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301.
302.
在实地考察和分析前人资料的基础上,简要地介绍了山东昌乐锆石的产出特征。通过常规的宝石学测试方法、X-射线荧光光谱分析和激光剥蚀电感耦合等离子体质谱仪(LA-ICP-MS)对该地区锆石的物理性质、内外部特征及化学成分进行了研究。结果表明,该地区锆石粒度较大,整体透明度较好,颜色呈深浅不一的褐色,以深褐色为主;主要由ZrO2和SiO2组成,微量元素主要有Fe,Ti,P,Sc,Ni等杂质元素,还有部分放射性元素和稀土元素;放射性元素主要为U和Th,Th/U比值均大于0.4(1个数据例外);稀土元素以富钇族元素为特征,富集HREE,明显的Ce正异常(2~13),微弱的Eu负异常(0.69~0.76)。另外,昌乐锆石放射性核素的放射性比活度非常低。综合特征表明,昌乐锆石是一种具有利用价值的宝石资源。 相似文献
303.
The mineralogical-petrographic, petrochemical, and geochemical characteristics of the trondhjemite-granodiorite intrusions widespread among the volcanoterrigenous rocks of the eastern part of the Voronezh crystalline massif are studied. The rocks are characterized by cotectic quartz-plagioclase differentiation and differentiated (La/Yb = 31) REE pattern and are enriched in LILE with a decrease in the K/Rb and Zr/Hf ratios and an increase in the Th/U ratio by 1.5–2 times relative to subduction trondhjemites and their volcanic analogs from the modern and young island arcs. These data allow us to conclude that generation of the trondhjemite magma is a result of melting of the rocks of the continental crust during collision. The concordant (SHRIMP) age of trondhjemites is 2047 ± 11 Ma, and the age of zircon cores probably entrapped from the host rocks by the trondhjemitic melt is 2172 ± 17 Ma. 相似文献
304.
O. Yu. Bogdanova A. I. Gorshkov G. V. Novikov Yu. A. Bogdanov 《Geology of Ore Deposits》2008,50(6):462-469
The mineralogy and structural features of the main types of ferromanganese deposits—nodules, micronodules, Co-bearing crusts, crustlike nodules, and low-temperature hydrothermal manganese crusts and ferruginous ochers—are considered. The correlation between their mineral composition and structure is shown. The proposed classification of mineral types is based on characteristic assemblages of Fe and Mn minerals. 相似文献
305.
An application of a new method in permafrost environment assessment of Muli mining area in Qinghai-Tibet Plateau,China 总被引:1,自引:2,他引:1
The permafrost environment in the Muli mining area, an opencast mining site in the Qinghai-Tibet Plateau, China, is now undergoing
significant degradation because of the ongoing mining activities. The permafrost environment in this mining site had already
been evaluated by previous study, in which analytic hierarchy process was applied. Although this method can roughly characterize
the permafrost environment of this mining site, it has limitations by being easily affected by man-made factors. In view of
this limitation, this study attempts to employ a new method, the catastrophe progression method, to estimate the current stage
of the permafrost environment in this mining area. The results show that, by catastrophe progression method, currently the
calculated indexes of the permafrost freezing–thawing disintegration, permafrost thermal stability, permafrost ecological
fragility, and the permafrost environment are 0.43 (general situation), 0.77 (general situation), 0.71 (bad situation) and
0.83 (general situation), respectively. These values imply that the permafrost environment has been damaged by anthropologic
activities to a certain degree and potentially may be further degenerated. However, at this degree, a new equilibrium stage
of permafrost environment could be achieved if the current state of environmental degradation is stabilized and treatments
are constructed against further damages. 相似文献
306.
用固相反应法和sol-gel法合成了不同类型的磷灰石(AP),并采用TEM、XRD、IR、BET比表面积法及静、动态吸附等方法研究了不同AP的比表面积、结晶度、晶胞参数、结晶尺寸、晶格缺陷度、Ca/P摩尔比和煅烧温度等与吸氟能力的关系,结果表明:结晶度高、晶粒大的AP有较小的吸氟量,属表面单分子层化学络合吸附机理;酸活化的AP有较大的吸氟量,属溶解-沉淀与沉淀物表面纳米尺寸效应吸附的复合去氟机理;具纳米尺寸的HAP在常温、常压、无二次污染、小于11mg/L的低含氟浓度废水中且不酸化情况下有较大吸氟量,属纳米尺寸效应吸附机理。 相似文献
307.
308.
Re–Os and U–Pb Geochronology of Porphyry and Skarn Types Copper Deposits in Jilin Province,NE China 下载免费PDF全文
Yong Zhang Shu–Wen Xing Quan–Heng Song Yan Wang Zheng–Tao Yu Xiao–Hui Du Yu–Bo Ma Zeng–Jie Zhang 《Resource Geology》2015,65(4):394-404
Jilin Province in NE China lies on the eastern edge of the Xing–Meng Orogenic Belt. Mineral exploration in this area has resulted in the discovery of numerous large, medium, and small sized Cu, Mo, Au, and Co deposits. To better understand the formation and distribution of both the porphyry and skarn types Cu deposits of the region, we examined the geological characteristics of the deposits and applied zircon U–Pb and molybdenite Re–Os isotope dating to constrain the age of the mineralization. The Binghugou Cu deposit yields a zircon U–Pb age for quartz diorite of 128.1 ± 1.6 Ma; the Chang'anpu Cu deposit yields a zircon U–Pb age for granite porphyry of 117.0 ± 1.4 Ma; the Ermi Cu deposit yields a zircon U–Pb age for granite porphyry of 96.8 ± 1.1 Ma; the Tongshan Cu deposit yields molybdenite Re–Os model ages of 128.7 to 130.2 Ma, an isochron age of 129.0 ± 1.6 Ma, and a weighted mean model age of 129.2 ± 0.7 Ma; and the Tianhexing Cu deposit yields molybdenite Re–Os model ages of 113.9 to 115.2 Ma, an isochron age of 114.7 ± 1.2 Ma, and a weighted mean model age of 114.7 ± 0.7 Ma. The new ages, combined with existing geochronology data, show that intense porphyry and skarn types Cu mineralization was coeval with Cretaceous magmatism. The geotectonic processes responsible for the genesis of the Cu mineralization were probably related to lithospheric thinning. By analyzing the accumulated molybdenite Re–Os, zircon U–Pb, and Ar–Ar ages for NE China, it is concluded that the Cu deposits formed during multiple events coinciding with periods of magmatic activity. We have identified five phases of mineralization: early Paleozoic (~476 Ma), late Paleozoic (286.5–273.6 Ma), early Mesozoic (~228.7 Ma), Jurassic (194.8–137.1 Ma), and Cretaceous (131.2–96.8 Ma). Although Cu deposits formed during each phase, most of the Cu mineralization occurred during the Cretaceous. 相似文献
309.
REE Geochemistry of the Lead—Zinc Ores from the Jinding Lead—Zinc Deposit,Lanping,Yunnan 总被引:3,自引:1,他引:3
Nineteen volcanic and magmatic rock samples were collectecd from the Jinding leadzinc deposit and its surrounding areas in Yunnan.The ICP and AES analyses,feferred to the previous results,show that the metal minerals and altered rocks in the Jinding lead-zinc deposit display a decreasing trend of ∑REE from the early to late stages of mineralization,and similarities in REE distribution patterns,indicating that the ore fluids are characterized by high LREE enrichment,markedly negative δCe anomaly and slight δEu anomaly.These REE distribution paterns exhibit striking similarities to those of the Pliocene trachyte in the study area,both of which are similar in ∑REE,LREE/HREE ratio,δEu and δCe.The ore fluids besides the basin fluids in the deposit are also closely related to those associated with Pliocene trachyte magmas. 相似文献
310.
N. P. Romanovskii Yu. F. Malyshev M. V. Goroshko 《Russian Journal of Pacific Geology》2008,2(2):137-149
Evidence on the Paleozoic granitoids of the eastern part of the Central Asian Fold Belt (CAFB) was analyzed. A tectonic chart of orogenic belts was compiled. Sketch maps were constructed for the geodynamic settings of the formation of Paleozoic granitoids and the extensiveness of their occurrence. Two types of deep controlling structures were distinguished: zones of lithospheric faults and plumes, including the newly recognized Jiamusi-Bureya plume. It was sown that the distribution of large and superlarge Paleozoic ore deposits is related to these structures, primarily to plumes. Sites promising for large and superlarge deposits related to the Paleozoic granitoid magmatism were determined in the Russian Far East. 相似文献