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西江改道和羚羊峡的形成,是与第四纪以来新构造运动的作用有关。西江在肇庆地区曾有过两次改道,也就是说有三条河道,在不同时期.曾作为西江河道出现过。早期古河道是流经万都坳至金利接现道西江。更新世晚期.由于新构造的差异升降,旱峡成为西江在这一带第一次改道的中期古河道。更新世末,羚羊峡断裂斜切烂柯尾山,破碎带一面受西江正面而来的河水冲击,一面在山区沿破碎带受支沟的底蚀作用.当新河床低于旱峡原河床时,便袭夺了原河道之水,作第二次改道,形成了著名的“羚羊峡”。 相似文献
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本文采用“位场解释的奇点法和滤波”反演活对浙江境内4条长剖面的重力资料进行了解释。奇点法定义了归一化总矢量的相位的概念。重力场奇点处相位曲线发生反转，即从－～＋或从＋～－。利用相位图上的反转点可准确地确定构造位置。计算结果表明：江山～绍兴深大断裂在诸暨附近从应店街通过；江山－绍兴断裂和苏州－开化断裂均向南倾，可能是反映了一个巨大推覆体的南北边界。 相似文献
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本文描述了萧山虎山和长兴泗安晚泥盆世地层中的石松类化石,共有6个属9个种,其中包括1个新属和3个新种,分别:SpinolepidodendronhangzhouenseGen.etsp.nov,SublepidodendronXianshanensesp.nov,Eolepi-dodendronhushanensesp.nov.。认为浙江晚泥盆世植物化应归于以Leptopnloeumrhombicum-Sublepidodendronxi-aoshanense—Xihuphyllummegalofolium为代表的组合。 相似文献
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自上世纪八十年代以来浙江地矿厅局所属研究团队，紧随国际地学的发展趋势，利用构造地质区位的优势，开展了绍（兴）江（山）古陆碰撞带岩石建造序列、对接带深层韧性推复构造及造山作用边缘岩浆岩带的研究；继后又扩及至中国东南华夏古大陆以及西太平洋岛弧带。由是开启了中国南方大地构造研究史新的一幕。这项研究课题得到国家自然科学基金会连续十余年的资助，有关成果相继发表在科学通报、中国科学及国际地学口物，引起国内外地学界的高度关注和积极评价，新华社曾为此两次发表内参对其在台湾和国际学界的影响进行了报导。 相似文献
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琼东南盆地北礁凹陷中中新统丘形反射引起了广泛的关注，但成因却争议较大，在前人研究的基础上，利用覆盖整个盆地高测网密度的二维地震、深浅水钻井和高精度三维地震资料，分析了中新世北礁凹陷在盆地中的沉积背景和古地形以及古地形对底流的影响。研究表明，中新世北礁凹陷处于半深海的沉积环境，其古地形为近互相对称的漏斗 状（中间窄，两端宽），这样的古地形对底流的流速有加速作用，使晚中新世早期（１１．６Ｍａ）底流流速增大，从而底蚀北礁凹陷中中新统梅山组地层形成底流水道和丘（残丘），且古地形（对称漏斗）越窄处底流水道和丘的规模越大。首次在北礁凹陷发现中中新世漏斗状古地形对丘和水道的分布有控制作用，且对具有漏斗状古地形的其他凹陷丘形（状）反射研究具有重要的参考价值。 相似文献
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描记采于云南省沪西县城郊龙潭及阿庐古洞的金线喜巴属一新种，命名为阿庐金线喜巴Sinocyclocheilus aluensis Li et Xiao sp．nov。新种在外形上与狭孔金线喜巴S.angustiporus Zheng et Xiao（1985）相近，但有下列特征与之区别：1）新种头长显著大于体高；后者头长约等于体高。2）新种背鳍起点至吻端的距离大于至尾鳍基的距离；后者正相反。3）新种鳃孔大，上角超过眼上缘水平线；后者鳃孔小，上角低于眼上缘水平线。4）经线粒体细胞色素b基因测定，两者分子遗传距离为3．0％，提示是两个独立种。 相似文献
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舟山群岛的开化历史有史前（新石器）和史后（春秋战国）两部分的历史。作者根据传说联系出土出海文物，运用专业技术进行逻辑推理探讨，试图导出“塌东京”的所在地，在现今的舟山所属海域──黄大洋；并且还提出了“塌东京”和“长崇明”的必然因果关系。如果文中推断符合实际的话，那么对于发掘研究舟山海域的古文化──新石器时期的舟山海域及陆域的原始社会发展过程来说，具有十分重大的意义。 相似文献
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本文着重研究了扬子地台北缘上震旦统陡山沱组、灯影组及下寒武统下部岩家河段的微古植物组合特征。初步建立了Ⅰ、Ⅱ两个微古植物组合，分别与陡山沱村阶和灯影峡阶相对应，分析了微古植物组合在地层划分与对比及在震旦系－寒武系界线的划分上所起的作用。 相似文献
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山东莱阳盆地的昆虫化石最早为A.W.Grabau(1923)和C.Ping(1928)所描述,计6属8种。最近,洪友崇(1984)又描述了3属3种。这样,共计发表了9属11种。实际上,这个地区的昆虫化石极为丰富。本文所描述的6目12科16属19种只是最新采集的昆虫化石的一部分,其中有11新属13新种,4已知属新种和2已知种。张生、刘德正和上官义宁等同志帮助采集了标本;中国科学院南京地质古生物研究所胡 相似文献
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《中国海洋湖沼学报》2021,(3)
The diversity and distribution of Hippodonta species on the coast of China are largely unknown due to limited investigations. In this paper, we report the detailed morphology and ultrastructure of two new species: H. nanjiensis sp. nov., collected from intertidal sandy sediments of Nanji Islands, the East China Sea and H. qingdaoensis sp. nov., collected from intertidal sandy sediments of the No. 1 Bathing Beach in Qingdao City, the Yellow Sea. Both species occur mainly in the middle part of the intertidal zone. H. nanjiensis possesses a unique large round central area. H. qingdaoensis differs from congeners in having a unique stria pattern, wherein the areolae in the middle transapical striae are less developed or absent on the primary side of the valve, and two areolae per stria are apparent under light microscopy(LM). This study expands our knowledge of Hippodonta diversity and distribution on the coast of China. 相似文献
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A new muricid gastropod species,L ataxiena lutescena sp. nov.,is described and illustrated. The new species was recognized during reidentification of the Muricidae collection in the Marine Biological Museum,Chinese Academy of Sciences,Qingdao. The specimens of the new species were collected from the East and South China Seas off Fujian,Guangdong,and Hainan Provinces. Lataxiena lutescena sp. nov. is similar to Lataxiena blosvillei(Deshayes,1832) in general shape,but can be distinguished from the latter by the shell sculpture and radular characteristics. Lataxiena lutescena sp. nov. also resembles Lataxiena bombayana(Melvill,1893),but differs from that species in the shell shape and anal notches and in lacking short spines on the shell. 相似文献
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《中国海洋湖沼学报》2021,(5)
A new genus and species of axiid shrimp,Carolinaxius kexuae gen.et sp.nov.is described and illustrated based on a single specimen collected from an unnamed seamount in the Caroline Ridge,Northwest Pacific.Although both chelipeds are mis sing,the specimen can be distinguished from other axiid genera by a combination of characteristics:narrowly triangular ro strum;median carina and lateral gastric carina each with one prominent tooth;submedian gastric carinae converging po steriorly,with teeth;cornea weakly pigmented,eyestalk with acute distome sial tooth on dorsal surface;male pleopod 1 two-articled;pleopod 2 with appendix interna and appendix masculina;pleopods 3-5 with appendix interna.The molecular phylogeny suggests the new genus is most closely related to another recently described genus living inside hexactinellid sponges on seamounts in the Indian Ocean,Montanaxius Dworschak,2016.However,it differs from Montanaxius in the shape of the rostrum,the arrangement of teeth on the carapace,and the shape of the eyestalk.Besides,the significant molecular differences support the two belonging to different genera. 相似文献
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Two new species of free-living marine nematode from mangrove habitats in Xiamen Bay are identified.Anoplostoma tumidum sp.nov.is characterized by relatively short outer labial setae(0.86–1.00 h.d.),long tail(c 7.2–8.9,c' 8.3–10.5),an instinct swollen distal portion of slender spicule(Sc 94–101 μm),and well developed copulatory bursae without bursal papillae.A.tumidum sp.nov.differs from all valid species of genus Anoplostoma in copulatory apparatus of males with a distinct swollen distal portion of spicule,and a relatively obvious constriction of head.A.paraviviparum sp.nov.is characterized by relatively long outer labial setae(1.11–1.22 h.d.),and tail(c 6.6–8.5,c' 8.6–10.2);elongated spicules with distinct knob-like proximal and pointed distal ends(Sc 46–69 μm);distinct strip-like gubernaculum(length with 11–15μm);well developed copulatory bursae with precloacal papillae and post-cloacal papillae;and a distinct constriction of head.A.paraviviparum sp.nov.is similar to A.viviparum Bastian,1865,but differs in the reproductive mode of female and the constriction of head. 相似文献
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《中国海洋湖沼学报》2021,(5)
The genus Munidopsis has high biodiversity in seamount habitats.In this study,two new Munidopsis species,Munidopsis ahyongi sp.nov.and Munidopsis carolinensis sp.nov.from the Caroline Ridge in the tropical western Pacific Ocean were described.M.ahyongi sp.nov.is very similar to a group of species in the M.serricornis complex,but can be readily distinguished from the related species in having the oblique posterior orbital margins,2 spines on the lateral carapace margin,and a relatively longer rostral median spine.M.carolinensis sp.nov.is different from two related species primarily in having oblique frontal margins,blunt outer orbital angles,straight lateral margins of the rostrum,scale-like rugae on sternites 5-7,and less spinose pereopod 1(chelipeds,P1) merus and carpus.Aside from the morphological comparisons,DNA barcode analysis and phylogenetic analysis based on the cytochrome c oxidase subunit I gene(COI) were employed for the identification of these new species. 相似文献
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A new species of deep-water barnacle that belongs to the family Scalpellidae is described from the South China Sea. A rcoscalpellum liui sp. nov. is morphologically similar to A rcoscalpellum gryllum Zevina,but differs from the latter by the absence of longitudinal striae on the capitular plates and the presence of caudal appendages with few terminal setae. 相似文献