Citation: | SHENG Jiangyuan, YAN Zhuoyu, FU Heping, MA Xiao, ZHANG Haiyang, ZHAO Qiang, XU Hong. SPATIAL VARIATION AND GENESIS OF MIOCENE ANKERITE IN WELL XIYONG 2[J]. Marine Geology Frontiers, 2021, 37(6): 39-48. doi: 10.16028/j.1009-2722.2021.051 |
Post-Neogene reef dolostone occurs widely in the Xisha Islands and a great amount of ankerite has been found in the well of Xiyong 2. However, the research on ankerite is rare in literatures. In this paper, the ankerite-dolomites in the interval of 407~570 m of the well Xiyong 2 are analyzed with X-ray powder diffraction upon the basis of previous research data. It is found that the Miocene ankerite mainly occurs in the first Member of the Upper Miocene Huangliu Formation of the well Xiyong 2, while the ferroan dolomite dominates the second member. The porosity of dolomite shows a positive relationship with the amount of ankerite. The higher the porosity of dolomite rock, the higher the ankerite content. The crystal cell parameters of the Mesozoic dolomite and ankerite in this region are large, suggesting that they are rich in calcium and iron. The order degree of the dolomite-ankerite in well Xiyong 2 is greatly affected by Fe2+ content and the increase in Fe2+ will reduce its order degree. Therefore, it is not appropriate to suppose that the dolomite in the well Xiyong 2 of Xisha is simply formed by penecontemporaneous dolomitization. There was a great deal of volcanic activity in the Xisha Islands during Late Miocene, and the magmatic hydrothermal fluid may provide enough Fe2+ and heat for the formation of ankerite. In the late diagenetic period, the first member of Huangliu Formation with good porosity was greatly affected by volcanic activities. The heat and rich Fe2+ input promoted the transformation of dolomite to ankerite, and a large number of ankerite was then formed. However, in the second Member of Huangliu Formation with poor porosity there formed only ferroan dolomites.
[1] | PETTIJOHN F J, 沉积岩[M]. 李汉瑜, 徐怀大, 胡伯良, 等, 译. 北京: 石油工业出版社, 1981, 340-421. |
[2] | 由雪莲,贾文强,徐帆,等. 铁白云石矿物学特征及原生次生成因机制[J]. 地球科学,2018,43(11):4046-4055. |
[3] | BOYD P W. A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization[J]. Nature,2000,407(6805):695-702. doi: 10.1038/35037500 |
[4] | TAKATA H,KUMA K,IWADE S,et al. Spatial variability of iron in the surface water of the northwestern North Pacific Ocean[J]. Marine Chemistry,2004,86(3/4):139-157. |
[5] | СЫРОМЯТНИКОВ Ф В,ВОРОБЬЕВ И М. 铁白云石交代方解石的实验研究[J]. 陈国玺,译. 地质地球化学,1976,10(1):22-25. |
[6] | 宋辉,焦养泉,吴立群,等. 松辽盆地南部钱家店铀矿床后生蚀变作用及其对铀矿床的约束[J]. 地球科学,2016,41(1):153-166. |
[7] | 于志超,刘可禹,赵孟军,等. 库车凹陷克拉2油气储层成岩作用和油气充注特征[J]. 地球科学,2016,41(3):533-545. |
[8] | 张军涛,何治亮,岳小娟,等. 鄂尔多斯盆地奥陶系马家沟组五段富铁白云石成因[J]. 石油与天然气地质,2017,38(4):776-783. doi: 10.11743/ogg20170414 |
[9] | 牟雨亮,王甘露,付勇,等. 黔东南石英脉型金矿床中铁白云石流体包裹体研究[J]. 中国地质调查,2017,4(5):24-30. |
[10] | 何起祥,张明书. 西沙群岛新第三纪白云岩的成因与意义[J]. 海洋地质与第四纪地质,1990,10(2):45-55. |
[11] | 许红,张金川,蔡峰. 西沙群岛中新世生物礁矿物相研究及其意义[J]. 海洋地质与第四纪地质,1994,14(4):15-23. |
[12] | 魏喜,祝永军,许红,等. 西沙群岛新近纪白云岩形成条件的探讨:C、O同位素和流体包裹体证据[J]. 岩石学报,2006,22(9):2394-2404. doi: 10.3321/j.issn:1000-0569.2006.09.016 |
[13] | 王振峰,时志强,张道军,等. 西沙群岛西科1井中新统—上新统白云岩微观特征及成因[J]. 地球科学(中国地质大学学报),2015,40(4):633-644. |
[14] | XU H,ZHANG W,WEI K,et al. Ferroan dolomites in Miocene sediments of the Xisha Islands and their genetic model[J]. Journal of Oceanology and Limnology,2018,36(1):165-180. |
[15] | 朱伟林,王振峰,米立军,等. 南海西沙西科1井层序地层格架与礁生长单元特征[J]. 地球科学(中国地质大学学报),2015,40(4):677-687. |
[16] | 吕炳全,徐国强,王红罡,等. 南海新生代碳酸盐台地淹没事件记录的海底扩张[J]. 地质科学,2002(4):23-32. |
[17] | 谭迪光. X射线衍射定量分析:自身稀释法[J]. 钢铁钒钛,1985(3):61-65. |
[18] | 张海洋,许红,赵新伟,等. 西永2井中新世白云岩储层特征与成岩作用[J]. 海洋地质前沿,2016,32(3):41-47. |
[19] | 章福平,胡祝庆,纪佩珍. 用粉末X射线衍射数据计算晶胞参数的方法[J]. 纺织高校基础科学学报,1996,9(2):170-173. |
[20] | 黄思静. 碳酸盐岩实验室研究方法(一)[J]. 矿物岩石,1990,10(1):114-117. |
[21] | REEDER R J,DOLLASE W A. Structural variation in the dolomite-ankerite solid-solution series:an X-ray,Mossbauer,and TEM study[J]. American Mineralogist,1989,74(9):1159-1167. |
[22] | 曾理,万茂霞,彭英. 白云石有序度及其在石油地质中的运用[J]. 天然气勘探与开发,2004,27(4):64-66,72. doi: 10.3969/j.issn.1673-3177.2004.04.015 |
[23] | 朱井泉,李永铁. 藏北羌塘盆地侏罗系白云岩类型、成因及油气储集特征[J]. 古地理学报,2000,2(4):30-41. doi: 10.3969/j.issn.1671-1505.2000.04.004 |
[24] | 王少飞,杨奕华,徐雁前,等. 陕甘宁盆地定边地区奥陶系巨厚白云岩的成因分析[J]. 天然气地球科学,1996,7(3):14-21. |
[25] | 史基安. 塔里木盆地西北缘震旦系和古生代白云岩成因及储集[J]. 沉积学报,1993,11(2):43-50. |
[26] | 戴朝成,郑荣才,刘华国,等. 辽东湾盆地沙河街组湖湘白云岩成因研究[J]. 成都理工大学学报(自然科学版),2008,35(2):187-193. |
[27] | 柳益群,李红,朱玉双,等. 白云岩成因探讨:新疆三塘湖盆地发现湖相喷流型热水白云岩[J]. 沉积学报,2010,28(5):861-867. |
[28] | 吴世敏,周蒂,丘学林. 南海北部陆缘的构造属性问题[J]. 高校地质学报,2001,7(4):419-426. doi: 10.3969/j.issn.1006-7493.2001.04.006 |
[29] | 冯英辞,彦文欢,姚衍桃,等. 西沙群岛礁区的地质构造及其活动性分析[J]. 热带海洋学报,2015,34(3):48-53. doi: 10.3969/j.issn.1009-5470.2015.03.006 |
[30] | 孙嘉诗. 南海北部及广东沿海新生代火山活动[J]. 海洋地质与第四纪,1991,11(3):45-67. |
[31] | 曹佳琪,张道军,翟世奎,等. 西沙岛礁白云岩化特征与成因模式分析[J]. 海洋学报,2016,38(11):125-139. |
Distribution of islands and reefs in the Xisha sea area and location of the well Xiyong 2
Stratigraphic column based on the core of well Xiyong 2
Characteristics of dolomite in well Xiyong 2
X-ray powder diffraction spectrum of ankerite,dolomite and calcite in well Xiyong 2
Pore types of dolomite in well Xiyong 2
Variation of dolomite and ankerite with depth in well Xiyong 2[18]