Granite‐related overpressure and volatile release in the mid crust: fluidized breccias from the Cloncurry District,Australia

The source and transport regions of fluidized (transported) breccias outcrop in the Cloncurry Fe‐oxide–Cu–Au district. Discordant dykes and pipes with rounded clasts of metasedimentary calc–silicate rocks and minor felsic and mafic intrusions extend several kilometres upwards and outwards from the contact aureole of the 1530 Ma Williams Batholith into overlying schists and amphibolites. We used analytical equations for particle transport to estimate clast velocities (≥20 m sec^?1), approaching volcanic ejecta rates. An abrupt release of overpressured magmatic‐hydrothermal fluid is suggested by the localization of the base of the breccias in intensely veined contact aureoles (at around 10 km, constrained by mineral equilibria), incorporation of juvenile magmatic clasts, the scale and discordancy of the bodies, and the wide range of pressure variation (up to 150 MPa) inferred from CO₂ fluid inclusion densities and related decrepitation textures. The abundance of clasts derived from depth, rather than from the adjacent wallrocks, suggests that the pressure in the pipes was sufficient to restrict the inwards spalling of fragments from breccia walls; that is, the breccias were explosive rather than implosive, and some may have vented to the surface. At these depths, such extreme behaviour may have been achieved by release of dissolved fluids from crystallizing magma, in combination with a strongly fractured and fluid‐laden carapace, sitting under a strong, low permeability barrier. The relationship of these breccias to the Ernest Henry iron‐oxide–Cu–Au deposit suggests they may have been sources of fluids or mechanical energy for ore genesis, or alternately provided permeable pathways for later ore fluids.     

STATISTICAL ASPECTS OF POTTERY QUANTIFICATION FOR THE DATING OF SOME ARCHAEOLOGICAL CONTEXTS*

This paper describes some statistical analyses of a particular archaeological material (pottery) originating at some sites in the city of Tours. An important part of the archaeological study of pottery is the comparison of ceramic assemblages to establish the absolute dates of contexts. In this paper, a statistical model is built to assess this comparison. The statistical procedure uses classical tools (correspondence analysis, linear regression and resampling methods) in an iterative scheme. Archaeologists may find in the paper a useful set of known statistical methods, while statisticians can learn a method of ‘arranging’ well‐known techniques. No method is new, but their combination is characteristic of this application.     

1960年以来中国古文字学的发展(下)——钱存训著《书于竹帛》英文本第二版后序

三、石刻、玉文、及陶文 在早期,石、玉、陶器是文字记载最普通也是最耐久的媒体.石刻最早的例子是秦石鼓,大概是春秋晚期或战国早期的产品,后来就成为传载永久文件最相宜的媒体,如墓志以及儒、释、道家的经典①.正如钱教授在此书中所解释,纸的最早的用途之一就是拓印石碑或其他石刻.有文字的石刻记录与有铭文的青铜器记录是同样的散漫.据说现在存有10万块刻石,但仅有3万件拓片问世,最近有几部拓片合集和索引出版②.