Massive dolomitization of a Messinian reef in the Great Bahama Bank: a numerical modelling evaluation of Kohout geothermal convection

The hypothesis that Kohout thermal convection may have induced the massive dolomitization of the 60 m thick lowest more reefal unit in well Unda [top of Great Bahama Bank (GBB)] is evaluated through numerical modelling. A two‐dimensional (2‐D) section, including lithological and petrophysical data, together with datings for the sediments of the GBB, was used in the basin model TEMISPACK to reconstruct the history of the whole platform, with a focus on the reef unit. Simulations showed that during high sea‐level periods, Kohout convection is a valid mechanism in the settings of the GBB, although the convection cell remains flat in most cases because of high permeability anisotropy. This mechanism induces rapid fluid flow in the superficial as well as in the deeper parts of the platform, with velocities of at least two orders of magnitude higher than with compaction alone. Lithology appears as a strong control of fluid circulations at the margin scale through the permeability anisotropy, for which a critical value lies between values of 10 and 100. The reefal unit in Unda is part of a larger area determined by the lithologic distribution, in which flow velocities are significantly higher than in the rest of the platform. These velocities are high enough to bring the magnesium necessary to precipitate the observed amounts of dolomite, within durations in agreement with the available time of post‐reef deposition high sea level(s). However, neither fluid flow pattern nor flow velocities are able to explain the preferential massive dolomitization of the lower reef unit and the complete absence of dolomite in the upper one.     

Dative for Accusative Case Interchange in Epistolary Formulas in Greek Papyrus Letters

Greek papyrus letters preserve not only instances of the replacement of the dative case; they also show the use of the dative instead of the accusative case as direct object and disjoint infinitival subject. This interchange is mostly found in epistolary phrases, namely the salutation formula (?σπ?ζομα? σε) and the initial (ε?χομα? σε ?για?νειν) and final (?ρρ?σθα? σε ε?χομαι) health wishes. The phonetic similarity of the pronouns might have created the circumstances for case confusion. Contamination of the constructions reflects the difficulties of the scribes to construct conservative epistolary phrases and, thereby, diachronic phraseological variation might reflect language change. In salutation formulas, the use of a dative Addressee could be explained by analogical overextension from the category of communication verbs taking a dative complement. The decline of the accusative and infinitive construction might be one of the reasons why the accusative disjoint infinitival subject is replaced by the dative case in health wishes.     

The Implications of Immigration Federalism for Non-citizens’ Rights and Immigration Opportunities: Canada and Australia Compared

This article explores the development of immigration federalism in Australia and Canada (expressed through the establishment of state/provincial/territorial immigrant selection programs) and its implications for immigrants’ rights and immigration opportunities. Given the very limited scholarship on the issue, and the lack of previous comparative studies on immigration federalism in Australia and Canada, our research is exploratory by nature. Our finding is that provincial/state/territorial programs offer some advantages to prospective applicants (such as increased immigration opportunities), but, at the same time, raise a number of concerns (such as an increased dependence on employers). As our study reveals, the costs and benefits of immigration opportunities under state/provincial/territorial programs differ for skilled and low-skilled workers, whereby the latter are given only limited access to permanent residence, and on more onerous conditions than skilled workers. Drawing on these findings, we identify areas in need of further research and policy response.     

Cultural and trade practices in Sincu Bara (Senegal): a multi-proxy investigation

The Sincu Bara site in Senegal is one of the most famous archeological sites in Western Africa. Here we present the results of a multi-proxy study that combined microscopic analyses, carbon content, stable carbon isotope (δ¹³C) and radiocarbon (¹⁴C) measurements. This investigation exhibits a chronological framework in two phases: from 400 yr AD to 650 yr AD and 650 yr AD to 900 yr AD. Furthermore, it shows that besides basic potteries, some potsherds are notable for a temper exclusively made with human-harvested C4 plants. Finally, the ¹⁴C analysis performed on the organic slip strongly indicates the use of bitumen or bitumen-derived products for red slip preparation. This suggests the establishment of trade relationships with Nigerian and/or Trans-Saharan populations as early as 400 yr AD.