Downward hydrocarbon migration predicted from numerical modeling of fluid overpressure in the Paleozoic Anticosti Basin,eastern Canada

The Anticosti Basin is a large Paleozoic basin in eastern Canada where potential source and reservoir rocks have been identified but no economic hydrocarbon reservoirs have been found. Potential source rocks of the Upper Ordovician Macasty Formation overlie carbonates of the Middle Ordovician Mingan Formation, which are underlain by dolostones of the Lower Ordovician Romaine Formation. These carbonates have been subjected to dissolution and dolomitization and are potential hydrocarbon reservoirs. Numerical simulations of fluid‐overpressure development related to sediment compaction and hydrocarbon generation were carried out to investigate whether hydrocarbons generated in the Macasty Formation could migrate downward into the underlying Mingan and Romaine formations. The modeling results indicate that, in the central part of the basin, maximum fluid overpressures developed above the Macasty Formation due to rapid sedimentation. This overpressured core dissipated gradually with time, but the overpressure pattern (i.e. maximum overpressure above source rock) was maintained during the generation of oil and gas. The downward impelling force associated with fluid‐overpressure gradients in the central part of the basin was stronger than the buoyancy force for oil, whereas the buoyancy force for gas and for oil generated in the later stage of the basin is stronger than the overpressure‐related force. Based on these results, it is proposed that oil generated from the Macasty Formation in the central part of the basin first moved downward into the Mingan and Romaine formations, and then migrated laterally up‐dip toward the basin margin, whereas gas throughout the basin and oil generated in the northern part of the basin generally moved upward. Consequently, gas reservoirs are predicted to occur in the upper part of the basin, whereas oil reservoirs are more likely to be found in the strata below the source rocks. Geofluids (2010) 10 , 334–350     

The Impact of Privatization on Land Inheritance among Samburu Pastoralists in Kenya

Privatization of communal land among a community of pastoralists in northern Kenya creates a gap in social institutions relating to land inheritance. This analysis shows that the emergence of a new rule for inheritance is a complex social process and that new rules do not arise automatically. Using theories of institutions and collective action, this study examines the process through which rules of inheritance are emerging in Siambu since land privatization. Drawing on in‐depth interviews, observations and household surveys, this study reveals why collective action around inheritance norms has been difficult to achieve. In the absence of such action, no single norm of inheritance has emerged. Rather, several different practices currently co‐exist. A considerable amount of evidence suggests that livestock inheritance rules that favour eldest sons will become the norm for land as well, but there are also reasons to doubt this outcome. What this case demonstrates is that institutional gaps are not necessarily or automatically filled; institutions do not simply arise when needed. When collective action fails, multiple practices and norms may co‐exist leading to a certain degree of institutional instability.     

A Wavelet‐Based Extension of Generalized Linear Models to Remove the Effect of Spatial Autocorrelation. 基于小波扩展广义线性模型消除空间自相关的影响

Biogeographical studies are often based on a statistical analysis of data sampled in a spatial context. However, in many cases standard analyses such as regression models violate the assumption of independently and identically distributed errors. In this article, we show that the theory of wavelets provides a method to remove autocorrelation in generalized linear models (GLMs). Autocorrelation can be described by smooth wavelet coefficients at small scales. Therefore, data can be decomposed into uncorrelated and correlated parts. Using an appropriate linear transformation, we are able to extend GLMs to autocorrelated data. We illustrate our new method, called the wavelet‐revised model (WRM), by applying it to multiple regression with response variables conforming to various distributions. Results are presented for simulated data and real biogeographical data (species counts of the plant genus Utricularia [bladderworts] in grid cells throughout Germany). The results of our WRM are compared with those of GLMs and models based on generalized estimating equations. We recommend WRMs, especially as a method that allows for spatial nonstationarity. The technique developed for lattice data is applicable without any prior knowledge of the real autocorrelation structure.     

Site maintenance practices and settlement social organization in Iron Age Karnataka, India: Inferring settlement places and landscape from surface distributions of ceramic assemblage attributes

This paper investigates the spatial organization of social relations in settlement contexts through a quantitative and distributional analysis of surface ceramic attributes from Iron Age Period (1200–300 BC) archaeological sites in Southern India. The results discern variation in depositional contexts across each site, from which I infer a variety of basic settlement activity structures (e.g., site maintenance, trash disposal, residence, animal husbandry, metallurgy, ritual). I use these results, together with further analyses of artifact and feature distributions, to infer a basic suite of places, place-making practices and some of the social relations and organizational structures that produced these historically unique Iron Age settlement landscapes.     

Are Members of Business for Social Responsibility More Socially Responsible?

This study examines the association between corporate social performance (CSP) practices and membership in Business for Social Responsibility (BSR) between 1992 and 2006. BSR is a business association that seeks to help its members adopt enhanced CSP practices. While there is an emerging literature examining voluntary initiatives as alternative policy mechanisms to regulations, most research is focused on initiatives that emphasize environmental protection. Further, studies suggest that membership in strictly voluntary initiatives tends to be associated with lower environmental performance because of “free‐riding” behavior by participants. BSR differs along two dimensions when compared with other voluntary initiatives examined in the literature. First, it is a comprehensive voluntary social initiative that helps firms from diverse industries address multiple CSP issues simultaneously. Second, it might limit opportunism by not offering blanket certification to its participants. Our results indicate that BSR members exhibit greater levels of positive social impacts without demonstrating significantly different levels of negative social impacts. This suggests that participation in voluntary initiatives that avoid granting blanket certifications may be associated with the adoption of new corporate social responsibility practices but not linked to the shedding of entrenched routines that produce negative externalities.     

Paleoclimates and the emergence of fortifications in the tropical Pacific islands

Paleoclimatic data from the tropical Pacific islands are compared to archaeological evidence for fortification construction in the Holocene. The results suggest that in some regions, people constructed more fortifications during periods that match the chronology for the Little Ice Age (AD 1450–1850) in the Northern Hemisphere. Periods of storminess and drought associated with the El Niño Southern Oscillation have less temporal correlation with the emergence of fortifications in the Pacific, but significant spatial correlation with the most severe conditions associated with this cycle. These temporal and spatial correlations require additional study to investigate possible causal relationships.