Characteristics of Carbonate Micro-Shapes in Zoophycos Burrows from the Lower Permian Taiyuan Formation in North China and Their Significance
-
摘要: 华北地区下二叠统太原组碳酸盐岩中的Zoophycos遗迹化石十分丰富,根据其潜穴充填物颜色的不同,可将太原组Zoophycos分为四种类型,即具黑色、灰色、灰白色、红色充填物的Zoophycos。本文选取河南焦作和山西附城太原组剖面中具有代表性的Zoophycos样品,利用扫描电子显微镜和能谱仪对其潜穴中的充填物进行了超微特征观察及元素组成测定,发现了大量成因与微生物相关的碳酸盐岩微形体(单体矿物和集合体),识别出球状(表面光滑的球状体、表面具有不定形细粒结构的球状体、表面呈刺状细粒结构的球状体和球状集合体)、杆状(刺杆状分枝形网状体、刺杆状单体、螺旋杆状单体、双列杆状体、光滑直线形杆状单体、末端膨大的光滑杆状体)、簇状、网状、瓶状和似脑球状等6种形态类型,其中多数显示出不同的微生物结构。这一发现表明,Zoophycos遗迹化石并非简单的觅食迹或食物储藏所,其造迹生物与微生物很可能存在互利共生关系。此次研究有助于探索地质微生物作用对地球化学过程的影响,并为精细分析该研究区太原组碳酸盐岩的形成过程及其沉积演化提供了微观资料。Abstract: The Lower Permian Taiyuan Formation in North China, well exposed in western Henan and south central of Shanxi province, consists of littoral, neritic, lagoon and tidal flat deposits in the epicontinental sea carbonate platform. It conformably contacts with both the overlaying Middle Permian Shanxi Formation and the underlaying Upper Carboniferous Benxi Formation. The lithology of the Taiyuan Formation mainly composed of thin bedded to middle bedded, grey to dark grey biological clastic limestone, sandstone, siltstone, carbonaceous shale and coal beds. Body fossils are abundant in every layer limestone of the Taiyuan Formation, such as fusulinida, brachiopoda, gastropods, coral, crinoid, and so on. The ichnofossil Zoophycos with high abundance are discovered in carbonate rocks of this stratum, which can be divided into four types-Zoophycos with black, grey, off-white or red fillings based on the different colors of burrow fillings, and other ichnofossils associated with Zoophycos commonly are Chondrites, Nereites, Palaeophycos, Rhizocorallium, Gordia, Taenidium, Teichichnus, Planolites and Thalassinoides. In this paper, representative Zoophycos specimens are chosen from Jiaozuo cross section, western Henan province and Fucheng cross section, southeastern Shanxi province. Specimens used to test are cleaned up with distilled water, and dried in a drying box, then fixed on sample holders with conducting resin, at last coated with gold in ion sputtering apparatus. After specimen preparation, a scanning electron microscopy (SEM, model number: JSM-6390/LV) is used to observe morphology and structure of carbonate micro-shapes in specimens, and Energy Disperse Spectroscopy (EDS, model number: INCA-ENERGY 250) is applied to test their composition. Six kinds of carbonate micro-shapes (single mineral and aggregates) related to microbes are recognized by observing Zoophycos burrow fillings, which are spheroid-like, rhabditiform, areatus, net-like, vase-like and cerebrum-like, most of which show the different microbial structures. Based on spheroids' surface features, individual size and occurrence features, carbonate spheroids can be further divided into four types, including ①Spheroid-like carbonates with smooth surface (type 1),well-preserved, and most are 2 to 15 μm in diameter; ②Spheroid-like carbonates with unshaped surface and fine grain structure (type 2), the diameters of these spheroids range mostly from 2 to 10 μm, their outside surfaces show well-organized fine grain structure, but grain shapes are irregular; ③Spheroid-like carbonates with thorn surface and fine grain structure (type 3), the their diameters are 6 to 9 μm, their outside surfaces display well-organized fine grains; ④Spheroid-like carbonate aggregates (type 4) with smaller diameter, appearing in groups, and distributing intensively, embedded within calcite crystals. The spheroids present as monomer or multi-monomer in types 1-3, but occurred as groups in type 4. Based on surface features, individual shape and branch feature, carbonate micro-shape of rhabditiform can be further divided into six types, i.e., ①net-like rhabditiform with thorn surface (type 1), with obvious branches, showing an irregular network; ②rhabditiform with thorn surface (type 2), arranging in parallel to each other and appearing in groups; ③rhabditiform with spiral form (type 3), showing as a spiral, and occurring separately; ④rhabditiform with biserial form (type 4), arranging closely with smooth surface and occurring separately; ⑤rhabditiform in a straight line with smooth surface (type 5), displaying round cross section and appearing dispersedly; ⑥rhabditiform with smooth surface and expanding tail end (type 6), with tail expanding spheres and appearring independently. Areatus carbonate aggregates appear as druse, and showing granular, needle-like, sheet structures, surrounded by well-crystallized calcite. The monomers of net-like carbonate aggregates varied in shape, which interweave and overlap each other, forming irregular networks. Vase-like carbonate micro-shapes like a vase or a calabash, existing in isolation. Cerebrum-like carbonate micro-shapes, with unshaped fine grain structures on their surface, their composition mainly composed of CaCO3. Above carbonate micro-shapes found in the Zoophycos burrow filling indicates that these burrows is not a simple grazing trace or food storehouse, and it is likely to exsit a set of mutually beneficial and symbiotic relationships between the Zoophycos-maker and microbes. Microcosmic analysis showing, a part of the carbonate micro-shapes found in the Taiyuan Formation contains microbial structures, however, which is not yet enough to determine what kind of microbe species they are. On condition that combining the study of geo-microbial fossils and molecular fossils, it will be helpful to determine biological classification units and ecological characteristics of geo-microbes. This research contributes to explain the relationship between macro-organism and micro-organism, and to explore how the geomicrobial processes affect geochemical processses, and to provide new microcosmic data for finely analyzing the formation process and sedimentary evolution of carbonatite in Taiyuan Formation of the study area.
-
Key words:
- geomicrobiology /
- carbonate micro-shapes /
- Zoophycos /
- Taiyuan Formation /
- North China
-
[1] 龚一鸣, 胡斌, 卢宗盛, 等. 中国遗迹化石研究80年[J]. 古生物学报, 2009, 48(3):322-337[Gong Yiming, Hu Bin, Lu Zongsheng, et al. Study of trace fossils in the past eighty years in China[J]. Acta Palaeontologica Sinica, 2009, 48(3): 322-337] [2] 胡斌, 齐永安. 华北上石炭统太原组灰岩中的Zoophycos痕迹组构[J]. 煤田地质与勘探, 2000, 28(1):12-15[Hu Bin, Qi Yong'an. Zoophycos ichnofabric in limestones of Taiyuan Formation, North China[J]. Coal Geology & Exploration, 2000, 28(1): 12-15] [3] 胡斌, 周方, 宋慧波. 河南焦作地区下二叠统太原组遗迹化石及其沉积环境[J]. 古地理学报, 2010, 12(5):577-588[Hu Bin, Zhou Fang, Song Huibo. Ichnofossils and their sedimentary environments in the Lower Permian Taiyuan Formation in Jiaozuo area, Henan province[J]. Journal of Palaeogeography, 2010, 12(5): 577-588] [4] Hu Bin, Song Huibo, Liu Shunxi, et al. Sedimentary facies, ichnofossils and storm deposits in the Lower Permian Taiyuan Formation, Jiaozuo city, Henan province, central China[J]. Acta Geologica Polonica, 2010, 60(1): 45-52 [5] Seilacher A. Bathymetry of trace fossils[J]. Marine Geology, 1967, 5(5/6): 413-428 [6] Wetzel A, Werner F. Morphology and ecological significance of Zoophycos in deep-sea sediments off NW Africa[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 1981, 32: 185-212 [7] Wetzel A. The New Zealand Zoophycos revisited: morphology, ethology, and paleoecology-some notes for clarification[J]. Ichnos, 1992, 2: 91-92 [8] Olivero D. Zoophycos distribution and sequence stratigraphy. Examples from the Jurassic and Cretaceous deposits of Southeastern France[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 1996, 123(1/2/3/4): 273-287 [9] Olivero D. Early Jurassic to Late Cretaceous evolution of Zoophycos in the French Subalpine Basin (southeastern France)[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2003, 192(1/2/3/4): 59-78 [10] Kotake N. Paleoecology of the Zoophycos producers[J]. Lethaia, 1989, 22(3): 327-341 [11] Kotake N. Non-selective surface deposit feeding by the Zoophycos producers[J]. Lethaia, 1991, 24(4): 379-385 [12] Kotake N. Deep-sea echiurans: possible producers of Zoophycos[J]. Lethaia, 1992, 25(3): 311-316 [13] Bromley R G.Zoophycos: strip mine, refuse dump, cache or sewage farm?[J]. Lethaia, 1991, 24(4): 460-462 [14] Löwemark L, Schäfer P. Ethological implications from a detailed X-ray radiograph and 14C study of the modern deep-sea Zoophycos [J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2003, 192(1/2/3/4): 101-121 [15] Fu S, Werner F. Is Zoophycos a feeding trace?[J]. Neus Jahrbuch fur Geologie und Paläontologie, Abhandlungen, 1995, 195(1/2/3): 37-47 [16] Miller W, D' Alberto L. Paleoethologic implications of Zoophycos from Late Cretaceous and Paleocene limestones of the Venetian Prealps, northeastern Italy[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2001, 166(1/2): 237-247 [17] Bromley R G, Hanken N M. Structure and function of large, lobed Zoophycos, Pliocene of Rhodes, Greece[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2003, 192(1/2/3/4): 79-100 [18] Gong Y M, Xu R, Xie S C, et al. Microbial and molecular fossils from the Permian Zoophycos in South China[J]. Science in China Series D: Earth Sciences, 2007, 50(8): 1121-1127 [19] Gong Y M, Shi G R, Weldon E A, et al. Pyrite framboids interpreted as microbial colonies within the Permian Zoophycos spreiten from southeastern Australia[J]. Geological Magazine, 2008, 145(1): 95-103 [20] Gong Y M, Shi G R, Zhang L J, et al. Zoophycos composite ichnofabrics and tiers from the Permian neritic facies in South China and south-eastern Australia[J]. Lethaia, 2010, 43(2): 182-196 [21] 宋慧波, 胡斌, 张璐, 等. 河南省太原组沉积时期岩相古地理特征[J]. 沉积学报, 2011, 29(5):876-888[Song Huibo, Hu Bin, Zhang Lu, et al. Characteristics of lithofacies paleogeography of the Taiyuan Formation sedimentary period, Henan province[J]. Acta Sedimentologica Sinica, 2011, 29(5): 876-888] [22] 宋慧波, 金毅, 胡磊, 等. 豫西地区下二叠统太原组遗迹组构及其沉积环境[J]. 地质学报, 2012, 86(6):972-984[Song Huibo, Jin Yi, Hu Lei, et al. Ichnofabrics and their sedimentary environment of the Lower Permian Taiyuan Formation, western Henan[J]. Acta Geologica Sinica, 2012, 86(6): 972-984] [23] 吴贤涛, 胡斌, 王观忠, 等. 豫西焦作地区上石炭统浅海碳酸盐中的风暴沉积[J]. 沉积学报, 1987, 5(4):1-13[Wu Xiantao, Hu Bin, Wang Guanzhong, et al. Storm deposits in Upper Carboniferous shallow marine carbonates of Jiaozuo, Henan[J]. Acta Sedimentologica Sinica, 1987, 5(4): 1-13] [24] 河南省地质矿产局. 河南省区域地质志[M]. 北京:地质出版社, 1989:205-214[Henan Department of Geology and Mineral Industries. Regional Geology of Henan Province[M]. Beijing: Geological Publishing House, 1989: 205-214] [25] 龚一鸣, 徐冉, 谢树成, 等. 遗迹化石Zoophycos中的微生物和分子化石[J]. 中国科学(D辑):地球科学, 2007, 37(6):713-719[Gong Yiming, Xu Ran, Xie Shucheng, et al. Microorganism and molecular fossil in Zoophycos ichnofossil[J]. Science China (Seri. D): Earth Sciences, 2007, 37(6): 713-719] [26] 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] [27] 温志峰, 刘显太, 钟建华, 等. 柴达木盆地新近纪叠层石中微生物化石组合的发现与钙化方式研究[J]. 地质学报, 2010, 84(2):263-271[Wen Zhifeng, Liu Xiantai, Zhong Jianhua, et al. Discovery of microorganism fossil and study on microorganism induced calcification in Miocene stromatolites, Qaidam Basin, China[J]. Acta Geologica Sinica, 2010, 84(2): 263-271]
计量
- 文章访问数: 1031
- HTML全文浏览量: 11
- PDF下载量: 933
- 被引次数: 0