用户名: 密码: 验证码:
陕南宁强地区前寒武系—寒武系界线附近微体骨骼化石及其沉积环境的研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
前寒武系-寒武系界线的研究一直是古生物学界所关注的热点问题,在这一界线附近发生的生物演化事件也一直是古生物学界的热点。陕西南部宁强地区的埃迪卡拉系-寒武系地层出露完整,化石丰富,是研究前寒武系-寒武系界线附近生物演化事件的理想区域。
     本文通过大量的野外实地踏勘、样品采集、室内微体化石处理、SEM扫描电镜照相、岩石光面和薄片的磨制等一系列方法,对陕南宁强,勉县,西乡等地的数个剖面进行了数次重点野外观测,并在室内处理小壳化石及伴生的胚胎化石4000余个,早期的骨骼化化石克劳德管、震旦管200余个,磨制光面20个,薄片200余个。
     从古生物和古生态学的角度对原始锥石、阿纳巴管类、原牙形刺、克劳德管化石等进行了讨论,主要结论为:
     1、对一种特殊的两侧对称、横切面为十边形的原始锥石进行了形态学描述,认定其属于六角锥石属,增加了一项新的形态学用语(侧脊角),推测其与五辐射的Punctatus具有亲缘关系。推测其可能营游泳或漂浮生活,其空腔可能具有一定的浮力,下部有用于滤食和呼吸的软体部分;
     2、对阿纳巴管管体的弯曲角度提出了新的解释,认为其营直立生长,弯曲的产生是由于管体倒伏后继续直立生长的结果。将阿纳巴管与埃迪卡拉三辐射的奇异骨骼化石进行了形态学的比较,根据形态学的相似性推测其可能具有演化上的关系;
     3、根据前人研究的成果,对原牙形刺化石进行总结讨论,并对一种形态特殊、保存相对完好的原牙形刺化石进行了描述,推测其可能属于原牙形刺保存的捕食结构;
     4、克劳德管是最早的骨骼化石,也被认为是极具潜力的埃迪卡拉纪标准化石之一本文通过大量的实体化石和薄片观察,总结了克劳德管的类型,认为其只具有一种结构,即不具有共壁的克劳德管,其形态上存在的差别可能是埋藏偏差导致的。根据观察我们推测,其管体可能营直立生长,且套锥具有收缩功能;
     5、对胚胎化石进行了重点讨论。寒武纪的胚胎化石常常缺失处于卵裂过程的个体,这也引起了很多猜想和假设,本文对研究中发现的可能处于卵裂期的胚胎化石进行了重点讨论,部分标本从形态学上可以与陡山沱期的胚胎化石进行比较,并根据发育的连续性建立了一球多管的发育机制。最后对宽川铺的大量的球形化石进行了统计学上的分析;
     6、通过大量的野外踏勘和镜下薄片观察,讨论了宽川铺生物群的沉积环境和埋藏条件,根据丘状交错层理的宏观结构和薄片上反映的微观沉积结构,推测其可能是风暴沉积;
The Precambrian-Cambrian boundary is a critical paleobiological concern and receives increasingly important scientific attentions. Ediacaran successions are well-exposed in the Ningqiang area of southern Shaanxi Province, South China where abundant fossil materials have been well-known and thus would be an ideal study area providing important insights into our understanding of Precambrian-Cambrian biotic evolutions.
     Filed sampling, laboratory analysis, SEM photography, thin-sectioning, and slabbing are conducted in this study. More than 4,000 Early Cambrian specimens of Small Shelly Fossils and the co-occurring animal embryos and more than 200 specimens of latest Ediacaran skeletonized fossils Cloudina and Sinotubulites are recovered from phosphorites and cherts of the Early Cambrian Kuanchuanpu Formation and dolostones of the latest Ediacaran Beiwan Member of the Dengying Formation, respectively. In addition, more than 20 polished slabs and more than 200 thin-sections are studied to constrain the depositional environments of these fossils.
     Morphology, taxonomy, and paleoecology of a variety of taxa, including Conulariids, Anabarites, Protoconodonts, Cloudinids, are discussed in this paper:
     1. Morphology of a newly found bilaterial Conulariids is described with a new morphological term. This new taxon is ascribed to Hexangulaconulariids. This taxon is presumed to be a nekton or plankton and the hollow lumen may have been capable of generating buoyancy. Within the lower part of the lumen, however, possesses the respiratory and feeding organs. We postulated that this taxon may have close phylogenetic relationships with the pentagonal fossil Punctatus.
     2. Anabarites is interpreted as a erect benthos and the curved tube is due to the destructive influence of storm-generated events. Morphology of anabarites is compared with an Ediacaran tri-symmetrical skeletal fossil and they may have close taphonomic links.
     3. A review and discussion on Protoconodonts are summarized on the basis of previous study. In addition, a well-preserved Protoconodont showing unusual morphological feature is described and interpreted as possible predatorial texture remains on Protoconodont.
     4. Cloudina has been suggested to be the earliest biomineralized fossil and a potential index fossil in the Ediacaran. Observed from body fossils and thin-sections, we suggest that all specimens share the same morphology and thus only one taxon is existed. The seemingly morphological differences are resulted from taphonomic bias. Cloudina is an erect epi-bethos and funnel-shaped walls of this tubular fossil don't eccentrically intersected.
     5. This study is focused on the discussion of animal embryos. The lack of cleavage-stage embryo forms has led to inaccurate assumptions on this fossil. Possible cleavage-stage forms are discussed and compared with Ediacaran embryos from the Doushantuo Formation and a "one egg, multiple tubes"-like developmental sequence-an initially developed egg and diversified tubular forms of post-egg stage-is reconstructed. Statistical analysis is also included in this study.
     6. A sedimentary interpretation-the Kuanchuanpu assemblage was deposited in storm-generated sediments-is drawn on the basis of not only hummocky cross stratification seen on the outcrops but also microfacies evidence observed in thin-sections.
引文
1.蔡耀平,华洪.高家山生物群中的黄铁矿化作用[J].科学通报,2006,20:2404—2409
    2.陈均远,迟慧梅.贵州前寒武纪陡山沱组磷酸盐化胚胎和幼虫及其亲缘性.科学通报[J],2005,50(12):1750-1757
    3.陈均远,彭晴晴.寒武纪早期疑难生物类群阿纳巴管(Anabarites)亲缘性的探讨[J].古生物学报,2007.44(1):57-65
    4.陈孟莪,陈祥高,劳秋元.陕南震旦系上部地层中的后生动物化石[J].地质科学,1975,2(2):181—190
    5.陈孟莪.四川峨眉麦地坪剖面震旦系-寒武系界限的新认识及有关化石群记述[J].地质科学,1982.3(4):253-262
    6.陈孟莪.震旦纪生命大爆发[J].前寒武纪研究进展,1999a,22(3):36-47
    7.陈梦莪.寒武世最早期的古胚胎化石新观察[J].地质科学,1999b.34(4):525—527
    8.陈永权,蒋少涌,凌洪飞.早寒武纪小壳化石的地球化学研究[J].地球学报,2005,26(增刊):195-19
    9.陈哲,孙卫国.陕南晚震旦世后生动物管状化石Cloudina和Sinotubulites [J].微体古生物学报,2001,18(2):180-202
    10.陈哲,孙卫国,华洪陕南晚震旦世Gaojiashania的保存特征及其形态解释[J].古生物学报,2002,41(3):448-454
    11.迟慧梅,陈均远,李家维.前寒武纪瓮安生物群具围卵腔结构的胚胎及其发育序列[J].古生物学报,2003,42(3):448-451
    12.储雪蕾.新元古代雪球事件[J].矿物岩石地球化学通报,2004,23(2):233-238
    13.丁莲芳,李勇,安国勤.论陕南震旦系-寒武系界线[J].西安地质学院学报,1983,2:9-23
    14.丁莲芳,张录易,李勇等.科学技术出版社.扬子地台北缘晚震旦世-早寒武世早期生物群研究[M].北京:科学技术文献出版社,1992,1-156
    15.丁莲芳,李勇,陈会鑫.湖北宜昌震旦系-寒武系界线地层Micrhystridium Regulare化石的发现及其地层意义[J].微体古生物学报,1992,9(3):303-309
    16.董熙平.寒武纪胚胎Markuelia的发育序列[J].科学通报,2007,52(5):572-577
    17.范德廉,叶杰,场瑞英,黄忠祥.扬子地台前寒武-寒武纪界线附近的地质事件与成矿作用[J].沉积学报,1987,5(3)81-95
    18.郭成贤,肖传桃,朱忠德中.扬子地区震旦-寒武系界线附近事件地层学[J].江汉石油学院学报,1999,21(2):1—844
    19.何廷贵.扬子地台早寒武世锥石动物及其早期演化[J].成都地质学院学报,1987,14(2): 7-18
    20.胡修棉,王成善,李祥辉.大洋缺氧事件的碳稳定同位素响应[J].成都理工学院学报,2001,28(1):1-6
    21.华洪,陈哲,张录易.Shaanxilithes在贵州的发现及其意义[J].地层学杂志.2004a,28(3):265-269
    22.华洪,陈哲,张录易.陕南早寒武世磷酸盐化囊胚期及原肠胚期动物化石[J].科学通报,2004b,49(2):177-180
    23.华洪,陈哲,张录易.陕南新元古代末期微体管状疑难化石.古生物学报[J],2005,44(4):487-93
    24.华洪,张录易,张子福,等.陕南末元古代高家山生物群主要化石类群及其特征[J].古生物学报,2000a,39(4):507-515
    25.华洪,张录易,张子福,等.晚震旦世高家山生物群化石新材料.古生物学报[J].2000b39(3):381-390
    26.华洪,张录易,张子福,等.高家山生物群化石组合面貌及其特征[J].地层学杂志,2001,25(1):13-17
    27.华洪,张录易,谢从瑞.陕南新元古代末期奇异骨骼化石新发现及其意义[J].地球学报,2002,23(5):387-394
    28.华洪,张录易,陈哲.陕南晚震旦世骨骼化石中的微生物磷酸盐化作用[J].古生物学报,2003,42(2):189-199
    29.贾志海,洪天求.新元古代九里桥组中的风暴活动记录及生物学响应[J].中国科学技术大学学报,2005,35(6):789-898
    30.李国祥,钱逸.磷酸盐化球状化石研究述评[J].微体古生物学报,1999,16(3):287-296
    31.李朋,华洪,张录易,等.陕南早寒武世磷酸盐化的Punctatus及其个体发育序列[J]. 科学通报,2007a,52(18):2153-2160
    32.李朋,华洪,张录易,等.陕南早寒武世壳体Anabarites内部结构及亲缘关系探讨[J].古生物学报,2007b,46(3):327-333
    33.李朋.高家山生物群沉积特征与碳同位素地球化学研究[M].硕士学位论文,2008,西北大学
    34.李勇.上扬子晚震旦世地层古生物研究[M].博士学位论文.2002,西北大学
    35.林世敏,张运芬,张录易,等.陕南震旦系上统高家山组发现的后生动物、遗迹化石和宏观藻类[J].陕西地质,1956,4(1):9-17
    36.刘宝珺,许效松,等.中国扬子地台西缘寒武纪风暴事件与磷矿沉积[J].沉积学报,1987,5(3):29-41
    37.刘云焕.宽川铺生物群与瓮安生物群中的球形类化石研究[M].硕士学位论文,2002,长安大学
    38.刘云焕,李勇,邵铁全,等.陕西南部早寒武世原始锥石类Carinachitids两新种记述[J].微体古生物学报,2005,22(3):311-321
    39.刘云焕,李勇,邵铁全,等.陕西宁强地区早寒武世磷酸盐化Punctatus新材料[J].古生物学报,2006a,45(1):95-101
    40.刘云焕,李勇,邵铁全,等.陕西早寒武世磷酸盐化Punctatus奇异星状口盘的发现及其形态功能分析[J].微体古生物学报,2006b,23(1):62-69
    41.刘云焕,邵铁全,韩建等.陕南早寒武世早期磷酸盐化Punctatus发育模式研究[J].微体古生物学报,2009,26(3):243-248
    42.罗惠麟,蒋志文,武希彻,等.云南东部震旦系-寒武系界线[J].昆明:云南人民出版社1982.163-200
    43.罗惠麟.中国晚前寒武纪至早寒武世生物事及前寒武系-寒武系界线[J].地层学杂志,1992,12(1)12-19
    44.罗惠麟,胡世学,陈良忠,等.昆明地区早寒武世澄江动物群[M].昆明:云南科技出版社,1999.1-129
    45.马国干,李华芹,张自超.华南地区震旦系时限范围的研究[J].中国地质科学院宜昌地质矿产研究所所刊.1984,13:1-17
    46.马永生主译.碳酸盐微相—分析、解释及应用[M].北京:地质出版社,566-567
    47.钱逸.华中西南区早寒武世梅树村阶的软舌螺纲及其它化石[J].古生物学报,1977,
    16(2):255-275
    48.钱逸.中国小壳化石研究现状与展望.微体古生物学报[J],1992,9(3):327-329
    49.钱逸.中国小壳化石分类学与生物地层学[M].北京:科学出版社.1999,1-60
    50钱逸,李国祥,蒋志文,等.我国寒武系底部几种磷酸盐化保存的蓝菌类化石[J].微体古生学报,2007,24(2):222-228
    51.邵铁泉,李勇,等.陕西宁强早寒武世磷酸盐化具星状表饰胚胎化石研究[J].微体古生物学报,2006,23(3):275-280
    52.施春华.磷矿的形成与Rodinia超大陆裂解、生物爆发的关系—以贵州瓮安、开阳织金磷矿为例[M].博士学位论文,2005,中国科学院地球化学研究所
    53.孙毅霖.寒武纪生命大爆发现象的困惑与思考[J].自然辩证法通讯,2008,30(173):101-107
    54.王为,谭惠忠.贝壳堤的形成与风暴沉积-以广东台山长湾贝壳堤为例[J].热带地理,2003,23(3):209-213
    55.吴朝东.湘西震旦-寒武纪交替时期古海洋环境的恢复[J],2007(增刊)45-57
    56.吴贤涛,胡斌,王观忠,张国成.豫西焦作地区上石炭统浅海碳酸岩盐中的风暴沉积[J].沉积学报,1984,5(4):75-83
    57.刑裕盛,岳昭.中国震旦系-寒武系界线[J].中国科学院地质研究所所刊,1984,10:111-125
    58.徐过冬,范代读.古风暴学研究进展地球科学进展[J].地球科学进展,2007,22(12):1274-1280
    59.薛耀松,唐天福,俞从流等.贵州瓮安-开阳地区陡山沱期含磷岩系的大型球形绿藻化石[J].古生物学报,1995,34(8):688-706
    60.杨春亮,沈保丰,宫晓华.我国前寒武纪地质研究进展与展望[J].地层学杂志,2005,29(增刊)98-110
    61.杨杰东,孙卫国,王银喜,等.云南晋宁梅树村剖面前寒武系-寒武系界线化石Sm-Nd同位素年龄测定.中国科学,1992,(3):322-327
    62.杨瑞东.晚震旦世陡山沱期后生生物群的古生态环境探讨[J].岩相古地理,1999a,19(5): 53-59
    63.杨瑞东,赵元龙.我国早期后生动物群的特异埋藏机理探讨[J].沉积学报,1999b,17(1):161-165
    64.殷继成,丁莲芳,何廷贵,等.四川峨嵋-甘洛地区震旦纪地层古生物及沉积环境[M].成都:四川人民出版社,1980.1-231
    65.尹崇玉,岳昭,高林志.磷酸盐化原肠胚化石在瓮安陡山沱组磷块岩中的发现[J].科学通报,2001,46(12):1036-1039
    66.岳昭.Olivooides属的微结构及其系统位置[J].中国地质科学院地质研究所所刊,1986,43(17):1858-1862
    67.岳诏.扬子地台前寒武系-寒武系过渡层骨骼微化石生物地层学及古生物学[M].硕士学位论文,1990,中国地质科学院
    68.岳昭,S Bengtson.寒武纪大爆发中的磷酸盐化胚胎化石[J].科学通报,1998,43(17):1858-1862
    69.张二朋,牛道韫,霍有光,等.秦巴及邻区地质-构造特征概论[M].北京:地质出版社,1993.35-52
    70.张国栋,王益友,朱静昌,颜建平.现代滨岸风暴沉积-以舟山普陀岛、朱家尖岛为例[J].沉积学报,1987,5(2):17-32
    71.张录易.陕西宁强晚震旦世晚期高家山生物群的发现和初步研究[J].西安地质矿产研究所所刊,1986,13:67-88
    72.张录易,华洪.震旦纪晚期管壳化石类群及其意义[J].古生物学报,2000,39(3):326--333
    73.张录易,华洪,谢从瑞.新元古代末期高家山生物群研究新进展与展望[J].中国地质,200128(9):19-24
    74.张卫红.发育生物学[J].北京:科学教育出版社,2001:1-200
    75.张晓东.四川盆地北缘寒武系含磷岩系的沉积环境研究[M].硕士学位论文,西安地质学院,1987:1-65
    76.赵自强,刑裕盛,丁启秀,等.湖北震旦系[M].武汉:中国地质大学出版社,1988.97-110
    77.周传明.贵州瓮安地区上震旦统碳同位素特征[J].地层学杂志,1997,21(2):124-129
    78.周红瑞,陈健强.沉积学及古地理教程[M].北京:地球科学出版社,2004.186-189
    79. Bengtson S, The structure of some Middle Cambrian conodonts and the early evolution of conodont structure and function. Lethaia[J],1976, (9),185-206
    80. Bengtson S, Yue Z.1992. Predatorial borings in late Precambrian mineralized exoskeletons.Science[J],1992,257:367-369
    82. Bengtson S, Yue Z. Fossilized Metazoan Embryos from the Earliest Cambrian[J]. Science,1997,277:1645-1648
    83. Mcllroy D., Szaniawsk.A lower Cambrian protoconodont apparatus from the Placentian of southeastern Newfoundland [J], Lethaia,2000(33):95-102
    84. Cai Y P, Hua H. Pyritization in the Gaojiashan Biota. Chinese Science Bulletin[J],2007, 52(5):645-650
    85. Condon D, Zhu M Y, Bowring S, et al., U-Pb ages from the Neoproterozoic Doushantuo Formation, China[J]. Science,2005,308:95-98
    86. Chen D, Dong W, Zhu B, et al., Pb-Pb ages of Neoproterozoic Doushantuo phosphorites in South China:constraints on early metazoan evolution and glaciation events[J]. Precambrian Research,2004,132:123-132
    87. Chen Z, Bengtson S, Zhou C M, et al., Tube structure and original composition of Sinotubulites:shelly fossils from the late Neoproterozoic in southern Shaanxi, China[J]. Lethaia,2007,2:1-9
    88. Hua H, Pratt B R, Zhang L Y. Borings in Clouditza Shells:Complex Predator-Prey Dynamics in the Terminal Neoproterozoic[J]. Palaios,2003,18:454-459
    89. Hoffman P F, Kaufman A J, Halverson G P, et al, A Neoproterozoic snowball earth[J]. Science,1998,281:1342-1346
    90. Hua H, Pratt B R, Zhang L Y. Borings in Clouditza Shells:Complex Predator-Prey Dynamics in the Terminal Neoproterozoic. Palaios[J],2003,18:454-459
    91. Hua H, Chen Z, Zhang L Y. Early Cambrian phosphatized blastula-and gastrula-stage animal fossils from southern Shaanxi[J]. Chinese Science Bulletin,2004,49(5): 487-490
    92. Hua H, Chen Z, Yuan X L, et al., Skeletogenesis and asexual reproduction in the earliest biomineralizing animal Cloudina[J]. Geology,2005,33(4):277-280
    93. Hua H, Chen Z, Yuan X L. The advent of mineralized skeletons in Neoproterozoic Metazoa-new fossil evidence from the Gaojiashan Fauna[J]. Geological Journal,2007, 42:263-279
    94. J Vannier, M Steiner, E Renvoise, S.-X Hu and J.-P Casanova Early Cambrian origin of modern food webs:evidence from predator arrow worms Biological Science 2007,274, 627-633
    95. Knoll A H, Walter M R. Latest Proterozoic stratigraphy and earth history. Nature,1992, 356:673-678
    96. Li J W, Chen J Y, Hua T. Precambrian Sponges with Cellular Structures. Science, 16.1998,279:879-882
    97. Li P, Hua H, Zhang L Y, et al., Lower Cambrian phosphatized Punctatus from southern Shaanxi and their ontogeny sequence[J]. Chinese Science Bulletin,2007,2820-2828
    98. Rosen, S. Uber einige neue Problemmatica in einem fossilfuhrenden Kalksein aus dem nordschwedichen Hochgebirge[J]. Bull. G.I. U. Uppsala,1999,16:159-168

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700