Although spectral libraries based on surface features have been built in our country,it is not still reported that the practical spectral library system aimed at the attributes information classification and extraction to the terrain element on survey and updating relief map.Targeting knowledge,ration and practice of the spectral data on the terrain information,by use of ORALCE database and VC++ programming technique,we design a database system which integrated data collecting,data conversion,search and query,visual analyzing and continuum removal,etc,and can provide us with technique support and experimental environment for automatic classification to terrain element attributes.
Abstract The South China Block is one of the largest continental blocks located on the East Asian continent. The early Palaeozoic Wuyi–Yunkai orogen of the South China Block (known as the Caledonian orogen in Europe) is a major orogenic belt in East Asia and represents the first episode of extensive crustal reworking since Neoproterozoic time. Although this orogen is key to deciphering the formation and evolution of the South China Block, details about the orogen remain poorly defined. The Songshutang and Wushitou ultramafic–mafic units in southern Jiangxi Province, South China, have 206 Pb– 238 U ages of c . 437 Ma, suggesting a Silurian formation age. All the Songshutang and Wushitou ultramafic–mafic rocks show relatively flat chondrite-normalized rare earth element patterns, depletions in Nb, Ta, Zr, Hf and Ti, and low ϵ Nd (t) values from −9.12 to −5.49 with negative zircon ϵ Hf (t) values from −10.84 to −2.58, resembling a typical arc magma affinity. Geochemical and isotopic data indicate that the newly identified ultramafic–mafic rocks, along with the reported Silurian mafic rocks in South China, possibly originated from the similar partial melting of an ancient subducted slab, fluid/sediment and metasomatized lithospheric mantle with varying degrees of fractional crystallization. In conjunction with other records of magmatism and metamorphism in South China, a late-orogenic extensional event led to the melting of the sub-continental lithospheric mantle in Silurian time and generated ultramafic–mafic rocks with a limited distribution along the Wuyi–Yunkai orogen and widespread late-orogenic granitic plutons in the South China Block.
The water resource is a key factor in solving the problems being encountered by oasis development,which is related to the interaction between eco-environment and economy development.The basic concept of water-saving ecosystem was analyzed,and a green development path of livestock industry was pointed out on the base of the balance of ecological protection and economic development in Minqin oasis.Water-saving irrigation grassland is not only the foundation of the livestock industry,but also the valid way for changing the pattern of water use and economic growth,and the countermeasures and suggestions about the oasis grassland construction were pointed out in Minqin Oasis.
Abstract. The late Jurassic Tongshankou and Yinzu plutons in southeast Hubei have been investigated for their contrasting metal mineralization features. The former is closely associated with porphyry Cu‐Mo mineralization, while the latter is barren of metal mineralization, althouth both are located very close to each other. The Tongshankou granodiorite porphyries and the Yinzu granodiorites are geochemically similar to adakites, e.g., high Al 2 O 3 and Sr contents and La/Yb and Sr/Y ratios, enriched in Na 2 O, depleted in Y and Yb, very weak Eu anomalies and positive Sr anomalies. However, different geochemi‐cal characteristics exist between the two plutons: the Tongshankou adakitic rocks (1) are relatively enriched in SiO 2 , K 2 O, MgO, Cr, Ni, and Sr and depleted in Y and Yb; (2) have higher degree REE differentiation; (3) have positive Eu anomalies in contrast with very weak negative or unclear Eu anomalies in the Yinzu rocks; and (4) isotopically have relatively higher eP Nd(t) values (‐5.19 to ‐5.38) and lower initial 87 Sr/ 86 Sr ratios (0.7060 to 0.7062), while the Yinzu adakitic rocks have relatively lower eP Nd(t) values (‐7.22 to ‐8.67) and higher initial 87 Sr/ 86 Sr ratios (0.7065 to 0.7074). The trace element and isotopic data demonstrate that the Tongshankou adakitic rocks were most probably originated from partial melting of delaminated lower crust with garnet being the main residual mineral whereas little or no plagioclase in the source. On the contrary, the Yinzu adakitic rocks were likely derived from partial melting of thickened lower crust, with residual garnet and a small quantity of plagioclase and hornblende in the source. Interactions between the adakitic magmas and mantle peridotites possibly took place during the ascent of the Tongshankou adakitic magmas through the mantle, considering that MgO, Cr, and Ni contents and eP Nd(t) values of the adakitic magmas were possibly elevated and initial 87 Sr/ 86 Sr ratios were possibly lowered due to the contamination of mantle peridotites. In addition, the Fe 2 O 3 of the adakitic magmas was likely released into the mantle and the oxygen fugacities (ƒ o2 ) of the latter were obviously possibly raised, which made metallic sulfide in the mantle oxidized and the chalcophile elements such as Cu were incorporated into the adakitic magmas. The ascent of the adakitic magmas enriched in Cu and Mo will lead to the formation of porphyry Cu‐Mo deposit. Nevertheless, the Yinzu adakitic magmas were possibly lack of metallogenetic materials due to not interacting with mantle peridotite, and thus unfavorable to metal mineralization.
Data format of CAD often don’t accord with requirements of GIS. The paper analyzes the existent problem during data format transformation from Auto CAD to GIS. Based on GML, a kind of new data format conversion method is put forward and it solves the problem of the data sharing between AutoCAD system and GIS system. After practice certificating, this method can really perform data transformation without any losses.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)