Freezing and melting behaviors of H2O‐NaCl‐CaCl2 solutions in fused silica capillaries and glass‐sandwiched films: implications for fluid inclusion studies

Fluid inclusions of the H₂O‐NaCl‐CaCl₂ system are notorious for their metastable behavior during cooling and heating processes, which can render microthermometric measurement impossible or difficult and interpretation of the results ambiguous. This study addresses these problems through detailed microscopic examination of synthetic solutions during cooling and warming runs, development of methods to enhance nucleation of hydrates, and comparison of microthermometric results with different degrees of metastability with values predicted for stable conditions. Synthetic H₂O‐NaCl‐CaCl₂ solutions with different NaCl/(NaCl + CaCl₂) ratios were prepared and loaded in fused silica capillaries and glass‐sandwiched films for microthermometric studies; pure solutions were used with the capillaries to simulate fluid inclusions, whereas alumina powder was added in the solutions to facilitate ice and hydrate crystallization in the sandwiched samples. The phase changes observed and the microthermometric data obtained in this study have led to the following conclusions that have important implications for fluid inclusion studies: (i) most H₂O‐NaCl‐CaCl₂ inclusions that appear to be completely frozen in the first cooling run to ?185°C actually contain large amounts of residual solution, as also reported in some previous studies; (ii) inability of H₂O‐NaCl‐CaCl₂ inclusions to freeze completely may be related to their composition (low NaCl/(NaCl + CaCl₂) ratios) and lack of solid particles; (iii) crystallization of hydrates, which is important for cryogenic Raman spectroscopic studies of fluid inclusion composition, can be greatly enhanced by finding an optimum combination of cooling and warming rates and temperatures; and (iv) even if an inclusion is not completely frozen, the melting temperatures of hydrohalite and ice are still valid for estimating the fluid composition.     

从海上交通看中国与百济的关系

2～7世纪的东亚世界,正处于国家整合和社会变革的非常时期。其时位于朝鲜半岛西海岸的国家——百济与中国大陆各朝代的交往最为密切和频繁,成为中国大陆、朝鲜半岛和日本列岛诸国之间沟通联系的重要使者和促进东亚汉字和儒学文化圈形成的重要媒介。透过古代史籍文献中的有关记载和考古的发现研究,以连接中国大陆东部和朝鲜半岛西部的海上交通为切入点,可以从航海史的角度揭示中国与百济之间来往和交流的历史面貌。     

曹操高陵的考古发现与研究

考古发现的西高穴二号墓,其墓葬形制、规格明确。通过与其墓葬形制、规格相近的东汉晚期河北定县北陵头M32、徐州土山东汉墓、山东济宁普育小学汉墓和三国时代偃师杏园M36和M34、安徽马鞍山朱然及其家族墓、马鞍山宋山东吴墓、南京上坊孙吴墓等对比研究,西高穴二号墓应为东汉晚期至魏晋时期高等级墓葬。西高穴二号墓出土遗物研究,又进一步推定该墓时代为东汉晚期。通过对西高穴二号墓发现的刻铭石牌文字内容和字体时代、西高穴二号墓出土男性人头骨与文献记载的曹操去世年龄、西门豹祠遗址和邺城遗址与西高穴二号墓相对分布位置、出土"鲁潜墓志"与西高穴二号墓地望关系、西高穴二号墓的地势和"不树不封"现象与历史文献记载、中国古代帝王陵墓与都城位置关系等六方面,论证西高穴二号墓墓主人就是曹操,西高穴二号墓就是"曹操高陵"。     

THE LETTER KILLS: ON SOME IMPLICATIONS OF 2 CORINTHIANS 3:62

The paper focuses on an argument put forward by Augustine in his De doctrina Christiana: there are passages in the Bible that need to be read in a literal, contextual, and ultimately rhetorical perspective. This approach to the Bible (usually overshadowed by Augustine's own parallel emphasis on the importance of allegory) was needed to deal with customs—for instance the patriarchs' polygamy—that had to be evaluated, Augustine argued, according to standards different from those prevailing in the present day. This need inspired Augustine to utter some sharp remarks on the need to avoid (as we would say today) ethnocentric, anachronistic projections into the Biblical text. The long‐term impact of Augustine's argument was profound. The emphasis on the letter played a significant role in the exchanges between Christian and Jewish medieval readings of the Bible, which affected Nicholas of Lyra's influential commentary (Postilla). The same tradition may have contributed to Valla's and Karlstadt's audacious hermeneutic remarks on the Biblical canon, which covertly or openly focused on contradictions in the Biblical text, questioning the role of Moses as author of Deuteronomy. Traces of those discussions can be detected in Spinoza's Tractatus theologico‐politicus. The paper suggests that the emphasis on a literal, contextual reading of the Bible provided a model for secular reading in general. The possible role of this model in the aggressive encounter between Europe and alien cultures is a matter of speculation.     

Urban growth drivers in a Europe of sticky people and implicit boundaries

We investigate urban GDP per capita growth across the EU12 usingdata for functionally defined cities—rather than administrativeregions. We test hypotheses on the role of human capital, EUintegration and fragmentation of urban government and explorespatial dependence and mechanisms of spatial interaction. Resultsare acceptable on standard econometric tests without measuresof spatial interaction but there is spatial dependence. If variablesreflecting spatial adjustment are included, they are statisticallysignificant and eliminate spatial dependence. Not only do theresults now provide consistent estimates of parameters, butthey also support relevant theoretical insights and show nationalborders are still significant barriers to economic adjustment.People in Europe are sticky so it is unreasonable to assumespatial disparities will disappear. Our findings also implythat cities in Europe form national rather than a single continentalsystem.     

Are rocks still water‐wet in the presence of dense CO2 or H2S?

The various modes of acid gas storage in aquifers, namely structural, residual, and local capillary trapping, are effective only if the rock remains water‐wet. This paper reports an evaluation, by means of the captive‐bubble method, of the water‐wet character in presence of dense acid gases (CO₂, H₂S) of typical rock‐forming minerals such as mica, quartz, calcite, and of a carbonate‐rich rock sampled from the caprock of a CO₂ storage reservoir in the South‐West of France. The method, which is improved from that previously implemented with similar systems by Chiquet et al. (Geofluids 2007; 7 : 112), allows the advancing and receding contact angles, as well as the adhesion behavior of the acid gas on the mineral substrate, to be evaluated over a large range of temperatures (up to 140°C), pressures (up to 150 bar), and brine salinities (up to NaCl saturation) representative of various geological storage conditions. The water‐receding (or gas‐advancing) angle that controls structural and local capillary trapping is observed to be not significantly altered in the presence of dense CO₂ or H₂S. In contrast, some alteration of the water‐advancing (or gas‐receding) angle involved in residual trapping is observed, along with acid gas adhesion, particularly on mica. A spectacular wettability reversal is even observed with mica and liquid H₂S. These results complement other recent observations on similar systems and present analogies with the wetting behavior of crude oil/brine/mineral systems, which has been thoroughly studied over the past decades. An insight is given into the interfacial forces that govern wettability in acid gas‐bearing aquifers, and the consequences for acid gas geological storage are discussed along with open questions for future work.     

Fluid dynamics and fluid‐structural relationships in the Red Lake mine trend,Red Lake greenstone belt,Ontario, Canada

The Red Lake mine trend, a deformation zone in the Archean Red Lake greenstone belt that hosts the world‐class Campbell‐Red Lake gold deposit, is characterized by abundant foliation‐parallel iron‐carbonate ± quartz veins with banded colloform‐crustiform structures and cockade breccias overprinted by silicification and gold mineralization. There is an apparent incompatibility between the cavity‐fill structures of the veins and breccias (typically developed at shallow crustal depths) and the upper greenschist to lower amphibole facies metamorphic conditions recorded in the host rocks (indicating relatively deep environments). This, together with the development of veins along the foliation plane, represents an enigmatic problem that may be related to the interplay between fluid dynamics and stress field. We approach this problem through systematic study of fluid inclusion planes (FIPs) in the vein minerals, including the orientations of the FIPs and the pressure–temperature conditions inferred from fluid inclusion microthermometry. We find that fluid inclusions in the main stage vein minerals (pregold mineralization ankerite and quartz and syn‐ore quartz) are predominantly carbonic without a visible aqueous phase, whereas many inclusions in the postore stage contain an aqueous phase. Most FIPs are subvertical, and many are subparallel to the foliation. High fluid pressure coupled with the high wetting angles of the water‐poor, carbonic fluids may have been responsible for the abundance of brittle deformation features. The development of subvertical FIPs is interpreted to indicate episodic switching of the maximum principal compressive stress (σ₁) from subhorizontal (perpendicular to the foliation) to subvertical (parallel to the foliation) orientation. The subvertical σ₁ is favorable for the formation of foliation‐parallel veins, as fractures are preferentially opened along the foliation in such a stress regime, the origin of which may be linked to the fluid source.