塔里木盆地塔中—古城地区奥陶系碳酸盐岩台地边缘相特征及演化     

王冠  樊太亮  刘海龙 《现代地质》2014,(5)

塔里木盆地塔中—古城地区奥陶系碳酸盐岩台缘带的存在早已被证实,但由于地层深度大、钻井少、地震资料品质有限且经历多次构造运动,导致台缘带的空间展布、位置迁移等都尚无确凿定论。综合分析钻测井、地震剖面、岩心等资料,按时间顺序将研究区奥陶系台缘相带的发育分为3个阶段:下奥陶统蓬莱坝组有明显的镶边型台缘发育,近南北走向,整体呈"S"型展布;中下奥陶统鹰山组的台缘带与蓬莱坝组的展布范围大体相似,但在古隆1井处呈现反"S"型分布,镶边型和缓坡型都存在,相带变窄,略向台地内部收缩;上奥陶统恰尔巴克组—良里塔格组时期存在塔中南、北两个台缘相带,北坡台缘为缓坡型,南坡宽度略大且坡度变陡,为镶边型。奥陶纪台缘带的平面迁移整体呈现从南北向近"S"型逐渐变为开口向西的"V"型的特点;早中奥陶世台地边缘相带开始向盆地内部迁移,台地边缘—斜坡带也主要呈退积-加积式发育。奥陶纪晚期,海平面大幅下降,地层遭到严重剥蚀,残余的台缘带分布明显缩小。大规模迅速海退之后,晚奥陶世的新一轮海进导致台地边缘相带向台地高部位逐步退缩。  相似文献   

Does the CDM discourage emission reduction targets in advanced developing countries?     

Paula Castro 《Climate Policy》2013,13(2):198-218

Under the Kyoto Protocol, developing countries can voluntarily participate in climate change mitigation through the Clean Development Mechanism (CDM), in which industrialized countries, in order to meet their mitigation commitments, can buy emission reduction credits from projects in developing countries. Before its implementation, developing-country experts opposed the CDM, arguing that it would sell-off their countries’ cheapest emission reduction options and force them to invest in more expensive measures to meet their future reduction targets. This ‘low-hanging fruit’ argument is analysed empirically by comparing marginal abatement cost curves. Emissions abatement costs and potentials for CDM projects are estimated for different technologies in eight countries, using capital budgeting tools and information from project documentation. It is found that the CDM is not yet capturing a large portion of the identified abatement potential in most countries. Although the costs of most emissions reduction opportunities grasped are below the average credit price, there are still plenty of available low-cost opportunities. Mexico and Argentina appear to use the CDM predominantly for harvesting the low-hanging fruit, whereas in the other countries more expensive projects are accessing the CDM. This evidence at first sight challenges the low-hanging fruit claim, but needs to be understood in the light of the barriers for the adoption of low-cost abatement options.  相似文献   

Marginal abatement cost curves: a call for caution     

Fabian Kesicki  Paul Ekins 《Climate Policy》2013,13(2):219-236

Legal commitments to reduce CO₂ emissions require policy makers to find cost-efficient means to meet these obligations. Marginal abatement cost (MAC) curves, which illustrate the economics associated with climate change mitigation, have recently attracted a great amount of attention. A number of limitations with MAC curves are explained by the implication they should be just one tool in a broader set of decision-making aids used in assessing climate policy. MAC curves, for example, omit ancillary benefits of greenhouse gas emission abatement, treat uncertainty in a limited manner, exclude intertemporal dynamics and lack the necessary transparency concerning their assumptions. MAC curves based on the individual assessment of abatement measures suffer from additional shortcomings such as the non-consideration of interactions and non-financial costs, a possibly inconsistent baseline, double counting and limited treatment of behavioural aspects. Reducing emissions from deforestation and forest degradation exhibit many of the above-mentioned problems, making it particularly difficult to capture in a cost curve. Policy makers should therefore be cautious when interpreting MAC curves, pay attention to the underlying assumptions, consider non-financial costs and be aware of the important uncertainties and underlying path dependencies.  相似文献   

内蒙古乌拉特后旗乌兰敖包地区石炭系—二叠系阿木山组沉积环境     

韩伟  刘溪  李金超  史冀忠 《中国区域地质》2012,(10):1684-1691

对内蒙古乌兰敖包地区野外剖面进行观测,结合剖面岩性组合、地层古生物、沉积构造、岩石学等沉积特征分析,认为剖面整体分为3段。下段为辫状河三角洲相向滨海相过渡,中段为碳酸盐台地相,上段为滨、浅海相。剖面沉积特征反映了该区石炭系—二叠系阿木山组沉积环境位于盆地边缘,经历了陆相向海相的转变,属于上超沉积。沉积相研究及边缘相的确定从沉积学角度证明额济纳旗及其邻区在石炭纪—二叠纪时期是一个裂谷盆地。研究成果可为盆地演化和沉积相研究提供依据。  相似文献   

兰州市区地质灾害气象预警区划探讨     

高晖  张永军  刘武 《甘肃地质》2013,22(1):61-64

甘肃省地矿局2012年度成果汇报会于2013年1月21日至24日在兰州召开,梁育才副局长、张新虎副巡视员兼总工程师、局机关相关处室、各院总工和主要项目负责人共100人参加了会议。会议全面总结了2012年度地质勘查成果,交流地质找矿经验。各院总工汇报了全年地质勘查工作,局对各院找矿成果进行验收和考核。2012年度全局共承担各类  相似文献   

Interannual variations of surface winds over China marginal seas     

孙澈  闫晓梅 《中国海洋湖沼学报》2012,30(6):922-932

In a study of surface monsoon winds over the China marginal seas, Sun et al. (2012) use singular value decomposition method to identify regional dominant modes and analyze their interdecadal variability. This paper continues to evaluate the interannual variability of each dominant mode and its relation to various atmospheric, oceanic and land factors. The findings include: 1) The intensity of the winter monsoon over the East China Sea is highly correlated with the Siberian High intensity and anti-correlated with the latitudinal position of the Aleutian Low as well as the rainfall in eastern China, Korean Peninsula and Japan; 2) The western Pacific subtropical high is significantly correlated with the summer monsoon intensity over the East China Sea and anti-correlated with the summer monsoon over the South China Sea; 3) The winter monsoon in a broad zonal belt through the Luzon Strait is dominated by the ENSO signal, strengthening in the La Ni a phase and weakening in the El Ni o phase. This inverse relation exhibits interdecadal shift with a period of weak correlation in the 1980s; 4) Analysis of tidal records validates the interdecadal weakening of the East Asian summer monsoon and reveals an atmospheric bridge that conveys the ENSO signal into the South China Sea via the winter monsoon.  相似文献   

Methods to evaluate the impacts of physio- geographical pattern on spatio-temporal disparity of regional development     

LI Guosheng  GUO Zhaocheng  LIAO Heping 《地理学报》2008,18(2):225-236

With the rapid economic development during the last 30 years in China, more and more disparities have emerged among different regions. It has been one of the hot topics in the fields of physical geography and economic geography, and also has been the task for Chinese government to handle. Nevertheless, to quantitatively assess the impacts of physio-geographical patterns (PGP) on the regional development disparity has been ignored for a long time. In this paper, a quantitative method was adopted to assess the marginal ef-fects of the PGP on spatio-temporal disparity using the partial determination coefficients. The paper described the construction of the evaluation model step by step following its key scien-tific thinking. Total GDP, per capita GDP, primary industrial output value and secondary in-dustrial output value were employed in this study as the indicators to reflect the impacts of PGP on the regional development disparity. Based on the evaluation methods built by re-searchers, this study firstly analyzed the temporal impacts of the PGP on spatio-temporal disparity of the regional development in China during the past 50 years, and then explained the spatial differences at each development stage. The results show that the spatio-temporal disparity in China is highly related to the PGP, and that the marginal contribution rate could be employed as an effective way to quantitatively assess the impact of the PGP on spa-tio-temporal disparity of the regional development.  相似文献   

Rossby波模型对西北太平洋海表面高度年际变异的可预测性研究     

张永垂  张立凤 《海洋与湖沼》2013,44(6):1409-1417

根据海洋Rossby波的西传特性, 使用一阶斜压Rossby波模型对北太平洋海表面高度的年际变异进行了回报和预测研究。回报结果表明, Rossby 波模型能够较好地模拟北太平洋海表面高度的年际变异。尤其是黑潮延伸区的下游, 模拟结果与卫星观测的相关系数达到0.8以上。预测结果表明, Rossby 波模型在两个纬向分布的海域有显著的预报能力, 分别位于高纬度中部和副热带环流西部。前者可提前5—6年, 后者可提前2—4年。此外, 重点开展了Rossby波模型在西北太平洋的预报能力研究。结果表明, Rossby波模型对中国的边缘海有着很好的预测能力, 包括南海北部、台湾以东和东海黑潮海域, 分别在提前32、40和52个月时能取得最佳的预测效果。  相似文献   

Hilbert spectrum and intrinsic oscillation mode of dynamic response of a bilinear SDOF system： influence of harmonic excitation amplitude   总被引：1，自引：0，他引：1  

张郁山梁建文  胡聿贤 《地震工程与工程振动(英文版)》2005,4(1):17-26

Under harmonic wave excitation, the dynamic response of a bilinear SDOF system can be expressed by the Hilbert spectrum. The Hilbert spectrum can be formulated by (1) the inter-wave combination mechanism between the steady response and the transient response when the system behaves linearly, or (2) the intra-wave modulation mechanism embedded in one intrinsic mode function (IMF) component when the system behaves nonlinearly. The temporal variation of the instantaneous frequency of the IMF component is consistent with the system nonlinear behavior of yielding and unloading. As a thorough study of this fundamental structural dynamics problem, this article investigates the influence of the amplitude of the harmonic wave excitation on the Hilbert spectrum and the intrinsic oscillatory mode of the dynamic response of a bilinear SDOF system.  相似文献   

川北下寒武统仙女洞组台缘斜坡碳酸盐岩重力流沉积          下载免费PDF全文

廖纪佳  马思豪  廖明光  林丹 《高校地质学报》2018,24(2):263

基于重力流剖面的野外观察、露头解剖及镜下鉴定等分析手段,对四川盆地北部下寒武统仙女洞组台缘斜坡碳酸盐 岩重力流沉积及发育机制进行了研究。研究区位于仙女洞组,主要沉积粉砂质泥岩、生屑泥晶灰岩、藻灰岩等3种岩石类 型;根据层面上产出形态的不同,将该区碳酸盐岩重力流沉积分为似瘤状碳酸盐岩重力流沉积和角砾型碳酸盐岩重力流沉 积2类。结合露头区重力流沉积物粒度及岩性变化,将碳酸盐岩重力流沉积由下至上划分出5个发育期次,期次内部重力流 沉积物由细变粗,纵向上呈现出明显的叠置关系,与仙女洞组时期所经历的海退环境大致吻合。地震、风暴浪等触发机制 导致台缘斜坡上部松散沉积的灰泥丘块体发生破碎并沿斜坡发生滑塌,伴随水体注入,大块砾石在沉积物-水体混合的环 境中发生破碎搅动,形成大小不等的块体,深水底流等作用对未固结或弱固结的砾屑灰岩进行溶蚀、改造,最终形成了层 面形态特征不同的2类似瘤状碳酸盐岩重力流沉积。角砾型碳酸盐岩重力流沉积则主要是未破碎的巨型灰泥丘块体经搬运 和短距离滑塌,最终与似瘤状砾屑灰岩共同沉积而成。  相似文献