沉积硼酸盐热作用过程中的硼同位素变化

建立温度与硼同位素变化的关系是研究沉积硼酸盐成岩-变质作用中硼同位素地球化学行为的关键,这有助于准确认识硼酸盐δ11 B值所代表的地质意义.本文以自然产出的三方硼砂和钠硼解石为材料,结合热分解特征研究了不同热作用过程中硼同位素变化.200℃下硼酸盐经历结晶水的脱水反应,此过程中三方硼砂和钠硼解石δ11B值分别由6.48±0.14‰降低到5.41±0.27‰和由-13.27±0.11‰降低到-15.93±0.23‰.1‰～3‰的硼同位素变化与自然界观察到的由脱水作用形成的次生硼酸盐比原生硼酸盐δ11 B值低2‰～4‰的现象一致.200～300℃间经历羟基的脱水过程,伴随着1‰～2‰的硼同位素降低,此过程中三方硼砂和钠硼解石δ11 B值分别由5.41±0.27‰降低到3.73±0.26‰和由-15.93±0.23‰降低到-17.11±0.11‰.300～670℃间硼酸盐经历物相转化过程,三方硼砂和钠硼解石δ11B值分别由3.73±0.26‰升高到4.59±0.08‰和-17.11±0.11‰升高到-16.08±0.20‰.此过程1‰的硼同位素升高是由硼-氧骨架结构改变造成的.本实验结果可以指示沉积硼酸盐的形成过程,以及埋藏过程中的硼同位素变化规律.硼酸盐脱水过程中会形成具有更高δ11 B值的流体,其可能显著影响内生硼矿的硼同位素组成,因此讨论硼同位素地质意义不能与海相-非海相环境中的硼同位素组成进行简单对比,需要考虑流体演化过程中的硼同位素变化.     

MINERALOGY

20061993 Chen Ruoyu ( Department ofChemical Engineering, Jiangsu PolytechnicUniversity, Changzhou 213016, China); XiaShuping Thermal Dehydration Mechannsmof Ulexite from Xiao Chaidan Salt Lake (Ac-ta Mineralogica Sinica, ISSN 1000 - 4734,CN52-1045/P, 25(4), 2005, p.374-378,5 illus., 4 tables, 11 refs.)Key words: ulexite, water of dehydrationThermal dehydration process of ulexite,NaCa[B5O6(OH)6]·3H2O, was investigatedby the isothermal-isobaric method, thermalanalysis (I)TA), X-…     

国内水硅硼钠石的首次发现

水硅硼钠石于1987年在河南省泌阳凹陷发现,产于新生代第三纪含碱岩系油页岩中,它的发现填补了我国该矿物的空白。水硅硼钠石简约化学式为NaBSi2O5(OH)2。晶体特征是:球粒状及束状集合体,板状、柱状晶体;无色透明,二轴晶负光性;Ng=1.534、Nm=1.532、Np=1.512。水硅硼钠石对于解释所在碱矿床的沉积环境和物质来源有一定意义。     

Mg—Al水滑石纳米晶热分解行为的TG—MS研究

利用热重-质谱联用仪(TG-MS)和多晶XRD对水热法制备的Mg-Al水滑石纳米晶的热分解行为进行表征研究表明:Mg-Al水滑石的热性能与其晶体化学特征有密切的关系。Mg-Al水滑石的热分解过程可分为4个阶段:①T≤280℃时,失层间H2O;②T=280℃~380℃时,失层板中[Mg—OH—Al]结构单元OH-;③T=380℃~580℃时,失层板中[Mg—OH—Mg]结构单元的OH-;④T=395℃~580℃时,层间CO32-逸出。后两个阶段有较大重叠性。[Mg—OH—Mg]中OH-和CO32-最大逸出量对应的温度明显不一致。[Mg—OH—Mg]中OH-的逸出是导致层状结构破坏的诱因,热分解的阶段性随升温速率提高而表现得明显。Mg-Al水滑石的热分解行为受扩散控制。     

含钙铝铁水解聚合产物的矿物学研究Ⅱ:热分解特性

分别以NaOH和Ca(OH)2作为碱化剂,合成了聚合氯化铝铁(PAFCNa,PAFCCa),比较样聚合氯化铝(PACNa,PACCa)、聚合氯化铁(PFCNa,PFCCa),制成低温干燥样进行热分解检测.热重分析证明,PAFCCa中的含水量高,主要是配位水与结晶水.当n(Al)/n(Fe)>5:5后,PAFCCa的含水量平均为42.3%.按Ca6Al2(SO4)3(OH)12·26H2O分子式计算,钙矾石的结构水(含OH水)含量为43.06%,两者含水量相当接近.TG-DTG热分析结果支持XRD对PAFCCa中存在含Ca3Al2(OH)12柱体的类钙矾石结构体的认定.PAFC-Ca根据其DTG曲线上的125℃和180℃两个脱水速率(肩)峰可以判别其中有无钙矾石结构体,以及相对量的多少.     

马鞍山绿松石中水的振动光谱表征及其意义

在室温和变温条件下对安徽马鞍山绿松石中水的结构特征进行红外吸收光谱和激光拉曼光谱分析研究,结果表明:绿松石中部分水分子与Cu2 结合成[Cu(H2O)4]2 水合离子,并在很大程度上制约了绿松石的颜色;马鞍山地区绿松石中结晶水的脱失温度约为303℃～310℃,结构水的脱失温度约为346℃～375℃。绿松石中H2O,OH-的振动是导致其水的激光拉曼光谱形成的主要原因,ν(OH)振动导致的强拉曼特征谱峰在3470 cm-1,3502 cm-1～3505 cm-1之间的弱谱峰则隶属3470 cm-1的次级谱峰,ν(H2O)的拉曼谱峰主峰位于3442 cm-1～3449 cm-1处。由ν(MFe,Cu-H2O)伸缩振动致平缓的拉曼谱峰主要分布在3074 cm-1～3303 cm-1附近。     

热处理电气石的物相转变

通过差热分析（DTA）、热处理和X射线衍射分析（XRD）等手段，研究我国西北某地区产的黑色电气石在热处理过程中的相转变过程，实验发现850℃热处理2h，电气石晶体结构的[Si6O18]复三方环和[BO3]三角结构已开始破坏，并出现新的物相－莫来石（Al2.35Si0.64O4.82)，铝硼氧化物（Al5BO9)和赤铁矿（Fe2O3)；890℃时，电气石分解形成的莫来石（Al2.35Si0.63O4.82)和赤铁矿（Fe2O3)量增加，并有新物相（Al2O3)9。97(B2O3)1.99形成；1010℃时，莫来石合成体系的Si、Al和O的原子个数比发生了变化（Al4.868Si1.132O9.566)，出现矽线石（Al2SiO5)、镁橄榄石（Mg2SiO4)、顽辉石（Mg(SiO)3)和镁铝硅硼酸盐（Mg2Al4Si4B4O37)等新物相。     

经国际矿物协会(I.M.A.)新矿物与矿物命名委员会批准1983-1984年发表的新矿物

化学成分式参考文献锗石阿硫锡铅矿砷钮铅铀矿轻硅铁锰石碱钒石氟碳铝钠石钮黄锑华多水硅钙锰石钙贝塔石锡铜把矿抒锗铁铝石水硼铝钙矾水硅锰钙被石铬镁电气石ArgutiteAschamal二刀iteGe 02PboBi:匀(Pb,Ba)(Uo:)6(Bio)一〔(A:,p)o‘〕2(OH)1,·3HZO(Mg,卜ez争一于e,+,M”2+,口)‘2511。(0,OH).0(Na,K)xv亮+v息叙01。(o。90>x>0 .54)Na7AIH:(CO:)一卜:卜e告寸。;Bi里户::Sb:.。。o;caM。盒+51:o,。·7H:o(Ca,La,Th,U),(Nb,Ta,Ti)20PdZ Cu Sn卜eZ+Al:GeO:(OH):Ca6(AI,51)2(50‘)2(B(OH)O(OH,0)l:·26H20Ca Mn I3eZS…     

准噶尔盆地下二叠统风城组硅硼钠石发育特征及其富集成因探讨

准噶尔盆地玛湖凹陷下二叠统风城组沉积于火山—碱湖蒸发环境中,发育有厚层碱盐和优质烃源岩,同时还发育世界罕见的硅硼钠石,其富集程度居世界首位。本文基于岩芯、薄片、背散射图像观察及流体包裹体和硼同位素测试分析,试图探讨风城组富集硅硼钠石的原因。矿物学研究发现,硅硼钠石是成岩作用产物,以交代碳酸盐矿物为主,包括碳钠钙石、碳钠镁石、氯碳钠镁石、方解石、天然碱,甚至是极少见的钡方解石。风城组硅硼钠石中原生盐水包裹体均一温度为100 ℃~116 ℃,硅硼钠石的δ11B在0.33‰~2.13‰之间,结合前人硅硼钠石合成实验成果,认为硅硼钠石的B来源于原始沉积环境中的深部热液流体,受地表及浅埋藏过程中温度压力的限制,硅硼钠石主要形成于深部成岩环境中（>3 000 m）。玛湖凹陷风城组之所以较世界上其他新生代碱湖沉积物更发育硅硼钠石,一方面在于沉积过程中其岩浆热液活动更为强烈,另一方面在于成岩作用时间更为漫长,使硅硼钠石交代作用更为充分。     

具磷灰石假象绿松石的热性能

绿松石的热性能分析在对其水的结构特征、呈色机理等的研究中具有重要指示作用.采用热重-差热分析(TG-DSC)、红外光谱(IR)和X-射线粉晶衍射(XRD) 分析方法, 对安徽马鞍山具磷灰石假象绿松石的热性能特征进行了研究.研究结果显示从室温到1100℃, 假象绿松石的热相变可划分为6个变化阶段: 100~200℃时, 为吸附水脱水阶段; 250~330℃, 假象绿松石中羟基和晶格水分子脱失; 330~750℃为非晶态物相阶段; 约750℃时为新物相形成阶段; 750~1100℃为具磷石英结构磷酸铝的形成阶段; 1100℃时磷酸铝的结晶有序度增加.假象绿松石结构及水的存在形式、总量和结合方式制约和影响着颜色的变化.      

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

NONMETALS DEPOSITS

正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.)     

MATHEMATICAL GEOLOGY

正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology,     

PROSPECTING EXPLORATION

正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.)     

STRUCTURAL GEOLOGY

正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se-     

STRUCTURAL GEOLOGY

正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with     

PALEOZOOLOGY

正20141609 Chen Guiying(College of Earth Sciences,Guilin University of Technology,Guilin 541004,China);Han Nairen New Materials of Stylophora from the Upper Cambrian of the Jingxi Area,Guangxi,South China(Acta Palaeontologica Sinica,ISSN0001-6616,CN32-1188Q,52(3),2013,p.288-293,2 illus.,12 refs.)Key words:Stylophora,Guangxi     

GEOPHYSICS

正20140634 Cao Lingmin(Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China);Xu Yi Finite Difference Tomography of the Crustal Velocity Structure in Tengchong,Yunnan Province(Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074/P,56(4),2013,p.1159-1167,6illus.,35refs.,with English abstract)