Abstract Nodular，striped and lump-shaped siliceous rocks of the Permian are primarily distributed in the Maokou and Wujiaping Formations in Xuanhan region， Sichuan Province. The origins of the siliceous rocks have been researched systematically based on their lithological and geochemical characteristics. Field observations about the siliceous rocks suggest that the shape of siliceous rocks is diversified， and they contact with surrounding rocks in line shape. They are controlled by certain position in the section，and the lump-shaped siliceous rocks contain limestone nodules. Thin section analyses suggest the relic texture of calcite and dolomite rhombus pseudomorphic crystal could be found in the siliceous rocks. Field observations and thin section analyses suggest the origin of siliceous rocks is metasomatosis. The major element analysis indicates SiO2 is the main chemical composition(69.61％—99.21％)， others are extremely lower(0.01％—16.07％)， some major element ratios of Fe/Ti，(Fe+Mn)/Ti， Al/(Al+Fe+Mn)reflect the formation of siliceous rocks is associated with the hydrotherm activities， and the samples are projected in the unit where Fe being rich in the Al-Fe-Mn diagram; Some trace element ratios including Co/Ni， V， Ti/V， Th/U， Rb/Sr are relatively lower， and the samples are projected in the unit where Fe being rich in the(Cu+Co+Ni)-Fe-Mn diagram too; The REE(<10×10-6)is lower， Ce is remarkable negative anomalies， Eu is negative anomalies slightly， LREE/HREE is lower and the Eu/Eu* is relatively high. All these features above suggest that there may be hydrotherm participating in during the sedimentary process，and siliceous rocks are formed by metasomasis during the diagenetic process.
About author: Zhou Xinping was born in 1984. Now he is a master candidate in Yangtze University， and is mainly engaged in sedimentology. E-mail: zhouxp198491@163.com.
Cite this article:
. Geochemical characteristics and origin of the Permian siliceous rocks in Xuanhan region of Sichuan Province[J]. JOURNAL OF PALAEOGEOGRAPHY, 2009, 11(6): 670-680.
. Geochemical characteristics and origin of the Permian siliceous rocks in Xuanhan region of Sichuan Province[J]. JOPC, 2009, 11(6): 670-680.
毕华.1994.栖霞灰岩中燧石结核成因的新证据［J］.地层学杂志，18(4). 陈先沛，高计元，陈多福，等.1992.热水沉积作用的概念和几个岩石学标志［J］.沉积学报，10(3):124-126. 冯增昭，何幼斌，吴胜和，等.1991.中下扬子地区二叠纪岩相古地理［M］.北京:地质出版社，33-41. 高长林，何将启.1999.北大巴山硅质岩的地球化学特征及其成因［J］.地球科学——中国地质大学学报，24(3):246-249. 林良彪.2008.川东二叠纪层序充填与沉积物分布规律［D］.四川成都:成都理工大学，23-65. 刘新宇，颜佳新.2007.华南地区二叠纪栖霞组燧石结核成因研究及其地质意义［J］.沉积学报，25(5):730-734. 刘岫峰.1991.沉积岩实验室研究方法［M］.北京:地质出版社，1-299. 马永生，牟传龙，谭钦银，等.2007.达县—宣汉地区长兴组—飞仙关组礁滩相特征及对储集层的制约［J］.地学前缘，14(1):182-190. 牟传龙，马永生，王瑞华，等.2005.川东北地区上二叠统盘龙洞生物礁成岩作用研究［J］.沉积与特提斯地质，25(1-2):198-202. 牟传龙，谭钦银，余谦，等.2004.川东北地区上二叠统长兴组生物礁组成及成礁模式［J］.沉积与特提斯地质，24(3):65-71. 王东安，陈瑞君.1999.东昆仑中段奥陶系硅岩地球化学特征及沉积大地构造环境判别［J］.古地理学报，1(1):41-53. 王立亭，陆彦邦，赵时久，等.1994.中国南方二叠纪岩相古地理与成矿作用［M］.北京:地质出版社，7-12. 王卓卓，陈代钊，汪建国.2007.广西南宁地区泥盆系硅质岩地球化学特征及沉积意义［J］.沉积学报，25(2):239-245. 吴志亮，李峰.1996.热水沉积成岩成矿作用——以阿尔泰泥盆纪火山沉积盆地为例［M］.北京:地质出版社，48-49. 夏邦栋，钟立荣，方中，等.1995.下扬子区早二叠世孤峰组层状硅质岩成因［J］.地质学报，69(2):127-138. 徐跃通.1996.浙江西裘晚元古代层状硅质岩热水沉积地球化学标志及其沉积环境意义［J］.地球化学，25(6):600-608. 严贤勤，孟凡巍，袁训来.2006.徐淮地区新元古代九顶山组燧石结核的地球化学特征［J］.微体古生物学报，23(2):295-302. 杨海生，周永章，杨志军，等.2003.热水沉积硅质岩地球化学特征及意义——以华南地区为例［J］.中山大学学报(自然科学版)，42(6):111-115. 杨江海，杜远生，朱杰.2007.甘肃景泰崔家墩奥陶统阴沟组砂岩化学组分特征及物流区构造背景判别［J］.古地理学报，9（2）：197-206. 杨瑞东，张传林，罗新荣，等.2006.新疆库鲁克塔格地区早寒武世硅质岩地球化学特征及其意义［J］.地质学报，80(4):598-605. 尹国勋.1988.河南焦作地区太原群灰岩中燧石的成因及成岩作用标志［J］.焦作矿业学院学报，(2，3):173-177. 于炳松，陈建强，李兴武，等.2004.塔里木盆地肖尔布拉克剖面下寒武统底部硅质岩微量元素和稀土元素地球化学及沉积背景［J］.沉积学报，22(1):59-66. 朱同兴.1989.安徽南部下二叠统结核状硅质岩和层状硅质岩的沉积学特征及其成因探讨［J］.岩相古地理，43(5):1-6. Adachi M， Yamamoto K， Sugisaki R， et al.1986. Hydrothermal chert and associated siliceous rocks from the northern Pacific: Their geologic significance indication of ocean ridge activity［J］. Sedimentary Geology，47(\{1/2\}):125-148. Bostrom K， Kramemer T， Gantner S.1973.Provenance and accumulation rates of opaline silica， Al， Fe， Ti， Mn， Ni and Co in Pacific pelagic sediment［J］. Chemical Geology，11(\{1/2\}):123-148. Bostrom K， Peterson M N A.1969. The origin of Al-Poor ferromaganoan sediments in areas of high heat flow on the East Pacific Rise［J］. Geology，7:427-447. Bostrom K， Rydell H， Joensuu O.1979. Langbank: An exhalative sedimentary deposit［J］. Economic Geology，74(5):1002-1011. Bostrom K.1983. Genesis of Ferromanganese Deposits-Diagnostic Criteria for Recent and Old Deposits［M］. New York: Plenum Press， 473-483. Marching V， Gundlach H， Moller P， et al.1982. Some geochemistry indicators for diserimination between diagenetic and hydrothermal metalliferous sediments［J］. Marine Geology，50(3):241-256. McLennan S M， Taylor S R.1980. Th and U in sedimentary rocks: Crustal evolution and sedimentary recycling［J］. Nature， 285: 621-625. Murray R W， Buvhholtz ten Brink M R， Gerlach D C， et al.1991. Rare earth， major， and trace elements in chert from the Franciscan Complex and Monterey Group: Assessing REE sources to fine grained marine sediments［J］.Geochemical et Cosmochimica Acta， 55:1875-1895. Murray R W.1994. Chemical criteria to identify the depositional environment of chert: General principles and applications［J］. Sedimentary Geology，90:213-232. Rona P A.1983. Hydrothermal Processes at Seafloors Spreading Centers［M］. New York: Plenum Press，539-555. Rona P A.1988. Hydrothermal mineralization of ocean ridges［J］. Canadian Mineralogy，26(3):447-465. Rosenbuer R J.1983. Hydrothermal alteration of greywacke and basalt by 4 mol Nael［J］. Economic Geology，2:1701-1710. Yamamoto K.1987. Geochemical characteristics and depositional environment of cherts and associated rocks in the Franciscan and Shimanto terrances［J］. Sedimentary Geology，52:65-108.
