滇黔地区陆相二叠系—三叠系界线附近粘土岩中发现微球粒

在滇东黔西地区的几条陆相二叠系-三叠系界线地层剖面研究中，二叠系-三叠系界线附近普遍存在1-2层非正常事件成因的粘土岩，并在粘土岩中发现了大量微球粒，依据化学成分，这些微球粒可分为硅质和钡质两类，笔者认为这种含微球粒的粘土岩成因很可能是，陨石撞地球诱发大规模火山爆发，其产物又经历正常喾作用并有非火山和撞击的正常沉积物混入，这些奇异的球粒，可能就是撞击的产物之一。     

滇东黔西地区陆相二叠—三叠系界线粘土岩特征

在滇东黔西地区，海相和陆相二叠－三叠系界线附近均有界线粘土岩存在。本文介绍了该区陆相界线粘土岩的特征，并探讨了其成因。这些粘土岩主要矿物成分为伊／蒙混层矿物（20％－80％）和高岭石（35％－80％），碎屑物中有锆石、磷灰石、六方双锥石英、其他类型石英和微球粒等。提出界线粘土岩中的物质主要是火山成因，也有正常沉积物的加入，可能还拌有撞击作用的影响。     

阿刀亥矿区CP2煤段粘土岩夹矸研究

内蒙大青山煤田ＣＰ２煤段含粘土岩夹矸多达４０余层。与上覆ＣＰ３砾岩段冲刷接触的煤段顶板和顶部粘土岩夹矸，为伊利石或伊利石－高岭石粘土岩。其下煤段中夹矸及底板为高岭石粘土岩，均发生了不同程度的铵云母化和一水硬铝石化。鳞片状、纤维状、条片状及晶粒假象铵云母沿粘土岩夹矸的节理裂隙呈脉状产出；微、细晶一水硬铝石沿碳质碎屑条带及富有机质的高岭石基质条带分布。这些特征表明，在有Ｋ＾＋离子带入的开放条件下，粘土     

栖霞宅科地区含矽线石榴黑云片岩岩石地质特征及原岩恢复

栖霞宅科地区含矽线石榴黑云片岩是古元古代荆山群禄格庄组安吉村段主要岩性,主要造岩矿物为黑云母、石英、斜长石、钾长石、石榴子石、矽线石,岩石层位稳定,为高角闪岩相变质岩。用岩石化学和地球化学特征的方法进行判别发现,其原岩为一套化学上属中—强等分异的海相和海陆交互相沉积的粘土岩。     

新汶 肥城太原组火山灰蚀变高岭石夹矸化学成分研究

在前人研究成果的基础上,从化学成分特征这一角度,对山东新汶、肥城煤田太原组高岭石粘土岩夹矸进行了主常量元素、微量元素及稀土元素分析。结果不仅进一步证明了,研究区高岭石粘土岩夹矸确由火山灰降落于泥炭沼泽或泥炭坪环境后经蚀变而成,而且通过对微量及稀土元素分析结果的研究,提出该层夹矸的形成可能受到不同期次及不同性质的火山物质影响的新见解,为含煤岩系中火山事件沉积的研究提供了新思路。      

四川绿豆岩提取钾肥及其综合利用新工艺试验研究

绿豆岩是一种富钾火山凝灰岩，因含有硅质豆粒，颜色鲜艳成绿色，故俗称绿豆岩。绿豆岩按后生变化结果可分力富钾凝灰岩（脱玻后的玻屑凝灰岩）和绿鳞石粘土岩。绿鳞石粘土岩经酸浸分解，析出非晶态二氧化硅，游离出钾、镁、铝等离子，按化工工艺流程生产出硫酸铵钾（俗称钾氮肥）、七水硫酸镁、氢氧化铝等产品。     

扬子板块北缘镇巴地区吴家坪组富Li-REE-Nb-V黏土岩地球化学特征及其地质找矿意义

沉积型锂矿主要产于黏土岩中,黏土岩的主微量元素可有效识别沉积物源及沉积环境。本文首次报道扬子板块北缘镇巴地区二叠系吴家坪组黏土岩锂、稀土、铌、钒等元素超异常富集的特征,基于详细的地球化学研究和区域地质资料,分析吴家坪组黏土岩的形成环境及沉积物源,并探讨扬子板块北缘锂、稀土找矿方向。研究表明,镇巴地区吴家坪组黏土岩产于晚二叠世,发育于吴家坪组与阳新组的平行不整合界面之上,代表了古风化壳沉积,黏土岩的Li2O最高品位0.39%,ΣREO（稀土氧化物总量）最高品位0.142%,V2O5最高品位0.26%,Nb2O5最高品位0.022%。主、微量元素地球化学特征指示黏土岩形成于咸化-半咸化海水相,氧化-还原过渡、碱性的沉积环境,对应于黏土岩化阶段。综合矿物学、地球化学、区域地质资料,认为研究区吴家坪组黏土岩来源于峨眉山大火成岩省的玄武岩,锂元素的富集与火山岩受流体交代-淋滤有关。扬子板块北缘广泛发育吴家坪组黏土岩,规模较大,锂、稀土、铌、钒综合成矿效果较好,找矿潜力巨大,应重点关注与沉积间断面有关的关键金属矿产,助力新一轮找矿突破。     

Study on the physical disintegration characteristics of Subang claystone subjected to a modified slaking index test

Some instability problems were found on natural or engineered slopes mostly lying on Subang claystones. The instability problems included excessive erosion, slumps and rock falls. The field performance surveys of the problems suggested that the claystones physically weather rapidly so that the rock properties they exhibit during excavation often change to properties with a more characteristic of soil. Such a phenomenon is generally known as a slaking process. In order to gain better understanding about the slaking of Subang claystones, a series of experimental laboratory studies were carried out involving a modified slaking index test. Claystone samples used in this study were obtained from their exposures along the Northern West Java area of Indonesia. Petrographic analysis was correspondingly performed to identify mineral and texture/fabric, and in turn, to determine the inherent factors of the rocks which might affect the slaking process. The stssudy results indicated that the claystones were characterized by high to very high slaking properties having a maximum slaking index (I_s) of 57.4% and a mean I_s of 43.8%. Major dispersion slaking on sample surfaces and high cracking in response to excessive swelling were recognized as main slaking modes within the claystones. All samples lose progressively less material through the five wet–dry cycles of a slaking index test, indicating a decelerated slaking rate. It was evident that the main inherent factors controlling the slaking process were expandable clay mineral smectite, non-clay mineral pyrite and soluble mineral calcite. Moreover, a quite important of inherent bonding material and stress release energy in the slaking characteristics of the claystones was revealed by a closure phase of an initial hairline crack during unloading.     

Back-analysis of roof conditions in the Great Northern Seam,Newcastle Coal Measures,Australia, using voussoir beam theory

Summary A typical roof profile for mine openings in the Great Northern Seam consists of a thin coal layer and several metres of claystone. From field evidence and shear flow analysis, the anchorage of fully grouted roof bolts in the claystone may fail. If so, the claystone may act as an extra load on the coal beam. Using voussoir beam theory, the relation between the minimum thickness of the coal beam, the thickness of the failed claystone and the width of the entry has been determined. The analysis is satisfactory for field performance observed in a number of case studies. Proposals are made on possible improvements to mining techniques.     

Chemistry of Late Early Triassic Siliceous Claystone ('Toishi-type' Shale) from the Oritate Area, Sambosan Belt, Kyushu, Southwest Japan

Abstract. Inorganic chemical compositions are determined for late Early Triassic siliceous claystone ('Toishi-type' shale) and associated chert from Oritate area, Sambosan Belt, Kyushu, southwest Japan. The siliceous claystone is similar in chemical composition to Post-Archean Australian Shale (PAAS), but is depleted in Ca, Sr, Mn, and Fe and slightly enriched in Cu, Zn, P, and rare earth elements (REEs). The siliceous claystone and associated chert have flat REE patterns with positive Eu anomalies and no distinct Ce anomaly. The siliceous claystone and associated chert have largely constant Ti/Al, Th/Al, and Nb/Al ratios compared to the variable ratios found in siliceous shale and sandstone deposited close to land in a trench setting. This suggests that the claystone and chert were deposited in a deep-sea pelagic environment and were derived mainly from the suspended fraction, including eolian dust and material transported from distant lands, rather than from turbidity currents that occurred close to land. The low Ca contents of the analyzed rocks indicate deposition below the calcium-carbonate compensation depth. The depletion of Mn and Fe, and no distinct Ce anomaly in the Oritate siliceous claystone are also evident, being similar to those in samples from the Sasayama and Kinkazan sections in the Mino-Tanba Belt, where oceanic anoxia developed during the Late Permian to earliest Triassic. This might suggest that oceanic anoxia prevailed through to the late Early Triassic.