Historical mining and smelting in the Vosges Mountains (France) recorded in two ombrotrophic peat bogs     

B. Forel  F. Monna  C. Petit  O. Bruguier  R. Losno  P. Fluck  C. Begeot  H. Richard  V. Bichet  C. Chateau 《Journal of Geochemical Exploration》2010

Two peat sequences were sampled in the vicinity of the main mining districts of the Vosges Mountains: Sainte-Marie-aux-Mines and Plancher-les-Mines. Lead isotopic compositions and excess lead fluxes were calculated for each of these radiocarbon-dated sequences. Geochemical records are in very good agreement with the mining history of the area, well known over the last millennium. Except for an anomaly corresponding to the Middle Bronze Age which has not yet been resolved, there is no clear geochemical evidence of local metal production in the Vosges before the 10th century as excess lead deposition archived between 500 BC and 500 AD is attributed to long-range transport of polluted particulate matter. The approach described here can be applied to other mining districts where archaeological evidence is scarce or even lacking, but where past exploitation is suspected.  相似文献   

Shear Modulus and Damping Ratio of Organic Soils     

P. Kallioglou  Th. Tika  G. Koninis  St. Papadopoulos  K. Pitilakis 《Geotechnical and Geological Engineering》2009,27(2):217-235

The paper presents results from a laboratory investigation into the dynamic properties of natural intact and model organic soils by means of resonant-column tests. The natural intact organic soils were sands, cohesive soils and peats with varying content of calcium carbonate. The model organic soils were formed in laboratory by mixing kaolinite and paper pulp. The influence of various soil parameters, such as strain level, confining stress, void ratio, plasticity index, organic content and secondary consolidation time on shear modulus, G, and damping ratio, DT, is presented and discussed. The test results on natural organic soils show that only high organic contents (OC ≥ 25%) have significant influence on G and DT at both small and high shear strains. For the model organic soils, however, a significant influence of even lower values of organic content (5% ≤ OC ≤ 20%) on G at small strains and DT at both small and high strains is observed.  相似文献   

Characterization and quantification of inorganic constituents of tropical peats and organic-rich deposits from Tasek Bera (Peninsular Malaysia): implications for coals     

Raphael A. J. Wüst  Colin R. Ward  R. Marc Bustin  Michelle I. Hawke 《International Journal of Coal Geology》2002,49(4)

Since the Carboniferous, tropical latitudes have been the site of formation of many economic coal deposits, most of which have a restricted range of mineralogical composition as a result of their depositional environment, climatic conditions, and diagenesis. Mineralogical and microscopic investigations of tropical peats from Tasek Bera, Peninsular Malaysia, were performed in order to better understand some of these factors controlling the nature, distribution and association of inorganic matter in peat-forming environments. Distribution and nature of the inorganic fraction of peat deposits give insight into the weathering conditions and detrital input into the mire system. Because the inorganic composition of peat deposits is determined by plant communities, height of water table, and climate, the results of the quantitative and qualitative analysis can be used to reconstruct palaeoclimatic conditions.Tasek Bera is a peat-accumulating basin in humid tropical Malaysia with organic deposits of low- to high-ash yield and thus representative of many ancient peat-forming environments. Clay minerals dominate the mineralogical composition of the peat and organic-rich sediments, while quartz and clays dominate the underlying siliciclastic deposits. Kaolinite is the most abundant clay mineral in the organic deposits with minor amounts of illite and vermiculite. Particle size analyses indicate that >50% of the inorganic detrital fraction is <2 μm. Most detrital quartz grains range in size from fine silt to fine sand. The fine sand fraction accounts for a maximum of 5 wt.% of the inorganic constituents. In addition, abundant biogenic and non-biogenic, Al- and Si-rich amorphous matter occur. In the ombrotrophic (low-nutrient) environment, biogenic inorganic material contributes up to >75% of the ash constituents. As a consequence, the vegetational communities make an important contribution to the inorganic and overall ash composition of peats and coals. The ash content of the often inundated peat consists on average of 10% opaline silica from diatoms and sponge spicules, while the ash of the top deposits may have up to 50% biogenic silica. Hence, Al- and Si-hydroxides and the opaline silica from diatoms and sponges represent a large repository of Al and Si, which may form the basis of mineral transformation, neoformation and alteration processes during coalification of the peat deposits. As a result, most coal deposits from paleotropical environments are anticipated to have little to no biogenic inorganic material but high amounts of secondary clays, such as kaolinite (detrital kaolinite, resilisified kaolinite, or desilisified gibbsite) or illite, and various amounts of detrital and authigenetic quartz.  相似文献   

RS和GIS支持下的三江平原沼泽湿地动态变化研究   总被引：81，自引：19，他引：81  

汪爱华  张树清  何艳芬 《地理科学》2002,22(5):636-640

以景观生态学理论为基础，采用遥感（RS）和地理信息系统（GIS）相结合的方法，探讨了三江平原沼泽湿地的动态变化特征。结果表明，三江平原沼泽湿地主要分布在富锦、同江和抚远三个县（市），其总面积占全区总面积的51.42%;1980-2000年间三江平原沼泽湿地的分布面积显著下降，1980-1996年间沼泽湿地面积减少了51.33%，1996年之后减少速度明显下降。同时沼泽湿地景观的破碎化显著，斑块数量增加了46%，斑块密度净增加两倍。1980年、1996年、2000年景观的分维湿地面积变化较之全区变化不显著外，其它地区均发生较为显著的变化。  相似文献   

大兴安岭泥炭微量元素分布特征及其环境意义   总被引：6，自引：4，他引：6  

朱颜明  霍文毅 《地理科学》1997,17(2):158-162

采用原子吸收光谱和等离子体发射光谱等现代仪器分析方法对大兴安泥炭生趣剖面中Ｃｕ，Ｐｂ，Ｚｎ，Ｃｄ，Ｈｇ，Ｃｒ，Ｎｉ，Ｍｎ，Ｓｒ，Ｂａ等１２种微量元素进行了测定，结果表明，大兴安岭地区古莲，图强泥炭地和同一泥炭地沼泽泥炭发育的不同阶段，微量元素含量分布规律不十分明显，与俄国斯典型同类泥炭相比，Ｍｎ含量俄罗斯泥炭明显高于大兴安岭泥炭，Ｚｎ，Ｃｏ，Ｂ含量大兴安岭泥炭明显高于俄罗期泥炭。  相似文献   

On the information of mire depositional environment     

马学慧  王荣芬 《中国地理科学(英文版)》1992,2(2):164-172

Mire is the product of the Quaternary. It mostly formed, developed and declined after the postglacial age. Therefore the chemical element analysis, spore-pollen analysis, 14C dating, mire plant determination for mire sediment, and the study on hierarchy relation of mire sediment, can provide a lot of information for restoring paleogeography, paleoclimate and environmental change. So some people called mire sediment-peat as "database of environment".  相似文献   

瑞典泥炭沼泽分布、利用与保护     

卜兆君 《世界地理研究》2007,16(3):99-105

瑞典是泥炭沼泽广布，泥炭沼泽学研究历史悠久的国家。基于实地考察、交流与文献整理，分析了瑞典泥炭沼泽分布与成因、泥炭沼泽研究、利用及保护状况。早期的瑞典沼泽学者在泥炭沼泽分类、演化及沼泽植物地理学研究等方面处于国际领先地位，对学科的发展做出了重大贡献。目前，瑞典在泥炭沼泽的利用与保护方面也走在世界的前列，特别是泥炭沼泽合理利用与保护及恢复并举，值得我国湿地管理部门借鉴。  相似文献   

THE STUDY ON LATENT AND SENSIBLE HEAT FLUX OVER MIRE IN THE SANJIANG PLAIN   总被引：3，自引：0，他引：3  

JIA Zhi-Jun ~    SONG Chang-Chun~  SUN Li~   《湿地科学》2006,4(1):13-20

Energy exchange is one of the most importantprocesses in wetland ecosystems,because it has agreat influence on temperature,water transport,plantgrowth,productivityetc.(Dennison and Berry,1989).On small scales,understanding of surface en-ergy exchange is n…  相似文献   

Peat/coal type and depositional environment—are they related?     

T. A. Moore  J. C. Shearer   《International Journal of Coal Geology》2003,56(3-4):233-252

Four bogs in New Zealand were investigated in order to understand the relationship between peat type and depositional environment. This relationship is important because peat type translates into coal type, and coal types can ultimately be used to infer how and under what conditions the original peat bog formed. In our study, no correlation was found between peat type and depositional environment in the four bogs examined. Moreover, no correlation was found between peat type and either tectonic setting or climate. Water table level and degree of fluctuation are the only parameters which seem to have a good causative relationship on peat type.The bogs, Whangamarino, Moanatuatua and Kopouatai in the North Island and Sponge Swamp in the South Island, all have different depositional settings ranging from coastal plain, to fluvial-meandering and fluvial-braided river floodplain. We found no diagnostic peat types that would allow those different environments to be distinguished from studies of the peat. Data from other tropical and temperate climate peat bogs also support our contention that no diagnostic peat types can distinguish particular depositional settings. However, the level and variability of water table does have a correlation, one that is also seen in bogs elsewhere.From our observations, we infer that the validity of using maceral ratios (directly related to coal type) to indicate depositional environment should be questioned. At best, coal type only represents to what degree the original plant components were degraded, but not how they were degraded. To infer other parameters such as depositional environment, tectonic setting or climate, other data (e.g. distribution of surrounding sediment types, palynology, etc.) must be collected and assessed.  相似文献   

The permanence of stream networks in Britain: Further comments     

T. P. Burt  J. C. Oldman 《地球表面变化过程与地形》1986,11(1):111-113

Previous surveys of the stream network in an area of blanket peat moorland in the Southern Pennines, England, are reassessed with reference to the publication of a new ordnance survey 1:10000 Metric Edition map for the area. It is concluded that a significant number of low order streams are still omitted on the new map, and that the use of field surveys remains essential in such heavily dissected terrain.  相似文献