Comment on “207Pb–206Pb single-zircon evaporation ages of some granitoid rocks reveal continent-oceanic island arc collision during the Cretaceous geodynamic evolution of the Central Anatolian crust, Turkey” – Boztug, D., Tichomirowa, M. & Bombach, K., 2007, JAES 31, 71–86

A continent-oceanic island arc collision model was proposed as a new geodynamic scenario for the evolution of the Cretaceous Central Anatolian granitoids in the Central Anatolian crystalline complex (CACC) by Boztug et al. (2007b) [Boztug, D., Tichomirowa, M., Bombach, K., 2007b. 207Pb–206Pb single-zircon evaporation ages of some granitoid rocks reveal continent-oceanic island arc collision during the Cretaceous geodynamic evolution of the central Anatolian crust, Turkey. Journal of Asian Earth Sciences 31, 71–86]. The key aspects of this model include an intra-oceanic subduction in the Neotethyan Izmir-Ankara Ocean, formation of an island arc and its subsequent collision with the northern margin of the Tauride–Anatolide Platform. The identical scenario was initially proposed by Göncüoglu et al. (1992) [Göncüoglu, M.C., Erler, A., Toprak, V., Yalınız, K., Olgun, E., Rojay, B., 1992. Geology of the western Central Anatolian Massif, Part II: Central Areas. TPAO Report No: 3155, 76 p] . Moreover, the weighted mean values of the reported 207Pb–206Pb single-zircon evaporation ages by Boztug et al. (2007b) [Boztug, D., Tichomirowa, M., Bombach, K., 2007b. 207Pb–206Pb single-zircon evaporation ages of some granitoid rocks reveal continent-oceanic island arc collision during the Cretaceous geodynamic evolution of the central Anatolian crust: Turkey. Journal of Asian Earth Sciences 31, 71–86] from A-type granitoids in the CACC seem to be miscalculated and contrast with the field data.     

“Traditional” women, “modern” water: Linking gender and commodification in Rajasthan, India

In this paper, I analyze the connections made between women and water in a Rajasthani drinking water supply project as a significant part of drinking water’s commodification. For development policy makers, water progressing from something free to something valued by price is inevitable when moving economies toward modernity and development. My findings indicate that water is not commodified simply by charging money for it, but through a series of discourses and acts that link it to other “modern” objects and give it value. One of these objects is “women”. I argue that through women’s participation activities that link gender and modernity to new responsibilities and increased mobility for village women involving the clean water supply, a “traditional” Rajasthani woman becomes “modern”. Water, in parallel, becomes “new”, “improved” and worth paying for. Women and water resources are further connected through project staff’s efforts to promote latrines by targeting women as their primary users. The research shows that villagers applied their own meanings to latrines, some of which precluded women using them. This paper fills a gap in feminist political ecology, which often overlooks how gender is created through natural resource interventions, by concerning itself with how new meanings of “water” and “women” are mutually constructed through struggles over water use and its commodification. It contributes to critical development geography literatures by demonstrating that women’s participation approaches to natural resource development act as both constraints and opportunities for village constituents. It examines an under-explored area of gender and water research by tracing village-level struggles over meanings of latrines.     

The geoarchaeology of Iron Age “moated” sites of the Upper Mae Nam Mun Valley,N.E. Thailand. I: Palaeodrainage,site–landscape relationships and the origins of the “moats”

The study focuses on the “moated” Iron Age sites of N.E. Thailand, first identified as significant prehistoric settlement sites in the 1940s from aerial photography. Two more recent photograph sets are used to map the surficial geology and prehistoric site distribution for a study area west of Phimai, N.E. Thailand, with a focus on site–landscape relationships and, in particular, relationships between site location and form and patterns of palaeodrainage. The derived record of the surficial geology reflects several phases of palaeodrainage, characterized by differing locations and types of former river channels. Of note is the differentiation between a recent period in which river channels, including those presently active, are single-string meandering channels, and an older period of broad belts of meandering multistring channels. The prehistoric site distribution correlates closely with the older drainage, and for many, the encircling channels (the “moats”) are closely associated with former river channels. These relationships provide a critical and novel model for site distribution; several implications arise, supported by emerging field evidence, and introducing issues for archaeological debate: (i) there is no need, as has been done in the past, to invoke prehistoric artificial forms of drainage associated with the sites; (ii) the definition of the encircling channels as “moats” is seriously called into question; and (iii) the inferred geomorphological evolution of the floodplain implies past changes in environmental parameters such as run-off, climate or biophysical environments. Since the sites are all located in or beside ancient meander belts, these parameters should now be introduced into archaeological discussions regarding the establishment, history, evolution, and abandonment of the Iron Age sites. Methodologically, this article illustrates the need to be aware of the complexity of aerial photograph interpretation in archaeological survey, showing that careful analysis of aerial photograph information may have a significant impact upon the modeling of prehistoric interpretations. Further stratigraphical studies will be reported subsequently, and will refine the models presented here. © 1999 John Wiley & Sons, Inc.     

Compositional classification of “kimberlitic” and “non-kimberlitic” ilmenite

Ilmenite is one of the common kimberlitic indicator minerals recovered during diamond exploration, and its distinction from non-kimberlitic rock types is important. This is particularly true for regions where these minerals are present in relatively low abundance, and they are the dominant kimberlitic indicator mineral recovered. Difficulty in visually differentiating kimberlitic from non-kimberlitic ilmenite in exploration concentrates is also an issue, and distinguishing kimberlitic ilmenite from those derive from other similar rocks, such as ultramafic lamprophyres, is practically impossible. Ilmenite is also the indicator mineral whose compositional variety has the most potential to resolve provenance issues related to mineral dispersions with contributions from multiple kimberlite sources.

Various published data sets from selected kimberlitic (including kimberlites, lamproites, and various ultramafic lamprophyres) and non-kimberlitic rock types have been compiled and evaluated in terms of their major element compositions. Compositional fields and bounding reference lines for ilmenites derived from kimberlites (sensu stricto), ultramafic lamprophyres, and other non-kimberlitic rock types have been defined primarily on MgO–TiO₂ graphs as well as MgO–Cr₂O₃ relationships.     

Paragenesis of “box-work geodes”, Tampa Bay, Florida

An unusual suite of silicified rocks was excavated during a recent harbour-deepening project in Tampa Bay, Florida. These rocks, which we have termed “box-work geodes”, are composed of convoluted, intersecting silica walls enclosing cavities which are either voids or filled with relatively pure monoclinic palygorskite. The “box-work geodes” are interpreted as having formed in shallow lagoonal environments, similar to the Coorong Lagoon of South Australia. Synaeresis of syngenetic palygorskite was followed by opal deposition and case hardening of the material. Subsequent chemical deposition of chalcedony, megacrystalline quartz, barite, and calcite on the void facing walls indicates an open chemical system.

The existence of opal saturated lagoons, as inferred from the “box-work geodes”, suggests that much of the replacement chert, porcelanite, and silicified fossils in the Tertiary deposits of peninsular Florida formed in the shallow subsurface. Subsequent weathering of carbonates and clays not encapsulated in the box works has resulted in formation of a green montmorillonite residual clay bed.     

Spring temperature variability in northern Fennoscandia AD 1693–2011

A reconstruction of spring (April–May) temperature for northern Fennoscandia developed from the Tornionjoki (Tornio river) long cryophenological record of ice break‐up dates, back to AD 1693, is presented. The record is strongly climatically sensitive and explains 67% of the variance in the instrumental data over the last 150 years. The record exhibits a stepped decrease in the duration of the river's ice cover by 14 days, equivalent to an increase in April–May mean temperature of approximately 2.5°C over the last three centuries. The relationship between the date of ice break‐up, and accumulated daily mean temperatures (>0°C) is investigated. Uncertainty in the observation of ice break‐up is also considered in addition to the potential of this time series for regional climate model validation. Copyright © 2011 John Wiley & Sons, Ltd.