Discriminant Effect of Sedimentary Environment by the Sr/Ba Ratio of Different Exising Forms

Key words: 
• ratio of strontium to barium /
• existing form /
• geochemical behavour /
• identification of sedimentary environment

Abstract: The ratio of strontium to barium is a universal indicator for distinguishing depositional environments. Usually, the value of Sr/Ba more or less than 1 should be responsible for marine or continental deposit, respectively. However, the authenticity of this indicator has nowadays been suspected, even negated by most of sedimentologists and geochemists because of some contradictions or opposite explanations with geological facts. By comparison study of the ratio of (Sr/Ba)_Tratio of total Sr to total Ba in bulk sediment analysis, and the ratio of (Sr/Ba)_A ratio of dissolvable Sr to dissolvable Ba that were extracted in dilute hydrochloric acid from the different environment of the modern Yellow (Huanghe) river delta in this paper, it is suggested that the ratio of (Sr/Ba)_T is not sensitive for environment variation while the (Sr/Ba) _Ashows the sensitive diversity with different sedimentary environments and, moreover,the former results are unreliable because of the disturbance of bulk Sr Ba exiting in terrigenous minerals (for example, feldspar, biotite, ect.) over the Sr and Ba formed in sedimentation. Finally, an attempt is made to evaluate the method of distinguishing sedimentary environments in use of the ratio of strontium to barium.