Abstract:
This study discussed the sedimentary geochemistry characteristics and the palaeosedimentary environmental significance of the Zhujiang Formation in well HZ21 at Huizhou depression, Pearl River Mouth basin, on the basis of geochemical analyses of 21 rock samples. The results indicated:Al
2O
3、Fe
2O
3、K
2O、TiO
2、V、Cr and Rb remarkably were positively correlated with each other; SiO
2 was apparently negatively correlated with Al
2O
3、Fe
2O
3 and TiO
2,and weakly negatively correlated with K
2O; Sr and CaO positively correlated with each other; P
2O
5 positively correlated with Al
2O
3、Fe
2O
3、K
2O and TiO
2, and negatively correlated with SiO
2, and weakly negatively correlated with CaO. The analytic result of the value of 10
3(Sr/Ca) and V/Cr revealed that the depth of sedimentary water increased from bottom to top in the Zhujiang Formation of well HZ21, and the variation regularities were consistent with the conclusions of sedimentary facies. The analytic result of the value of 10
2 (MgO/Al
2O
3) and V/Cr revealed that the salinity was similar from the bottom to the top of Zhujiang Formation, but decreased slightly in the top of Zhujiang Formation. Based on the characters of Rb/Sr and MgO/CaO, NSQ1 and NSQ2 were deposited in cool-dry climate condition, NSQ3 and NSQ4 were deposited in warm-wet climate condition. In summary, the geochemical characteristics and the sedimentary environment are closely correlated, and the geochemical characteristics can be regarded as a mark in the sedimentary facies recognition.