The influence of poorly interconnected fault zone flow paths on spring geochemistry

Thermal springs commonly occur along faults because of the enhanced vertical permeability afforded by fracture zones. Field and laboratory studies of fault zone materials document substantial heterogeneities in fracture permeabilities. Modeling and field studies of springs suggest that spatial variations in permeability strongly influence spring locations, discharge rates and temperatures. The impact of heterogeneous permeability on spring geochemistry, however, is poorly documented. We present stable isotope and water chemistry data from a series of closely spaced thermal springs associated with the Hayward Fault, California. We suggest that substantial spatial variations observed in δ¹⁸O and chloride values reflect subsurface fluid transport through a poorly connected fracture network in which mixing of subsurface waters remains limited. Our measurements provide insight into the effect of fracture zone heterogeneities on spring geochemistry, offer an additional tool to intuit the nature of tectonically induced changes in fault zone plumbing, and highlight the need to consider local variations when characterizing fracture zone fluid geochemistry from spring systems with multiple discharge sites.     

清代寡妇立嗣问题探析

In the Qing Dynasty, widows who did not remarry could become the right subject of adopting an heir. There were two main types, adoption by order and adoption by affection. Sometimes an heir with a different surname could also be adopted. Some relatively economic compensation actions were taken in the adoption. The widows’ right of adoption was restricted by such factors as patriarchy, clan, feudal ethical codes and conventions. However, the widows could appropriately use law to protect their rights and interests. Meanwhile, when the magistrates judged cases about adoption, they were usually apt to support the widows’ requests so as to protect the rights and interests of social vulnerable group with fully applying the right of discretion. Translated by Chen Cheng from Shixue Yuekan 史学月刊 (Journal of Historical Science), 2007, (6): 34–42     

An experimental study of nitrogen flux in llamas: is N preferentially excreted?

Nitrogen isotope analysis is now commonly used to investigate the diets, and to a lesser extent, the environments of ancient populations. These studies assume that mammals are predictably enriched in ¹⁵N over their food, and concomitantly, that ¹⁵N becomes increasingly concentrated as one moves up the food chain. The literature commonly states that this ¹⁵N-enrichment of mammalian tissues is due to preferential excretion of light nitrogen (¹⁴N), but there are few data to support this assertion. To address the gap, we conducted two nitrogen flux trials in which four llamas (Lama glama) were fed high- and low-protein diets. The ratios of fecal nitrogen loss to urinary nitrogen loss were 0.30 and 0.88 on the high- and low-protein diets respectively. Feces were enriched in ¹⁵N by approximately +3‰ on both diets, whereas urinary nitrogen was depleted in ¹⁵N (−2.1‰) on the low-protein diet, but not significantly different from intake δ¹⁵N on the high-protein diet. Most importantly, there was no statistically significant difference between dietary and total excreta δ¹⁵N on either diet. Given these data and theoretical considerations, we argue that the nitrogen influx and efflux of adult mammals at steady state should be isotopically commensurate. However, during growth, diet change, thermal or nutritional stress, animals may not be at steady state and fractionation between intake and excreta δ¹⁵N may occur.     

Raven,Ellen and Helga L. Lasschuijt [Edd.]: ABIA. South and Southeast Asian Art and Archaeology Index. Volume Two,parts 1 and 2

Indo-Iranian Journal -     

Apor, Éva and Helen Wang [Edd.], Catalogue of the Collections of Sir Aurel Stein in the Library of the Hungarian Academy of Siences compiled by John Falconer,Agnes Kárteszi,Agnes Kelecsényi,Lilla Russell-Smith

Indo-Iranian Journal -     

The Construction Process of the Angkor Monuments Elucidated by the Magnetic Susceptibility of Sandstone*

The Angkor monuments in Cambodia are mainly constructed of grey to yellowish‐brown sandstones. No differences in the constituent minerals and in the chemical composition of the sandstones have been confirmed among the monuments. However, we have found their magnetic susceptibility a useful parameter by which to distinguish them. The principal monuments of Angkor Wat, Ta Prohm, Preah Khan, Banteay Kdei and Bayon, constructed from the Angkor Wat period to the Bayon period (from the beginning of the 12th century to the beginning of the 13th century ad ), were investigated in detail using a portable magnetic susceptibility meter. We succeeded in dividing the periods of construction into stages. This elucidated the enlargement process of the monuments and correlated their construction stages.