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描述采于云南省的金线属 鱼类一新种──犀角金线鲃（Ｓｉｎｏｃｙｃｌｏｃｈｅｉｌｕｓｒｈｉｎｏｃｅｒｏｕｓ，ｓｐ．ｎｏｖ）以头上长有一长角、眼小、侧线完全、体表裸露无鳞等区别于该属所有已知种。 相似文献
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描记采于贵州省茂兰自然保护区境内一洞穴的中国野鲮亚科（Labeoninae）一新属长臀鲮属Longanalus．sp nov和一个新种大鳍长臀鲮Longanalus macrochirous sp nov。新属以臀鳍分枝鳍条为7根等特征．区别于该亚科所有属；新种以偶鳍发达．胸鳍后伸达到腹鳍基，腹鳍后伸超过臀鳍起点等显著特征命名大鳍长臀鲮。 相似文献
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描记采于贵州省茂兰自然保护区境内一洞穴的中国野鲮亚科(Labeoninae)一新属长臀鲮属Longanalus,spnov和一个新种大鳍长臀鲮Longanalus macrochiroussp nov。新属以臀鳍分枝鳍条为7根等特征,区别于该亚科所有属;新种以偶鳍发达,胸鳍后伸达到腹鳍基,腹鳍后伸超过臀鳍起点等显著特征命名大鳍长臀鲮。 相似文献
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四海山地区的二长—正长花岗岩具有细粒→粗粒的结构演化和酸性→偏酸富碱性的成分演化特点，并含有 Ｓ 型花岗岩中的典型副矿物钛铁矿，岩石化学成分显示其富硅富铝，稀土配分模式为地壳重熔型，综合判别图解表明它们属造山后期侵入岩。其源岩为硅铝质地壳，属 Ｓ 型花岗岩。认为所有以硅铝质地壳（ 包括灰色片麻岩和变质沉积岩） 为源岩岩浆的花岗岩都应属于 Ｓ 型花岗岩 相似文献
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《国土资源导刊(湖南)》2009,(4)
长沙县位于湖南中东部，紧邻长沙市，属江南典型丘陵地区，全县处于东亚季风湿润区，气候温和，热量丰富，雨水充沛，四季分明，生长期长，适合水稻、茶、花卉苗木等多种作物生长。辖内土地总面积1997平方公里，人口73.8万，耕地总面积863431亩，基本农田768000亩，人均耕地1．17亩。 相似文献
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铁岭地区太古宙花岗岩系由独立封闭的几个灰色片麻岩体组成，属英云闪长岩─奥长花岗岩系列。锆石单颗粒Ｐｂ－ｐｂ年龄为２５４８－２５５３Ｍａ。片麻岩体中包裹有斜长角闪岩、磁铁石英岩等变质表壳岩。花岗岩系稀土元素具有强分馏形式，形成于晚太古代大陆及大陆边缘环境，其北部为吉黑褶皱带寒武系变质岩系。华地地台与吉黑地槽之间由海西－燕山期中酸性侵入岩填充，形成宽约５＝１０ｋｍ的岩浆活动带。 相似文献
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辽南金州地区的太古宙侵入岩 总被引：2，自引：0，他引：2
辽南金州地区的太古宙变质侵入岩，是由得胜片麻杂岩为代表的早期ＴＴＧ岩系和由亮甲店片麻岩、小黑山片麻岩及赵屯片麻岩组成的晚期石英闪长岩—低硅英云闪长岩—花岗岩系构成的，早期岩系呈奥长花岗岩演化趋势，晚期岩系显钙碱性演化趋势，属太古宙常见的两类岩石系列，其源岩来源陆壳，是陆壳角闪岩或石榴角闪岩部分溶融的产物。 相似文献
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鞍子山超单元中的四个单元，不同程度地发育就位叶理及同源闪长质包体。从早期单元到晚期单元随着就位叶理强度的减弱，同源闪长质包体数量减少，压扁变形程度降低，二者产状一致。同源闪长质包体应变指数ｋ值总体为０＜ｋ＜１，属三轴压扁型应变椭球体，楔形侵入膨胀式就位机制。根据同源闪长质包体应变测量结果，运用Ｘ／Ｒｉ＝Ｙ／Ｒｆ公式计算出鞍子山超单元发生气球膨胀后的体积比初始体积大１．７０倍，岩浆体积横向拓宽了７０％。 相似文献
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ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｔｈｅｆｉｒｓｔｐａｐｅｒｏｆｔｈｉｓｓｅｒｉｅｓ (ＬｉａｎｄＬｉｕ ,2 0 0 2 ) ,ｗｅｒｅｐｏｒｔｅｄ 3ｇｅｎｅｒａｗｉｔｈ 7ｓｐｅｃｉｅｓｏｆＰｏｎｔｏｎｉｉｎａｅ,ｃｏｌｌｅｃｔｅｄｂｙｔｈｅＪｏｉｎｔＣｈｉｎｅｓｅ ＧｅｒｍａｎＭａｒｉｎｅＢｉｏｌｏｇｙＥｘｐｅｄｉｔｉｏｎｓｔｏＨａｉｎａｎＩｓｌａｎｄ(ｗｉｎｔｅｒｏｆ1 990ａｎｄｓｐｒｉｎｇｏｆ 1 992 ) .Ｔｈｅｐｒｅｓｅｎｔｐａｐｅｒｒｅｐｏｒｔｓａｎｏｔｈｅｒ 6ｇｅｎｅｒａ ,ｗｉｔｈ 9ｓｐｅｃｉｅｓ,ｆｒｏｍＨａ… 相似文献
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朝阳沟破火山口出露面积约８０ｋｍ２，呈椭圆状，受北东与北西两组基底断裂控制，火山活动期为晚侏罗－早白垩世。火山活动以爆发为主，具多期次脉动喷发特点。岩浆演化由早期至晚期呈由中性到酸性，火山喷发序次由外向内由老至新，岩石结构由细至粗，晚期潜火山岩相正长斑岩沿放射状断裂侵入。 相似文献
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五圩矿田位于广西南丹-河池锡多金属成矿带的南端,主干构造为NNW向的不对称短轴背斜,其上叠加了NE、SN、EW 3个方向的褶皱,它们在丹池带上都有表现.文章通过大量共轭节理、层面擦痕、断层派生小构造、次级褶皱等构造要素野外观测,室内计算,恢复了五圩矿田中生代(印支-燕山期) 4期构造应力场,各期主压应力方位依次为NEE、NW-SE、N WW-SEE及NNE向,前两期为印支期,后两期为燕山期.并探讨了其力源:印支期来源于古特提斯板块向北俯冲与江南古陆向南推移形成的SN向顺时针区域力偶;燕山期来源于丹池断裂的右旋或左旋走滑活动. 相似文献
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Sang Koo Hwang Chang Oh Choo 《东北亚地学研究》2006,9(1):60-79
IntroductionThe northeastern Cheongsong area is underlainby a sequence of sedi mentary rocks together within-trusive and extrusive volcanic rocks all of late Creta-ceous age(Lee&Hong,1973;Ki m&Park,1970;Hwang,1998).Theintrusions,comprising astock,a plug and numerous dikes,are well exposedat the current surface due tothe enormous erosion ofany sedi mentary or volcanic covered rocks.Thedikes forma dike swarmand some are intruded intothe plug.The dikes swarm may represent the subsurfaceexpress… 相似文献
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Several NNW-trending Cretaceous rhyolite dikes in the northeastern Cheongsong area of southern Korea contain spherulitic fabrics and are locally quarried as an ornamental stone. The dikes, part of the Cheongsong dike swarm, contain a variety of spherulites which are characterized by radial array of acicular intergrowths from fibrous quartz and alkali feldspars. They are classified as some simple, multiple and compound spherulite types from flower-like patterns, and the types are different each other in spatial distribution within the dikes. The various radial fabrics suggest that they crystallized under the different cooling mechanisms and processes in rapidly cooling dikes. Spheroids lacking a flower-like pattern may be precipitated after compositional segregation in a supercooled magma. Simple acicular spherulites could be crystallized by devitrification of true glass which cooled rapidly below the transformation temperature, whereas layered multiple spherulites could result from a crystallization of supercooled magma at relatively rapid cooling rates above the transformation temperature. Acicular multiple spherulites could be produced from a combination of the above three mechanisms operating at slower cooling rates. 相似文献
16.
Kosmas Pavlopoulos Aris Leontaritis Constantin D. Athanassas Chara Petrakou Dimitris Vandarakis Kosnstantinos Nikolakopoulos Leonidas Stamatopoulos Katherina Theodorakopoulou 《山地科学学报》2018,15(5):948-965
This study deals with the analysis of the glacial processes that have affected the relief of Mt Chelmos in northern Peloponnesus, Greece during middle and Late Pleistocene. The goal was to compile a combined geomorphological-geological map of the study area which would enable the chronological stratification of the glacial landforms cropping up on Mt. Chelmos. Chronological stratification was further aided by optically stimulated luminescence (OSL) dating. The map served as the basis upon which the reconstruction and discussion on the phases of the Middle-Late Quaternary paleoclimatic history of Mt. Chelmos have been made. A sophisticated semiautomated method was first used to analyze the Digital Elevation Model (DEM), combined with Aster, Quickbird and ALOS imagery in order to identify glacial and periglacial, as well as karstic features. Then, these features along with other nonrecognizable features from the remote-sensing images were documented in the field. In this way, several glacial landforms were identified, such as moraines and cirques, indicating extended glaciation phases during the middle and Late Pleistocene. Additionally, a ground moraine located at an altitude of 1900-2050 m, within the Spanolakos glacial valley, was dated using the OSL-dating method. The resulting ages indicate a phase of glacier advance/stabilization during MIS-5b (89-86 ka), which is in consistence with pollenrecord evidence from Greece and the Mediterranean. 相似文献
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This paper reports the occurrence of a marine brachyuran crab species Eucrate alcocki Serène, in Serène et al., 1973, of the family Euryplacidae Stimpson, 1871, for first time from India, based on a male specimen
from Parangipettai fish landing centre in Bay of Bengal, Southeast Coast of India. Although morphologically corresponding
with what is currently defined as E. alcocki, the color pattern of the carapace of the present specimen is rather different from that of the Chinese material-only the
anterior fifth of the carapace is marked with scattered red spots, the rest of the surface is yellowish, with four unusually
shaped red blotches which almost look like Sanskrit characters. 相似文献
18.
张志南 《中国海洋湖沼学报》1992,(1)
Two nematode species of the genus Dorylaimopsis (Family Comesometidae) from the Bohai Sea are described. Dorylaimopsis rabalaisi n. sp. similar to D. punctata Ditlevsen, 1918 from which it can be separated by the small size, short and simple spicules without ventral apophyses or joint line. Dorylaimopsis turneri n. sp. differs from the closest species Dorylaimopsis angelae (Inglis, 1967) by its higher values of de Man ratio 'a', much shorter spicules and higher ratio of gubernacular to spicules length. A key to species of the genus based on the key by Jensen (1979) is given . 相似文献
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Miamiensis avidus Thompson Moewus,1964,is a cosmopolitan and well-known marine pathogenic ciliated protist.However,the taxonomy of this species up to now has remained controversial,especially with respect to the validity of the morphologically similar species,Philasterides dicentrarchi,which was considered as a junior synonym of M.avidus.In this study,a population of M.avidus was collected from the skin of pharaoh cuttlefish(Sepia pharaonis) cultured near the East China Sea,Ningbo,China and its morphology and phylogeny were investigated in detail based on living characters,infraciliature,small subunit(SSU) r DNA and ITS1-5.8 S-ITS2 region sequences.In addition,the morphometrics of a previously reported free-living population,collected from the Bohai Sea,were rechecked and analyzed.We compared the present two isolates with all historic populations of M.avidus and P.dicentrarchi,and found that their morphological characters were either highly similar or exactly identical,indicating that they are the same morphospecies.However,the phylogenetic analyses based on SSU r DNA or ITS1-5.8 S-ITS2 region sequences revealed that most M.avidus and P.dicentrarchi populations formed one clade,and the two isolates of M.avidus from Weifang and American Type Culture Collection clustered in another clade,which indicated that there might be cryptic species in Miamiensis avidus. 相似文献
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Based upon analysis of the seasonal fluctuation of GSI (gonado-somatic index), the spawning period of the hairtail extends from April to October. The maximum time difference between the early and the late brood individuals is about half a year. It is possible to distinguish the early brood and the late brood on the basis of the diameter of the first ring, setting 1.32 mm as a border line. Therefore, the identification of the first ring was solved in dispute.The maturation stages can be identified on the basis of the macroscopical and microscopical characteristics of the ovary; i.e., immature (II-A, B), maturing (III-C, D, E, IV-F), mature (IV-G, V-H, VI-I) and recovering (VII-J). Maturation is completed in the course of one year from different brood seasons. The smallest size at first maturity in female was about 170-180 mm in length and 80-100 grams in weight.There were two discrete groups in autumn which shown the same population unit in which those individuals may separate temporarily into different 相似文献