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61.
本文针对危机矿山深部及周边找矿的难度大、勘探周期短的特点,提出了一套以找矿为目的,集直升机大比例尺航空物探测量、数据处理、解释为一体的高分辨率航磁方法技术.这些方法包括硬架式直升机航磁测量方法、曲面位场处理方法、精细反演解释方法等.应用该方法在湖北黄石大冶铁矿中布钻,已有两孔见富磁铁矿及伴生的铜、金矿,见矿最大厚度为14.6m.因此,高分辨率航磁方法在危机矿山进一步挖潜工作中可以实现快速找矿目的. 相似文献
62.
We investigate the electronic structures of one and two monolayer iron phthalocyanine (FePc) molecules on Au(111) surfaces. The first monolayer FePc is lying flat on the Au(111) substrate, and the second monolayer FePc is tilted at ~15° relative to the substrate plane along the nearest neighbour [101-] direction with a lobe downward to the central hole of the unit cell in the first layer. The structural information obtained by first-principles calculations is in agreement with the experiment results. Furthermore, it is demonstrated that the electronic structures of FePc molecules in one-monolayer FePc/Au(111) system are perturbed significantly, while the electronic structures of FePc molecules in the second monolayer in two-monolayer FePc/Au(111) system remain almost unchanged due to the screening of the buffer layer on Au(111). 相似文献
63.
Sherry M. Lippiatt Matthew T. Brown Maeve C. Lohan Carolyn J.M. Berger Kenneth W. Bruland 《Estuarine, Coastal and Shelf Science》2010
This study examines the distribution of leachable particulate iron (Fe) in the Columbia River, estuary, and near-field plume. Surface samples were collected during late spring and summer of 2004–2006 as part of four River Influence on Shelf Ecosystems (RISE) cruises. Tidal amplitude and river flow are the primary factors influencing the estuary leachable particulate Fe concentrations, with greater values during high flow and/or spring tides. Near the mouth of the estuary, leachable particulate Fe [defined as the particulate Fe solubilized with a 25% acetic acid (pH 2) leach containing a weak reducing agent to reduce Fe oxyhydroxides and a short heating step to access intracellular Fe] averaged 770 nM during either spring tide or high flow, compared to 320 nM during neap tide, low flow conditions. In the near-field Columbia River plume, elevated leachable particulate Fe concentrations occur during spring tides and/or higher river flow, with resuspended shelf sediment as an additional source to the plume during periods of coastal upwelling and spring tides. Near-field plume concentrations of leachable particulate Fe (at a salinity of 20) averaged 660 nM during either spring tide or high flow, compared to 300 nM during neap tide, low flow conditions. Regardless of tidal amplitude and river flow, leachable particulate Fe concentrations in both the river/estuary and near-field plume are consistently one to two orders of magnitude greater than dissolved Fe concentrations. The Columbia River is an important source of reactive Fe to the productive coastal waters off Oregon and Washington, and leachable particulate Fe is available for solubilization following biological drawdown of the dissolved phase. Elevated leachable Fe concentrations allow coastal waters influenced by the Columbia River plume to remain Fe-replete and support phytoplankton production during the spring and summer seasons. 相似文献
64.
65.
Metapelitic granulites from the Anosyen domain of southeastern Madagascar are exposed in three intercalated formations: the Amparihy, Bakika and Ihosy formations. Although mineralogically distinct from each other, the rocks from these formations show very similar bulk‐rock compositions when measured on a FeT basis. The preserved mineral assemblages thus do not reflect differences in the ratios of the main rock‐forming oxides (i.e. Al2O3:FeT:MgO), but instead reflect variations in the pre‐metamorphic oxidation state of the protolith rocks. These differences in oxidation state are manifested via differences in iron speciation – either Fe+2 or Fe+3. The relatively reduced rocks of the Amparihy Formation preserve the assemblage bi–sp–sill–g–cd, which contrasts markedly with the mostly garnet and spinel‐absent bi–cd–sill–mt assemblages preserved in the strongly oxidized rocks of the Ihosy Formation. Compositionally intermediate rocks of the Bakika Formation are garnet bearing, but sillimanite‐absent, and contain the assemblage sp–g–cd–mag. Modelling of these rocks in the Na2O–CaO–K2O–FeO–MgO–Al2O3–SiO2–H2O–TiO2–O system suggests that they evolved along a heating and cooling P–T path with only limited decompression accompanying cooling on the retrograde path. Peak temperatures and pressures of ~880–920 °C and 6–6.5 kbar are inferred for the majority of the Anosyen domain, with slightly lower peak temperatures (~840 °C) estimated in the extreme northwest of the area. The high‐temperature and relatively low‐pressure nature of metamorphism suggests high geothermal gradients existed during orogenesis, which in southern Madagascar is related to the amalgamation of Gondwana (580–520 Ma). Although metamorphic temperatures may have been augmented via thermal advection from the emplacement of the syn‐ to post‐tectonic Ambalavao suite, the high geothermal gradients nevertheless suggest thin and consequently hot lithosphere existed prior to orogenesis. 相似文献
66.
P. R. Dawes R. H. Smithies J. Centofanti D. C. Podmore 《Australian Journal of Earth Sciences》2013,60(6):635-639
Contacts between Archaean granites and greenstones in the northeastern part of the Pilbara Craton have been described as intrusive and tectonic. New field observations in the Shay Gap region demonstrate that greenstones of the Gorge Creek Group unconformably overlie the Muccan and Warrawagine batholiths. Regionally, the unconformity is marked by a persistent but relatively thin basal clastic sequence, locally with a granite boulder conglomerate, overlain by ore‐bearing banded iron‐formation, fine‐grained clastic rocks and chert. The granite basement is dated at 3443 ± 6 Ma. The precise age of the hiatus is unknown but its maximum effect might have been the removal of a substantial thickness of Early to Middle Archaean strata. 相似文献
67.
Immature samples of the Permian Kupferschiefer from the Lower Rhine Basin in N.W. Germany were analysed for tetrapyrrole pigment type and abundance. The sediment, thought to have been deposited in a marine regime with enhanced salinity, was found to contain high concentrations of metalloporphyrins. The porphyrins are complexed to nickel (Ni) and oxovanadium (V=0), but high abundances of iron (Fe) porphyrins were also detected using UV/visible spectroscopy and mass spectrometry. The presence in the latter of series of aetioporphyrins, cycloalkanoporphyrins, di-cycloalkanoporphyrins and benz-cycloalkanoporphyrins was confirmed by accurate mass measurements; HPLC co-injection of deoxophylloerythroetioporphyrin (C32 DPEP) with the demetallated iron porphyrins indicated its presence in the sediment as an iron complex. The study provides the first evidence for the occurrence of Fe porphyrins in geological samples other than coals and lignites, and reports the highest concentrations in sedimentary organic matter to date. 相似文献
68.
游离氧化铁形态转化对红粘土工程性质的影响 总被引:6,自引:5,他引:6
本文通过模拟环境中的有机质使游离氧化铁形态转化对典型红粘土工程性质的影响试验,系统地测试了游离氧化铁的形态分布与物性指标的关系。试验结果表明,在渍水条件下,游离氧化铁的形态转化对红粘土性质的影响不显著,但在渗水条件下,由于游离氧化铁的流失使得胶结作用减弱,它对红粘土工程性质的影响逐渐明显,其潜在的危害仍然是不容忽视的。 相似文献
69.
微波等离子体炬原子发射光谱法测定铁和铝的研究 总被引:2,自引:0,他引:2
研究了低功率微波等离子体炬原子发射光谱法(MPT-AES)对Fe,Al的测定。样品经气动雾化后,分别以流动注射与连续式两种方式引入MPT。考察了用这两种进样方式时MPT-AES的分析性能,证明低功率MPT-AES具有良好的分析特性。 相似文献
70.
以岷江冲积物、黄壤残积物发育成的水稻土为对照,研究了紫色砂岩泥岩母质发育成的紫色水稻土氧化铁的形态及其含量和转化。揭示了紫色水稻土具有无定形铁含量,铁活化度较高,氧化铁的转化作用较弱等独特的发生特性。 相似文献