岩矿中固定铵的岩石地球化学研究

在许多极端的情况下，特别是在高铵、酸性还原条件下，能形成一些含铵的矿物如水氨长石等[1]，然而在大多数的地质环境中按的数量是很低的，这也是关于岩石中的氮的丰度和同位素的研究少得可怜的原因[2]。尽管如此，最近对地壳中的氮的循环的进一步了解表明氮体系可用来解释许多岩石学的难题，特别是在岩浆形成过程中沉积岩／变沉积岩的示踪（ItiharaandHonma，1979；Hall，1987，1988）及从沉积岩／变沉积岩中产生的流体的有关性质的揭示（Dllit等，1986；Beb0Ut“］）。在土壤、水下沉积物中，由于环境中存在的接及其含有大量的粘土矿…     

山东金伯利岩中蒙山矿的研究

本文报道了我国山东蒙阴金伯利岩中蒙山矿的一些研究成果。作者在该区采集的蒙山矿与锶钛铁矿-镧铀钛铁矿族(Crichtonite-davite group)矿物等结构和成分介于钡蒙山矿(lindsleyite)与蒙山矿(mathiasite)之间,其BaO含量为2.13—2.89wt％,K_2O含量为0.75—1.27wt％,K/Ba原子比为0.898—1.938;特别富Cr_2O_3、ZrO_2和LREE_2O_3。本文还阐述了山东蒙山矿的类质同象和晶体结构特点,讨论其对地幔交代作用研究的启示。     

电导法测定岩矿中二氧化碳

作者自行设计酸分解反应器,与国产YZYT型电导法测碳仪连接,拟定了酸分解—电导法测定岩矿中碳酸盐的CO_2。本法操作简便、成本低廉、灵敏度较高(检出限为0.018mgCO_2),RSD一般不超过4％。方法已用于多种地质试样中CO_2的测定,结果满意。     

软岩相似材料配比实验研究

为制作软岩的相似模拟材料,选用河砂为骨料、石灰和石膏作为胶结物、铁砂为增密剂、甘油为增塑剂、硼砂与水结合混合溶液为黏结材料,建立了4因素4水平的正交试验方案,进行了相似材料试样的物理力学性质实验,并通过实验结果的极差分析、方差分析及损伤分析,获得了相似材料各成分变化对试样物理力学性质的影响规律。结果表明,影响相似材料密度和力学性质的主要因素分别为河砂与铁砂的比例和甘油与石灰石膏的比例,而试样在最大荷载作用下损伤值为0.85~0.97范围,其基本已破坏。基于本文得到的相似材料物理力学性质指标,在目标强度和相似比确定的情况下,可以设计软岩相似材料的最优配比方案,满足软岩材料有关的相似试验要求。     

农用岩矿资源开发利用的新领域

本文阐述了农用岩矿资源的特点和湖南的资源概况。举例说明了其在改善农业生态环境,提高农产品质量及效益中的作用,并就湖南的情况提出了开发应用建议。     

岩矿样品中稀有气体同位素组成的质谱分析

利用MM5400质谱计建立了岩矿样品中He,Ne,Ar,Kr和Xe同位素组成的测定方法。仪器的工作状态稳定,且能将3He与HD的谱峰完全分开。在处理气体将非稀有气体尤其是碳的化合物用海绵钛炉充分消除,在测试Ne同位素组成时用烧结型不锈钢滤芯可以基本消除40Ar^2 对20Ne的干扰,必要时要进行校正;为了保证谱峰强度与相应元素量的大小之间的线性关系,质谱计主机中的气体量应控制合适,对宽甸新生代火山岩及地幔岩包体中稀有气体同位素组成的测定结果表明,中国东部上地幔具有大洋中脊玄武岩（MORB）型的源区特征。     

Batch and Column Experiments on Fluoride Removal from Waters Using Modified Zeolite

INTRODUCTIONNatural and m odified zeolites have been widely used inboth catalytic conversion processes and adsorption separationprocesses. Recently,because of their unique properties,growing interest has been focused on the zeolites for use in ionexchange separation in water softening,pollution abatem ent,energy production,agriculture,metal processing and biomedi-cal areas. Most of the previous work was concentrated on thecation exchange property of zeolites. Several zeolites werefound to…     

Using a modern analogue to interpret depositional position in ancient fluvial-tidal channels: Example from the McMurray Formation,Canada

The fluvial–tidal transition (FTT) is a complex depositional zone, where fluvial flow is modified by tides as rivers approach a receiving marine basin. Variations in the relative importance of tidal versus fluvial processes lead to a distinctive distribution of sediments that accumulate on channel bars. The FTT generally consists of three broad zones: (1) a freshwater-tidal zone; (2) a tidally influenced freshwater to brackish-water transition; and (3) a zone of relatively sustained brackish-water conditions with stronger tides. A very common type of deposit through the fluvial–tidal transition, especially on the margins of migrating channels, is inclined heterolithic stratification (IHS). At present, a detailed account of changes in the character of IHS across the FTT of a paleo-channel system has not been reported, although a number of modern examples have been documented. To fill this gap, we quantitatively assess the sedimentology and ichnology of IHS from seven cored intervals in three geographic areas situated within the youngest paleovalley (“A” Valley) in the Lower Cretaceous McMurray Formation of Alberta, Canada. We compare the data to trends defined along the FTT in the present-day Fraser River in British Columbia, Canada to interpret paleo-depositional position in the ancient fluvial–tidal channels.Analysis determined that the mean mudstone thickness is 8.2 cm in the southern study area (SA). Mean thickness increases to 11 cm in the central study area (CA), and decreases again to 4.4 cm in the northern study area (NA). The proportion of mudstone is 31% in SA, 44% in CA, and 27% in NA. Thickness-weighted mean bioturbation intensity in sands varied from 0.29 in SA and CA, to 0.28 in NA. On the other hand, thickness-weighted mean bioturbation intensity (BI) in mudstone increases from 1.46 in SA, to 1.77 in CA, and is 1.94 in NA. The ichnological diversity also increased from south to north.Sedimentological results show similar trends to those of the Fraser River, enabling the identification of a freshwater to brackish-water transition zone with tidal influence. The interpreted position of the transition is underpinned by the bioturbation intensity and trace-fossil diversity trends, indicating periodic brackish-water conditions throughout SA in the McMurray Formation during low river flow conditions. Together, these data suggest that a broad FTT existed in the “A” Valley, with fluvial-dominated channels to the south that experienced seasonal brackish-water inundation during base flow, and channels experiencing increasing brackish-water influence lying further north towards a turbidity maximum zone. The FTT zone appears to have extended for several hundred kilometers from south to north.Based on the sedimentological and ichnological data, as well as estimations of lateral accretion rates, we refute the commonly applied Mississippi River depositional analogue for McMurray Formation channels. Rather, we show that while not a perfect fit, the tidally influenced Fraser River shows much greater agreement with the depositional character recorded in McMurray Formation IHS. Future work on the McMurray system should focus on characterizing tide-dominated deltaic and estuarine systems, such as the Ganges-Brahmaputra, and on forward-modeling the evolution of tide-dominated and tide-influenced river systems.