地学前缘 ›› 2018, Vol. 25 ›› Issue (3): 285-293.DOI: 10.13745/j.esf.yx.2018-2-2

• 非主题来稿选登 • 上一篇    下一篇

南海北部陆坡沉积物中P-S-Fe的相互作用及其对划分硫酸盐甲烷转换带的指示意义

张劼，雷怀彦，杨鸣，陈勇，孔媛，卢毅   

  1. 1. 厦门大学 海洋与地球学院, 福建 厦门 361005
    2. 厦门大学 近海海洋环境科学国家重点实验室, 福建 厦门 361005
  • 收稿日期:2017-08-10 修回日期:2017-12-27 出版日期:2018-05-15 发布日期:2018-05-15
  • 作者简介:张劼(1988—)，男，博士研究生，海洋地质学专业，从事水合物地质与地球化学研究。E-mail: Chandler@stu.xmu.edu.cn
  • 基金资助:
    国家自然科学基金项目(41276046,41773078)；国家重点基础研究发展计划“973”项目子课题(2009CB21951)

The interactions of P-S-Fe in sediment from the continental slope of northern South China Sea and their implication for the sulfatemethane transition zone.

ZHANG Jie,LEI Huaiyan,YANG Ming,CHEN Yong,KONG Yuan,LU Yi   

  1. 1. College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China
    2. State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China
  • Received:2017-08-10 Revised:2017-12-27 Online:2018-05-15 Published:2018-05-15

PDF (PC)

256

摘要： 对南海北部陆坡台西南海域9734岩心沉积物中自生磷灰石磷（PCAF）和铁氧化物结合态磷（PFe）及4种活性Fe组分进行了分步提取测定。结果显示:沉积物自生磷灰石磷（PCFA）含量为0.34%～3.24%，是该站沉积物P的主要成分，其含量自海底向下反复波动;铁氧化物结合磷（PFe）含量为0%～1.38%，总体上出现多次升降。Fepy含量为0.05%～0.72%，平均含量为0.27%，Fecarb含量为0.14%～0.64%，平均含量为0.33%，在硫酸盐甲烷转换带（SMTZ）上部Fepy和Fecarb均出现上升现象，在SMTZ下部Fepy迅速下降而Fecarb含量缓慢上升。Feox含量为0.32%～0.73%，平均含量为0.46%；Femag含量为0.18%～0.34%，平均含量为0.25%。Feox和Femag含量变化趋势基本一致。结合沉积物总硫（TS）、酸可挥发性硫（AVS）及孔隙水中硫酸根（SO2-4）等指标分析可得出：9734柱中两种SO2-4还原模式产生的CO2- 3均会抑制磷灰石晶体的凝聚成核作用；可以利用Fepy和Fecarb含量的反向变化及Feox和Femag的迅速升高对SMTZ上下部进行判定划分；PCAF和PFe含量在SMI界面以下的往复波动的现象为研究水合物不稳定分解影响的环境范围及古SMI界面提供了新的思路。

关键词: 硫酸盐甲烷转换带, 甲烷水合物, 铁组分, 磷形态, 早期成岩作用

Abstract: PCFA, PFeand four kinds of active Fe components in sediment core 9734 from the continental slope of the northern South China Sea gas hydrate potential zone, near Jiulong Methane Reef, were extracted and analyzed. The results showed that the sedimental PCFA is the dominant P ingredient at this location, with its content fluctuating downwards from the seabed from 0.34% to 3.24%. PFe content was found to be 01.38%, displaying several upanddown fluctuations. Similarly, Fepy and Fecarb contents fluctuated between 0.050.72% and 0.140.64%, with averages of 0.27% and 0.33%, respectively; both contents increased at the top of SMTZ, while Fepy content decreased sharply and Fecarb content increased slowly at the bottom of SMTZ. And Feox and Femag contents varied between 0.320.73% and 0.180.34%, with averages of 0.46% and 0.25%, respectively. The variation trends of Feox and Femag were similar. Combining with TS, AVS, SO2-4 and other indicators, our analysis showed that CO2-3, produced by two types of reductive reactions in core 9734, inhibited the formation of apatite core; and furthermore, SMTZ can be identified quickly from sharp increments of Feox and Femag contents and opposite variation trends of Fepy and Fecarb. Recurrent fluctuations of PCFA and PFe under SMI, as observed in this study, shall provide us with new ideas in studying paleoSMI and the range of effects from decomposition of methane hydrate.

Key words: sulfate methane transition zone, methane hydrate, iron components, phosphorus forms, early diagenesis

中图分类号: