The origin of the opal-layer full of todorokite veinlets in polymetallic nodules from the Eastern Pacific Ocean

doi:10.3969/j.issn.1001-909X.2015.02.004

Abstract

Abstract: There are three main manganese oxides in polymetallic nodules. They are vernadite、todorokite and birnessite. Different manganese oxides have their specific origins and growth environments. It is found that there is a special opal-layer which is full of todorokite veinlets in the polymetallic nodules from the Eastern Pacific Ocean. Microscope、EPMA (Electron Probe MicroAnalysis) and ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometer) methods were used to find out the micro-structure and geochemical features of the opal-layer and its surrounding minerals, in order to investigate the origin of the opal-layer. It shows that: (1) The special opal-layer and its surrounding area are mainly composed of todorokite,vernadite and opal. (2) Todorokite has high reflectivity and Mn/Fe ratio. It is mainly composed of MnO and of diagenetic origin. (3) Vernadite has moderate reflectivity and low Mn/Fe ratio. It is mainly composed of MnO and FeO, it is of hydrogenic origin. (4) Opal has low reflectivity. It is mainly composed of SiO₂ and of biogenic origin. A model was set up for the formation of the opal-layer and the todorokite veinlets inside. It could be divided into 5 stages as follows:(1)In the oxidizing environment, vernadite was formed on the surface of the half-buried nodule.(2) The dissolving of biogenic opaline silica leaded to a vast amount of colloidal silica in the upper water of the seafloor. The colloidal silica deposited on the surface of the half-buried nodule, forming the opal-layer.(3) In the oxidizing environment, vernadite was formed on the surface of the half-buried nodule. At the same time, the diagenesis of the nodule and dehydration of opal led to the formation of cracks in the opal-layer.(4) The nodule was buried by the silica-rich sediments. In the reducing environment, the todorokite veinlets formed in the previous cracks by the invasion of interstitial water from the surrounding sediments.(5) The nodule re-exposured in the water, forming vernadite on its surface in the oxidizing environment.

Key words: the Eastern Pacific Ocean, the area between Clarion and Clipperton, polymetallic nodules, opal, todorokite

CLC Number:

P744

ZHUANG Dan-dan, CHU Feng-you, ZHU Ji-hao. The origin of the opal-layer full of todorokite veinlets in polymetallic nodules from the Eastern Pacific Ocean[J]. Journal of Marine Sciences, 2015, 33(2): 19-29.

References

[1] HEIMENDAHL M V, HUBRED G L, FUERSTENAU D W, et al. A transmission electron microscope study of deep-sea manganese nodules[J]. Deep Sea Research and Oceanographic Abstracts, 1976, 23(1): 69-79.
[2] KOLBE H, SIAPNO B. Manganese nodules. Further resources of nickel and copper on the deep ocean floor[J]. Geoforum, 1974,5(4): 63-82.
[3] ZHANG Fu-yuan. The evaluation principles and methods to delimit mining aeras of manganese nodules[M]. Beijing: Ocean Press, 2001: 39-41.
张富元. 大洋多金属结核资源评价原理和矿区圈定方法[M]. 北京:海洋出版社,2001: 39-41.
[4] IIZASA K, TAKENOUCHI S. Alteration of deep-sea manganese nodules from the Northern Central Pacific Basin[J]. Marine Geology, 1989,39(3): 205-218.
[5] HALBACH P, MARCHIG V, SCHERHAG C. Regional variations in Mn, Ni, Cu, and Co of ferromanganese nodules from a basin in the Southeast Pacific[J]. Marine Geology, 1980, 38(4): M1-M9.
[6] SHAN Lian-fang. Geochemistry and origin of manganese minerals in marine manganese nodules[J]. Geochimica, 1994,23(1): 91-94.
单连芳. 大洋锰结核中锰矿物的地球化学性质及其成因[J]. 地球化学,1994, 23(1): 91-94.
[7] CHEN Jian-lin. Preliminary research of manganese nodules in the Central Pacific Basin[J]. Acta Oceanologica Sinica, 1990,12(6):794-799.
陈建林. 中太平洋海盆锰结核之初步研究[J]. 海洋学报, 1990,12(6):794-799.
[8] HALBACH P, HEBISCH U, SCHERHAG C. Geochemical variations of ferromanganese nodules and crusts from different provinces of the Pacific Ocean and their genetic control[J]. Chemical Geology, 1981,34(1-2): 3-17.
[9] BARAJASA A M, VERGESB E L, LECLAIREC L. Characteristics of manganese nodules from the Central Indian Basin: Relationship with the sedimentary environment[J]. Marine Geology, 1991, 101(1-4): 249-265.
[10] ZHAO Jian-ru, CHU Feng-you, YANG Ke-hong, et al. Manganese mineral components, compositional characteristics and their implication for genesis of cobalt-rich crusts from C seamount in Central Pacific[J]. Journal of Marine Science, 2009,27(1):15-21.
赵建如,初凤友,杨克红,等.中太平洋C海山富钴结壳铁锰矿物的组成、成分特征及其成因意义[J].海洋学研究, 2009,27(1):15-21.
[11] IIZASA K, TAKENOUCHI S. Todorokite veinlets in Opal-A layers of deep-sea manganese nodules from the Northern Central Pacific[J]. Mining Geology, 1989, 39(5): 325-333.
[12] HU Da-qian, CHU Feng-you, YAO Jie. Research of the vernadite in ferromanganese crusts from the Central Pacific Ocean[J]. Journal of Jilin University: Earth Science Edition,2009,34(4):706-710.
胡大千,初凤友,姚杰. 中太平洋富钴结壳水羟锰矿研究[J]. 吉林大学学报:地球科学版, 2009,34(4): 706-710.
[13] KOSCHINSKY A, HALBACH P. Sequential leaching of marine ferromanganese precipitates: Genetic implications[J]. Geochimica et Cosmochimica Acta, 1995,59(24): 5 113-5 132.
[14] CHEN Jian-lin, ZHANG Fu-sheng, LIN Cheng-yi. The todorokite in polymetallic nodules in East Pacific Ocean[J]. Acta Sedimentologica Sinica, 1996,14(Supp.):171-180.
陈建林,张富生,林承毅. 东太平洋多金属结核中的钡镁锰矿[J]. 沉积学报, 1996, 14(增刊): 171-179.
[15] LYNN D C, BONATTI E. Mobility of manganese in diagenesis of deep-sea sediments[J]. Marine Geology, 1965 3(6): 457-474.
[16] BONATTI E, FISHER D E, JOENSUU O, et al. Postdepositional mobility of some transition elements, phosphorus, uranium and thorium in deep sea sediments[J]. Geochimica et Cosmochimica Acta, 1971,35(2): 189-201.
[17] KING R J. Minerals explained 4: Opal (Silica)[J]. Geology Today, 1986, 2(2): 59-61.
[18] JOHNSON T C. Biogenic opal preservation in pelagic sediments of a small area in the eastern tropical Pacific[J]. Geological Society of America Bulletin, 1976,87(9):1 273-1 282.
[19] TREGUER P, NELSON D M, VAN BENNEKOM A J, et al. The silica balance in the world ocean: A reestimate[J]. Science, 1995,268(5 209): 375-379.
[20] BOSTROM K, KRAEMER T, GARTNER S. Provenance and accumulation rates of opaline silica, Al, Ti, Fe, Mn, Cu, Ni and Co in Pacific pelagic sediments[J]. Chemical Geology, 1973,11(2): 123-148.
[21] LEWIN J C. The dissolution of silica from diatom walls[J]. Geochimica et Cosmochimica Acta, 1961, 21:182-98.
[22] QIN Ya-chao. Research progress in early diagenesis of biogenic silica[J]. Geological Review, 2010,56(1): 89-98.
秦亚超. 生物硅早期成岩作用研究进展[J]. 地质论评, 2010,56(1): 89-98.
[23] ILER R K. Effect of adsorbed alumina on the solubility of amorphous silica in water[J]. Journal of Colloid and Interface Science, 1973,43(2): 399-408.
[24] BURNS V M, BURNS R G. Post-depositional metal enrichment processes inside manganese nodules from the north equatorial Pacific[J]. Earth and Planetary Science Letters, 1978,39(3): 341-348.
[25] BURN V M, BURNS R G. Authigenic todorokite and phillipsite inside deep-sea manganese nodules[J]. American Mineralogist, 1978,63(9-10): 827-831.
[26] HEYE D. Growth conditions of manganese nodules: Comparative studies of growth rate, magnetization, chemical composition and internal structure[J]. Progress in Oceanography, 1978,7(5-6): 163-239.
[27] BIRNBAUM S J, WIREMAN J W. Bacterial sulfate and pH: Implications for early diagenesis[J]. Chemical Geology, 1984,43(1-2): 143-149