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1.
本文总结了塔里木盆地西北缘露头剖面和典型钻井(草1井与托甫2井)剖面柯坪塔格组岩电及生物特征,并在此基础上对中央隆起区32口主要钻井的柯坪塔格组进行连井地层划分对比及地震剖面标定追踪。结合对等T0图分析,探讨了研究区柯坪塔格组三段分布规律。研究表明,柯坪塔格组上段分布最广,除麻扎塔格-塘参1-顺南地区以南没有发育外,其余地区均有发育,地层厚度一般在100—300m不等,在顺托果勒地区及方1井区以北分布厚度最大,超过了300m。柯坪塔格组上段总体分布表现出南薄北厚、东西分布不均的特点。柯坪塔格组中段与柯坪塔格组下段分布局限,仅在和4-顺西1-顺南3-塔中32井以北地区有发育。柯坪塔格组中段厚度一般只有40—60m,柯坪塔格组下段厚度一般为200—300m,两者厚度均表现出南薄北厚的分布特点。  相似文献   

2.
提要描述的珊瑚化石采自塔里木盆地西部伽师县西克尔地区,含珊瑚的地层是兰多维列统的柯坪塔格组。柯坪塔格组是目前塔里木盆地唯一有珊瑚的志留纪地层,西克尔又是塔里木盆地仅知有柯坪塔格组珊瑚动物群的地区,对我国志留纪古生物地理区系研究有重要意义。文内描述的柯坪塔格组珊瑚动物群包含床板珊瑚2属3种,日射珊瑚1属2种和皱纹珊瑚1属1种,属种名单是Paleofavosites schmidti Sokolov,P.schmidti borealis Sokolov,Schedohalysites raregonopora sp.nov.,Mcleodea jiashiensis sp.nov.,M.xikeerensis sp.nov.和Kodonophyllum cf.undulatun He and Huang。  相似文献   

3.
洞庭盆地下第三系新河口组腹足类口盖化石   总被引:1,自引:1,他引:0  
一、概述下第三系新河口组由作者1972年建立。建组剖面在湖南省沅江县黄茅洲区新河口沅4井250—425m井段,厚175m。此组见于洞庭盆地沅江凹陷东次凹钻孔中,厚度变化40.5—383.7m。也分布在沅江县新河口、南大膳、金南、南丰院等地,面积约90km~2。为湖盆快速收缩时期沉积,主要是一套弱氧化环境下的浅水湖  相似文献   

4.
塔里木西北的中华棘鱼化石及地质意义   总被引:12,自引:2,他引:10  
文章记述了塔里木巴楚县北闸衣木干他乌组中的棘鱼鳍刺化石,并简要回顾了产自长江中、下游地区(扬子区)中华棘鱼群化石的研究结果。经比较后认为,两地所产的棘鱼鳍刺化石总体上是相似的,其中锅顶山组或坟头组中和衣木干他乌组中所产的更为接近。一般来说,衣木干他乌组的层位也应和锅顶山组或坟头组的大致相当,同为中志留统。衣木子他乌组时代的更正,又使得塔里木和扬子地区中古生代地层的框架能很好地进行对比,进而证实,塔里木和扬子地区在志留纪时曾是相互邻近或彼此相连。  相似文献   

5.
湖南涟源雷鸣洞中泥盆世礁组合剖面的生态特征   总被引:4,自引:0,他引:4  
雷鸣洞礁组合发育在湘中桥头河向斜北翼的中泥盆统棋子桥组中。剖面位于雷鸣洞以北,涟源和宁乡两县交界处的一个采石场内。属于礁核亚相的地层厚81m,地貌上形成约30m高的陡崖。礁组合剖面在古地理位置上处于浅海碳酸盐台地的边缘。主要造礁生物是层孔虫和珊瑚。  相似文献   

6.
依兰-伊通地堑北部早白垩世孢粉组合新发现   总被引:1,自引:0,他引:1  
近年来,在汤原断陷钻井地层中发现了较丰富的早白垩世孢粉化石,本文依据汤原断陷汤D7井458.0-1100.0m井段新发现的孢粉化石,建立了3个孢粉化石组合,即:Cyathidites-Pilosisporites-Cardioangulina组合,Taxodiaceaepollenites-Pinuspollenites-Cyathidites组合和Cyathidites-Cicatricosisporites-Triporoletes-Pilosisporites组合。孢粉组合完全可以与松辽盆地登娄库组对比,其时代为早白垩世阿普第一阿尔必期。  相似文献   

7.
本文选取南海北部琼东南盆地崖北凹陷Y-2-X井2 197.6~4 288.5 m井段60个样品进行了沟鞭藻化石分析,结果每个样品均发现了沟鞭藻化石,共鉴定34属60种.根据沟鞭藻分布特征,对研究井段的地层进行了划分.2 197.6~2 548.1 m井段,沟鞭藻化石稀少,未建立组合.2 709.7~4 288.5 m建...  相似文献   

8.
通过对珠江口盆地荔湾凹陷超深水井W22井3 266~3 991 m井段72个样品开展有孔虫和钙质超微化石分析,讨论了该层段的地层划分并确定了其年代。研究层位含有丰富的有孔虫和钙质超微化石,详细的生物地层学分析显示其属于渐新世。其中,有孔虫分析发现3 390 m以下为早渐新世P18-P21a带沉积、3 380 m以上为晚渐新世P21b-P22带至N4带下部沉积,显示其地层年代为33-23 Ma;而钙质超微化石分析则揭示出该层位包含了自NP25带底部到NP21带的地层,下渐新统/上渐新统的沉积界限在3 390 m左右, Coccolithus formosus的末现面出现在3 841 m表明钻井3 841 m以深地层年代大于32.92 Ma,但更深地层未发现始新世钙质超微化石,表明底部年龄仍为早渐新世,但推测已经接近渐新世/始新世界限(33.89 Ma)。荔湾凹陷渐新世经历了从陆架浅海到上陆坡半深海环境的演变。  相似文献   

9.
拉萨地区Procyclolitidae的一些石珊瑚化石   总被引:1,自引:0,他引:1  
一、前言本文记述的石珊瑚动物群系产自西藏拉萨地区晚三叠世麦隆岗组。麦隆岗组为一套碳酸盐岩与碎屑岩沉积,分布于拉萨以北,西起千马沟,经麦隆岗,东至墨竹工卡县的拉东,呈东西两端窄的纺锤形,东西长约100余Km,地层出露厚度1,787m。北侧与燕山期花岗岩侵入接触或与老地层呈断层接触,南侧逆掩于白垩系之上(插图1)。  相似文献   

10.
松辽盆地松科1井南孔晚白垩世介形类生物地层   总被引:2,自引:0,他引:2  
松科1井是世界上第一口陆相白垩纪科学钻井,其南孔获取自泉头组三段顶部至嫩江组二段底部的连续地层记录。本文以松科1井南孔岩心样品介形类化石的系统鉴定和统计分析为基础,共建立15个介形类化石组合带,自下而上分别为:1)C ypridea subtuberculis perga-Mongoloc ypris longicau...  相似文献   

11.
Evolutionary biology has a complex relationship with ideas of chance, purpose, and progress. Probability plays a subtle role; strikingly, founding figures in statistics were motivated by evolutionary questions. The findings of evolutionary biology have been used both in support of narratives of progress, and in their deconstruction. Likewise, professional biologists bring to their scientific work a set of preconceptions about chance and progress, grounded in their philosophical, religious, and/or political views. From the religious side, questions of purpose are ever‐present. We explore this interplay in five broad categories: chance, progress, intelligence, eugenics, and the evolution of religious practices, each the subject of a semester long symposium. The intellectual influence of evolutionary biology has had a broad societal impact in these areas. Based on our experience, we draw attention to a number of relevant facts that, while accepted by experts in their respective fields, may be unfamiliar outside them. We list common areas of miscommunication, including specific examples and discussing causes: sometimes semantics and sometimes more substantive knowledge barriers. We also make recommendations for those attempting similar dialogue.  相似文献   

12.
This study deals with four form or organ genera from the Upper Mississippian (Chester Series) of the Illinois Basin, and provides evidence that they were produced by a single natural genus with gymnospermous affinity. The plant remains—compressions, impressions, petrifactions, and specimens that combine compression or impression with petrifaction—allow examination of both external morphology and internal anatomy. The specimens include foliage corresponding to Rhodea, stems and petioles corresponding to Heterangium, and synangiate fructifications corresponding to either Telangium or Telangiopsis. The stems and foliage are considered parts of the same plant because of the identity of the anatomical and cuticular features of petioles attached to stem and those petioles with attached foliage. The fertile material is regarded as part of the same plant because: (1) The anatomy of axes of the fertile specimens is like that of the sterile specimens. (2) A single specimen may contain both sterile Rhodea-type axes and fertile regions. (3) Axes bearing synangia have the same size and patterns of divisions as the sterile foliage. Features that indicate lyginopterid affinities include: (1) Equal forking of the petiole. (2) Presence of fiber bands in the outer cortex and sclerotic nests in the inner part of the cortex. (3) Crowded circular bordered pits on the lateral walls of the metaxylem tracheids. (4) The presence of a small amount of secondary xylem. A variety of structural details of the stem and petiole suggest the genus Heterangium. The phyletic position of the plant that produced Rhodea, Telangium, Telangiopsis, and Heterangium is reviewed in light of such discoveries as the presence of a planated frond that lacks a lamina and the presence of both monolete and trilete microspores in a single synangium.  相似文献   

13.
1. Freshwater fishes are the most northerly of freshwater ectotherms, followed by frogs. North American freshwater snakes, turtles, and salamanders do not range farther north than southernmost Canada. 2. Freezing and desiccation are the main challenges during terrestrial hibernation of ectotherms. Oxygen depletion, water balance, and ionic balance are the major problems for air breathing ectotherms that hibernate underwater. 3. The importance of accumulation of energy stores for overwintering among fishes depends upon the length and severity of the winters, whether or not there is springtime reproduction, body size, latitude, and the availability and use of food during overwintering. 4. Fishes can decrease energy demands during the winter by reductions in activity, metabolic depression, and entrance in semi-torpidity. 5. Adaptations for coping with hypoxia and anoxia among overwintering freshwater fishes may include metabolic depression, a decrease in blood O2 affinity, microhabitat selection, air breathing, short-distance migration, biochemical modifications aimed at adjusting glycolytic rates, and alcoholic fermentation. 6. Freshwater turtles have a worldwide northern limit of approximately 50° N, which means that some species spend about half of their lives hibernating. 7. Aquatic turtles normally hibernate underwater, although occasionally they hibernate on land. In water they usually hibernate in a hypoxic or anoxic (mud) environment and in relatively shallow water. Wintertime movements of unknown frequency occur in some species. 8. The hatchlings of many turtle species can overwinter in the nest. Among northern species this behaviour is most common among painted turtles, whose hatchlings can withstand freezing. 9. Mortality among adult turtles is probably highest during the hibernation cycle. 10. Temperature appears to the most important cue for entry and exit from hibernation among freshwater turtles. 11. Little is known of the energetics of overwintering turtles. Energy stores for overwintering may be more important at lower latitudes than at higher ones, due to the higher metabolic rates of overwintering, but non-feeding, southern turtles. 12. The ability of turtles to tolerate submergence is a function of temperature, degree of water oxygenation, latitude of origin, efficacy of extrapulmonary respiratory pathways, and metabolic rate. 13. For turtles that hibernate in an anoxic hibernaculum, and for those without sufficient extrapulmonary uptake of O2 to allow metabolism to be completely aerobic, the most important physiological perturbation is an acidosis developed from a continuing production of lactate. If sufficient O2 can be obtained, the most likely factors limiting hibernation time are water balance and ion balance. 14. Mechanisms of turtles for coping with acidosis include metabolic depression, integumental CO2 loss, bicarbonate buffering, and changes in ion concentrations that minimize the decrease in SID (strong ion difference). The most important among the latter are a decrease in plasma [Cl-] and large increases in plasma calcium and magnesium. 15. Turtles are unique among reptiles in their ability to maintain both cardiovascular and nervous system function during prolonged anoxia. 16. Turtles gain weight from water uptake during submerged hibernation, but apparently maintain some kidney function; however, osmoregulation is one of the least known areas of the physiology of hibernation. 17. Recovery of turtles upon emergence commences with a rapid hyperventilatory compensation of pH, followed by a slower adjustment of ion levels. Basking speeds recovery greatly. 18. While hibernation of turtles in the northern parts of their ranges is most likely very stressful physiologically, northern range limits are more likely to be determined by reproductive restraints than by the rigors of extended hibernation. 19. The superior ability of turtles to tolerate anoxia may be more the result of an annual hibernation than of their diving habits during active periods of the year. 20. Freshwater snakes usually hibernate on land. However, they appear to be capable of aquatic hibernation and may not do so because of the risk of death from anoxia. 21. Some species of terrestrial snakes are known to hibernate underwater, and are able to do so in the laboratory for months. In the field, this behaviour is considered opportunistic, as there is no evidence to suggest that any snakes can tolerate extended anoxia.  相似文献   

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—A mass fragmentographic method for the assay of phenylethylamine (PEA) and a number of related amines in several biological materials is described. The gas chromatographic column employed for this analysis is a 12ft 1/8 in. o.d. steel column packed with 0.5% OV22+ 2% SE54 + 1% OV210 coated on 80/100 mesh chromosorb W (HP). The mass spectral characteristics of these amines are illustrated, compared, and discussed. Of the various monoamines which could be measured, only PEA, m- and p-tyramine were detected in measurable quantities. Phenylethanolamine and p-octopamine were found in trace amounts in urine, plasma, cerebrosponal fluid, and rat brain. No diurnal variation in the urinary excretion of PEA, m- and p-tyramine was observed. Plasma concentration of PEA or p-tyramine did not significantly change 1 h after eating a breakfast. Furthermore, consuming 200 g of Cadbury milk chocolate containing about 1 mg of PEA, 0.1 mg of phenylethanolamine and 10 mg of p-tyramine did not significantly alter urine excretions of these three amines. In the brain, as has been reported by others, we found that PEA and p-tyramine are not evenly distributed and that the highest concentrations are found in the hypothalamus and caudate. From the results obtained we concluded that PEA, m- and p-tyramine are probably produced from endogenous sources and that the direct contribution of diet to their urine excretion is small.  相似文献   

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