The impact of change in fluid seepage intensity on iron and phosphorus cycling in chimney-like seep carbonates
-
摘要:
冷泉碳酸盐岩形成过程中渗漏流体特征的变化可以改变参与的碳、硫等元素循环的生物地球化学过程，但对铁（Fe）和磷（P）元素循环及相关生物地球化学过程的影响目前还不清楚。本文对南海东沙海域一个冷泉碳酸盐岩烟囱横截面进行了矿物学、碳和硫地球化学及Fe和P组分进行了分析。结果显示，生物成因甲烷的厌氧氧化作用导致了极端13C亏损的自生碳酸盐的形成（δ13CVPDB＜−55.5‰），并且形成过程中由于水合物分解，加入了富18O 流体，使得烟囱碳酸盐岩表现出异常高的氧同位素组成（5.5‰～5.8‰）。烟囱外层矿物组成以方解石为主，内层以文石为主，内层烟囱样品形成于更强的甲烷渗漏强度条件。样品中最主要的含磷物质是自生磷酸盐（PAuth），并且最高含量出现在烟囱内层。相比外层烟囱样品，内层铁氧化物含量更低，但是铁结合态磷（PFe）含量更高，推测可能是有蓝铁矿的形成。综合上述结果表明，在形成冷泉碳酸盐岩的强渗漏条件下，甲烷渗漏强度的增强会影响PAuth和PFe的丰度，可能更有利于蓝铁矿和自生磷灰石的形成，从而对冷泉环境中的磷和铁循环产生影响。
Abstract:During the formation of seep carbonates, variations in fluid seepage affect the biogeochemical processes that drive the cycling of various elements, such as carbon and sulfur. However, such an influence on iron (Fe) and phosphorus (P) cycling and related biogeochemical processes remains unclear. In this study, mineral compositions, carbon and sulfur geochemistry, Fe and P component were investigated on a cross section of a chimney-like seep carbonate sample collected from the Dongsha area of the South China Sea. Results reveal that the anaerobic oxidation of biogenic methane led to the formation of the extremely 13C-depleted authigenic carbonate rocks (δ13CVPDB＜−55.5‰), and the addition of enriched 18O fluids from the dissociation of gas hydrates results in abnormally high oxygen isotope composition (5.5‰–5.8‰) observed in the chimney carbonates. Combined with the dominant minerals with calcite in the outer layer of the chimney carbonates and aragonite in the inner layer, we inferred that the carbonates in the inner layer were formed at the later stage under stronger methane seepage condition. The most significant P-bearing mineral in the samples is authigenic phosphate (PAuth), and the highest content is in the inner layer of the chimney carbonates. Compared with the outer chimney sample, the inner layer has lower Fe oxide content, but higher Fe-bound P (PFe) content, indicating the formation of vivianite. Therefore, we believe that under a stronger seepage condition during the formation of seep carbonates, an enhanced intensity of methane seepage can affect the abundance of PAuth and PFe, which may favor the formation of vivianite and authigenic phosphates, thereby influencing Fe and P cycling in cold-seep environments.
-
Keywords:
- methane seepage /
- phosphorus component /
- iron component /
- phosphorus cycle /
- seep carbonate
-
-
![]()
图 1 采样位置和样品情况
a: 位于东沙海域的采样站位九龙甲烷礁site 3；b: 冷泉碳酸盐岩烟囱样品横切面和取样点S1到S10。冷泉碳酸盐岩烟囱的横截面直径约10 cm，用牙钻间隔约0.8 cm取一个点，共取10个点。
Figure 1. Sampling location and subsamples
a: The sampling site located in the Dongsha sea area, known as Methane Reef Site 3; b: the subsample of seep carbonates chimneys from S1to S10. The cross-section diameter of the seep carbonates chimneys is about 10 cm, and one point was taken about 0.8 cm apart for 10 points in total.
![]()
图 3 冷泉碳酸盐岩烟囱样品的碳、硫含量（a）以及碳和氧稳定同位素组成（b）
Figure 3. Carbon and sulfur content (a), and carbon and oxygen stable isotope compositions (b) of the seep carbonate chimney samples
![]()
图 4 冷泉碳酸盐岩烟囱的不同铁和磷组分含量
Figure 4. Contents of different iron and phosphorus component of seep carbonates chimneys
![]()
图 5 冷泉碳酸盐岩烟囱样品各铁组分和磷组分相对百分占比
a：铁组分相对百分占比，b：磷组分相对百分占比。
Figure 5. Relative proportions of iron and phosphorus component in the seep carbonate chimney samples
a: Relative proportions of the iron component, b: relative proportions of the phosphorus component.
![]()
图 6 冷泉碳酸盐岩烟囱样品的晶质铁氧化物（FeOx2）和非晶质氧化铁含量（FeOx1）分别与铁结合态磷（PFe）的投点图
图中红色点为冷泉碳酸盐岩烟囱内层样品，黑色点为冷泉碳酸盐岩烟囱外层样品。
Figure 6. The cross-plot of crystalline iron oxides (FeOx2) and amorphous iron oxide content (FeOx1) from cold seep carbonate chimney samples vs iron-bound phosphorus (PFe), respectively
The red dots are seep carbonate chimney samples. The black dots are samples from the outer layers of seep carbonates.
-
[1] Peckmann J, Thiel V. Carbon cycling at ancient methane–seeps[J]. Chemical Geology, 2004, 205(3-4):443-467. doi: 10.1016/j.chemgeo.2003.12.025
[2] Feng D, Qiu J W, Hu Y, et al. Cold seep systems in the South China Sea: An overview[J]. Journal of Asian Earth Sciences, 2018, 168:3-16. doi: 10.1016/j.jseaes.2018.09.021
[3] Lu Y, Sun X M, Lin Z Y, et al. Cold seep status archived in authigenic carbonates: Mineralogical and isotopic evidence from Northern South China Sea[J]. Deep Sea Research Part II:Topical Studies in Oceanography, 2015, 122:95-105. doi: 10.1016/j.dsr2.2015.06.014
[4] Gong S G, Hu Y, Li N, et al. Environmental controls on sulfur isotopic compositions of sulfide minerals in seep carbonates from the South China Sea[J]. Journal of Asian Earth Sciences, 2018, 168:96-105. doi: 10.1016/j.jseaes.2018.04.037
[5] Feng D, Chen D F, Roberts H H. Petrographic and geochemical characterization of seep carbonate from Bush Hill (GC 185) gas vent and hydrate site of the Gulf of Mexico[J]. Marine and Petroleum Geology, 2009, 26(7):1190-1198. doi: 10.1016/j.marpetgeo.2008.07.001
[6] Mazzini A, Svensen H, Hovland M, et al. Comparison and implications from strikingly different authigenic carbonates in a Nyegga complex pockmark, G11, Norwegian Sea[J]. Marine Geology, 2006, 231(1-4):89-102. doi: 10.1016/j.margeo.2006.05.012
[7] Ritger S, Carson B, Suess E. Methane-derived authigenic carbonates formed by subduction-induced pore-water expulsion along the Oregon/Washington margin[J]. GSA Bulletin, 1987, 98(2):147-156. doi: 10.1130/0016-7606(1987)98<147:MACFBS>2.0.CO;2
[8] Roberts H H, Aharon P. Hydrocarbon-derived carbonate buildups of the northern Gulf of Mexico continental slope: A review of submersible investigations[J]. Geo-Marine Letters, 1994, 14(2-3):135-148. doi: 10.1007/BF01203725
[9] Campbell K A. Hydrocarbon seep and hydrothermal vent paleoenvironments and paleontology: past developments and future research directions[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2006, 232(2-4):362-407. doi: 10.1016/j.palaeo.2005.06.018
[10] Paull C K, Chanton J P, Neumann A C, et al. Indicators of methane-derived carbonates and chemosynthetic organic carbon deposits: Examples from the Florida Escarpment[J]. Palaios, 1992, 7(4):361-375. doi: 10.2307/3514822
[11] Feng D, Chen D F. Authigenic carbonates from an active cold seep of the northern South China Sea: New insights into fluid sources and past seepage activity[J]. Deep Sea Research Part II:Topical Studies in Oceanography, 2015, 122:74-83. doi: 10.1016/j.dsr2.2015.02.003
[12] Wirsig C, Kowsmann R O, Miller D J, et al. U/Th-dating and post-depositional alteration of a cold seep carbonate chimney from the Campos Basin offshore Brazil[J]. Marine Geology, 2012, 329-331:24-33. doi: 10.1016/j.margeo.2012.10.001
[13] Peng X T, Guo Z X, Chen S, et al. Formation of carbonate pipes in the northern Okinawa Trough linked to strong sulfate exhaustion and iron supply[J]. Geochimica et Cosmochimica Acta, 2017, 205:1-13. doi: 10.1016/j.gca.2017.02.010
[14] Takeuchi R, Matsumoto R, Ogihara S, et al. Methane-induced dolomite “chimneys” on the Kuroshima Knoll, Ryukyu islands, Japan[J]. Journal of Geochemical Exploration, 2007, 95(1-3):16-28. doi: 10.1016/j.gexplo.2007.05.008
[15] Magalhães V H, Pinheiro L M, Ivanov M K, et al. Formation processes of methane-derived authigenic carbonates from the Gulf of Cadiz[J]. Sedimentary Geology, 2012, 243-244:155-168. doi: 10.1016/j.sedgeo.2011.10.013
[16] Peckmann J, Reimer A, Luth U, et al. Methane-derived carbonates and authigenic pyrite from the northwestern Black Sea[J]. Marine Geology, 2001, 177(1-2):129-150. doi: 10.1016/S0025-3227(01)00128-1
[17] Novikova S A, Shnyukov Y F, Sokol E V, et al. A methane-derived carbonate build-up at a cold seep on the Crimean slope, north-western Black Sea[J]. Marine Geology, 2015, 363:160-173. doi: 10.1016/j.margeo.2015.02.008
[18] 苏新, 陈芳, 陆红锋, 等. 南海北部深海甲烷冷泉自生碳酸盐岩显微结构特征与流体活动关系初探[J]. 现代地质, 2008, 22(3):376-381 SU Xin, CHEN Fang, LU Hongfeng, et al. Micro-textures of methane seep carbonates from the northern South China Sea in correlation with fluid flow[J]. Geoscience, 2008, 22(3):376-381.]
[19] 杨克红, 初凤友, 赵建如, 等. 南海北部冷泉碳酸盐岩矿物微形貌及其意义探讨[J]. 矿物学报, 2009, 29(3):345-352 YANG Kehong, CHU Fengyou, ZHAO Jianru, et al. Minerals’ Micro-Shape and Its Significance of Seep Carbonates in the North of the South China Sea[J]. Acta Mineralogica Sinica, 2009, 29(3):345-352.]
[20] Liang Q Y, Hu Y, Feng D, et al. Authigenic carbonates from newly discovered active cold seeps on the northwestern slope of the South China Sea: Constraints on fluid sources, formation environments, and seepage dynamics[J]. Deep Sea Research Part I:Oceanographic Research Papers, 2017, 124:31-41. doi: 10.1016/j.dsr.2017.04.015
[21] 邬黛黛, 吴能友, 叶瑛, 等. 南海北部陆坡九龙甲烷礁冷泉碳酸盐岩沉积岩石学特征[J]. 热带海洋学报, 2009, 28(3):74-81 WU Daidai, WU Nengyou, YE Ying, et al. Petrographic characteristics of authigenic carbonates from Jiulong methane reef of northern South China Sea[J]. Journal of Tropical Oceanography, 2009, 28(3):74-81.]
[22] Guan H X, Feng D, Wu N Y, et al. Methane seepage intensities traced by biomarker patterns in authigenic carbonates from the South China Sea[J]. Organic Geochemistry, 2016, 91:109-119. doi: 10.1016/j.orggeochem.2015.11.007
[23] Ge L, Jiang S Y, Yang T, et al. Glycerol ether biomarkers and their carbon isotopic compositions in a cold seep carbonate chimney from the Shenhu area, northern South China Sea[J]. Chinese Science Bulletin, 2011, 56(16):1700-1707. doi: 10.1007/s11434-011-4486-z
[24] 佟宏鹏, 冯东, 陈多福. 南海北部冷泉碳酸盐岩的矿物、岩石及地球化学研究进展[J]. 热带海洋学报, 2012, 31(5):45-56 TONG Hongpeng, FENG Dong, CHEN Duofu. Progresses on petrology, mineralogy and geochemistry of cold seep carbonates in the northern South China Sea[J]. Journal of Tropical Oceanography, 2012, 31(5):45-56.]
[25] Ge L, Jiang S Y, Swennen R, et al. Chemical environment of cold seep carbonate formation on the northern continental slope of South China Sea: Evidence from trace and rare earth element geochemistry[J]. Marine Geology, 2010, 277(1-4):21-30. doi: 10.1016/j.margeo.2010.08.008
[26] Han X Q, Suess E, Huang Y Y, et al. Jiulong methane reef: Microbial mediation of seep carbonates in the South China Sea[J]. Marine Geology, 2008, 249(3-4):243-256. doi: 10.1016/j.margeo.2007.11.012
[27] 陈多福, 黄永样, 冯东, 等. 南海北部冷泉碳酸盐岩和石化微生物细菌及地质意义[J]. 矿物岩石地球化学通报, 2005, 24(3):185-189 CHEN Duofu, HUANG Yongyang, FENG Dong, et al. Seep carbonate and preserved bacteria fossils in the northern of the South China Sea and their geological implications[J]. Bulletin of Mineralogy, Petrology and Geochemistry, 2005, 24(3):185-189.]
[28] 陈忠, 杨华平, 黄奇瑜, 等. 南海东沙西南海域冷泉碳酸盐岩特征及其意义[J]. 现代地质, 2008, 22(3):382-389 CHEN Zhong, YANG Huaping, Huang C Y, et al. Diagenetic environment and implication of seep carbonate precipitations from the southwestern Dongsha Area, South China Sea[J]. Geoscience, 2008, 22(3):382-389.]
[29] 陈忠, 黄奇瑜, 颜文, 等. 南海西沙海槽的碳酸盐结壳及其对甲烷冷泉活动的指示意义[J]. 热带海洋学报, 2007, 26(2):26-33 CHEN Zhong, Huang C Y, YAN Wen, et al. Authigenic carbonates as evidence for seeping fluids in Xisha Trough of South China Sea[J]. Journal of Tropical Oceanography, 2007, 26(2):26-33.]
[30] 葛璐, 蒋少涌, 杨涛, 等. 南海北部神狐海区冷泉碳酸盐岩的地球化学特征[J]. 矿物学报, 2009, 29(S1):370 GE Lu, JIANG Shaoyong, YANG Tao, et al. Geochemical characteristics of seep carbonates from Shenhu area, northern South China Sea[J]. Acta Mineral Sinica, 2009, 29(S1):370.]
[31] 刘关勇, 王旭东, 黄慧文, 等. 南海北部烟囱状碳酸盐岩记录的冷泉流体活动演化特征研究[J]. 地球化学, 2017, 46(6):567-579 LIU Guanyong, WANG Xudong, HUANG Huiwen, et al. Variations in fluid sources and seepages archived in carbonate chimneys from the northern South China Sea[J]. Geochimica, 2017, 46(6):567-579.]
[32] 韩喜球, 杨克红, 黄永样. 南海东沙东北冷泉流体的来源和性质: 来自烟囱状冷泉碳酸盐岩的证据[J]. 科学通报, 2013, 58(19): 1865-1873 HAN Xiqiu, YANG Kehong, HUANG Yongyang. Origin and nature of cold seep in northeastern Dongsha area, South China Sea: Evidence from chimney-like seep carbonates[J]. Chinese Science Bulletin, 2013, 58(30): 3689-3697.]
[33] 陈选博, 韩喜球. 南海东北陆坡烟囱状冷泉碳酸盐岩生长剖面的碳、氧同位素特征与生长模式[J]. 沉积学报, 2013, 31(1):50-55 CHEN Xuanbo, HAN Xiqiu. Carbon and oxygen isotope characteristics of the growth profile of a seep carbonate chimney from the northeastern slope of the south China sea and its formation model[J]. Acta Sedimentologica Sinica, 2013, 31(1):50-55.]
[34] 杨克红, 初凤友, 赵建如, 等. 南海北部烟囱状冷泉碳酸盐岩的沉积环境分析[J]. 海洋学报, 2013, 35(2):82-89 YANG Kehong, CHU Fengyou, ZHAO Jianru, et al. Sedimentary environment of the cold-seep carbonate chimneys, North of the South China Sea[J]. Acta Oceanologica Sinica, 2013, 35(2):82-89.]
[35] Sun Y D, Peckmann J, Hu Y, et al. Formation of tubular carbonates within the seabed of the northern south China sea[J]. Minerals, 2020, 10(9):768. doi: 10.3390/min10090768
[36] Jin M, Feng D, Huang K J, et al. Behavior of Mg isotopes during precipitation of methane-derived carbonate: Evidence from tubular seep carbonates from the South China Sea[J]. Chemical Geology, 2021, 567:120101. doi: 10.1016/j.chemgeo.2021.120101
[37] Hsu T W, Jiang W T, Wang Y. Authigenesis of vivianite as influenced by methane-induced sulfidization in cold-seep sediments off southwestern Taiwan[J]. Journal of Asian Earth Sciences, 2014, 89:88-97. doi: 10.1016/j.jseaes.2014.03.027
[38] Egger M, Rasigraf O, Sapart C J, et al. Iron-mediated anaerobic oxidation of methane in brackish coastal sediments[J]. Environmental Science & Technology, 2015, 49(1):277-283.
[39] Egger M, Jilbert T, Behrends T, et al. Vivianite is a major sink for phosphorus in methanogenic coastal surface sediments[J]. Geochimica et Cosmochimica Acta, 2015, 169:217-235. doi: 10.1016/j.gca.2015.09.012
[40] Liu J R, Izon G, Wang J S, et al. Vivianite formation in methane-rich deep-sea sediments from the South China Sea[J]. Biogeosciences, 2018, 15(20):6329-6348. doi: 10.5194/bg-15-6329-2018
[41] Wu D D, Xie R, Liu J, et al. Zone of metal-driven anaerobic oxidation of methane is an important sink for phosphorus in the Taixinan Basin, South China Sea[J]. Marine Geology, 2020, 427:106268. doi: 10.1016/j.margeo.2020.106268
[42] Zhou J L, Du M R, Li J W, et al. Phosphorus species in deep-sea carbonate deposits: implications for phosphorus cycling in cold seep environments[J]. Minerals, 2020, 10(7):645. doi: 10.3390/min10070645
[43] 胡钰, 刘春阳, 陈庆王, 等. 南海东沙海域甲烷渗漏活动对不同Fe组分和P形态组成的影响[J]. 地球化学, 2023, 52(4):439-447 HU Yu, LIU Chunyang, CHEN Qingwang, et al. Methane seepage impacts the compositions of different iron speciations and phosphorus fractions in the Dongsha area of the South China Sea[J]. Geochimica, 2023, 52(4):439-447.]
[44] Chen Q W, Hu Y, Peckmann J, et al. The formation of authigenic phosphorus minerals in cold-seep sediments from the South China Sea: Implications for carbon cycling below the sulfate-methane transition[J]. Marine and Petroleum Geology, 2023, 155:106425. doi: 10.1016/j.marpetgeo.2023.106425
[45] Poulton S W, Canfield D E. Development of a sequential extraction procedure for iron: implications for iron partitioning in continentally derived particulates[J]. Chemical Geology, 2005, 214(3-4):209-221. doi: 10.1016/j.chemgeo.2004.09.003
[46] Henkel S, Kasten S, Poulton S W, et al. Determination of the stable iron isotopic composition of sequentially leached iron phases in marine sediments[J]. Chemical Geology, 2016, 421:93-102. doi: 10.1016/j.chemgeo.2015.12.003
[47] Alcott L J, Krause A J, Hammarlund E U, et al. Development of iron speciation reference materials for palaeoredox analysis[J]. Geostandards and Geoanalytical Research, 2020, 44(3):581-591. doi: 10.1111/ggr.12342
[48] Ruttenberg K C. Development of a sequential extraction method for different forms of phosphorus in marine sediments[J]. Limnology and Oceanography, 1992, 37(7):1460-1482. doi: 10.4319/lo.1992.37.7.1460
[49] Huerta-Diaz M A, Tovar-Sánchez A, Filippelli G, et al. A combined CDB-MAGIC method for the determination of phosphorus associated with sedimentary iron oxyhydroxides[J]. Applied Geochemistry, 2005, 20(11):2108-2115. doi: 10.1016/j.apgeochem.2005.07.009
[50] Chen F, Hu Y, Feng D, et al. Evidence of intense methane seepages from molybdenum enrichments in gas hydrate-bearing sediments of the northern South China Sea[J]. Chemical Geology, 2016, 443:173-181. doi: 10.1016/j.chemgeo.2016.09.029
[51] Hu Y, Feng D, Peckmann J, et al. The crucial role of deep-sourced methane in maintaining the subseafloor sulfate budget[J]. Geoscience Frontiers, 2023, 14(3):101530. doi: 10.1016/j.gsf.2022.101530
[52] Hu Y. Pore water geochemistry and quantification of methane cycling[M]//Chen D F, Feng D. South China Sea Seeps. Singapore: Springer, 2023: 129-148.
[53] Hu Y, Luo M, Peckmann J, et al. Quantifying the extent of authigenic carbonate formation in shallow marine sediments through a correlation between carbonate precipitation rate and sulfate flux[J]. Geophysical Research Letters, 2023, 50(19):e2023GL104296. doi: 10.1029/2023GL104296
[54] Bohrmann G, Greinert J, Suess E, et al. Authigenic carbonates from the Cascadia subduction zone and their relation to gas hydrate stability[J]. Geology, 1998, 26(7):647-650. doi: 10.1130/0091-7613(1998)026<0647:ACFTCS>2.3.CO;2
[55] 杨克红, 于晓果, 初凤友, 等. 南海北部甲烷渗漏系统环境变化的碳、氧同位素记录[J]. 地球科学, 2016, 41(7):1206-1215 YANG Kehong, YU Xiaoguo, CHU Fengyou, et al. Environmental changes in methane seeps recorded by carbon and oxygen isotopes in the northern South China Sea[J]. Earth Science, 2016, 41(7):1206-1215.]
[56] Ruttenberg K C. The global phosphorus cycle[J]. Treatise on Geochemistry, 2014, 10:499-558.
[57] Egger M, Hagens M, Sapart C J, et al. Iron oxide reduction in methane-rich deep Baltic Sea sediments[J]. Geochimica et Cosmochimica Acta, 2017, 207:256-276. doi: 10.1016/j.gca.2017.03.019
[58] Slomp C P, Mort H P, Jilbert T, et al. Coupled dynamics of iron and phosphorus in sediments of an oligotrophic coastal basin and the impact of anaerobic oxidation of methane[J]. PLoS One, 2013, 8(4):e62386. doi: 10.1371/journal.pone.0062386
[59] Egger M, Kraal P, Jilbert T, et al. Anaerobic oxidation of methane alters sediment records of sulfur, iron and phosphorus in the Black Sea[J]. Biogeosciences, 2016, 13(18):5333-5355. doi: 10.5194/bg-13-5333-2016
[60] Kraal P, Burton E D, Rose A L, et al. Sedimentary iron–phosphorus cycling under contrasting redox conditions in a eutrophic estuary[J]. Chemical Geology, 2015, 392:19-31. doi: 10.1016/j.chemgeo.2014.11.006
[61] 张劼, 雷怀彦, 杨鸣, 等. 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[J]. 地学前缘, 2018, 25(3):285-293 ZHANG Jie, LEI Huaiyan, YANG Ming, et al. 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[J]. Earth Science Frontiers, 2018, 25(3):285-293.]
[62] Filippelli G M. The global phosphorus cycle: past, present, and future[J]. Elements, 2008, 4(2):89-95. doi: 10.2113/GSELEMENTS.4.2.89
[63] März C, Riedinger N, Sena C, et al. Phosphorus dynamics around the sulphate-methane transition in continental margin sediments: Authigenic apatite and Fe(II) phosphates[J]. Marine Geology, 2018, 404:84-96. doi: 10.1016/j.margeo.2018.07.010
下载:
计量
- 文章访问数: 108
- HTML全文浏览量: 7
- PDF下载量: 62
