Sedimentary facies and sea-level change across the Middle-Upper Devonian boundary at Caiziyan section， Guangxi: The mid-Givetian regression and its timing in South China
Li Hua1, Ma Xueping1, Wei Longming2
1 School of Earth and Space Sciences， Peking University， Beijing 100871 2 Department of Resource and Environment， Guilin University of Technology， Guilin 541004， Guangxi
Abstract The Caiziyan section was located in a platform margin zone， with relatively abundant benthic and common-rare pelagic fossils， which may be regarded as a quite suitable reference section for stratigraphic correlation and division. On the basis of lithofacies and biofacies characteristics， sea-level change history is reconstructed for the interval from the Givetian to the Early Frasnian times. The Early Givetian Donggangling Formation of the study area may represent deposits under a persistent transgressive phase， probably with a slight sea-level fall at the end of the Lower varcus Zone. The lower part of the “Gubi” Formation is complex in lithology， probably resulting from extensive sea-level changes， including a significant transgressive event at the initial period of the Lower hermanni-cristatus Zone and the long-recognized mid-Givetian regression， whose timing has been precisely determined to be the Upper varcus Zone for the first time. The Late Givetian deposits host abundant tabulate corals and reef-associated bioclasts， including stromatoporoids， crinoid stems etc.， implying that the study area was probably located on the upper slope in front of a reef complex. The upper part of the “Gubi” Formation(conodont falsiovalis to lower transitans zones)is characterized by alternating medium-thin and thick bedded limestones(mainly with bioclasts of level-bottom organisms)， which indicates a change from fore-reef to fore-shoal environments， probably with little overall sea-level change across the Middle-Upper Devonian boundary. The Rongxian Formation(basal part)is characterized by grayish to gray-white thin-bedded to massive limestones， which may represent a significant sea-level rise in the Middle transitans Zone in South China. The finely-medium crystalline dolostone layer at Caiziyan is within the Upper varcus Zone， with normal marine fossils including corals and conodonts. The proposed interpretation for this dolostone layer is that a substantial sea-level fall event happened in the Upper varcus Zone in the Guangxi area， based on temporal and spatial correlation of the dolomitized layers and evidence of sea-level fall in other sections.
About author: Li Hua， born in 1981. Now she is engaged in biostratigraphy and sedimentology in Peking University as a doctor candidate. E-mail: jujuli.student@sina.com. About the corresponding author Ma Xueping is a professor of Peking University. He is mainly engaged in paleontology， stratigraphy and sedimentology in Peking University. E-mail:maxp@pku.edu.cn.
Cite this article:
Li Hua,Ma Xueping,Wei Longming. Sedimentary facies and sea-level change across the Middle-Upper Devonian boundary at Caiziyan section， Guangxi: The mid-Givetian regression and its timing in South China[J]. JOURNAL OF PALAEOGEOGRAPHY, 2009, 11(5): 503-512.
Li Hua,Ma Xueping,Wei Longming. Sedimentary facies and sea-level change across the Middle-Upper Devonian boundary at Caiziyan section， Guangxi: The mid-Givetian regression and its timing in South China[J]. JOPC, 2009, 11(5): 503-512.
白顺良， 金善燏， 宁宗善. 1982. 广西及临区泥盆纪生物地层［M］. 北京: 北京大学出版社， 1-165. 陈代钊， 陈其英. 1994. 华南泥盆纪沉积演化及海水进退规程［J］. 地质科学， 29(3):246-255. 杜远生， 龚一鸣， 刘本培， 等. 1996. 华南板块泥盆纪层序地层及海平面变化［J］. 岩相古地理， 16(6):14-23. 杜远生， 龚一鸣， 吴诒， 等. 1997. 黔桂地区泥盆纪层序地层和台内裂陷槽的形成演化［J］. 沉积学报， 15(4):11-17. 杜远生， 龚一鸣， 张哲， 等. 2009. 南华海泥盆纪烃源岩的古氧相和缺氧环境模式——以广西中、上泥盆统为例［J］. 古地理学报， 11(1):28-36. 龚一鸣， 吴诒， 杜远生. 1994. 黔桂泥盆纪层序地层及海平面变化的频幅、速度和相位［J］. 地球科学， 19(5):575-586. 龚一鸣， 吴诒， 杜远生， 等. 1997. 华南泥盆纪海平面变化节律及圈层耦合关系［J］. 地质学报，71(3):212-226. 侯鸿飞， 马学平. 2005. 国际泥盆系GSSP与华南泥盆系划分［J］. 地层学杂志， 29(2):154-159. 侯鸿飞， 王士涛. 1988a. 中国的泥盆系［M］. 北京: 地质出版社， 1-348. 侯鸿飞， 万正权， 鲜思远， 等. 1988b. 四川龙门山地区泥盆纪地层古生物及沉积相［M］. 北京: 地质出版社， 487. 江大勇， 丁干， 白顺良. 2000. 广西六景泥盆纪吉维阶—弗拉斯阶界线层牙形石生物地层［J］. 地层学杂志，24(3):195-200. 邝国敦， 赵明特， 陶业斌. 1989. 中国海相泥盆系标准剖面—广西六景泥盆系剖面［M］. 湖北武汉: 中国地质大学出版社， 1-251. 李镇梁. 2005. 广西泥盆纪至早石炭世地层的平行不整合［J］. 南方国土资源， (11):24-29. 廖卫华， 马学平. 2007. 华南浅海相泥盆系吉维特阶和弗拉阶四射珊瑚组合特征［J］. 古生物学报， 46(2):213-224. 沈建伟. 1995. 广西桂林泥盆纪牙形刺组合序列与海平面变化［J］. 微体古生物学报， 12(3):251-273. 谭正修， 董振常， 唐晓珊. 1987. 论棋梓桥灰岩［J］. 地层学杂志， 11(2):77-90. 汤朝阳， 王敏， 姚华舟， 等. 2006. 白云石化作用及白云岩问题研究述评［J］. 东华理工学院学报， 29(3)： 205-210. 吴诒， 龚一鸣， 杜远生. 1997. 华南泥盆纪层序地层及海平面变化［M］. 湖北武汉: 中国地质大学出版社， 1-110. 吴诒. 1997. 华南泥盆纪层序地层系、统、阶界线的建立与生物地层、年代地层界线的对比［J］. 岩相古地理，17(4):29-39. 张学丰， 胡文瑄， 张军涛. 2006. 白云岩成因相关问题及主要形成模式［J］. 地质科技情报， 25(5):32-40. 钟铿， 吴诒， 梁演林， 等. 1992. 广西的泥盆系［M］. 湖北武汉: 中国地质大学出版社， 1-384. 朱袁智， 沙庆安， 郭丽芬， 等. 1997. 南沙群岛永暑礁新生代珊瑚礁地质［M］. 北京: 科学出版社， 63-70. Bai S L， Bai Z Q， Ma X P， et al. 1994. Devonian Events and Biostratigraphy of South China［M］. Beijing: Peking University Press， 1-303. Chen D Z， Tucker M E， Jiang M S. 2001a. Carbonate sedimentation in a starved pull-apart basin， Middle to Late Devonian， southern Guilin， South China［J］. Basin Research， 13: 141-167. Chen D Z， Tucker M E， Jiang M S， et al. 2001b. Long-distance correlation between tectonic-controlled， isolated carbonate platforms by cyclostratigraphy and sequence stratigraphy in the Devonian of South China［J］. Sedimentology， 48: 57-78. Chen D Z， Tucker M. E， Zhu J Q， et al. 2002. Carbonate platform evolution: From a bioconstructed platform margin to a sand-shoal system(Devonian， Guilin， South China)［J］. Sedimentology， 49: 737-764. Chen D Z， Qing H R， Yang C. 2004. Multistage hydrothermal dolomites in the Middle Devonian(Givetian)carbonates from the Guilin area， South China［J］. Sedimentology， 51: 1029-1051. Hou H F， Ji Q， Wang J X. 1988. Preliminary report on Frasnian-Famennian events in South China［J］. Canadian Society of Petroleum Geologists Memoir， 14(3):63-69. House M R. 2002. Strength， timing， setting and cause of mid-Palaeozoic extinctions［J］. Palaeogeography， Palaeoclimatology， Palaeoecology, 181: 5-25. Kuang G D， Zhang Z W， Li J X， et al. 1996. Devonian and Carboniferous Stratigraphy， Sedimentary Facies and Paleontology of Guangxi Zhuang Autonomous Region［M］. In: 30th IGC(International Geological Congress)Field Trip Guide. Beijing: Geological Publishing House, T 348: 1-32. Li H， Ma X P， Wei L M. 2009. A Middle-Upper Devonian boundary section in the open platform， platform margin facies of Guilin， South China［J］. Acta Geologica Sinica(English Edition)83(3):524-534. Ma X P， Wang C Y， Racki G， et al. 2008. Facies and geochemistry across the Early-Middle Frasnian transition(Late Devonian)on South China carbonate shelf: Comparison with the Polish reference succession［J］. Palaeogeography， Palaeoclimatology， Palaeoecology, 269: 130-151. Warren J. 2000. Dolomite: Occurrence， evolution and economically important associations［J］. Earth-Science Reviews， 52: 1-81. Wu Y. 1996. Study on Devonian sequence stratigraphy and sea-level change in Guangxi［J］. Guangxi Geology, 9(1， 2): 54-69. Yans J， Corfield R M， Racki G， et al. 2007. Evidence for perturbation of the carbon cycle in the Middle Frasnian punctata Zone(Late Devonian)［J］. Geological Magazine, 144: 263-270.
