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1.
对发现于浙江省宁海县茶园乡道士桥村附近的上新统嵊县群中的多个化石木材料进行了解剖研究,并对其分类和系统位置进行了讨论。根据解剖特征鉴定出2种化石木。一种为久内枫香树(Liquidambar hisauchi),属于金缕梅科枫香树属,其组合特征为:生长轮明显;散孔材;梯状穿孔板具横隔10~23条;螺纹加厚仅出现在导管末端;导管直径在50~100μm之间;射线宽1~3列。另一种为岛仓栎(Quercus shimakurae),属于壳斗科栎属,其组合特征为:生长轮极明显;环孔材;单管孔;晚材管孔火焰状径列;早材管孔直径最大达300μm,明显比晚材管孔大;单穿孔;轴向薄壁组织星散聚合状和离管带状;射线具单列和极宽2种类型。本研究从大化石角度进一步证明栎属和枫香树属为当时植被的重要组成成分。  相似文献   

2.
河南义马和鄂尔多斯盆地中侏罗世几种成煤植物   总被引:5,自引:0,他引:5  
何德长  张秀仪 《现代地质》1993,7(3):261-265,T004
本文用木材解剖法对河南义马和鄂尔多斯盆地中侏罗世低煤级的丝炭的木材进行了研究。丝炭的材料具有鉴定属种的价值。其中有些重要材料是不能从矿化木获得的,如交叉场纹孔的类型,射线细胞径向壁有无纹孔,韧皮部有无厚壁组织(纤维或石细胞),筛域的资料;如果是苏铁类,树干的角质层材料等。通过研究建立了一个新属,两个新种和一个未定种,并统计了它们在各地煤层中的含量。  相似文献   

3.
元谋土林的形成条件及发育速率   总被引:1,自引:0,他引:1  
陈述云  张建云 《云南地质》1994,13(4):383-391
土林是一种流水侵蚀地貌,云南元谋发育之土林即为一例,其形态婀娜多姿,风格粗犷浑厚,是颇具特色的地貌类型。作者通过对元谋盆地新生代河湖相地层、新构造运动、土址、气候、植被的综合研究,对土林的形成条件、发育如此规模(单体土柱高达27m)及其成因进行了探讨,首次应用侵蚀模数类比法计算土林的形成时间及发育速率。  相似文献   

4.
研究了云南西部龙陵县上新世的化石木。鉴定出两种木材类型。杜鹃花科杜鹃属的似腋花杜鹃Rhododendron cf. racemosum Franchet,其主要木材特征有散孔材,生长轮略明显,导管具多角形轮廓,螺纹加厚出现在整个导管壁上,梯状穿孔板,射线异形II型。松科华山松Pinus armandii Franchet的主要特征有交叉场纹孔窗格状,具正常轴向和纵向树脂道,且泌脂细胞壁薄,射线管胞内壁平滑或具稀疏的微锯齿。两种类型的化石木在我国均属首次报道。根据化石木结构和现代相应树种和植被的生境范围,当时植物生长于亚热带温凉湿润的山地环境,其海拔大约在1800米左右。  相似文献   

5.
浙江新昌下白垩统馆头组是我国南方地区为数不多的白垩纪木化石产出层位。本文报道了新昌地区馆头组木化石新材料及其内含真菌菌丝化石。木化石具明显生长轮,管胞径壁纹孔南洋杉式(多数单列、椭圆形、紧挤排列,偶见双列互生排列);交叉场纹孔南洋杉式;木射线单列式,多数2~11个细胞高。当前木化石新材料具有与现生南洋杉科植物相类似的木材解剖特征,显示其应归入贝壳杉型木属(Agathoxylon Hartig)。鉴于该类型木化石的分类现状仍有待厘清,将其定为Agathoxylonsp.。木化石内含真菌菌丝化石,管状,具横隔,平直或弯曲,常以不同角度分叉,菌丝壁光滑,具典型的锁状联合,属于担子菌类。当前木化石木材组织具有明显的木材腐朽特征,与现代真菌造成的木材白腐一致,推断此真菌化石为木材白腐菌。新昌地区贝壳杉型木属木化石新材料的发现进一步丰富了馆头组木化石的多样性,有助于增进对南方地区早白垩世植物群组成特征的认识。当前真菌菌丝化石是我国南方地区首次发现白垩纪担子菌化石,为探究白垩纪时期森林生态系统真菌与植物的相互作用提供了新的化石证据。  相似文献   

6.
杨铁汾  赵江天 《地球科学》1994,19(4):421-426,T001
在甘肃合作地区早三叠世地层中发现了钙质超微化石,共属3种,共文描述了2个新属3个新种。它们位于斜坡脚-盆地的深海沉积环境中,与早三叠世早期双壳类Claraia共生,其下部有具早三叠世面貌的孢粉组合。经能谱成成分分析,这些化石为钙质。这些钙质微化石的发现使钙质超微化石的时代分布的可靠记录延至早三叠世。为今后中生代地层的划分对比及钙质超微化石的演化研究提供了较好的资料。文中依据所发现的钙质超微化石对沉  相似文献   

7.
云南元谋盆地干润变性土中次生方解石特征及形成   总被引:1,自引:0,他引:1  
土壤新生体对于研究区域环境变化、营养元素释放以及次生成矿作用具有重要意义。利用化学分析、X射线衍射、偏光显微镜和扫描电子显微镜等探讨云南省元谋盆地干润变性土钙质结核中的次生方解石的特征和形成过程。结果表明,钙质结核中次生方解石含量高,晶形完整;钙质结核以及次生方解石形成既取决于气候,也与微地形有关。次生方解石的形成过程及特征反映了自全新世以来元谋盆地主要处于干热气候环境中。  相似文献   

8.
通过对苏北盆地TZK9孔的磁性地层和重矿物组合分析,探索了该地区晚上新世以来沉积物的物源变化特征。古地磁结果显示,TZK9孔的M/G界线位于250.3 m,B/M界线位于78.5 m,并很好记录了2次正极性亚时(Jaramillo和Olduvai),分别位于129.0~150.2 m与172.55~192.80 m,通过沉积速率外推获得该钻孔的底界年龄约为3.0 Ma。对TZK9孔重矿物组合、特征指数进行分析,并结合淮河及长江下游的重矿物组合特征,揭示在距今3.0~2.6 Ma其沉积物主要来自于淮河流域。而相比晚上新世,第四纪的磷灰石、锆石、金红石、电气石含量增加,表明该地区开始受到了长江流域的影响,而第四纪以来重矿物特征指数(ZTR)逐渐增大可能主要受控于全球气候变化。   相似文献   

9.
胡绍锦 《云南地质》2005,24(3):321-327
记述滇池盆地含煤层中首次发现的上新世剑齿象化石,包括脊棱齿象属的一个新种昆明脊棱齿象(Stegolophodon kunm ingensissp..nov.)、似元谋剑齿象(Stegodonaff.yuan-m ouensis)、玉溪剑齿象、师氏剑齿象等。这一剑齿象化石组合的发现,对研究新生代象类和滇池盆地的演化史,重新划分盆地煤系地层具有重要意义。  相似文献   

10.
新疆库木库里盆地发育有巨厚的渐新统一更新统陆相沉积序列,记录了青藏高原西部自渐新世以来的隆起过程和幅度,盆地主夷平面形成于中中新世以后,上新世以前,该盆地中新世山旺生物群及上新世Cyprideis介形类动物群的发现显示了青藏高原中新世夷平作用这后的再次隆升并对中国自然环境变化产生了重大影响,导致中国西部生物组合由中新世晚期类似于现代江南山地的种类转变成为上新世以适应咸水环境为优势的组合,形成了西部内陆强蒸发的干旱环境,生物分异度大幅度降低,特别是库木里盆地晚更新世晚期乳动物化石的发现和含化石层的研究及区域对比,表明20-30ka以来高原存在一次幅度超逾百米的快速隆升。  相似文献   

11.
“元谋组”及“元谋动物群”含义的厘定   总被引:5,自引:1,他引:5  
讨论了云南元谋盆地的“元谋组”,“元谋动物群”的含义和时代。元谋组应只指钱方等人的“元谋组”的第四段地层 ,相应的动物群称为“元谋人”动物群。钱方等人的第三段地层应称甘棠组 ,其动物群名称为甘棠动物群。甘棠组和元谋组的时代分别为早更新世早期和晚期。  相似文献   

12.
元谋盆地的新第三纪地层   总被引:4,自引:1,他引:3  
宗冠福 《地层学杂志》1996,20(2):138-145
元谋北部芝麻地段新发现的动物化石层位相当于小河组下部的湖相地层,据之将小河组分为上下两部分,并进一步探讨元谋盆地含古猿动物化石层的地质时代。  相似文献   

13.
A new species, Tsuga nanfengensis sp. nov. (Pinaceae), is described on the basis of lignified fossil wood from the late Miocene of the Xianfeng Basin, central Yunnan, southwestern China. Detailed observation of the fossil wood specimens show the following characteristics: distinct growth rings, absence of resin canals, uniseriate bordered pits in the radial wall of tracheids, ray tracheids and piceoid and cupressoid cross-field pits. These features indicate similarities to the wood of extant Tsuga canadensis, T. chinensis, and T. dumosa. According to the fossil record, Tsuga was present in Xundian County during the Miocene. Today Tsuga is drought intolerant, preferring wet conditions with no extant species growing naturally in Xundian County. The presence of Tsuga in the Miocene of Xundian County indicates a humid climate consistent with previous palaeoclimatic reconstructions showing a wetter and probably shorter dry season in the Miocene, relative to the present day. Therefore, the change in the local climate such as increasing aridity through the Miocene might explain the local extinction of Tsuga from central Yunnan.  相似文献   

14.
黄河上游河段的形成年代依然存在争论,而银川盆地是黄河上游物质的主要沉积区之一,该盆地沉积序列的研究能为了解黄河上游的物质来源和形成年代提供重要线索。对银川盆地钻孔(PL02)底部进行了碎屑锆石U-Pb测年和碎屑组分统计研究,并与上游黄河沉积物以及盆地周边贺兰山和鄂尔多斯高原西部的锆石U-Pb年龄数据和碎屑组分数据进行了对比分析。结果表明贺兰山和鄂尔多斯高原西部并不是银川盆地晚上新世沉积物的物质供应区,而是黄河将银川盆地以上河段地区物质输送到银川盆地。这一结果进一步证明了黄河上游兰州—银川段在晚上新世已经形成的观点。  相似文献   

15.
中国几个主要哺乳动物地点的晚上新世—早更新世界线   总被引:2,自引:0,他引:2  
计宏祥 《地层学杂志》1993,17(3):161-170
<正> 中国的第三系—第四系界线的讨论和第三系、第四系剖面的研究,历史悠久,发表过不少论文。30多年来的工作大致在几个方面较多:1.黄土沉积剖面;2.河湖相沉积剖面;3.洞穴沉积剖面;4.海相沉积及滨海相平原沉积剖面。在磁性地层学方面研究及划分第四纪下限,有三种不同的划分:1.地层段的下限与奥特威亚时底界一致,大致是190万年;2.以松山/高斯转换的位置,约248万年;3.上限同高斯顶界一致(248万年),下限在300万年左右。  相似文献   

16.
Specimens of fossil wood preserved lignified in Pliocene brown coal and identified as Pinus armandii Francher come from an opencust coalmine at Longling in western Yunnan Province,China. Phytochemical investigation of the fossil wood isolated using liquid column chromatography seven compounds(1-7)including a new fluorene derivative named 11,11-dimethyl-11H-benzo[b]fluorene.A further 28 volatiles were detected by gas chromatography-mass spectrometry(GC-MS).Spectroscopic investigation methods,including MS and 1D and 2D-NMR techniques elucidated the structure of the seven compounds.Two types of natural products,isopimara and stilbene commonly occuring in extant and Plincene fossil P.armandii indicate phytochemical fidelity during burial under certain circumstances in sediments.Discovery of stilbenes that can inhibit the activities of wood-destroying fungi in the Pliocene P.armandii prompts the assumption that the chemical preservation of this Pliocene fossil wood of P.armandii in brown coal might contribute to the presence of inner natural inhibitors against wood-destroying fungi.  相似文献   

17.
Specimens of fossil wood preserved lignified in Pliocene brown coal and identified as Pinus armandii Francher come from an opencast coalmine at Longling in western Yunnan Province, China. Phytochemical investigation of the fossil wood isolated using liquid column chromatography seven compounds (1-7) including a new fluorene derivative named 11,11-dimethyl-11H-benzo[b]fluorene. A further 28 volatiles were detected by gas chromatography-mass spectrometry (GC-MS). Spectroscopic investigation methods, including MS and 1D and 2D-NMR techniques elucidated the structure of the seven compounds. Two types of natural products, isopimara and stilbene commonly occuring in extant and Pliocene fossil P. armandii indicate phytochemical fidelity during burial under certain circumstances in sediments. Discovery of stilbenes that can inhibit the activities of wood-destroying fungi in the Pliocene P. armandii prompts the assumption that the chemical preservation of this Pliocene fossil wood of P. armandii in brown coal might contribute to the presence of inner natural inhibitors against wood-destroying fungi.  相似文献   

18.
In order to reconstruct the palaeoclimate, a number of fossil wood pieces were collected and investigated from two new fossil localities situated in the Dhemaji and Lakhimpur districts of Assam. They belong to the Tipam Group considered to be of Middle–Late Miocene in age and show affinities with Gluta (Anacardiaceae), Bischofia (Euphorbiaceae), Bauhinia, Cynometra, Copaifera-Detarium-Sindora, Millettia-Pongamia, and Afzelia-Intsia (Fabaceae). The flora also records a new species of Bauhinia named Bauhinia miocenica sp. nov. The assemblage indicates a warm and humid climate in the region during the deposition of the sediments. The occurrence of some southeast Asian elements in the fossil flora indicates that an exchange of floral elements took place between India and southeast Asia during the Miocene.  相似文献   

19.
In Europe, fossil fruits and seeds of Rhodoleia (Hamamelidaceae) have been described from the Upper Cretaceous to the Miocene, whereas no fossil record of Rhodoleia has been reported in Asia, where the modern species occur. Herein, 21 fossil leaves identified as Rhodoleia tengchongensis sp. nov. are described from the Upper Pliocene of Tengchong County, Yunnan Province, Southwest China. The fossils exhibit elliptic lamina with entire margins, simple brochidodromous major secondary veins, mixed percurrent intercostal tertiary veins, and looped exterior tertiaries. The leaf cuticle is characterized by pentagonal or hexagonal cells, stellate multicellular trichomes, and paracytic stomata. The combination of leaf architecture and cuticular characteristics suggests that the fossil leaves should be classified into the genus Rhodoleia. The fossil distributions indicate that the genus Rhodoleia might originate from Central Europe, and that migrated to Asia prior to the Late Pliocene. Additionally, insect damage is investigated, and different types of damage, such as hole feeding, margin feeding, surface feeding, and galling, are observed on the thirteen fossil leaves. Based on the damage frequencies for the fossil and extant leaves, the specific feeding behavior of insects on Rhodoleia trees appears to have been established as early as the Late Pliocene. The high occurrence of Rhodoleia insect herbivory may attract the insect-foraging birds, thereby increasing the probability of pollination.  相似文献   

20.
A new Late Pennsylvanian species of gymnospermous fossil wood, Zalesskioxylon xiaheyanense sp. nov. is described from the Lower Taiyuan Formation (Stephanian B-C) near the village of Xiaheyan, Ningxia Hui Autonomous Region, northwestern China. The specimen consists only of silicified secondary xylem. The tracheids are pycnoxylic with 2–3 seriate bordered pits, arranged in subcircular or hexagonal alternate (araucaroid) pattern. The pores of the pits are small, linear, and regularly tilted. Xylem rays are homogeneous, uniseriate, 1–25 cells high. Cross-fields are filled with numerous mixed simple pits of various sizes. Growth rings, axial parenchymatous elements and resin canals are absent. The geographic distribution of Zalesskioxylon woods is reviewed. Zalesskioxylon xiaheyanense sp. nov. grew at low latitudes, and because of the lack of growth rings, probably lived under relatively uniform climatic conditions. Our new species supplements the poorly known distribution of Carboniferous wood in China.  相似文献   

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