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1.
The geological features now exposed at Mormon Point, Death Valley, reveal processes of extension that continue to be active, but are concealed beneath the east side of Death Valley. Late Cenozoic sedimentary rocks at Mormon Point crop out in the hangingwall of the Mormon Point low-angle normal fault zone, a fault zone that formed within a releasing bend of the oblique-slip (right-normal slip) fault zone along the east side of Death Valley. The late Cenozoic sedimentary rocks were part of the valley when the low-angle fault zone was active, but during late Quaternary time they became part of the Black Mountains block and were uplifted. Rocks and structures exposed at Mormon Point are an example of the types of features developed in a releasing bend along the margins of a major pull-apart structure, and in this example they are very similar to features associated with regional detachment faults. The oldest sedimentary rocks in the hangingwall of the Mormon Point low-angle fault zone dip steeply to moderately east or north-east and were faulted and rotated in an extensional kinematic environment different from that recorded by rocks and structures associated with younger rocks in the hangingwall. Some of the younger parts of the late Cenozoic sedimentary rocks were deposited, faulted and rotated during movement on the Mormon Point low-angle normal fault. Progressively, strata are less faulted and less rotated. The Mormon Point low-angle normal fault has an irregular fault surface whose segments define intersections that plunge 18°-30°, N10°-40°W, with a maximum of 22°, N22°W that we interpret to be the general direction of slip. Thus, even though Death Valley trends north, movement on the faults responsible for its formation was at least locally north-northwest. Gouge and disrupted conglomerates along the faults are interpreted to have formed either as adjustments to accommodate space problems at the corners of blocks or along faults that bounded blocks during their displacement and rotation. The younger units of the late Cenozoic sedimentary rock sequence and the geomorphic surfaces developed on them are rarely faulted, not rotated, and overlap the Mormon Point low-angle faults. Active faults cut Holocene alluvium north of the late Cenozoic rocks and form the present boundary between Mormon Point and the Black Mountains. The distribution of active faults defines a releasing bend that mimics the older releasing bend formed by the Mormon Point low-angle fault zone. Rocks and structures similar to those exposed above the Mormon Point low-angle fault zone are probably forming today beneath the east side of Death Valley north-west of Mormon Point.  相似文献   

2.
大别山地区黄山松和油松树轮宽度的气候意义   总被引:5,自引:1,他引:4  
本文基于2010年采自大别山地区黄山松、油松树轮资料分别建立了树轮宽度标准年表,利用相关函数检验了年表与附近的麻城气象站1959-2009年月平均最高气温、月平均气温、月平均最低气温和月降水量之间关系,旨在探讨黄山松、油松树轮宽度的气候意义。研究结果显示,平均敏感度、标准差、信噪比等统计量黄山松年表均高于油松年表,表明黄山松年表较油松年表包含更多的气候信息,具有更高的树轮气候学研究价值。黄山松径向生长主要受当年2-7月平均气温限制,任何月份及月份组合降水量对黄山松径向生长的限制作用均不显著;油松径向生长主要受当年5-6月降水总量限制,任何月份及月份组合气温对油松径向生长的限制作用均不显著。研究表明,在中国亚热带暖湿地区,气候要素的年际变化亦可对部分树种径向生长具有较强的限制作用,树木年轮宽度的变化对气候具有指示意义。研究结果将进一步弥补中国亚热带暖湿地区树轮宽度年表的不足,为树轮气候重建研究提供参考和依据。  相似文献   

3.
章古台固沙林主要树种根际土壤性质研究   总被引:13,自引:2,他引:11  
研究了章古台固沙林樟子松、油松、赤松和杨树4个树种的根际土壤, 结果表明: 不同树种根际土壤pH值低于非根际土壤, 有机质含量均高于非根际土壤; 除杨树外, 根际土壤CEC(阳离子代换量)均低于非根际土壤; 而交换性酸度、水解性酸度和全盐量均高于非根际土壤, 盐基饱和度均低于非根际土壤; 根际土壤中全N、碱解N、速效K表现为富集, 速效P表现为亏缺, 其中樟子松亏缺最为严重; 不同树种根际土壤微生物数量和酶活性均高于非根际土壤。  相似文献   

4.
ABSTRACT. The landscape of Salt Lake City, Utah, drew considerable comment between 1849 and 1870 from non-Mormon travelers. These experiences, chiefly of overland emigrants, foreign travelers, and military personnel, include first impressions, feelings on entry, and later reactions. The setting, material landscape, Mormon citizenry, and travelers' attitudes toward early Salt Lake City Mormon customs and institutions are discussed.  相似文献   

5.
Dominant groups tend to construct the meaning of places to justify and sustain their ideology and orthodoxy in order to solidify power and to maintain their control over others. New outsider groups whose ideology disrupts the established order and sovereignty of the dominant group can be labeled transgressive ( Sibley 1995; Cresswell 1996 ). Transgressions of hegemonic spaces force dominant groups to reexamine themselves and to reaffirm or to modify their position. This concept of transgression is used to examine the controversy surrounding the building of the Brigham Young University Jerusalem Center in the mid‐1980s in Jerusalem. The public outcry among some Israelis over the building of this educational edifice concerned the potential use of the Jerusalem Center as a focal point for Mormon (Latter‐day Saints) proselytizing efforts. We examine the way the Jerusalem Center was viewed and depicted by its opponents, suggesting how basic geographic concepts such as scale and site further refine the concept of spatial transgression for buildings and urban redevelopment.  相似文献   

6.
气候变化对我国红松林的影响   总被引:8,自引:0,他引:8  
卫林  贺庆棠 《地理研究》1995,14(1):17-26
在对红松适生范围、生态习性等广泛深入调查分析基础上,依据环境因子对树木生长影响的作用规律,首先推出一个能反映红松年生长量与水热因子间关系的W-T模式,进而分析了各种可能的气候变化对红松生长量与分布的影响。结果表明,气温升高,无论降水增减,都将使红松适生范围与生长量大幅度减少。但在可预见的气候变化范围内,红松不会退出我国的东部山地。  相似文献   

7.
彭剑峰  王婷 《地理科学》2015,35(5):644-651
利用大别山西部的3个黄山松(Pinus taiwanensis Hayata)树木年轮采样点的样本,建立3个标准年表,其特征值都表明黄山松树木年轮宽度中含有较高的环境信息;年表间相关密切,区域主要受气候因子影响、南北差异显著;年表与气候因素的相关也显示不同环境生长的黄山松差异性要大于共性;同样多元线性回归也确定该研究区影响树木生长的主导因子为前一年10月的均温,而前一年8月的降水同样起着非常重要的作用。不同要素的模拟结果有较好的一致性,但极端气候条件下树木的生长差异显著。  相似文献   

8.
云南省松材线虫病风险评估GIS平台开发   总被引:1,自引:0,他引:1  
松材线虫病被称为松树的"癌症"。云南省针叶树种面积大,松材线虫寄主多,地形复杂,虫病防治难度大。综合运用.NET平台、ArcEngine组件技术、ArcSDE空间数据库引擎技术、SQL Server数据库技术,在云南省气象、空间、松材线虫数据基础上,建立一个云南省松材线虫病风险评估GIS平台,主要包括图层控制、风险评估、疫点操作、地图显示、专题图输出等功能,对云南省松材线虫病疫情进行更加精细化、标准化、可视化的评估。  相似文献   

9.
ABSTRACT. In order to view the establishment of new religions centers and how they are received by local populations, I analyze such basic geographical concepts as scale, space, location, and image. I see how these can alter the perception and further refine the concept of spatial transgression in three case studies in Israel: the building of the Mormon Center in Jerusalem, the establishment of the Bahá‘í Gardens in Haifa, and the struggle to build a mosque in Nazareth. In this article I seek to identify the factors influencing the presence or absence of conflict to help explain the different “stories” revealed. The article also constitutes an addition to the literature on Israeli (and Palestinian) religiogeographical controversies by focusing on nonmainstream or nondominant cases and by comparing the relative roles of different factors that shape the success or failure of spatial transgressions in religious geography.  相似文献   

10.
William Norton 《Area》2003,35(4):418-426
Cultural geography might benefit from consideration of radical behaviourism and from interpretation and application of the concepts of behaviour analysis. The basic concept is that of operant conditioning, referring to the environment reinforcing behaviours that are most adaptive and effective in achieving reinforcers and avoiding aversive stimuli. The concept of rule-governed behaviour facilitates incorporation of cognition into behaviour analyses, accommodating the fact that many consequences are delayed. These concepts are applied in an analysis of nineteenth-century Mormon settlement in the American West. This argument for an objectivist approach is laden with social scientific baggage not favoured in contemporary cultural geography.  相似文献   

11.
树木年轮资料的可靠性分析——以陕西华山松为例   总被引:8,自引:0,他引:8  
依据陕西华山的华山松树木年轮宽度、最大密度与最小密度年表,以及对树木生长模拟结果,本文分析了树木径向生长对气候因子(气温和降水)的响应状况。结果表明树木年轮生长的多种指标均能相互印证,并具有生理学意义,从而证实了它们作为气候变化的代用资料是可靠的。这不仅强调了树木年轮多途径分析的必要性,而且为重建过去气候变化提供了依据。  相似文献   

12.
ABSTRACT. Early work by D. W. Meinig delimiting “The Mormon Culture Region” focused on the spread of the Church of Jesus Christ of Latter‐day Saints (lds ) in a core, domain, and sphere scheme that recognized diffusion of a fast‐growing group bent on shifting its station from cultural edge to religious mainstream. Such a changeover from fringe belief to international force lacks any widely circulated rule book. The lds and its followers today extend influence through diverse, distinct pathways: making missionaries a recognizable global force, offering education on church‐controlled university campuses, emanating wholesomeness, entering high‐security federal service, and attaining national political power. But nothing so locks in an lds message as the standard‐plan meetinghouses, in uniform styles, that mark church presence in North America and other continents. This work analyzes that architecture and examines its fit within lds expansion and presentation of self, not just in the Salt Lake City church but even as imitated by outcast outliers.  相似文献   

13.
Coarse woody debris affects many streams in forested regions throughout the world. These effects include lateral channel migration, bank slumping, and aggradational or erosional features related to flow redirection. The extent of effect is dependent on the ability of the system to resist the new forces derived from flow redirection. This study on the Pine River, Ontario, looks at how obstructions that are perpendicular to downstream flow modify fluid behavior. Results show that fluctuations in speed and approach azimuth vary considerably depending on the position of the sample relative to the obstruction. The use of time-averaged (1 sec., 30 sec.) recordings of fluid speed and azimuth at selected channel locations shows how flow adjusts to external controls as it moves away from the obstruction zone, giving an indication of the spatial extent of the obstruction influence. These data are represented as a function of the diameter of the obstruction relative to the surrounding flow depth (obstruction ratio), and then are compared to results found in other debris obstructions on the Pine River and Wilmot Creek. Flow obstruction dimensions in the study site equal 26.5 trunk diameters (the average diameter of the tree trunk measured five times along its length), and range between 16.9 and 56.7 trunk diameters on the Pine River (n = 48) and between 7.4 and 63.5 trunk diameters on Wilmot Creek (n = 1066). Knowledge of these spatial relationships may allow for better management of woody debris in streams, primarily from the perspective of aquatic habitat. Multiquadric interpolation formed the basis for plotting fluid vector fields, showing the behavior of flow as it approached and moved through the obstruction zone. This is compared to studies of flow in unobstructed meanders in an attempt to quantify obstruction influence, and is used to provide a depiction of flow under these circumstances. [Key words: flow patterns, woody debris, influence zones, stream management.]  相似文献   

14.
本文运用了群落相似系数、种间相遇机率指数、生态位分布型和食性研究,观测分析了同一山体两侧山坡八块样地冬季鸟类群落状况。在哀牢山西坡观测到鸟类44种,东坡观测到28种,其中13种为两坡共有。西坡除种多样性较高外,鸟类生态类型也与东坡有别。所有这些差别与哀牢山地理位置,西南季风影响所形成的东西坡植被和气候等环境因素有关。文章还分析了人类活动对森林演替和鸟类群落的影响。  相似文献   

15.
3S技术在松材线虫病监测预警中的应用研究现状   总被引:3,自引:1,他引:2  
松材线虫病是一种林业上最具危险性、毁灭性的病害,通过分析3S技术及其特、松材线虫病的起源及其危害情况,综述3S技术在松材线虫病监测预警中的应用研究现状,提出利用中低分辨率遥感卫星数据在时间序列上的累计环境变化响应,结合GIS技术、人工智能等技术来监测松材线虫病是一种新方法,讨论了3S技术应用于松材线虫病监测存在的问题及研究方向。  相似文献   

16.
以因冰雪灾害造成森林资源损失较为严重的福建省长汀县为例,选取受灾乔木林为研究对象,结合实地踏查和典型抽样统计数据,评估森林乔木层C贮量损失并分析其主要影响因素.分析结果表明:冰雪灾害造成长汀县乔木林地受损面积达40178.87hm^2,占灾前面积的19.1%;损失蓄积95.69×10^4m^3,占灾前蓄积的38.6%,折合成森林乔木层C贮量损失34.55×10^4t,占灾前C贮量的41.4%,受损最为严重的四都、红山、古城等6个乡(镇、场)都靠近武夷山脉南麓;同一区域相同的立地条件下,针叶树种比阔叶树种受灾严重,松组和杉组C贮量相对损失比均超过阔叶树组的3倍,其中松组C贮量损失23.02×10^4t,占总C贮量损失的66.6%,占灾前松组C贮量的65.0%;中龄林C贮量损失12.84×10^4t,占灾前中龄林C贮量的56.6%,相对损失比最大,近成过熟林次之,幼龄林最小;海拔越高,C贮量损失比例越大,海拔450m以上区域C贮量损失达30.15×10^4t,占总C贮量损失的87.3%;迎风坡面和山脊西北侧的乔木林受灾相对严重,朝西、西北、北3个方向的C贮量损失20.11×1064t,占总C贮量损失的58.2%;位于中上部坡位的乔木林受灾相对严重,且坡位越高,C贮量损失越大.  相似文献   

17.
基于ArcEngine的松材线虫病预警系统设计   总被引:1,自引:0,他引:1  
松材线虫病是最具毁灭性的一种病虫害,至今尚未找到经济有效的根治方法。影响松材线虫病发生的因子数据非常庞大,加上松材线虫病的发生、蔓延具有时间性和空间性,原有的数据及测报方法很难适应松材线虫病的监测、预警的要求。通过结合ArcEngine组件技术、.NET平台技术和Oracle数据库技术,进行了松材线虫病预警系统的总体设计,包括系统逻辑架构的设计、系统功能的设计、系统数据库的设计,并对预警模型作初步分析。该系统的建立实现了对松材线虫病因子数据的信息化管理,逐步走向了科学化、规范化、标准化和可视化。  相似文献   

18.
小陇山国家级自然保护区油松种群更新及生存   总被引:1,自引:0,他引:1  
以种群生命表及生存分析理论为基础,以林木径级结构代表年龄结构,采用分段匀滑技术,编制小陇山自然保护区油松种群特定时间生命表,绘制死亡率曲线、消失率曲线、存活曲线、生存函数曲线,分析种群数量动态特征,并对其年龄跟胸径进行线性回归。结果表明:1.油松种群年龄结构表现为稳定型。2.油松种群死亡率和消失率曲线变化趋势基本一致,存活曲线趋于Deevey-Ⅱ型。4个生存函数曲线表明,油松种群具有前期稳定、中后期锐减和末期衰退的特点。3.油松年龄与其胸径线性相关。  相似文献   

19.
Religion and the expansion of religious sites throughout the built environment have a long and conflict-ridden history. This paper examines the development of three controversial religious sites in Israel that have developed in recent decades in an effort to better understand the kinds of political, social, and locational circumstances that cause some new sites to be regarded as spatially transgressive. The three sites examined here are the Mormon Center in Jerusalem, the Baha'i Gardens in Haifa, and the Church/Mosque in Nazareth. The study is based primarily on 75 structured, open interviews with stakeholders and decision-makers.The broader aim of the paper is to generate a better understanding of the concept of spatial transgression through systematic investigation based on the methodology of “framing.” This methodology provides a comprehensive vocabulary for perceptions, referred to as “frames,” and offers a detailed and systematic typology of frames based on the literature and the empirical data (grounded research) of the case studies.The main findings fall within the three aggregated super-frames identified in the research: “Process,” “Values,” and “Issues.” Of these, the Process super-frame was found to be dominant in all three cases. Comparing the different frames in the three cases enabled us to identify the factors that influenced the transgression process. It also facilitated a better understanding of the different “stories” involved and the concept of spatial transgression, which was found to exist on a scale ranging from low to high intensity. This paper also proposes a framing typology that may prove useful for understanding and mapping similar cases elsewhere.  相似文献   

20.
樟子松沙地适应性的初步研究   总被引:17,自引:1,他引:17  
李胜功 《中国沙漠》1994,14(1):60-67
根据樟子松形态、生态和生理特征,初步分析讨论了其沙地适应性。  相似文献   

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