.90%,MgO: ND-2.36%, P2O5: ND-0.192%, MnO: 0.015-0.291%, SiO2: 44.13-89.86%.The difference between estuary and bay is related to distribution of chemical contents of surface sediment. Abundance of Fe2O3, carbonate, P2O5, MnO and pH is high in bay than in estuary, but that of Eh and Fe3+/Fe2+ is high in estuary than in bay. All of these are closely relted to environment factors.Five oxidation-reduction zones of strong oxidation zone, weak oxidation zone, weak reduction zone, reduction zone and strong reduction zone have been divided according to the Q-model cluster analysis from parameters of Eh, Fe3+/Fe2+, organic matter and total nitrogen.