大安寨石灰岩的成岩作用与成岩圈闭

Daanzhai limestone in the Szechuan Basin consists of biosparite, biomicrite and micrite, with intercalations of black shales. Daanthai limestone is of lake origin and known as oil reservoir rocks. There are five layers of reservoir rocks, of which D-3 is the most important in Shuangsijiao oil field. Stained thin sections were studied for 250 limestone samples from the oil field. In addition to non-ferrous calcite, three phases of ferrous calcite were identified in Daanzhai limestone, which are ferrous calcite Ⅰ (0.5 to 1.5% FeO), ferrous calcite Ⅱ (1.5 to 2.5% FeO) and ferrous calcite Ⅲ (2.5 to 3.5% FeO). Shuangsijiao off field belongs to diagenetic trap type. It has been confirmed that the non.ferrous sparry calcite cementation and solution (vug) of the second period control the distribution of commercial oil wells, which are located in southeastern part of the structure trap.     

小秦岭金矿田中的两种罕见矿物—碲铅铋矿和自然碲

碲铅铋矿和自然碲产于河南省小秦岭含金石英脉矿床中。碲铅铋矿化学成分平均值(%)为:Te44.06,Bi40.24,Pb14.23,并含有微量的Ag、Au、Hg、Fe、Ni、Cu等元素。理论化学式为(Bi,Pb)_3Te_4,其中Bi>Pb。共生矿物有自然金、碲金矿、破银矿、碲铅矿、碲金银矿、碲铋矿;方铅矿、闪锌矿、黄铁矿、黄铜矿等。 自然碲反射色为纯白微带乳色,非均质性清楚,偏光色为蓝灰-棕灰色。显微硬度为H_v=85.1kg/mm~2(25g)。共生矿物有碲金银矿、碲银矿、黄铜矿等。化学成分中碲含量达98.44％,并含Ag、Cu、W、Fe、Pt等微量元素。     

沈丘球粒陨石考察研究

1987年2月22日3时25分,在河南省沈丘县老城镇一带陨落了一次陨石。已收集到两块:杨洼(1号)陨石重14.25公斤,入地深度38厘米;魏营(2号)陨石重76.7克,比重3.64,微磁性。经实物对比,二者皆为灰褐色、有熔壳,原应为一体之物。用2号样化验分析,已发现27种化学元素。镜下鉴定见有:辉石、橄榄石、金属铁-镍、陨硫铁、铬铁矿及玻璃质矿物等。硅酸盐部分(80.02％)大于金属部分(19.97％)应属石陨石大类。因陨石中矿物球粒状结构明显,故称球粒陨石。总观沈丘陨石特征,可命名为:橄榄古铜辉石球粒陨石。与1977年12月1日,陨落在河南信阳的球粒陨石相比,矿物成分和结构等都大同小异。