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1.
泥盆纪华南板块古地理的位置及其漂移   总被引:9,自引:0,他引:9  
华南板块在泥盆纪位于古赤道附近,早—中泥盆世之交,广西那艺古纬度为 0°36',泥盆纪—石炭纪之交贵州睦化地区古纬度为4°10'10″,赤道附近温湿的气候使华南板块上各种生物,无脊椎动物,脊椎动物,植物高度繁盛,发育,都有很高的分异度。泥盆纪时期华南板块向北缓慢移动,移动速率为0.22 ~0.26cm/a。其原因可能与特提斯洋的活动有关。  相似文献   

2.
滇东-黔西南泥盆纪时位于古特提斯洋东缘,构造格局可划分为特提斯洋板块的哀牢山大洋裂谷系,扬子板块的滇东南-黔南被动陆缘裂谷系和滇东北-黔南陆内裂谷系三个构造单元。三裂谷系中发育有三个性质和内部结构不同的沉积盆地。盆地中晚古生代沉积建造和火山活动受盆内同沉积断裂拉张和走滑控制,在每一盆地中泥盆纪沉积相展布格局和岩相古地理演化与裂谷系中同沉积断裂活动相对应。  相似文献   

3.
甘蒙北山地区板块构造演化与铜多金属矿成矿系列研究   总被引:7,自引:3,他引:4  
结合板块构造理论和成系列概念,提出了成矿系列新的研究方法。甘蒙北山地区位于哈萨克斯坦板块和塔里木-中朝板块交汇部位,其板块构造演化分为前震旦纪古板块活动时期、震旦一泥盆纪现代体制板块活动时期和石炭-二叠纪裂谷活动时期,不同构造单元演化阶段控制了不同的含矿建造、成矿作用时空分布及演化序列和矿床共生组合。按照板块构造演化及其与铜多金属矿成矿作用时空分布和成矿作用演化序列的关系,划分出北山地区铜多金属矿古大陆区(缘)成矿系列,洋缘火山带成矿系列、岛弧-弧后盆地成矿系列和裂谷带成矿系列。  相似文献   

4.
早寒武世疑源类的古生物地理学意义   总被引:1,自引:0,他引:1  
根据早寒武世疑源类在全球的古地理分布,并参考古地磁和动物化石等方面的资料,进行了早寒武世疑源类的古地理分区。结果表明:早寒武世在全球范围内可分为2个疑源类古地理大区,即波罗的海-北美-亚、澳大区和地中海大区;我国西南地区早寒武区筇竹寺期,可根据疑源类分为两个生态区,即扬子区和江南区。这一研究结果为今后各区生态结构分析,提供了重要基础资料。  相似文献   

5.
中国南方东部的大地构造背影控制着古地理演化特征,不同构造单元内沉积盆地的性质存在着显著差别。早三叠世的中下扬子混积盆地属克拉通力缘盆地,而上饶和明溪碎屑岩盆地则为大陆边缘断陷盆地。在整个三叠纪,区域性大断裂对沉积相的分布具有显著的控制作用。绍兴-宜春断裂作为构造分区的界限、控制了其两侧古地理的发展。古地理演化是构造运动地直观响应,中国南方三叠纪的地壳抬升、台地浅滩化、海水退出与印支运动密切相关。  相似文献   

6.
中国南方东部的大地构造背景控制着古地理演化特征,不同构造单元内沉积盆地的性质存在着显著差别。早三叠世的中下扬子混积盆地属克拉通边缘盆地,而上饶和明溪碎屑岩盆地则为大陆边缘断陷盆地。在整个三叠纪,区域性大断裂对沉积相的分布具有显著的控制作用。绍兴—宜春断裂作为构造分区的界限,控制了其两侧古地理的发展。古地理演化是构造运动的直观响应,中国南方三叠纪的地壳抬升、台地浅滩化、海水退出与印支运动密切相关  相似文献   

7.
晋宁旋回的若干古老地体经拼合形成原始华南大陆地壳;澄江旋回破裂解体;加里东旋回经多次拉张、挤压后,扬子陆块与华夏陆块拼合形成统一的华南板块;海西—印支旋回在挤压上升背景上平静拉伸张裂,最后发生大陆碰撞;燕山—喜马拉雅旋回发生拉张断陷。泥盆纪古构造格局表现为华南海西期古大陆板块及其南、西缘的被动大陆边缘。可划分出华南陆块、右江-南岭被动陆缘、南秦岭-龙门山-盐瀑、丽江被动陆缘、钦防残留海槽以及它们的次一级构造环境。  相似文献   

8.
华北板块北缘东段古生代沉积特征及盆地演化研究进展   总被引:2,自引:0,他引:2  
通过对吉林伊通、长春、永吉、桦甸等野外实地考察,结合前人研究成果,总结华北板块与西伯利亚板块碰撞拼贴方式、古亚洲洋南支洋闭合过程以及华北板块北缘沉积特征与盆地演化。研究区地质构造错综复杂,沉积体系保存不全;受中新生代构造的影响,叠加了中新生代构造变形、岩浆活动和成矿作用;地层被破坏,多为哑地层,上述原因导致对古亚洲洋闭合之前盆地的性质及演化认识不一,制约了对有关重要科学问题的深入研究。采用沉积学的方法,结合构造地质学、地球化学、古生物地层学、同位素测年等理论和方法,依据现存古生代地层和不同构造部位的沉积盆地类型及其基本特征,开展古生代构造古地理演化研究,恢复沟弧盆体系的分布以及岛弧的类型、时代,探讨古亚洲洋的闭合过程,将是探讨华北板块北缘东段构造演化特征的新思路。  相似文献   

9.
动物地理区划的聚类分析   总被引:3,自引:0,他引:3  
用聚类分析方法分析了中国及陕西省动物地理区划方案,结果表明聚类结果与区划方案基本一致,但台湾亚区和南海诸岛亚区与中国大陆动物区系差异较大。因此,应重新考虑这两个亚区的区划级别;属于蒙新区的东部草原亚区的归属问题也值得考虑;省,州级动物地理区划应较多地考虑生态地理的条件及其原则。  相似文献   

10.
根据对170属三叶虫、210属腕足类及87属头足类的综合分析结果,本研究区可分为中亚-东亚区和北亚区(二者分别属于古太平洋大区和古大西洋大区)。中亚-东亚区包括哈萨克斯坦、塔里木及华北3个分区,其中哈萨克斯坦分区包括哈萨克斯坦、中亚南天山及新疆准噶尔,以三叶虫 OpsimasaphusHeptabronteus 以及腕足类 Ishimia, ShlyginiaEoanastrophia 为代表;塔里木分区以三叶虫 Taklamakania 属为代表,另有丰富的 Lituitidae 和 Oncoceratidae 科头足类;华北分区包括华北地台区,鄂尔多斯及祁连等地区,以头足类比较丰富及其地方性为特色。北亚区分为西伯利亚、阿尔泰-萨彦和兴蒙3个分区,其中西伯利亚分区以三叶虫 Monorakos、腕足类 Evenkina, EvenkinorthisLenatoechia 以及头足类 Intejacerida 目为代表;阿尔泰-萨彦分区以三叶虫 Malinaspis 和腕足类 Ujukites 为代表;兴蒙分区包括我国东北及蒙古东部,除局部性的地方分子外,特征分子不明显。值得指出的是,哈萨克斯坦分区含有许多广泛分布于北美、华南、塔里木和华北鄂尔多斯地区的种属,意味着它当时处于两大区的过渡地位。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

15.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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