Non-destructive pXRF of mafic stone tools

Archaeological use of non-destructive pXRF has been most systematically applied to the classification and provenancing of volcanic glass (obsidian) artefacts. Comparable work has yet to be developed for non-vitreous artefacts. We report results of pXRF analysis for a sample of grey to black (mafic) aboriginal hatchets from Sydney and adjacent coastal regions to the north and south. The study shows both broad and detailed classification is achievable depending on rock type and degree of elemental depletion or enrichment of the samples. PXRF analysis reveals not only distinct patterns of resource use between the three regions of this study but also enables a high degree of geographic resolution in the case of the basalt artefacts of our sample. We conclude that non-destructive pXRF is effective for reliable characterisation of non-vitreous stone artefacts that have a sufficiently complex and enriched compositional signature (i.e., unaltered basalts); with ∼50% of the basalt hatchets in our sample matched with spatially and geologically specific sources.     

Reanimating Anarchist Geographies: A New Burst of Colour

Abstract: The late nineteenth century saw a burgeoning of geographical writings from influential anarchist thinkers like Peter Kropotkin and Élisée Reclus. Yet despite the vigorous intellectual debate sparked by the works of these two individuals, following their deaths anarchist ideas within geography faded. It was not until the 1970s that anarchism was once again given serious consideration by academic geographers who, in laying the groundwork for what is today known as “radical geography”, attempted to reintroduce anarchism as a legitimate political philosophy. Unfortunately, quiet followed once more, and although numerous contemporary radical geographers employ a sense of theory and practice that shares many affinities with anarchism, direct engagement with anarchist ideas among academic geographers have been limited. As contemporary global challenges push anarchist theory and practice back into widespread currency, geographers need to rise to this occasion and begin (re)mapping the possibilities of what anarchist perspectives might yet contribute to the discipline.     

Route Choice in Hilly Terrain

The orienteering route choice problem involves finding the fastest route between two given points, with running speed determined by various properties of the terrain. In this study, I consider only the effect of climbing or descending on running speed. If a runner's pace p (the reciprocal of speed) varies linearly with gradient m, the straight‐line route always is fastest. However, a nonlinear formulation for p(m), with d²p/dm² > 0, will more accurately model runners’ capabilities. As a result, critical gradients may exist for ascent and/or descent, such that optimal routes will never ascend or descend more steeply than the critical gradient. I review and propose several formulations for the pace function p(m) and calculate their critical gradients. In principle, the Euler–Lagrange equation can be used to find optimal routes between arbitrary points on any topography where the height can be expressed as a smooth function of horizontal coordinates. I obtain first integrals of this equation for idealized landforms: hillsides with straight contours and axisymmetric hills. Next, optimal routes are computed for various combinations of start‐ and endpoints on these landforms based on various pace functions. These routes are classified as either subcritical or maximal steepness: The former ascends or descends less steeply than the critical gradient; the latter takes the line of steepest ascent where it is not steeper than the critical gradient, but follows a curve at the critical gradient where the slope is steeper. In some cases, the optimal route zigzags up or down a hill along sections of a critical‐gradient curve. El problema de trazo y selección de ruta en terrenos accidentados (orienteering route choice problem) consiste en encontrar la ruta más rápida entre dos puntos dados, cuando la velocidad de desplazamiento está en función a varias propiedades del terreno. En este estudio, el autor sólo considera el efecto de subir o bajar sobre la velocidad de desplazamiento. Si el paso p de un individuo (la inversa de la velocidad) varía linealmente con la pendiente m, la ruta en línea recta siempre es la más rápida. Sin embargo, una formulación no lineal de p (m), con D2P / dm 2> 0, resulta en un modelo más preciso de las capacidades de los individuos que se desplazan por el terreno. Como resultado, es posible que existan gradientes críticos tanto para el movimiento de ascenso como el de descenso. En dicho caso, las rutas óptimas nunca ascenderán o descenderán por gradientes más pronunciados que las identificadas comode gradiente crítico. El autor revisa y propone varias fórmulas para una función de paso p (m) y calcula los gradientes críticos respectivos. En principio, la ecuación de Euler‐Lagrange puede ser utilizada para trazar las rutas óptimas entre puntos arbitrarios en cualquier topografía en donde la altura pueda ser expresada como una función suavizada de las coordenadas horizontales. El autor calcula las integrales de esta ecuación para dos formas terrestres idealizadas: laderas con contornos rectos, y colinas con simetría axial. A continuación, las rutas óptimas son calculadas para diversas combinaciones de puntos de inicio y destino de estos accidentes geográficos basados en varias funciones de paso. Una vez identificadas, estas rutas se clasifican ya sea como subcríticas o como de máxima‐pendiente. Las primeras ascienden o descienden gradientes menos pronunciadas que el gradiente crítico. Las segundas ascienden por la línea del gradiente más pronunciado que es menor que el gradiente crítico, pero siguen una curva en la gradiente crítica donde la pendiente es más pronunciada. En algunos casos, la ruta óptima se desplaza en zigzags hacia arriba o abajo de una colina a lo largo algunas secciones de una curva de gradiente crítica. 移动速度受制于地表形态的诸多属性,定向路线选择问题涉及给定两点之间最快路线查找。本研究仅考虑爬升或下降对移动速度的影响。如果奔跑者的步速p（速度的倒数）与坡度m呈线性相关,那么直线路线始终是最快的。然而,当d²_p∕ dm² > 0时,非线性方程p(m)具有更好的行进模拟性能。试验表明,在上坡或下坡的过程中存在一个临界的坡度值,相应地上坡或下坡的最佳路线坡度将一定不超过较陡的临界坡度值。本文总结并提出了函数p(m)的几个公式,并对其临界坡度值进行了估计。欧拉‐拉格朗日方程原则上可用于寻找任何地形中任意两点之间的最优路径,高度可表示为横坐标的光滑函数。首先,通过方程的一次积分得到理想化地形,即具有直等高线的山坡和对称的山地;然后在这些地形面上,基于起点和终点的多种组合和不同的步速方程计算最佳路线。计算路径被分类为次临界或最大坡度的路线：前者上坡或下坡的坡度大于临界坡度值;后者则在不超过临界坡度值时采用最陡上坡路径,但在坡度陡峭的地区遵循临界坡度曲线。在某些情况下,最优到达路径沿临界坡度曲线截面呈“之”字型曲折上下变化。     

Party commitment,vote switching and liberal decline in Australia∗

Electoral outcomes are determined in part by voters who switch their political allegiance between elections. Though the subject of extensive study in other countries, this floating vote has received comparatively little attention in Australia. This paper uses 1967 and 1979 survey data to analyse vote switching in Australian elections. We argue, firstly, that turnover tables based on recalled voting are, as research in other countries has shown, inaccurate reflections of the election result. As an alternative, we propose a measure of ‘potential’ vote switching based on the concept of lifetime voting. Secondly, using this concept of lifetime voting to derive a measure of party commitment allows the construction of a three‐fold typology of Australian voters — partisans, marginals and switchers. Finally, a longitudinal analysis of the voting patterns of these three groups indicates a gradual erosion of electoral commitment to the Liberal party, whereas Labor has largely retained its partisan base.     

Archaeological prospecting: A progress report

This article has two main aims: to show how the quality of resistivity surveys may be improved by the use of new probe configurations and consideration of seasonal effects on detectability of features; and secondly to describe the value of the new fluxgate gradiometers for rapid detailed magnetic surveys and for scanning substantial tracts of country for archaeological remains. Methods of survey presentation are also briefly described.