Petrogenesis of the Pt–Pd mineralized Jinbaoshan ultramafic intrusion in the Permian Emeishan Large Igneous Province,SW China

The Jinbaoshan ultramafic intrusion is a sheet-like body with a thick wehrlite unit in the center and thin pyroxenite units at the margins. PGE are enriched in several disseminated sulfide zones in the intrusion. Olivine from the intrusion has low Fo and depleted Ni contents compared to olivine from coeval Emeishan picrites. Whole rock major and trace element concentrations suggest that the Jinbaoshan wehrlites originally contained <30% trapped liquid. The total amount of sulfide in the rocks exceeds that which could have been dissolved in the trapped liquid. The Jinbaoshan wehrlites are interpreted to represent residual assemblages formed by dissolution of plagioclase by passing magma. No clear evidence of crustal contamination is indicated by S, Nd and Os isotopes. We envision that sulfide saturation occurred at depth due to olivine and chromite crystallization. Immiscible sulfide droplets were transported to the Jinbaoshan conduit where they accumulated and reacted with magma successively passing through the conduit to achieve high PGE concentrations.     

安徽大别山北部石榴辉石麻粒岩岩石历因及演化

石榴辉石麻粒岩主要产在北大别,以团块状,沿铁镁质超基性岩块走势分布。它们的主要矿物成分由石榴石、透辉石、紫苏辉石、斜长石等组成,在石榴石边部分别形成角闪石＋斜长石,紫苏辉石＋斜长石成成合晶结构。通过矿物温度压力计计算,高峰期变质温度７４０℃￣８９０℃,压力０．８￣１．５２ＧＰａ;退变质期温度７００℃￣８６２℃,压力０．６９￣０．７９ＧＰａ,表明石榴辉石麻粒岩ＰＴ轨迹为等温降压顺时针轨迹。通过主量元     

Glimmer der regionalmetamorphen Skarne Westmährens

Zusammenfassung Es wurden 28 Glimmerproben und 6 Proben anderer mit ihnen assoziierter Minerale aus westmährischen Skarnen chemisch untersucht. Die Glimmerproben stammten aus Skarngesteinen (Mg-Skarne, Amphibol-Biotit-und Cummingtonit-Biotit-Skarne, Almandin-Biotit-Schiefer der Randzonen der Skarnkörper) sowie aus Gneisen der Skarnhüllen und aus Pegmatiten, die die Skarne durchsetzen. Die Mg-Skarne enthalten Phlogopit, die anderen untersuchten Gesteine vorwiegend Siderophyllit-Eastonit. Almandinarme Assoziationen, wie Mg-Skarne und Cummingtonit-Skarne, enthalten aluminiumarme Glimmer, während sich die mit Al übersättigten Gesteine (mit Sillimanit oder Spinell) durch aluminiumreiche Glimmer auszeichnen. Der empfindlichste Indikator, der auf die Assoziation, aus welcher der Glimmer stammt, schließen läßt, ist Titan. Die größte Variabilität unter den Hauptkomponenten der Glimmer weist Fluor auf, und zwar sogar in Glimmern aus derselben Assoziation. Die wichtigste Assoziation mit Biotitführung in westmährischen präkambrischen Skarnen, nämlich die Almandin-Biotit-Schiefer der Ränder der Skarnkörper, entstand durch Austauschreaktionen während der Regionalmetamorphose aus Glimmerschiefern und tonerdereichen glimmerschieferähnlichen Gesteinen, unter Zufuhr von Fe, Mg und Mn aus den Skarnen. Die Glimmer westmährischer Skarngesteine werden mit Skarnglimmern anderer präkambrischer Gebiete der Welt verglichen.

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Micas of the metamorphic skarns in Western Moravia

Summary The author has investigated 28 mica specimens and 6 specimens of minerals associated with micas which were all recovered from West-Moravian Precambrian skarns, from their host rocks as well as from pegmatites which intersect the skarns. The magnesium skarns contain phlogopite, whereas the other skarn types, such as amphibole-biotite skarns, cummingtonite-biotite skarns, and almandite-biotite schists, as well as gneisses and pegmatites, contain siderophyllites-eastonites. The constituent micas of assemblages poor in aluminium, such as the magnesium skarns and cummingtonite skarns, are low in aluminium, whereas those associated in rocks with sillimanite and spinel are, on the other hand, rich in aluminium. Titanium is among all the main mica components most sensitive to the character of the assemblage, from which the mica was recovered. Fluorine, again, displays a relatively very broad range of concentrations, even in mica samples originating from the same assemblage. The most important assemblage containing micas are the almandite-biotite schists bordering those skarn bodies, which are situated in aluminium-rich mica schists. They developed in the course of regional metamorphism at the expense of mica schists by the action of iron, magnesium and manganese imported from the skarn. The micas of the West-Moravian skarns are compared with the micas of other Precambrian regions of the world.

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Mit 11 Abbildungen     

准东博格达山山前带二叠系芦草沟组重油的发育特征及其指示意义

二叠系芦草沟组是准噶尔盆地东部地区最重要的烃源岩层系和勘探目的层系之一。2013年中国地质调查局油气资源调查中心在准噶尔盆地南缘博格达山山前带实施的油页岩调查井JZK1井钻探过程中,发现二叠系芦草沟组重油。通过对JZK1重油和岩心样品有机地球化学的测试数据研究表明:二叠系重油原油演化程度适中,主要赋存于岩石裂缝中,且经历过后期生物降解作用;油源对比指示,原油来自于芦草沟组本身,属自生自储型油藏。据此推测西起乌鲁木齐市雅玛里克山,东至奇台的白杨沟,断续延长136 km,宽2~10 km,分布面积约2×10⁴ km²的芦草沟组均为下步油气勘探的有利区。基于钻井和过井地震测线的解释结果,指出存在推覆体上盘和推覆体下盘两个勘探领域,且推覆体下盘的原生油藏领域埋藏深、规模大,是下步勘探重点领域。     

Petrology and Petrogenesis of the Eclogite in Mt.Dabie Area,Central China

The occurrence,mineralogy and geochemistry of eclogites in the Mt.Dabie area show that they were subjected to a high-pressure metamorphism together with the country rocks,but their petrochemistry and REE geochemistry show some difference from those of the country rocks.The geochemical characteristics of the eclogites are similar to those of bot continental tholeiitic basalt and oceanic tholeiitic basalt.The rocks probably subducted to the upper mantle with the Dabie metamorphic complex.When elevated to the surface,they were subjected to different staes of retrogressive metamorphism.     

松辽盆地白垩系青山口组黑色页岩的形成环境及海水侵入的底流模式

通过对中央坳陷区两口钻井口剖面和东南隆起区野外露头剖面的沉积学、矿物学和地球化学研究,认为松辽盆地白垩系青山口组黑色页岩形成于稳定分层的湖相环境;周期性海水注入形成的底流是导致水体夯层和黑色页岩沉积的重要因素。     

昆仑山北麓阿羌黄土剖面AQS3层段记录的末次间冰阶千年尺度的气候波动

通过对昆仑山北麓阿羌黄土剖面AQS3层段的年代测试、粒度参数(Mz和σ)以及主要氧化物(SiO2,Al2O3,TOFE(Fe2O3 FeO)和(Al2O3 TOFE)/SiO2比值)分析,并结合区域相关地层反映的古环境和腹足类化石指示的古生态,认为AQS3记录了末次间冰阶19个旋回的干冷与暖湿的气候波动。其中,15个具有千年尺度旋回的各个温暖期能够较好地与GRIP冰芯氧同位素曲线中的D-O事件在时代和气候性质上进行一一对比。可能是由于地处毗邻冰川山麓、加之海拔较高,故该层段粒度与主要氧化物显示的气候变动的幅度并不大,然而却相当敏感。不仅于此,这种千年尺度的温暖气候变化在昆仑山北麓及其近邻区域也有明显的表现。例如,在昆仑山北麓普鲁地层剖面中,指示暖干气候作用下形成的含石膏等盐类的砂土砾石层的TL年龄为距今31000年、45500～41600年、45900年和54500年,可以依次与GRIPδ18O中的间冰段D/O6,D/O12,D/O13和D/O15进行对比;在阿尔金山北麓,类似的并具有荒漠漆的砂土砾石层的TL年龄为37200aB.P.和59700aB.P.,分别相当于D/O9和D/O17间冰段;在塔克拉玛干沙漠腹地的高阶地(海拔1310m),可能代表了剧烈升温的气候背景下,环塔里木盆地四周高山冰雪大量消融导致的塔克拉玛干沙漠腹地的"大湖期",其日历年为33197aB.P.,与GISP2冰芯氧同位素曲线在33000aB.P.的暖阶段相当。发生在昆仑山北麓及毗邻区域AQS3时期若干温暖阶段的地层学证据以及其在时间上能够与GRIP和GISP2冰芯氧同位素曲线相关暖峰的耦合,表明由阿羌剖面末次间冰阶粒度和主氧化物峰谷变化反映出来的多次冷暖波动,其根本原因还是受到北半球D/O振荡的强烈影响。     

Using CaO to stabilize arsenic sulfide slag by moderate temperature calcination

This study was conducted to investigate the stabilization of arsenic sulfide slag (ASS) with CaO calcinations at moderate temperature, including the effects of calcination temperature and different As/Ca molar ratios on arsenic leaching concentration. In the process of calcination for arsenic-contained waste, 90.95–97.23% of arsenic was reserved and the original waste was transformed into a dense and liquation state, which could physically wrap arsenic and reduce its leaching concentration. Meanwhile, the decrease in the As/Ca molar ratios was conducive to the formation of Ca₅(AsO₄)₃(OH). When As/Ca molar ratio was less than 1:8, there was excessive CaO and the ASS samples stopped reacting with CaO. The results showed that the leaching concentration of arsenic was 4.08 mg/L when As/Ca molar ratio was 1:8 and the ASS sample was calcined for 2 h at temperature of 550 °C. In the process, arsenic’s chemical reaction and physical wrapping resulted in a remarkable decrease in its leaching concentration.     

苏东区块盒8段储层微观孔隙结构特征研究

鄂尔多斯盆地苏东区块盒8段储层是典型的致密砂岩储层,影响储层质量的因素较为复杂。以铸体薄片、扫描电镜和物性分析等资料为基础,对储层微观孔隙结构特征进行了定性分析,同时应用恒速压汞方法对储层微观孔隙结构进行了定量表征。研究结果表明:苏东区块盒8段低渗储层物性主要受喉道控制,而不是孔隙;平均喉道半径越大,微观均值系数越小,相对大喉道越多,排驱压力越低,储层微观孔隙结构一般越好,反映储层微观孔隙结构品质越好因此,喉道是影响致密砂岩储层质量的主要微观地质因素。     

大别山榴辉岩的单矿物中He、Ar同位素特征

文中分析了大别榴辉岩的3对单矿物中的He、Ar质量分数及同位素组成。所有分析的矿物中，He主要是放射性成因的，而Ar主要是幔源的。He同位素特征更多地显示古洋壳的特征。He、Ar同位素体系表明其是放射性成因和富集地幔源混合的结果。