Instability in Principal Component Analysis and the Quantification of Polyphenism in Palaeontological Data

The occurrence of cryptic polyphenism (variation in morphological properties within a single species) in ammonites is used to exemplify the application of the multivariate set of techniques known in analytical chemistry as cross-validation to quantify and isolate deviating specimens (ecomorphs) in a genetically homogeneous sample. A byproduct of the analysis bears on a method of identifying redundant variables. A species of Nigerian Turonian (Cretaceous) ammonites of the genus Thomasites is used in the exemplification.     

Researching local elites: reflexivity, ‘situatedness’ and political-temporal contingency

Since the late 1970s, the UK has experienced a series of changes in the mechanisms of governing local economic development. This paper considers the methodological consequences of these recent changes. Drawing on two local elite-based case studies, involving semi-structured interviews, we reflect on our acquired ‘situated knowledge’ and argue that this is related to the contingent nature of our respective research access. We advocate that an approach sensitive to ‘research situatedness’ (with respect to the politics of time as a ‘research moment’) is essential to avoid over generalising from our experiences. To address this concern, the paper offers two concepts for debate – political-temporal contingency and the mode of entry.     

Equus species as stratigraphic markers reality or wishful thinking?

This paper addresses the use of fossil species of the horse Equus as stratigraphic markers in the Pliocene and Pleistocene. Current research shows that the species recently so used do not succeed one another in orderly fashion, but occur and co-occur at ages other than presupposed by the stratigraphic schemes (usually earlier). Horse species should be identified on their morphology, not on their stratigraphic age. ‘Subspecies’ of fossil horses do not conform to subspecies in zoology, as they lack a geographic range. They thus lack taxonomic status and stratigraphic significance and should be avoided.     

‘Competing Regionalisation’ Through Territory and Cluster Networks: Experiences from Post-Socialist Eastern Germany

‘New regionalism’ has become a buzzword in current debates on regions and regional governance. Much of this discussion revolves around the ‘right’ scale and structure of regional governance, implying changes to the ways in which the conventional main variables institutions, hierarchy and territoriality interact to circumscribe ‘regions’. The main difference between ‘old’ and ‘new’ regionalism is the degree of variability and responsiveness to locational strategies by businesses, i.e. essentially relative regional competitiveness, and thus by implication the question of territoriality and boundedness. Evidence ‘on the ground’ among policy makers, however, suggests that the changes may go further than theoretical arguments with their emphasis on territory and scale (Brenner, 2000, 2003) are suggesting. Much of the difference revolves around the distinction between technocratic, planning focused and firmly institutionalised understandings of territorially fixed regions within a government structure on the one hand, and more purpose driven, flexible, and inherently temporary and variable arrangements outside fixed government structures, whose territoriality is composed of the varying spatial background of the participating actors. Here, regional territoriality is an incidental rather than determining factor. The cleavage between ‘old’ and ‘new’ regionalism has become particularly obvious in post-socialist eastern Germany, where staid forms of traditional institutionalism and territorial governance had been transferred from ‘west’ to ‘east’. Increasingly, these arrangements appeared inadequate to respond to the vast and spatially widely varying challenges of post-socialist restructuring. The result has been a tentative emergence of new forms of regionalisation in between, and in addition to, the established ‘old regionalist’ approaches. Evidence from eastern Germany suggests that ‘new’ is not necessarily replacing ‘old’ regionalism’ in the wake of a shift in paradigm, but rather that the two coexist, with new forms of regionalisation sitting within established conventional territorial-administrative arrangements. This points to the emergence of a dual track approach to regionalisation, sometimes covering the same territory, more often relating to variably sized areas that overlap. Both forms of regionalisation aim at an internal and external audience, using varying images and employing different sets of actors when dealing with the two main sources/directions of consumption: internal (local) and external (corporate, competitive). By their very nature, however, these processes are varied and differ between places, rooted in particular local-regional constellations of policy-making pressures, actor personalities and established ways of doing things. This paper examines such processes for two regions in eastern Germany, both with distinctly different economic traditions and geographical contexts, aiming to illustrate the multi-layered process of regionalisation and region making. Inevitably, within the scope of this paper, the study cannot cover all possible models and regionalisation approaches across eastern Germany, because they not only differ between places, but also over time.     

Deconstructing Terminations I and II: revisiting the glacioeustatic paradigm based on deep-water temperature estimates

Benthic and planktonic oxygen isotope (δ¹⁸O_cc) and Mg/Ca analyses in two cores from the Northeast Atlantic have permitted the reconstruction of surface- and deep-water temperature (T_dw) and δ¹⁸O (δ¹⁸O_w) variations across the last two deglaciations. These records allow the timing of de-glacial melt-water pulses reaching the Northeast Atlantic to be compared with the evolution of local deep-water T_dw–δ¹⁸O_w conditions. Although each glacial termination is unique in detail, a similar pattern of hydrographic change is reconstructed for both deglaciations, with the first major decrease in deep-water δ¹⁸O_w (due to sea-level and/or purely local deep-water change) occurring in parallel with the onset of intensely cold glacial surface-water temperatures, and prior to a ‘terminal’ ice-rafting and melt-water event. The evolution of deep-water across both de-glaciations involved two transient incursions of cold, low-δ¹⁸O water into the deep Northeast Atlantic, the second of which was particularly pronounced each time. These pulses of cold deep-water are interpreted to reflect the incursion of water directly analogous to modern Antarctic Bottom Water (AABW), and containing a significant component of brine rejected during sea-ice formation. The results presented here show that the same type of transient changes in deep-water circulation that occurred across Termination I also occurred across Termination II, and that as a result of these deep-ocean changes, the timing of each benthic δ¹⁸O ‘termination’ cannot precisely reflect the timing of de-glacial sea-level change, as many palaeoceanographic interpretations (and some controversies) are prone to assume. Such ‘imprecision’ (in timing especially) may well extend to marine isotope stage (MIS) boundaries in general, as a principle of hydrographic variability and its expression in the geological record.     

Acacia exchanges: Wattles, thorn trees, and the study of plant movements

Plants are frequently moved around the world, creating new regional landscapes and environmental imaginaries. Building on previous work in environmental history and geography, we develop a three-part approach to analyzing plant movements and apply it to trees from the Acacia genus (sens. lat.) exchanged between Australia and the rest of the world. First, we investigate the agents, circuits, and frequencies of acacia movements, including transoceanic transfers, regional diffusion, and ecological dispersal. Second, we trace bundles of knowledge or technology that accompany the acacias, highlighting how they help shape regional biogeographies. Finally, we analyze how different societies, with distinct economies, politics, and environmental sensibilities, receive introduced plants. This approach allows us to see transferred plants as active agents in region-forming processes, and to avoid normative tropes like ‘miracle plants’ or ‘alien invasives’. The highlighted species include Acacia colei, Acacia melanoxylon, Acacia mearnsii, Acacia farnesiana, Acacia nilotica, Acacia mangium, and their close relatives.     

Isotope provinces, mechanisms of generation and sources of the continental crust in the Central Asian mobile belt: geological and isotopic evidence

The available geological, geochronological and isotopic data on the felsic magmatic and related rocks from South Siberia, Transbaikalia and Mongolia are summarized to improve our understanding of the mechanisms and processes of the Phanerozoic crustal growth in the Central Asian mobile belt (CAMB). The following isotope provinces have been recognised: ‘Precambrian’ (T_DM=3.3–2.9 and 2.5–0.9 Ga) at the microcontinental blocks, ‘Caledonian’ (T_DM=1.1–0.55 Ga), ‘Hercynian’ (T_DM=0.8–0.5 Ma) and ‘Indosinian’ (T_DM=0.3 Ga) that coincide with coeval tectonic zones and formed at 570–475, 420–320 and 310–220 Ma. Continental crust of the microcontinents is underlain by, or intermixed with, ‘juvenile’ crust as evidenced by its isotopic heterogeneity. The continental crust of the Caledonian, Hercynian and Indosinian provinces is isotopically homogeneous and was produced from respective juvenile sources with addition of old crustal material in the island arcs or active continental margin environments. The crustal growth in the CAMB had episodic character and important crust-forming events took place in the Phanerozoic. Formation of the CAMB was connected with break up of the Rodinia supercontinent in consequence of creation of the South-Pacific hot superplume. Intraplate magmatism preceding and accompanying permanently other magmatic activity in the CAMB was caused by influence of the long-term South-Pacific plume or the Asian plume damping since the Devonian.     

The Caesura: remarks on Wittgenstein’s interruption of theory, or, why practices elude explanation

This paper aims to bring the work of Ludwig Wittgenstein into contact with the growing interest and concerns over the status of practice, performance and non-representational ‘theory’ within human geography. Drawing predominantly on Wittgenstein’s later work, the aim is to use Wittgenstein’s comments to illuminate how certain presuppositions and idealisations over the nature of understanding and meaning are or have been built into our (social scientific) modes and methods of explanation. Thus Wittgenstein’s work is used as a diagnosis––a diagnosis of how the modus operandi of giving an explanation can, and often does, prevent us from acknowledging the practical and the performative, from witnessing the taking-place of meaning and understanding. The paper carries out this task by focusing first on Wittgenstein’s critique of the role of ‘rules’ and ‘rule-following’ in the construction of social scientific accounts and secondly, through a consideration of the implications of Wittgenstein’s ‘scenic’ style of writing through which he attempts to deconstruct the epistemo-methodological idealisations and representationalist desires of social analysis. The claim here is not that Wittgenstein’s work provides the solution to the problematics which confront us in considering the status (or otherwise) of practice, but rather that his work may provide us with other ways of going-on, ones more sensitive to the eventful, creative, excessive and distinctly uncertain realms of action.     

S-C Mylonites

Two types of foliations are commonly developed in mylonites and mylonitic rocks: (a) S-surfaces related to the accumulation of finite strain and (b) C-surfaces related to displacement discontinuities or zones of relatively high shear strain. There are two types of S-C mylonites. Type I S-C mylonites, described by Berthé et al., typically occur in deformed granitoids. They involve narrow zones of intense shear strain which cut across (mylonitic) foliation.Type II S-C mylonites (described here) have widespread occurrence in quartz-mica rocks involved in zones of intense non-coaxial laminar flow. The C-surfaces are defined by trails of mica ‘fish’ formed as the result of microscopic displacement discontinuities or zones of very high shear strain. The S-surfaces are defined by oblique foliations in the adjacent quartz aggregates, formed as the result of dynamic recrystallization which periodically resets the ‘finite-strain clock’. These oblique foliations are characterized by grain elongations, alignments of segments of the grain boundary enveloping surfaces, and by trails of grains with similar c-axis orientations.Examples of this aspect of foliation development in mylonitic rocks are so widespread that we suggest the creation of a broad class of S-C tectonites, and a deviation from the general tradition of purely geometric analysis of foliation and time relationships. Kinematic indicators such as those discussed here allow the recognition of kilometre-scale zones of intense non-coaxial laminar flow in crustal rocks, and unambiguous determination of the sense of shear.     

Evolution of the Yunkai Terrane, South China: Evidence from SHRIMP zircon U–Pb dating, geochemistry and Nd isotope

The Yunkai Terrane is one of the most important pre-Devonian areas of metamorphosed supracrustal and granitic basement rocks in the Cathaysia Block of South China. The supracrustal rocks are mainly schist, slate and phyllite, with local paragneiss, granulite, amphibolite and marble, with metamorphic grades ranging from greenschist to granulite facies. Largely on the basis of metamorphic grade, they were previously divided into the Palaeo- to Mesoproterozoic Gaozhou Complex, the early Neoproterozoic Yunkai ‘Group’ and early Palaeozoic sediments. Granitic rocks were considered to be Meso- and Neoproterozoic, or early Palaeozoic in age. In this study, four meta-sedimentary rock samples, two each from the Yunkai ‘Group’ and Gaozhou Complex, together with three granite samples, record metamorphic and magmatic zircon ages of 443–430 Ma (Silurian), with many inherited and detrital zircons with the ages mainly ranging from 1.1 to 0.8 Ga, although zircons with Archaean and Palaeoproterozoic ages have also been identified in several of the samples. A high-grade sillimanite–garnet–cordierite gneiss contains 242 Ma metamorphic zircons, as well as 440 Ma ones. Three of the meta-sedimentary rocks show large variations in major element compositions, but have similar REE patterns, and have t_DM model ages of 2.17–1.91 Ga and ε_Nd (440 Ma) values of −13.4 to −10.0. Granites range in composition from monzogranite to syenogranite and record t_DM model ages of 2.13–1.42 Ga and ε_Nd (440 Ma) values of −8.4 to −1.2. It is concluded that the Yunkai ‘Group’ and Gaozhou Complex formed coevally in the late Neoproterozoic to early Palaeozoic, probably at the same time as weakly to un-metamorphosed early Palaeozoic sediments in the area. Based on the detrital zircon population, the source area contained Meso- to Neoproterozoic rocks, with some Archaean material. Palaeozoic tectonothermal events and zircon growth in the Yunkai Terrane can be correlated with events of similar age and character known throughout the Cathaysia Block. The lack of evidence for Palaeo- and Mesoproterozoic rocks at Yunkai, as stated in earlier publications, means that revision of the basement geology of Cathaysia is necessary.     

Antiquity and long-term morphological stasis in a group of rove beetles (Coleoptera: Staphylinidae): Description of the oldest Octavius species from Cretaceous Burmese amber and a review of the “Euaesthetine subgroup” fossil record

The Staphylinine group of rove beetle subfamilies is a significant animal radiation, and one subordinate monophyletic clade – the ‘Euaesthetine subgroup’ – includes around 3000 species in subfamilies Euaesthetinae and Steninae and has a fossil record dating to the Early Cretaceous. Detailed morphological study of a new well-preserved Cretaceous Burmese amber fossil revealed strong evidence consistent with its taxonomic placement in the euaesthetine genus Octavius. We thus describe Octavius electrospinosus sp. nov., the first Cretaceous record of the genus and of the tribe Euaesthetini. Previously, the oldest records of Octavius and Euaesthetini were from the Eocene (Baltic amber) and discovery of O. electrospinosus sp. nov. therefore nearly doubles the minimum lineage age of Octavius, increasing it by 50 million years. We also briefly review the known Euaesthetine subgroup fossil record and tabulate summary data for all previously described fossils. All are placed in extant genera, and have visible diagnostic generic-level characters including some putative synapomorphies as judged by recent phylogenetic work. Including O. electrospinosus sp. nov., there are now four known Cretaceous species, all of which belong to either Octavius, Nordenskioldia, or Stenus. To explain the long-term morphological stasis in this group of rove beetles, we suggest that the continuous presence of mesic habitats may have buffered these lineages from strong selection for morphological change. Considering the fossils along with phylogenetic hypotheses we suggest the Euaesthetine subgroup originated in the Late Jurassic– Early Cretaceous and the Staphylinine group in the Early Jurassic. We emphasize the derived status of Cretaceous fossils in assessing possible divergence times and the significance of the pre-Cretaceous taphonomic bias for restricting more robust estimates. Further detailed morphological study of available fossils in a phylogenetic framework is badly needed to clarify the phylogenetic positions of these taxa.     

Geostatistical estimation of chemical contamination in stream sediments: The case study of Vale das Gatas mine (northern Portugal)

Based on an environmental geochemistry case study carried out in the neighbourhood of a W–Sn abandoned mine, the pollution in stream sediments was modelled through a Global Contamination Index. Such an index permits one to summarize the combination of deleterious elements in a single variable, obtained by the projection of samples onto the first axis of a PCASD (Principal Components Analysis of Standardized Data) applied to the entire n × p matrix containing the available concentrations of p = 16 elements in the set of n = 220 collected samples.In order to provide a sound basis for a coherent planning of the remediation process which will be put in operation in the affected area, it is necessary to balance the costs of reclaiming with the probabilities of exceeding the upper limits accepted for concentrations of environmentally harmful elements in sediments. Given these limits, they are back-transformed in the index values, providing a practical threshold between ‘clean’ and ‘contaminated’ samples. On the other hand, the minimum dimension of the cell to be reclaimed is restrained by the selected remediation process to be applied in the affected area. Hence, to meet the constraints of such a remediation process, it is required to estimate the probabilities of exceeding the index threshold in technologically meaningful sub-areas. For this end, the Indicator Block Kriging technique was applied, producing a series of maps where sub-areas to be reclaimed can be spotted for different probability levels. These maps, on which the decision making remediation agency can rely for its cost-benefit analysis, take into account both the spatial structure of ‘clean’ vs. ‘contaminated’ samples and the constraints of the reclaiming process.     

Temnospondyls from the Beaufort Group (Karoo Basin) of South Africa and Their Biostratigraphy

The Permo-Triassic Beaufort Group (Karoo Basin) of South Africa is biostratigraphically subdivided into eight, temporally successive assemblage zones based on therapsids (‘mammal-like reptiles’). The Temnospondyli, fossil tetrapods usually regarded as extinct amphibians, are second only to therapsids in terms of diversity and abundance in these strata, with nine higher-level taxa (‘families’) known. Temnospondyls are also playing an increasingly important role in biostratigraphy and correlation of the Beaufort strata. The lower Beaufort Group (Late Permian) contains six of the eight biozones, but only one temnospondyl ‘family’, the Rhinesuchidae, whose record in the Karoo is the richest in the world. However, rhinesuchid taxonomy remains in flux and the group is thus of limited biostratigraphic utility. The Early Triassic Lystrosaurus Assemblage Zone (middle Beaufort Group) contains the Rhinesuchidae, Amphibamidae, Lydekkerinidae, Tupilakosauridae, Rhytidosteidae, Mastodonsauridae and Trematosauridae, although the biostratigraphy of temnospondyls within this biozone is poorly constrained. The uppermost reaches of the Lystrosaurus biozone contain a paucity of fossils but includes ‘Kestrosaurus’ (Mastodonsauridae) and ?Trematosuchus (Trematosauridae), taxa previously thought to pertain to the lower part of the overlying Cynognathus biozone. The late Early to Middle Triassic Cynognathus Assemblage Zone (upper Beaufort Group) hosts the Mastodonsauridae, Trematosauridae, Brachyopidae, Laidleriidae and, possibly, the Rhytidosteidae. Based largely on the spatial and temporal distribution of mastodonsaurids, this biozone has been biostratigraphically subdivided into a lower A, middle B and upper C subzones, characterised by differing ages and faunas.     

Aeschnidiid nymphs from the Jehol biota (latest Jurassic–Early Cretaceous), China, with a discussion of the family Aeschnidiidae (Insecta, Odonata)

Undoubted fossil nymphs of the family Aeschnidiidae within the Aeschnidioidea of the Anisoptera, Odonata are identified and described and their phylogenetic relationship and bioecological characteristics are deduced. The nymphs discovered previously in China, Mongolia and Russia and considered to be aeschnidiids are, in fact, unrelated to this group. All nine Chinese species in six genera can be merged into one alone, Aeschnidium heishankowense. It is the first animal from the ‘Jehol biota’ of East Asia to be linked with the species known from the Lower Tithonian of Germany. The geological age of the oldest strata bearing the fossil nymphs is debatable; it could be latest Jurassic rather than Early Cretaceous.     

Senescence- and death-related alteration of chlorophylls and carotenoids in marine phytoplankton

This report extends previous work ([Louda et al., 1998a] and [Louda et al., 1998b]. Chlorophyll degradation during senescence and death. Organic Geochemistry 29, 1233–1251.) in which we detailed type-I (alteration) and -II (destruction) degradation of chlorophyll with representative fresh water phytoplankton. The present study covers similar experiments with marine phytoplankton, namely, a cyanobacterium (“ANA” Anacystis sp), a coccolithophore (“COC” Coccolithophora sp.), a dinoflagellate (“GYM” Gymnodinium sp.) and two diatoms (“CYC” Cyclotella meneghiniana and “THAL” Thalassiosira sp.). Mg loss (‘pheophytinization') was rapid and continuous in all species under room-oxic conditions and slow or sporadic under anoxic conditions. The proportion of dephytylated pigments (pheophorbides-a, chlorophyllides-a), relative to the phytylated forms (chlorophyll-a, pheophytins-a), increased over the first year under room-oxic conditions and in room-anoxic conditions only in “CYC”. Pheophorbide-a was converted to pyropheophorbide-a within 15 months only in “THAL” and “ANA”, and slightly in “COC”. After 9–15 months of oxic incubation, “COC” was found to contain traces of purpurin-18 phytyl ester. Consideration of carotenoid pigments is also included herein. All fucoxanthin containing species, except “THAL”, exhibited conversion of fucoxanthin to fucoxanthinol in room-oxic conditions. Diadinoxanthin was rapidly de-epoxidized to give diatoxanthin within the first 2–4 weeks. Diatoxanthin then disappeared from all species by 15 months with a concurrent increase in a pigment which we tentatively identify as a cis-zeaxanthin. Incubations of pure cultures are found to be an effective way by which to model the early type-I reactions for both chlorophylls and carotenoids. The influence of oxygen during senescence-death and the onset of early diagenesis is of paramount importance. The absence of oxygen and, by inference, aerobic microbiota, retards the breakdown of these pigments dramatically.     

A Late Hauterivian short-lived anoxic event in the Mediterranean Tethys: the ‘Faraoni Event’

A Late Hauterivian interval (127.5 Ma), called the ‘Faraoni Event’, which is characterised by the deposition of deep-marine black shales in the Mediterranean Tethys, is demonstrably of sufficient geological brevity to be qualified as an anoxic event. This event lies within the Pseudothurmannia catulloi ammonite subzone, coincides with the extinction of the calcareous nannofossil species Lithraphidites bollii, and records an increase in a globular planktonic foraminifer. High quantities of marine organic matter were preserved in pelagic successions from northern and central Italy, Switzerland, southeastern France, southern Spain and probably elsewhere in the Mediterranean Tethys and Atlantic Ocean. Carbon-isotope stratigraphy from Tethyan and Atlantic sections shows a minor positive excursion in the uppermost part of the Hauterivian and Lowermost Barremian, suggesting accelerated extraction of organic carbon from the ocean reservoir just after the ‘Faraoni Event’. The duration of this short event is less than 100 ka according to cyclostratigraphy and coincides with a third-order sea-level rise. It is likely that similar forcing mechanisms responsible for global OAEs operated during this short time interval. To cite this article: F. Baudin, C. R. Geoscience 337 (2005).     

Progression in sulfur isotopic compositions from coal to fly ash: Examples from single-source combustion in Indiana

Sulfur occurs in multiple mineral forms in coals, and its fate in coal combustion is still not well understood. The sulfur isotopic composition of coal from two coal mines in Indiana and fly ash from two power plants that use these coals were studied using geological and geochemical methods. The two coal beds are Middle Pennsylvanian in age; one seam is the low-sulfur (< 1%) Danville Coal Member of the Dugger Formation and the other is the high-sulfur (> 5%) Springfield Coal Member of the Petersburg Formation. Both seams have ash contents of approximately 11%. Fly-ash samples were collected at various points in the ash-collection system in the two plants. The results show notable difference in δ³⁴S for sulfur species within and between the low-sulfur and high-sulfur coal. The δ³⁴S values for all sulfur species are exclusively positive in the low-sulfur Danville coal, whereas the δ³⁴S values for sulfate, pyritic, and organic sulfur are both positive and negative in the high-sulfur Springfield coal. Each coal exhibits a distinct pattern of stratigraphic variation in sulfur isotopic composition. Overall, the δ³⁴S for sulfur species values increase up the section in the low-sulfur Danville coal, whereas they show a decrease up the vertical section in the high-sulfur Springfield coal. Based on the evolution of δ³⁴S for sulfur species, it is suggested that there was influence of seawater on peat swamp, with two marine incursions occurring during peat accumulation of the high-sulfur Springfield coal. Therefore, bacterial sulfate reduction played a key role in converting sulfate into hydrogen sulfide, sulfide minerals, and elemental sulfur. The differences in δ³⁴S between sulfate sulfur and pyritic sulfur is very small between individual benches of both coals, implying that some oxidation occurred during deposition or postdeposition.The δ³⁴S values for fly ash from the high-sulfur Springfield coal (averaging 9.7‰) are greatly enriched in ³⁴S relative to those in the parent coal (averaging 2.2‰). This indicates a fractionation of sulfur isotopes during high-sulfur coal combustion. By contrast, the δ³⁴S values for fly-ash samples from the low-sulfur Danville coal average 10.2‰, only slightly enriched in ³⁴S relative to those from the parent coal (average 7.5‰). The δ³⁴S values for bulk S determined directly from the fly-ash samples show close correspondence with the δ³⁴S values for SO₄^− 2 leached from the fly ash in the low-sulfur coal, suggesting that the transition from pyrite to sulfate occurred via high-temperature oxidation during coal combustion.     

‘It’s more than just what it is’: Defetishising commodities, expanding fields, mobilising change…

Commodity geographies are politically weak. Geographical pedagogy isn’t particularly engaging. Radical geography should make connections. But it rarely leaves room for interpretation. Too much seems to be too didactic. And to preach to the converted. That’s a problem that needs attention. So, is it possible to develop a radical, less didactic, geography? With research funding, publication and teaching the way they are? To engage more students, more heartily, in the issues studied? To promote social justice, critical citizenship, and participatory democracy? But not by setting out the right ways to think, be, or act. Some film-makers, artists and writers have been able to do this. It seems. Subtly and cleverly. Through projects attempting to de-fetishise commodities. But their politics have been placed largely in the background, between the lines of, or separated out from, the presentation of scenes, things, relations, bodies, lives and voices. Seen and unseen elements of their audiences’ lives. Re-connected. Perhaps. Through communication strategies giving audiences something to think about and to think with, to argue about and to argue with. Putting themselves in the picture, in the process. These less didactic materials may be difficult to master for an exam or an essay. They may not make it clear who or what’s right or wrong or what audiences are supposed to do. But they could engage them in less direct ways. When they’re shopping for petrol or fish, or when they’re doing or thinking about completely different things. Things that may not even come under the heading of ‘production’ or ‘consumption’. This approach might be labelled as ‘weak’, ‘relativist’, a bit too ‘cultural’ ‘post-modern’, or ‘defunct’. But it’s an approach that may be radical in effect because its ‘politics’ aren’t so straightforward or ‘up front’. This paper is about changing relationships between research, writing, teaching, learning and assessment; expanding fields of commodity geographies to include classrooms as sites not only of ‘instruction’, but also of learning, for researchers and their students¹; showing how such learning might usefully shape research and writing elsewhere in these fields for those engaged in this defetishising project.     

Translocal assemblages: Space, power and social movements

In this paper, I deploy an analytic of ‘translocal assemblage’ as a means for conceptualising space and power in social movements. I offer a relational topology that is open to how actors within movements construct different spatial imaginaries and practices in their work. In using the prefix ‘translocal’, I am signifying three orientations. First, translocal assemblages are composites of place-based social movements which exchange ideas, knowledge, practices, materials and resources across sites. Second, assemblage is an attempt to emphasise that translocal social movements are more than just the connections between sites. Sites in translocal assemblages have more depth than the notion of ‘node’ or ‘point’ suggests – as connoted by network – in terms of their histories, the labour required to produce them, and their inevitable capacity to exceed the connections between other groups or places in the movement. Third, they are not simply a spatial category, output, or resultant formation, but signify doing, performance and events. I examine the potential of assemblage to offer an alternative account to that of the ‘network’, the predominant and often de facto concept used in discussions of the spatiality of social movements. I draw on examples from one particular translocal assemblage based in and beyond Mumbai which campaigns on housing within informal settlements: Slum/Shack Dwellers International.     

Multivariate normality tests of planktonic foraminiferal data

Data of a microfossil group, the planktonic foraminifera, have been tested to determine the conformity of various real data distributions to univariate and multivariate normality and the effects that standard transformations have upon the distributions. Studies of two bivariate samples, one trivariate sample, and two quadrivariate samples of size data indicate that distributions frequently deviate greatly from multivariate normality. Univariate distributions are generally positively skewed and show a tendency for leptokurtosis. A logarithmic transformation improved both univariate and multivariate distributions but the number of distributions conformable to normality increased only slightly—from zero to one in the multivariate case and from one to four in the univariate case (totally 15 distributions). Arcsine (p/100) ^1/2 transformations of percentage data in two samples including 16 and 23 species, respectively, decreased highly significant deviations from multivariate normality but distributions remained greatly non-normal. Although markedly positively skewed and leptokurtic univariate distributions were improved in most instances, the number of normal distributions (two) did not change. It follows that neither of the transformations caused significant increases in the number of normal distributions but if it is assumed that the consequences of non-normality are less severe as the deviation from normality decreases, the transformations are justified.