Appraisal of the future climate of the Holocene in the Rocky Mountains

Consideration of the history of Holocene climate in the Rocky Mountains indicates that the over-all trend during the past 2500 yr has been toward increasing warmth, interrupted by cooler times of minor advances of cirque glaciers. Comparison of Holocene climatic history with the record of past interglacials in the region suggests that the present interglacial is not complete and that the climate may become first warmer and subsequently wetter before it is completed. Correlation of the timing of the regional glacial-interglacial record for the past 140,000 yr with the record of major sea level changes and with the calculated changes in the earth's insolation suggest that the present interglacial may be completed within a few millenia and that it may be followed by a significant cooling of the climate.     

Wavelets and the Generalization of the Variogram

The experimental variogram computed in the usual way by the method of moments and the Haar wavelet transform are similar in that they filter data and yield informative summaries that may be interpreted. The variogram filters out constant values; wavelets can filter variation at several spatial scales and thereby provide a richer repertoire for analysis and demand no assumptions other than that of finite variance. This paper compares the two functions, identifying that part of the Haar wavelet transform that gives it its advantages. It goes on to show that the generalized variogram of order k=1, 2, and 3 filters linear, quadratic, and cubic polynomials from the data, respectively, which correspond with more complex wavelets in Daubechies's family. The additional filter coefficients of the latter can reveal features of the data that are not evident in its usual form. Three examples in which data recorded at regular intervals on transects are analyzed illustrate the extended form of the variogram. The apparent periodicity of gilgais in Australia seems to be accentuated as filter coefficients are added, but otherwise the analysis provides no new insight. Analysis of hyerpsectral data with a strong linear trend showed that the wavelet-based variograms filtered it out. Adding filter coefficients in the analysis of the topsoil across the Jurassic scarplands of England changed the upper bound of the variogram; it then resembled the within-class variogram computed by the method of moments. To elucidate these results, we simulated several series of data to represent a random process with values fluctuating about a mean, data with long-range linear trend, data with local trend, and data with stepped transitions. The results suggest that the wavelet variogram can filter out the effects of long-range trend, but not local trend, and of transitions from one class to another, as across boundaries.     

青藏高原腹地温泉地区新生代生态环境演化与高原表面隆升过程分析

采自青藏高原腹地温泉地区新生代地层中的孢粉组合资料表明:从古新世到早中新世,古植被由早期的针阔叶混交林-森林草原植被向晚期的疏林草原植被演化,古气候也由亚热带暖湿气候向温凉气候演化;从上新世到早更新世,阔叶树种明显减少,而草本植物显著增多,反映气候开始向干冷方向演化;而中更新世晚期以来,出现稀疏草原植被向荒漠草原植被的演化,最终塑造了现代以藜、蒿为主的荒漠草原植被环境。高原腹地生态环境变化揭示了青藏高原自古新世以来至少经历了3次具有生态环境意义的表面隆升事件:古新世—早渐新世沱沱河组冲积扇砾岩沉积以及孢粉组合分析表明,青藏高原在白垩纪末—古新世初已隆升至1000～1500m,高原地形可能是高原(高山)与盆地相间的地貌格局;早中新世五道梁组植被中亚热带成分的显著增高,可能与高原表面隆升诱发高原季风而导致气候湿润有关,推测高原已隆升至2000～2500m;而中更新世晚期以草本植物为主,反映高原植被已经发生了转型,高原已隆升至3000m以上。     

从榴辉岩与围岩的关系论苏鲁榴辉岩的形成与折返

位于华北和扬子两板块碰撞带中的苏鲁榴辉岩形成的温压条件不但是超高压，而且是高温。榴辉岩的PTt轨迹表明其为陆-陆磁撞俯冲带的产物。榴辉岩的区域性围岩花岗质片麻岩为新元古代同碰撞期花岗岩，榴辉岩及其他直接围岩皆呈包体存在于其中，并见新元古代花岗岩呈脉状侵入榴辉岩包体中。区域性围岩新元古代花岗岩的锆石中发现有柯石英、绿辉石等包裹体，表明新元古代花岗岩的组成物质也经受过超高压变质作用，且榴辉岩与围岩新元古代花岗岩的锆石U-Pb体系同位素年龄基本相同。但新元古代花岗岩所记录的变质作用和变形作用期次（或阶段）却少于榴辉岩。椐上述可得如下推断：超高压榴辉岩与新元古代花岗岩岩浆是同时在碰撞带底部（俯冲板块前部）形成的；榴辉岩的第一折返阶段是由新元古代花岗岩岩浆携带上升的，其第二折返阶段是和新元古代花岗岩一起由逆冲及区域性隆起而上升，遭受剥蚀。     

白城市水稻种植区土壤的地球化学特征与水稻产量的相关性研究

吉林省白城市水稻种植区土壤的地球化学特征研究表明，土壤中的SiO2,TiO2,Al2O3,FeO,MnO和P2O5等主要元素的含量与水稻产量具有正相关性，而CaO和MgO等主要元素的含量与水稻产量呈负相关性。土壤中的稀土元素含量和水稻产量呈正相关性。     

汶川特大地震后成都盆地内隐伏断层活动性分析

成都盆地内主要有3条隐伏的活动断裂带,包括大邑断裂带、蒲江-新津断裂带和龙泉山断裂带,它们在第四纪都表现出了一定的活动性."512"汶川特大地震后,笔者实地考察的结果表明,在汶川特大地震中成都盆地中的隐伏断裂没有产生新的活动性,目前成都盆地不存在发生特大地震的危险性,是安全的.     

Transformation of the pore space during the simulation of the generation of hydrocarbon fluids in the Domanik horizon of the South-Tatar crest as an example

The main purpose of this paper is to study the factors that control changes in rock structure during catagenetic transformation of organic matter. Hydrocarbon generation and primary migration can be controlled by numerous parameters; the most important are temperature, pressure, hydrocarbon composition, and organic matter type and content. The influences of most of these parameters have been studied and experimentally demonstrated. However, there are a few works that are dedicated to the investigation of the texture features of rocks, as well as the quantitative content of the organic matter on the pore space transformation of rocks. Therefore, these parameters are the most important when studying the primary migration processes. It was found experimentally that the rock pore space after each stage of heating is transformed, forming new pore spaces and channels that connect the primary pores. A sample with a relatively low content of organic matter has been found to undergo fewer changes in pore-space morphology in comparison to rock that is saturated in organic content. It has been found that that the change of pore-space morphology depends on the original structure of the rocks. Most of the structural changes were observed during rock heating within 260–430°C; the most intense formation of hydrocarbons was revealed within this interval.     

马颊河上游南乐站径流变化分析

实测径流是自然与人类活动双重作用的结果。通过对1956～2000年马颊河上游南乐水文站的实测水文资料、流域降水资料以及通过控制断面以上流域的用水和引水资料进行还原的径流序列的分析，揭示了天然径流的变化敏感地反映了气候的变化，人类活动已远远超过气候变化对径流的影响。通过分析2个时段降雨径流关系，揭示了近20年来与1956～1979年相比，同样降水量条件下径流量的增大，反映了产汇流条件的明显变化。     

Investigating the spatial pattern of the characteristics of the onset and cessation of the rains in Nigeria

The characteristics of the onset and cessation of the rains investigated in this study are early, normal and late onset and cessation. The spatial pattern of these parameters were investigating for Nigeria using rainfall and potential evapotranspiration data analyzed for the period between 1959– 1990. Furthermore, 4 major rainfall producing mechanisms that could be responsible for the observed pattern of these parameters in Nigeria were also investigated using the stepwise multiple regression analysis. It was found that Inter-Tropical Discontinuity appeared as the most significant rainfall producing factor for predicting the spatial variation in the characteristics of the onset and cessation of the rains in Nigeria. This finding corroborates the zonal (north-south) pattern evident in the spatial distribution of the early, normal and late onset and cessation of the rains in the country. However, it was found that the combination of ITD and disturbance line together proved significant for explaining the spatial variation in the characteristics of the onset and cessation of the rains in Nigeria. Consequently, a south-northeast trend in the spatial pattern of each of early, normal and late onset and cessation of the rains is evident for the country. The combination of the 3 factors-ITD, disturbance line and relief were found to be significant for predicting the late onset and early cessation of the rains. However, the contribution due to relief factor is extremely low. It is observed that the occurrence of onset and cessation of the rains in Nigeria is generally erratic. The study showed further that the probability of the deviation of onset and cessation of the rains from normal is higher in the north than the southern part of the country. The significance of the observations of the study to selection of crops for cultivation and schedule of planting dates have been noted.     

柴达木盆地北缘东段托莫尔日特似蛇绿岩岩石组合特征

出露于柴达木盆地北缘加里东裂谷带东段托莫尔日特地区的一套酷似蛇绿岩的岩石组合 ,其地质、地球化学特征显示它们并不具备洋壳性质 ,而应为形成于陆壳内的 ,即没有洋壳出现的陆缘裂谷环境下的一种似蛇绿岩组合。提出了与蛇绿岩不同的动力学形成模式 ,所讨论的似蛇绿岩可能是并无洋壳出现的陆缘裂谷的较典型代表。     

Factors Determining the Location of the Chlorophyll Maximum and the Fate of Algal Production within the Tidal Freshwater James River

Longitudinal variation in factors affecting phytoplankton production were analyzed to better understand the mechanisms that cause the formation of a chlorophyll maximum within the tidal freshwater James River. Phytoplankton production was two- to threefold higher in the region where persistent elevated chlorophyll concentrations occurred. Near this site, the morphology of the James transitions from a narrow, deep channel to a broad expanse with shallow areas adjoining the main channel. Shallower depths resulted in greater average irradiance within the water column and suggest that release from light limitation was the principal factor accounting for the location of the chlorophyll maximum. Grazing rates were low indicating that little of the algal production was directly consumed by zooplankton. Low exploitation by zooplankton was attributed to poor food quality due to high concentrations of non-algal particulate matter and potential presence of cyanobacteria. Metabolism data suggest that two thirds of net primary production was respired in the vicinity of the chlorophyll maximum and one third was exported via fluvial and tidal advection. Comparison of water column and ecosystem metabolism indicates that the bulk of respiration occurred within the sediments and that sedimentation was the dominant loss process for phytoplankton.     

论扬子地区上奥陶统五峰组观音桥段的深海成因

通过对沉积速率与现代深海沉积速率的比较及古生态学、生物古地理学、海平面变化以及沉积特征综合的分析 ,认为观音桥段形成于深海环境中 ,且属深海等深流沉积。奥陶 -志留系之交广泛发生的高频火山事件可能是生物灭绝的主要和直接原因 ,而火山事件、铱和碳同位素异常事件与志留纪初期缺氧事件在奥陶 -志留系之交的耦合作用可能是 H irnantia- Dalmanitina动物群的灭绝的主要原因。     

Estimation of the influence of daily rotation of the earth on the stress state of the continental crust

The problem of formation of additional planetary stresses in the crust initiated by the action of tangential inertia mass forces that are caused by the daily rotation of the Earth is considered. It is established that the stress state formed in the crust has three levels of different geodynamic types: horizontal tension, shear, and compression with a meridional orientation of maximum compression. It is shown that the revealed deep zonality of planetary stresses can explain the regularity of representation of ruptures of various types for planetary fracturing.     

黄骅坳陷板桥凹陷沙河街组沙二段物源分析

多年油气勘探表明,黄骅坳陷板桥地区沙河街组具有丰富的油气资源。通过传统分析方法,包括古地貌分析、重矿物特征和砂体分布等资料,对区内沙二段的物源区及其母岩性质、物源方向进行了系统研究表明,板桥凹陷沙二段沉积物主要来自盆地北部燕山构造带和西部沧县隆起,且在盆内发生交互混源,而南部港西凸起物源作用较小。此次物源研究对该区下一步进行沉积相带的划分及储层预测具有重要指导意义。     

Lithogeochemistry of the fine-grained siliciclastic rocks of the Vendian Serebryanka Group of the Central Urals

Sedimentation environments were reconstructed for the Early Vendian successions of the western slope of the Central Urals, which comprises one of the most complete sections of the terminal Precambrian system in northern Eurasia. It was shown that, despite the presence of several diamictite levels in the sections of the Serebryanka Group, mature and multiply recycled fine-grained siliciclastic materials (CIA = 65–77) were delivered into the sedimentation basin over the whole Early Vendian. Based on the lithochemical characteristics of shales, the climate of Serebryanka time can be estimated as semiarid-semihumid, similar to that dominating in Late Vendian paleocatchments. Based on relatively high Mo/Mn values (0.011–0.024), it was suggested that anoxic or similar conditions existed in the basin of Buton time, whereas other sedimentary complexes of the Serebryanka Group were formed in well aerated environments. The systematics of Sr, Ba, Zr, Cu, and V in fine-grained siliciclastic rocks and Sr isotopic data for carbonate rocks indicate that the sediments were accumulated in a fresh-water basin. The values of trace-element indicator ratios, e.g., Th/Sc, La/Sc, Th/Cr and others, in the shales of the Serebryanka Group and Nd model age estimates indicate that a variety of mainly Early Proterozoic complexes, ranging from granitoids to basic rocks, occurred in the Early Vendian paleocatchments. The basic rocks were eroded most extensively probably in the end of Serebryanka time. Based on the Ce/Ce* values of shales, it was concluded that submarine volcanism had no significant influence on sedimentation processes in the Early Vendian. An exception is Koiva and Kernos time, when hematite-bearing shales were accumulated in association with pillow basalts in some zones of the basin. The distribution of the compositions of shales from various formations of the Serebryanka Group in discrimination diagrams suggests that the Early Vendian sedimentary sequences were formed in passive geodynamic settings.     

Geodynamics of the Riphean stage in the evolution of the northern passive margin of the East European Craton

The nearly parallel northwest-trending Onega-Kandalaksha, Kerets-Leshukonsky, and Barents paleorift zones located in the northeastern part of the East European Platform are interpreted as a common structural assemblage that was formed in the Middle-Late Riphean as a result of horizontal extension of the continental margin. Therefore, it is reasonable to combine these paleorift structural features into the common White Sea Rift System instead of subdividing them into two or more systems as done previously. The White Sea Rift System originated owing to the breakup of the ancient Paleopangea supercontinent 1300–1240 Ma ago. The latter event occurred as a result of the divergence of the Baltia and Laurentia continental plates that most probably was caused by mantle spreading within the hot equatorial belt of the Earth. The diffuse rifting of that time occurred in the form of near-parallel rifts developing progressively from the inner part of the continental plate toward its margin. A pericratonic sedimentary basin eventually formed at the passive margin of Baltia as a system of roughly parallel rift zones. The geologic and geophysical data show that the passive margin of the East European Platform formed in the Riphean, a phenomenon that corresponds with a model of large-scale extension of the lithosphere after the stage of early ocean-floor spreading. In the course of this process, the brittle upper crust was detached from the ductile lower crust. The geodynamic regime of the Riphean passive margin of the East European Platform probably was similar to the regime of the present-day Atlantic-type passive margins. The White Sea Rift System differs from the transverse Mid-Russian Paleorift System both in origin and age. The Mid-Russian Paleorift System is considered to have formed in the Late Riphean as a result of transtension along a mobile zone in the ancient basement. The lithosphere of northeastern Fennoscandia has experienced horizontal extension since the Middle Riphean, a phenomenon that is closely related to the evolution of the White Sea Rift System, i.e., to the formation of the passive margin of the Baltia continent.     

硫多金属矿床开采对水环境的影响——以福建大田地区矿产开发为例

闽西大田地区矿床采选冶活动对水土生态环境系统造成了严重的破坏，矿区采选矿废水pH值、SO4^2-浓度远远超过水环境标准，选矿废水和接纳采选矿废水的河流水体中Fe、Mn、Cu、Pb、Zn、Cd的含量大部分超过地面5类水标准，少部分超过4类水标准，矿区采选矿业废水是地表水金属污染的重要源头。矿业废水pH值与金属Fe、Mn、Cu、Pb、Zn、Cd的含量具有明显的负相关关系，SO4^2-浓度与金属离子Fe、Mn、Cu、Pb、Zn、Cd浓度具有较一致的变化规律。提出整治硫多金属矿山环境污染，应坚持因地制宜、矿业资源开发与环境保护并重的方针，用石灰石碱性中和酸性废水，隔离覆盖尾矿矿堆，对废弃矿山植树种草进行生态修复，对效益低下的开采矿山退矿还林，对严重环境污染的矿山实行关闭，对新开矿山要进行科学规划开发。     

印度板块向欧亚板块俯冲碰撞的新模式及其对青藏高原构造演化的影响

青藏高原南部与北部的断裂带走滑方向不同，断裂带在高原东、西两侧的展布规律和构造运动方式也存在极大的差异。通过高原南缘横向地球物理特征的对比，发现该地区东、西两侧深部岩石圈结构存在明显不同，表明印度次大陆向欧亚大陆俯冲碰撞的方式和强度在横向上差异明显。在充分利用高原地质研究最新成果的基础上，提出印度次大陆向欧亚大陆碰撞前地壳增厚及斜向碰撞是造成上述地质现象的根本原因，并由此对青藏高原构造演化的一些特点作了新的解释和探讨。     

浙闽淤泥质港湾表层沉积物的地球化学特征

采用原子吸收光谱法,对乐清湾及三都澳表层沉积物的15只样品,进行了分析,其结果显示,沉积环境,沉积物类型和泥沙来源,控制着乐清湾和三都澳金属元素及有机质迁移富集规律,并显示具有极为相似的分布特征。本区重金属元素的含量与其它区域相比,以及Fe/Mn比值,充分显示了它们的继承性和亲陆性,同时进一步说明本区表层沉积物,主要由潮流作用从口外海域搬运而来,受到长江口泥沙扩散的影响,其次是周围岛屿和山溪性河流的补给。     

A high-pressure experimental study on the evolution of the silicic magmatism of the Main Ethiopian Rift

In this contribution we report the results of an experimental study that investigated equilibrium and fractional crystallization of hydrous, transitional alkaline basalt at low oxygen fugacity, under lower to middle crustal conditions to constrain the generation of subaluminous and peralkaline differentiation products that typically occur in rift systems. The experiments reveal that liquids produced by equilibrium crystallization in the range 0.7–1 GPa cannot cross the subaluminous/peralkaline compositional divide. In contrast, fractional crystallization experiments under isobaric and polybaric conditions approach closer the naturally observed trend from subaluminous to evolved peralkaline products suggesting that polybaric differentiation starting at elevated pressures can indeed lead to the transition from subaluminous to peralkaline derivative liquids. The presence of water in the parental magmas of silicic derivative products is of prime importance for the fractionation equilibria as well as for the mobility of such magmas toward shallow crustal levels.

We suggest that peralkaline magmas in rift environments are indicative for differentiation under relatively low oxygen fugacity conditions in an extensional environment characterized by a high degree of crustal fracturing that allows rapid upward migration of mafic parental magmas and formation of shallow magma reservoirs. Crystallization–differentiation of parental, hydrous transitional alkaline basalt in such reservoirs is controlled by low pressure phase equilibria that typically evolve through early saturation of anorthite-rich plagioclase and suppressed amphibole crystallization resulting in ‘low-alumina’, peralkaline derivative liquids.