High‐temperature magmatic fluid exsolved from magma at the Duobuza porphyry copper–gold deposit,Northern Tibet

The Duobuza porphyry copper–gold deposit (proven Cu resources of 2.7 Mt, 0.94% Cu and 13 t gold, 0.21 g t^?1 Au) is located at the northern margin of the Bangong‐Nujiang suture zone separating the Qiangtang and Lhasa Terranes. The major ore‐bearing porphyry consists of granodiorite. The alteration zone extends from silicification and potassic alteration close to the porphyry stock to moderate argillic alteration and propylitization further out. Phyllic alteration is not well developed. Sericite‐quartz veins only occur locally. High‐temperature, high‐salinity fluid inclusions were observed in quartz phenocrysts and various quartz veins. These fluid inclusions are characterized by sylvite dissolution between 180 and 360°C and halite dissolution between 240 and 540°C, followed by homogenization through vapor disappearance between 620 and 960°C. Daughter minerals were identified by SEM as chalcopyrite, halite, sylvite, rutile, K–feldspar, and Fe–Mn‐chloride. They indicate that the fluid is rich in ore‐forming elements and of high oxidation state. The fluid belongs to a complex hydrothermal system containing H₂O – NaCl – KCl ± FeCl₂ ± CaCl₂ ± MnCl₂. With decreasing homogenization temperature, the fluid salinity tends to increase from 34 to 82 wt% NaCl equiv., possibly suggesting a pressure or Cl/H₂O increase in the original magma. No coexisting vapor‐rich fluid inclusions with similar homogenization temperatures were found, so the brines are interpreted to have formed by direct exsolution from magma rather than trough boiling off of a low‐salinity vapor. Estimated minimum pressure of 160 MPa imply approximately 7‐km depth. This indicates that the deposit represents an orthomagmatic end member of the porphyry copper deposit continuum. Two key factors are proposed for the fluid evolution responsible for the large size of the gold‐rich porphyry copper deposit of Duobuza: (i) ore‐forming fluids separated early from the magma, and (ii) the hydrothermal fluid system was of magmatic origin and highly oxidized.     

ESR dating of the Donggutuo Palaeolithic site in the Nihewan Basin, northern China

The fluvio-lacustrine sequences in the Nihewan Basin, northern China, provide important terrestrial archives about Palaeolithic settlements and, therefore, about early human occupation in high northern latitude in East Asia. Here we present detailed ESR dating of the Donggutuo Palaeolithic site, located in this basin. Four levels A, B, C and E of the Donggutuo archaeological layer yield ESR ages ranging from 1060±129 ka to 1171±132 ka with a mean of 1119±132 ka. The ages are consistent with the paleomagnetic data, which show that the Donggutuo Palaeolithic site lies just below the onset of the Jaramillo normal subchron (0.99–1.07 Ma). Furthermore, our results indicate that the reliable ESR dating range of bleached quartz using Ti-Li centre can be effectively extended to 1100 ka and the Ti-Li centre was zeroed before the last deposition, which requires improvement of the understanding of the bleaching mechanism conditions.     

电解法纸张脱酸研究

酸化是导致纸质档案、文物、图书等自毁的主要原因,现有脱酸方法实用性不强,需进行创新与突破。传统水溶液法,是一种常见的脱酸方法,具有对纸张安全、环境友好、操作简便、经济实惠、脱酸效果好的优点,也具有纸张浸泡处理时间长、脱酸速度慢的缺点。若能够克服其缺点,水溶液脱酸法会具有非常广泛的应用前景。本研究在传统水溶液法脱酸的基础上,利用酸化纸张湿润状态下与外加直流电源构成电解池的工作原理,采用电解法将纸张中的酸根离子移出,实现纸张快速脱酸。通过对比电解法与传统水溶液法对自然酸化纸张脱酸前后的外观与性能,探讨电解法的脱酸效果。结果表明,电解法可以有效地去除纸张中的酸根离子,降低纸张的酸度,既保留了传统水溶液脱酸简便可靠、绿色安全、成本低的优点,又克服了纸张长时间湿态导致的变形、膨胀的不足及工作效率低的缺点。     

OxCal校正软件在考古年代学中的应用

OxCal校正软件是一款常用的处理碳十四数据的程序,拥有72个基本指令与若干模型.该软件的基本指令有两种,分别是赋值型指令和结构型指令.OxCal校正软件运用在具体考古遗址(如王城岗龙山文化城墙和城壕以及古埃及阿马尔纳遗址)研究中时,要注意序列或阶段的选择.     

Melt formation in lime-rich proto-porcelain glazes

Early Chinese lime-rich glazes form an important step in the development of high-fired ceramics. This experimental study, based on the analysis of archaeological samples of proto-porcelain and replicated samples, explores the role of ash and glaze mixture preparation, firing temperature and duration, and cooling protocol for the quality and composition of the resulting glaze. It is demonstrated that the application of raw wood ash rich in potash produces low-potash glazes, that the melt formation follows a cotectic mechanism which needs extended firing times to reach equilibrium, and that the formation of a crystalline interaction layer depends more on the kiln cooling history and high-temperature soaking than on the glaze application method.     

《明史》若干地理记载正误

现存殿本《明史》地理中的若干失误或待斟之处,多由《明史》成书时徵引原始史料的失误或不审所致;而点校本《明史》地理中的若干瑕疵,多属误校或漏校。追源溯流,查考《明史》纂修所据的若干原始文献,并认真复核点校本的若干点校,发现其中的错漏或待斟之处,为进一步研究和利用《明史》以作参考。     

Polychromic structures and pigments in Guangyuan Thousand-Buddha Grotto of the Tang Dynasty (China)

This paper presents a multi-analytical study of the polychromy in the Guangyuan Thousand-Buddha Grotto. Samples taken from 15 locations in No. 512 and No. 689 caves are prepared as cross-sections for the analysis by optical microscopy (OM) and scanning electron microscopy coupled with backscattered electron imaging (SEM-BSE). The cross section analysis indicates that some paintings were repainted in the past. The chemical composition of each painting layer is obtained by scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM-EDX). The main pigments for 15 samples including green, red, blue, white and black paint layers, are identified by the combination of polarized light microscopy (PLM), Fourier Transform infrared spectrum (FT-IR), Raman spectroscopy (RS) and X-ray diffraction (XRD) analysis. The integrated analytical results reveal that the green pigments are malachite and atacamite; the red color is attributed to minium, hematite and cinnabar; the blue pigments are lazurite and organic blue materials; the white color is ascribed to anglesite and gypsum; and the black surface of polychrome is the accumulation of longtime smudging by folk burning incense in the devotional practice or the soot deposition resulting from burning bonfires in the caves. Some arsenic-containing pigment is detected in the green samples. This case study also demonstrates the advantages and the limitations of every analytical technique for the pigment identification, confirming the necessity of the integrated analytical techniques approach. The present results are not only useful to assist in the authenticity of the used pigment materials and history of the polychromic in the past, but also aimed at guiding the conservation scientists in taking into account materials and methods utilized in the past.     

陈黻宸的史学“四独”“五史”论

在挖掘中国传统史学的精华和吸收消化西方史学思想的基础上,陈黻宸糅合中西,提出了自己的"四独""五史"的史学思想。这些史学思想中既有对史家的要求,也包括了对读史之人的要求,其中处处透露着陈黻宸对史学性质的认识和"新史学"的影像。     

定窑、邢窑和巩义窑部分白瓷的成分分析及比较研究

为研究定窑、邢窑和巩义窑在白瓷烧造工艺的联系和区别,本工作使用能量色散X荧光光谱仪(ED-XRF)分析了这三个窑址出土的部分白瓷残片的胎釉化学组成。分析结果显示,三个窑址制胎所用的原料均以高岭土为主,是中国北方白瓷生产制胎原料采用的最主要的粘土类型。隋代邢窑胎体助熔剂原料曾使用长石类原料,从而生产"透影"白瓷而后期则加入钙质原料代替。定窑的白瓷胎体中加入了钙质原料作为助熔剂原料。巩义窑则以长石类原料为主。三个窑白瓷釉中主要助熔剂氧化物都是来自灰料的氧化钙,但含量明显不同,邢窑和定窑的白瓷釉中CaO含量显著低于巩义窑。比较结果表明,三个白瓷窑在胎釉配方工艺方面互有差别但也紧密联系,其中,定窑早期细白瓷的胎釉配方承继了邢窑唐代细白瓷制作的工艺传统。     

Luminescence age constraints on palaeo-earthquake events along the lingwu fault in the Yinchuan Basin,China

Optically stimulated luminescence (OSL) dating was applied to sediment samples in order to provide age constraints on the palaeo-earthquake events that are recorded in a trench on the Lingwu fault near Yinchuan on the northeastern margin of the Tibetan Plateau, China. Combining seventeen OSL ages with field observations in the trench shows that at least four events took place at this specific site, and that this fault has been active over the past 200 ka.