Bentonite deposits of Northern Patagonia

Some Argentine North Patagonia bentonite deposits have been characterised by chemical and differential thermal analysis (DTA), X-ray diffraction and Isoelectric Point (IEP), Cation Exchange capacity (CEC) and specific surface area (S) determinations.Samples with high degree of tetrahedral isomorphic substitution, and consequently high interlayer cation charge compensation, would be used as organic pollutant adsorbent when the adsorption was a cation exchange mechanism.     

Origins of the Rio Capim kaolinites (northern Brazil) revealed by δO and δD analyses

Deuterium (δD) and oxygen (δ¹⁸O) isotope data from the Rio Capim kaolin, northern Brazil, were combined with optical studies in order to better understand the genesis and evolution of the kaolinites. The results show that δ¹⁸O values from a lower soft kaolin unit range from 6.0‰ to 19.2‰ for Ka (size ranging from 1 to 3 μm) and Kb (size ranging from 10 to 30 μm) kaolinites, and from 15.4‰ to 24.9‰ for Kc (size < 200 nm) kaolinites. The δD values range from − 63.1‰ to 79.5‰ for the Ka + Kb kaolinites, and from − 68.8‰ to − 244.35‰ for the Kc kaolinites. An upper semi flint kaolin unit, dominated by Kc kaolinites, displays δ¹⁸O and δD values ranging from 15.1‰ to 21.8‰, and − 71.3‰ to − 87.4‰, respectively. Based on these data, and on the δ¹⁸O and δD values obtained for the surface meteoric water and groundwater, it can be concluded that the kaolinites are not in equilibrium with the modern weathering environment, but they reflect isotopic compositions of the formation time, probably due to the interaction with fossil groundwater. However, mineralogical contaminations derived from replacements of framework grains also had great influence in the isotopic composition of these kaolinites. In addition, the isotope values of the Kc kaolinites from the semi-flint kaolin unit is variable, which is due to the presence of Kc kaolinites of different origins, including kaolinites derived from the underlying soft kaolin unit, kaolinites formed during different phases of paleoweathering, as well as later phases of coarse-grained kaolinites formed along fractures. Due to these complexities, binary diagrams contrasting δ¹⁸O and δD values, worldwide applied for distinguishing supergenic from hypogenic kaolinites, as well as those formed under weathering conditions, can not be applied to interpret the origin of the kaolinites in the Rio Capim Kaolin.     

PETROLEUM PROSPECTIVITY OF CRETACEOUS FORMATIONS IN THE GONGOLA BASIN,UPPER BENUE TROUGH,NIGERIA: AN ORGANIC GEOCHEMICAL PERSPECTIVE ON A MIGRATED OIL CONTROVERSY

Organic geochemical studies of Cretaceous formations in the Gongola Basin, northern Nigeria, show TOC values that are generally higher than the minimum (0.5 wt %) required for hydrocarbon generation. Data from Rock‐Eval pyrolysis and biomarker studies indicate the presence of both terrestrial and marine derived Types II and III organic matter, which is immature in the Gombe Formation and of marginal maturity in the Yolde Formation. Immature Type III to IV OM is present in the Pindiga Formation; and Type III OM, with a maturity that corresponds to the conventional onset (or perhaps peak) of oil generation occurs in the Bima Formation. However, Bima Formation samples from the 4710 – 4770 ft (1435.6 – 1453.9 m) depth interval within well Nasara‐1 indicate Type I OM of perhaps lacustrine origin (H31R/H30 ratio generally ≤0.25). Although the Nasara‐1 well was reported to be dry, geochemical parameters (high TOCs, S₁, S₂ and Hls, low Tmax compared to adjacent samples, a bimodal S₂ peak on the Rock‐Eval pyrogram, a dominance of fluorinite macerals), together with generally low H3IR/H30 biomarker ratios within the 4710–4770 ft (1435.6–1453.9 m) interval, suggest the presence of migrated oil, perhaps sourced by lacustrine shales in the Albian Bima Formation located at as‐yet unpenetrated depths. The presence of the migrated oil in the Bima Formation and its possible lacustrine origin suggest that the petroleum system in the Gongola Basin is similar to that of the Termit, Doba and Doseo Basins of the Chad Republic, where economic oil reserves have been encountered.     

徽州民居与汉文化圈典型民居比较

徽派建筑从精神内核到形态、特征是汉文化圈重要建筑流派之一。为充分体现徽派建筑与汉文化圈其它建筑流派的区别,特将徽派建筑的典型代表民居建筑与北方四合院、陕北窑洞、福建土楼和江南水乡民居作简单地比较。     

Honorary Doctoral Degrees as Expressions of Political and Cultural Relationships at Nordic University Jubilees (1840–1911)

The traditional conferment of honorary doctorates on the occasion of university celebrations goes back to the beginning of the 19th century. However, particularly in Northern Europe, on the occasion of university jubilees, the solemn promotion of honorary doctors was still combined with the traditional and ceremonious interpretation of the normal doctor's promotion. Both ceremonies had its own function: the latter was conceived in the first place as a national celebration; the former was intended to radiate the international character and especially the (more or less) Scandinavianist attitude of the university. In this way the conferment of honorary degrees can be considered an ideal measure of the jubilee's general message. This thesis will be developed by means of seven university celebrations, which together offer an excellent overview of the development of the academic relationship between the Nordic countries: Helsinki's bicentenary in 1840, Dorpat's 50th anniversary in 1852, Lund's bicentenary in 1868, Uppsala's quartercentenary in 1877, Copenhagen's quartercentenary in 1879 and finally Kristiania's centenary and the foundation of the University of Iceland, both in 1911. In all these cases honorary degrees functioned as expressions of political and cultural relationships, rather than as academic degrees to honour a specific person.     

神木北部采煤塌陷区土壤与植被损害过程及机理分析

通过对神木北部矿区塌陷1,2,5,10 a和未塌陷区植物群落调查和土壤因子的测试,采用因子分析法评价不同塌陷年限下土壤质量和植被群落结构优劣,同时利用冗余和聚类分析研究植物与土壤之间的相互关系及其演变过程,并基于植被—土壤耦合模型判定不同塌陷年限土壤因子与植物群落耦合协调性。结果表明:1采煤塌陷导致土壤质量与植被群落结构退化,随塌陷时间的推移呈自然恢复趋势,但10 a后植物群落结构和土壤因子仍不能恢复至塌陷前水平;2塌陷区土壤有机质、水分和微生物是决定土壤质量和植物群落特征的关键因素,土壤硬度、速效养分和酶类是影响植物群落生产力和多样性的主要因子,而全效养分影响力相对较小;3塌陷区植物群落和土壤质量大体经过退化、改善和初步恢复3个不同的演化阶段;4植被与土壤的耦合协调性塌陷2 a后逐渐恢复,但至塌陷10 a仍未达到未塌陷地良好的耦合协调水平。神木北部矿区采煤对生态环境损害具有一定延续性,且生态系统自修复能力较弱,因此减少采动损害、实行自然与人工修复相结合应作为该区生态环境保护的指导原则。     

政府与世族利益博弈下的南北朝盐业政策变迁

在商品经济不发达的南北朝时期,食盐更突显出其在国家财政与社会经济中的重要地位与突出作用。但由于中央专制集权与世族利益的博弈,南北朝时期各时段的盐业政策不尽相同。南朝由于世族集团的强大和商品经济相对发展,政府实行食盐放任政策;北朝商品经济落后与中央权力相对强大,各朝以实行盐业专卖为主,但由于世族集团对盐业利益的争夺,盐业放任政策时有行之,因此北朝的盐业政策在时收时放中徘徊。南北朝盐业政策的变化与调整,反映出政府与世族在盐业中利益的博弈与双方力量的消长。     

南京长干寺出土的平经暗花丝织物研究

研究并分析了南京长干寺出土的平经类暗花丝织物实物,认为北宋时期,平纹地暗花织物的织造大多使用多综多蹑机,纹样简洁,花回小;斜纹地暗花织物的织造很可能使用束综提花机,以便生产出更大花回更多造型的组合纹样;中国古代传统的G-G显花技术仍被广泛采用,到辽宋以并丝织法织绫为最;织物艺术风格的淡然回归,织物织造技术的锐意进取当归功于北宋鼎盛繁荣之文化与空前发展之科技。最后推测性总结出北宋时期此类丝织品的纹样风格及决定其纹样风貌的织造工艺。