Discovery of Devonian Bryozoa in Longjiang, Guangxi and Its Geological Significance

doi:10.19657/j.geoscience.1000-8527.2020.040

Abstract

Abstract:

Devonian stratigraphy is well-developed and widely distributed in Guangxi, which provides a good target for studying the Devonian stratigraphic sequence and paleontology. Bryozoans were first discovered from the Devonian in Longjiang area (Longlin, Guangxi),including 21 species of 13 genera:Cystiramus sp., Eostenoporahuishuiensis, Fenestella? sp., Fistuliporacollina, Fistuliramusparallelus, F.mishanensis, F.parallelus grandoporus, F.pusillus, F.sp., Heloporahastifera, H. ninglangensis, Leptotrypa adhaerens, L. cf. adhaerens, L. lamellata, Meekopora wangyouensis, Orthoporasinensis, Petalotrypa tumida, P. cf.tumida, Semicoscimum cf. dushanensis, Rhombopora sp., and Streblotrypa sp.Based on the sedimentary environment and ecological characteristics of bryozoans from the Devonian Longjiang, the local sedimentary evolution is described as follows: (1) In Early Devonian, the sedimentary environment belonged to sand flat subfacies(tidal flat facies) during the earliest Devonian (D₁l), then evolved into mixed-flat subfacies (shore intertidal zone with alternating mud flat and sand flat) (D₁h)→platform-concave (alcove) subfacies of a half-limited-open-platform facies (D₁d) →low-energy subtidal zone (D_1-2s¹)→high-energy subtidal zone-tidal-flat facies (D_1-2s²). (2)In Middle Devonian, with the seawater deepened, the area transited into low-energy subtidal sedimentary environment (D_1-2s²)→platform shelf subfacies of the platform basin (D_1-2d). (3)In Late Devonian, basin subfacies(platform-basin facies)occurred with seawater deepening during the early stage (D₃l),and the same subfacies maintained till the late stage (D₃w)in spite of the slightly shallowing of seawater.

Key words: Devonian, bryozoan, palaeoecology, sedimentary environment, Longjiang,Guangxi

CLC Number:

P534.4
Q913

LI Yuewei, WANG Chengshan, LI Guobiao, XU Xing, MA Wen’en, LI Xingpeng, LÜ Changliang, LÜ Beibei, ZHANG Wenyuan, HAN Dandan. Discovery of Devonian Bryozoa in Longjiang, Guangxi and Its Geological Significance[J]. Geoscience, 2020, 34(04): 745-756.

Figures/Tables 4

Fig.1 Sketch map showing division of structural units in Guizhong Depression and the location of the study area(modified after refs.[24-25])

Fig.2 Devonian comprehensive column in Longjiang area, Luzhai, Guangxi

Fig.3 Representative elements of the Devonian bryozoan fauna in Longjiang, Luzhai, Guangxi

Fig. 4 Devonian typical lithology and fossils in Longjiang, Luzhai, Guangxi

References 37

[1]	杨敬之, 陆麟黄. 化石苔藓虫[M]. 北京: 科学出版社, 1965: 1-50.
[2]	郝家胜, 夏凤生, 杨群. 苔藓动物的起源与系统发生研究进展:形态学和分子生物学的证据[J]. 微体古生物学报, 2001,18(4):385-391.
[3]	武汉地质学院古生物教研室. 古生物学教程[M]. 北京: 地质出版社, 1979: 1-521.
[4]	ZIMMER R L. Morphological and developmental affinities of the lophophorates[M] //LARWOOD G P. Living and Fossil Bryozoa. London: Academic Press, 1973: 593-599.
[5]	任淑仙. 无脊椎动物学[M]. 北京: 北京大学出版社, 1990: 282-289.
[6]	HALANYCH K M, BACHELLER J D, AGUINALDO A M A, et al. Evidence from ¹⁸S ribosomal DNA that the lophophorates are protostome animals [J]. Science, 1995,267:1641-1643.
[7]	GIRIBET G, DISTEL D L, POLZ M, et al. Triploblastic relationships with emphasis on the acoelomates and the position of Gnathostomulida, Cycliophora, Platyhelminthes, and Chaetognatha: A combined approach of ¹⁸ Sr DNA sequences and morphology [J]. System Biology, 2000,49(3):559-562.
[8]	中国科学院南京地质古生物研究所. 外表似植物却拥有动物“内核”的苔藓虫[EB/OL].化石网[ 2018- 09- 28] http://www.uua.cn.
[9]	杨敬之. 关于中国之苔藓虫[J]. 地质论评, 1950,15(2):184.
[10]	杨敬之. 广西永淳中泥盆纪苔藓虫[J]. 古生物学报, 1954, 2(2):207-226,图版Ⅰ-Ⅲ.
[11]	胡兆珣. 广西横县中泥盆统郁江组中的苔藓虫新资料[J]. 古生物学报, 1965, 13(2):218-241,图版Ⅰ-Ⅳ.
[12]	胡兆珣. 贵州独山中泥盆世早期的变口目苔藓虫[J].古生物学报, 1980, 19(4):289-295,图版Ⅰ-Ⅱ.
[13]	杨敬之, 夏凤生.贵州独山和惠水王佑的泥盆纪苔藓虫[J]. 地质学报, 1976, 50(1):57-73, 图版Ⅰ-Ⅳ.
[14]	夏凤生, 马俊业. 滇西北横断山区晚古生代苔藓动物[J]. 微体古生物学报, 2009,26(4):351-384.
[15]	郭令智, 施央申, 马瑞士, 等. 论活动大陆边缘地质学研究的若干新问题[J]. 南京大学学报(自然科学版), 1985,21(4):689-697.
[16]	侯方浩, 黄继祥, 方少仙, 等. 中国南方泥盆纪、石炭纪深水沉积环境—沉积特征、构造活动及含油气性[J]. 西南石油学院学报, 1988,10(4):1-19.
[17]	柳淮之, 钟自云, 姚明. 扬子地块晚古生代裂谷与地体[J]. 桂林冶金地质学院学报, 1988,8(4):321-331.
[18]	林刚, 唐兰. 广西泥盆纪海盆的板块构造环境[J]. 中国区域地质, 1991(4):342-348.
[19]	广西壮族自治区地质矿产局. 广西泥盆纪沉积相古地理及矿产[M]. 南宁: 广西人民出版社, 1987: 1-292.
[20]	周怀玲, 张振贤, 吴怡. 广西泥盆纪的古地理格局[J]. 广西地质, 1988,1(1):65-70.
[21]	赵自强, 丁启秀. 中南区区域地层[M]. 武汉: 中国地质大学出版社, 1996: 71-123.
[22]	威尔逊. 地质历史中的碳酸盐相[M]. 冯增昭, 译.北京:地质出版社, 1981: 1-365.
[23]	关士聪, 演怀玉, 陈显群, 等. 中国海陆变、海域沉积相与油气:晚元古代—三叠纪 [M]. 北京: 科学出版社, 1984.
[24]	吴国干, 姚根顺, 徐政语, 等. 桂中坳陷改造期构造样式及其成因[J]. 海相油气地质, 2009,14(1):33-40.
[25]	陈粤, 黄文芳, 梁裕平, 等. 广西鹿寨地区鹿寨组一段黑色页岩特征及沉积环境分析[J]. 矿产与地质, 2017,31(3):605-612.
[26]	曾允孚, 刘文均, 陈洪德, 等. 华南右江复合盆地的沉积构造演化[J]. 地质学报, 1995,69(2):113-124.
[27]	陈洪德, 侯明才, 刘文均, 等. 海西—印支期中国南方的盆地演化与层序格架[J]. 成都理工大学学报(自然科学版), 2004,31(6):629-635.
[28]	梅冥相, 李仲远. 滇黔桂地区晚古生代至三叠纪层序地层序列及沉积盆地演化[J]. 现代地质, 2004,18(4):555-562.
[29]	OSBURN R C. The ecology of marine bryozoa[M] //HEDGPOTH J W. Treatise on Marine Ecology and Paleoecology. Washington: Geological Society of America, 1957: 641-672.
[30]	HINCKS T. A history of the British marine polyzoa[J]. Nature, 1880,23:51-52.
[31]	REMANE A. Einführung in die zoolgie der Nord-und Ostsee//GRIMP G, WAGLE R. Tierwelt Nord-und Ostsec. Leipzig:Akademische Verlagsgeselischaft, 1940: 1-2.
[32]	SCHÄFER W. Actuo-Palaontologie Nach Studien in der Nordsee[M]. Kramer: Frankfort, 1962: 1-666.
[33]	SEHOPF T J M. Paleoecology of ectoprocta (bryozoans)[J]. Journal of Paleontology, 1969,43:234-244.
[34]	杨敬之, 钱文龙. 论苔藓虫生态[J]. 微体古生物学报, 1987,4(3):329-334.
[35]	BROOD K. Cyclostomatous bryozoa from the Upper Cretaceous and Danian in Scandinavia[J]. Stockholm Contributions inGeology, 1972,26:1-464.
[36]	HARMELIN J G. Morphologic variation and ecology of the recent cyclostome bryozoan “idmonea” Atlantica from the Mediterranean [M] //LARWOOD G P. Living and Fossil Bryozoan, Recent Advances in Research. New York: Academic Press, 1973: 95-106.
[37]	ROSS J R P. Paleoecology of Ordovician bryozoa[M] //BRUTON D L. Aspects of the Ordovician System. Oslo: Palaeontolo-gical Contributions from the University of Oslo, 1984: 141-145.