• 
    

    
    

      99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看

      ?

      泰國(guó)北部中三疊世放射蟲(chóng)硅質(zhì)巖及其地球化學(xué)和沉積環(huán)境意義

      2012-04-01 07:22:45HATHAITHIPTHASSANAPAK,MONGKOLUDCHACHON,CHONGPANCHONGLAKMANI
      地球?qū)W報(bào) 2012年1期
      關(guān)鍵詞:沉積環(huán)境硅質(zhì)泰國(guó)

      泰國(guó)北部中三疊世放射蟲(chóng)硅質(zhì)巖及其地球化學(xué)和沉積環(huán)境意義

      E-mail: bthaithip@yahoo.com.

      Bedded cherts collected from northern Thailand,including Chiang Dao, Lamphun and Den Chai contain Middle Triassic radiolarian faunas. The faunas from Chiang Dao can be divided into two assemblages. The first assemblage includesEptingiumand other co-occurring species such asCryptostephanidium cornigerumDumitric?,Plafkerium antiquumSugiyama,Pseudostylosphaera compacta(Nakaseko and Nishimura),P. longispinosaKozur and Mostler,P.acrior(Bragin),P. japonica(Nakaseko and Nishimura),Parasepsagonsp. cf.P.variabilis(Nakaseko and Nishimura),Hozmadiasp. cf.H. gifuensisSugiyama,Triassospongosphaera multispinosa(Kozur and Mostler),Celluronta donaxSugiyama,Oertlispongussp. cf.O.diacanthusSugiyama,Paroertlispongus multispinosusKozur and Mostler, etc. The second assemblage consists ofTriassocampe deweveri(Nakaseko and Nishimura),YeharaiaannulataNakaseko and Nishimura,Hindeostylosphaera spinulosa(Nakaseko and Nishimura),Plafkerium contortumDumitric?, Kozur and Mostler,Pseudostylosphaera goestlingensis(Kozur and Mostler),P. timorensisSashida and Kamata andParoertlispongus rarispinosusKozur and Mostler. These assemblages indicate upper and uppermost Anisian, respectively.

      In Lamphun, radiolarian faunas are poorly preserved, having been recrystallized and can hardly be determined. However, some characteristics of these fauna are represented and have been assigned toTriassocampesp.,Eptingiumsp. andArchaeocenosphaerasp., which were common in the Middle Triassic.

      In Den Chai,Muelleritortis cochleata cochleata(Nakaseko and Nishimura) is abundant together withMuelleritortis cochleata tumidospinaKozur andMuelleritortis expansaKozur and Mostler. Other co-occurring species are composed ofPseudostylosphaera coccostyla coccostyla(Rüst),Pseudostylosphaera imperspicua(Bragin),Pseudostylosphaerasp.,Triassocampe deweveri(Nakaseko and Nishimura),Triassocampe scalarisDumitrica,Annulotriassocampe companilisKozur,Annulotriassocampe multisegmantusTekin,Annulotriassocampe sulovensis(Kozur and Mock),Annulotriasocampesp.,Pararuesticyrtiumsp. cf.P. illyricumKozur and Mostler,Pararuesticyrtiumsp. A,Pararuesticyrtiumsp.,Striatotriassocampe nodosoannulataKozur and Mostler,Japonocampe nova(Yao),Canoptum inornatusTekin,Canoptum levisTekin,Canoptumsp. A,Canoptumsp.,Corum kraineriTekin,Archaeocenosphaerasp. cf. A.laseekensisPessagno and Yang,Archaeocenosphaerasp.,Acanthosphaerasp., andPseudogodia? sp., with some occurrences ofOrbiculiforma karnica(Kozur and Mostler),Orbiculiformasp. cf.O. gazipasaensisTekin,Praeheliostaurussp.,Spongoserrula rarauanaDumitric?, andParonaellasp. All of them indicate a late Ladinian age.

      Geochemically, the analyzed Middle Triassic radiolarian cherts from these localities are of biogenic origin. They present slightly high SiO2content, which was possibly modified by diagenetic alteration. The relatively high content of Cr, Zr, Hf, Rb and Th and high positive correlation of these elements with Al and Ti, from the majority of cherts suggest a close relation to terrigenous component. The Ce anomaly (Ce/Ce*)(means 0.93, 0.85 and 0.85) is compatible with that of continental margin composition (0.67 to 1.52) (Murray et al. 1990), which is also consistent with low Eu anomalies (Eu/Eu*; means 0.91, 0.92 and 0.94). Furthermore, slightly low ratios of La and Ce NASC normalized (Lan/Cen; means 1.03, 1.13 and 1.13) and the low LREE and HREE ratios in most of the samples(Lan/Ybn; means 0.68, 0.85 and 0.62) are in agreement with the continental margin regime. Lan/Cenvs.Al2O3/(Al2O3+Fe2O3) discrimination diagrams also support the continental margin (residual basin,s. str.)interpretation.

      These geochemical results together with geological evidences suggest that during the Middle to late Middle Triassic, there were deep residual basins on both Inthanon and Sukhothai terranes. However,due to subduction complexity of the suture, tectonic history of the region is still equivocal.

      Palaeogeographically, it is widely accepted that the main Palaeotethys and coeval Cimmerian terranes are located to the west of the Inthanon and Sukhothai terranes. However, the evolution of the Nan-Uttaradit suture which was a candidate of Palaeotethys is still unclarified since numbers of Middle Triassic radiolarian chert localities were observed along western rim of this suture. However, the current research indicates that some of radiolarian cherts deposited in continental margin environments. We are currently conducting detailed biostratigraphy of chert sequences using radiolarian and other key index fossils observed along this suture in order to better understand the tectonic evolution of the suture and terranes and their relationship to the main Palaeotethys.

      Acknowledgements: The research has been supported by NSFC (41172202) and MOST Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences(Project number: GPMR201012)

      Middle Triassic Radiolarian Cherts from Northern Thailand and Their Geochemical Constraint for Depositional Environment

      Hathaithip THASSANAPAK1), Mongkol UDCHACHON2), FENG Qing-lai3),Chongpan CHONGLAKMANI4)
      1)Palaeontological Research and Education Centre, Mahasarakham University, Mahasarakham44150,Thailand;
      2)Department of Biology, Faculty of Science, Mahasarakham University, Mahasarakham44150, Thailand;
      3)State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan430074, China;
      4)School of Geotechnology, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima30000,Thailand

      Middle Triassic; Radiolarian chert; Northern Thailand; Geochemistry; Depositional environment

      10.3975/cagsb.2012.s1.30

      猜你喜歡
      沉積環(huán)境硅質(zhì)泰國(guó)
      硅質(zhì)巖研究進(jìn)展與思考*
      硅質(zhì)結(jié)核的巖石學(xué)、地球化學(xué)特征及成因綜述
      化工管理(2021年20期)2021-08-17 05:40:36
      微量元素在鶴崗盆地早白堊世沉積環(huán)境分析中的應(yīng)用
      廣西資興高速硅質(zhì)巖單面山地質(zhì)災(zāi)害分布規(guī)律及防治對(duì)策研究
      泰國(guó)的中秋節(jié)
      和順區(qū)塊煤系地層沉積環(huán)境分析
      我的泰國(guó)之旅
      幼兒園(2014年3期)2014-04-10 09:28:28
      孟津井田山西組沉積環(huán)境分析
      河南科技(2014年6期)2014-02-27 14:06:44
      《GANID HORSE RACING》
      海峽影藝(2013年3期)2013-11-30 08:15:56
      《PHUKET-VEGETARIAN》
      海峽影藝(2013年3期)2013-11-30 08:15:54
      博白县| 泸西县| 博客| 湘阴县| 临夏市| 城步| 双流县| 阜新市| 仁怀市| 沙雅县| 永昌县| 砀山县| 招远市| 汝南县| 琼海市| 华亭县| 临城县| 巩留县| 晋宁县| 精河县| 双柏县| 泽库县| 沙坪坝区| 达孜县| 华亭县| 天镇县| 丹寨县| 东兰县| 海门市| 青海省| 青海省| 凤翔县| 清流县| 沛县| 苏尼特右旗| 邢台市| 武山县| 阿巴嘎旗| 台山市| 门源| 长岛县|