Defining and measuring displacement: is relocation from restructured neighbourhoods always unwelcome and disruptive?

Current regeneration policy has been described as ‘state-led gentrification’, with comparisons made with the ‘social disruption’ caused by slum clearance of the 1950s and 1960s. This article takes issue with this approach in relation to the study of the restructuring of social housing areas. The terms ‘forced relocation’ and ‘displacement’ are often too crude to describe what actually happens within processes of restructuring and the effects upon residents. Displacement in particular has important dimensions other than the physical one of moving. Evidence from a recent study of people who have moved out of restructured areas shows that although there is some evidence of physical displacement, there is little evidence of social or psychosocial displacement after relocation. Prior attitudes to moving and aspects of the process of relocation—the degree of choice and distance involved—are important moderators of the outcomes. Issues of time and context are insufficiently taken into consideration in studies and accounts of restructuring, relocation and displacement

Melanesian back-arc basin and arc development: Constraints from the eastern Coral Sea

The eastern Coral Sea is a poorly explored area at the north-eastern corner of the Australian Tectonic Plate, where interaction between the Pacific and Australian plate boundaries, and accretion of the world's largest submarine plateau – the Ontong Java Plateau – has resulted in a complex assemblage of back-arc basins, island arcs, continental plateaus and volcanic products. This study combines new and existing magnetic anomaly profiles, seafloor fabric from swath bathymetry data, Ar–Ar dating of E-MORB basalts, palaeontological dating of carbonate sediments, and plate modelling from the eastern Coral Sea. Our results constrain commencement of the opening of the Santa Cruz Basin and South Rennell Trough to c. 48 Ma and termination at 25–28 Ma. Simultaneous opening of the Melanesian Basin/Solomon Sea further north suggests that a single > 2000 km long back-arc basin, with at least one triple junction existed landward of the Melanesian subduction zone from Eocene–Oligocene times. The cessation of spreading corresponds with a reorganisation of the plate boundaries in the area and the proposed initial soft collision of the Ontong Java Plateau. The correlation between back-arc basin cessation and a widespread plate reorganisation event suggests that back-arc basins may be used as markers for both local and global plate boundary changes.We thank the Captain and crew of R/V Southern Surveyor and Australia's Marine National Facility (MNF) for the success of voyage SS2012_V06. Mineral separation was done by John Simes and Belinda Smith Lyttle. We thank Hugh Davies for his attempts to locate old Solomon Sea dredge samples and Geoscience Australia and New Caledonia agencies for voyage support. We acknowledge funding from the Australian Research Council through grants DP0987713 and FT130101564 (MS), FL0992245 (SEW), IH130200012 (SZ) and DP130101946 (KJM). Support from the New Zealand Government through core funding to GNS Science (NM) is also acknowledged. We thank Robert Holm and an anonymous reviewer for their comments, which improved the quality of the manuscript

The Mount Perkins block, northwestern Arizona: An exposed cross section of an evolving, preextensional to synextensional magmatic system

This is the published version. Reuse is subject to Society of Exploration Geophysicists terms of use and conditions.The steeply tilted Mount Perkins block, northwestern Arizona, exposes a cross section of a magmatic system that evolved through the onset of regional extension. New 40Ar/39Ar ages of variably tilted (0–90°) volcanic strata bracket extension between 15.7 and 11.3 Ma. Preextensional intrusive activity included emplacement of a composite Miocene laccolith and stock, trachydacite dome complex, and east striking rhyolite dikes. Related volcanic activity produced an ∼18–16 Ma stratovolcano, cored by trachydacite domes and flanked by trachydacite-trachyandesite flows, and ∼16 Ma rhyolite flows. Similar compositions indicate a genetic link between the stratovolcano and granodioritic phase of the laccolith. Magmatic activity synchronous with early regional extension (15.7–14.5 Ma) generated a thick, felsic volcanic sequence, a swarm of northerly striking subvertical rhyolite dikes, and rhyolite domes. Field relations and compositions indicate that the dike swarm and felsic volcanic sequence are cogenetic. Modes of magma emplacement changed during the onset of extension from subhorizontal sheets, east striking dikes, and stocks to northerly striking, subvertical dike swarms, as the regional stress field shifted from nearly isotropic to decidedly anisotropic with an east-west trending, horizontal least principal stress. Preextensional trachydacitic and preextensional to synextensional rhyolitic magmas were part of an evolving system, which involved the ponding of mantle-derived basaltic magmas and ensuing crustal melting and assimilation at progressively shallower levels. Major extension halted this system by generating abundant pathways to the surface (fractures), which flushed out preexisting crustal melts and hybrid magmas. Remaining silicic melts were quenched by rapid, upper crustal cooling induced by tectonic denudation. These processes facilitated eruption of mafic magmas. Accordingly, silicic magmatism at Mount Perkins ended abruptly during peak extension ∼14.5 Ma and gave way to mafic magmatism, which continued until extension ceased

Recent investigations of the 0-5 geomagnetic field recorded by lava flows

Sherpa Romeo green journal (pre or post print only)We present a synthesis of paleomagnetic directional data collected from 873 lava flows at 17 different locations under the collaborative Time Averaged geomagnetic Field Initiative (TAFI). The data range from 05 Ma in age, and provide new high quality data with improved spatial coverage. Data quality at each site is measured using k, the best estimate of the Fisherian precision parameter, and its influence on inclination anomaly and VGP dispersion is evaluated by systematically excluding data with successively higher values of k. When combined with regional compilations from NW USA, SW USA, Japan, New Zealand, Hawaii, Mexico, S. Pacific and the Indian Ocean, a data set of 2283 pairs of declination and inclination data, with k>100, and VGP latitudes greater than 45 is obtained. This is a more than 7fold increase over similar quality data in the existing Global Paleomagnetic Database (GPMDB). The new data set spans 78 S to 53 N, and has sufficient temporal and spatial sampling to allow characterization of latitudinal variations in the timeaveraged field (TAF) and paleosecular variation (PSV) for the Brunhes and Matuyama epochs, and for the 0–5 Myr interval combined. PSV, as measured by dispersion of virtual geomagnetic poles, shows less latitudinal variation than predicted by current statistical PSV models. Variation of inclination anomaly with latitude is assessed using 2parameter zonal TAF models – these have axial quadrupole contributions of 2% – 4% of the axial dipole term, and axial octupole contributions of 3% – 5%. Approximately 2% of the octupole signature is likely the result of bias incurred by averaging unit vectors. The new data set provides significant improvement over previous compilations, and can contribute to a new generation of global paleomagnetic field models.Ye

New Remains of <i>Megathericulus patagonicus</i> Ameghino, 1904 (Xenarthra, Tardigrada) from the Serravallian (Middle Miocene) of Bolivia; Chronological and Biogeographical Implications

In this contribution, we describe new remains (skull and humeri) of the Megatheriinae Megathericulus patagonicus Ameghino, 1904, recovered from the middle Miocene fossiliferous locality of Quebrada Honda, Bolivia. We also discuss the taxonomic, biogeographical, and chronological relevance of this discovery. Referral of the new specimens described here to Megathericulus patagonicus is based on metric and morphological similarities with the holotype and a humerus that has been referred to this species. Shared features include: 1) molariforms that are mesiodistally compressed and rectangular in outline; 2) a relatively less compressed M1 with labial and lingual margins that converge slightly mesially; 3) a very long premolariform portion of the maxillae (rostrum); 4) anteriorly divergent lateral edges of the maxillae; 5) a prominent, median V-shaped notch (apex posterior) between the articular surfaces of the maxillae and premaxillae; and 6) a long, gracile humerus with a prominent anterolaterally positioned deltopectoral crest on the anterior surface and a clearly evident lateral musculo-spiral channel. Precise geographic and stratigraphic data exist for the described remains, which are closely associated with a tuff dated at 12.2–12.5 Ma (Serravallian, middle Miocene), making it the first accurately dated specimen referred to Megathericulus Ameghino, 1904.Facultad de Ciencias Naturales y Muse

Oligo-miocene subduction-related volcanism of the loyalty and three Kings ridges, SW Pacific: A precursor to Tonga-Kermadec arc

The SW Pacific region contains several ridges and basins that are inferred to represent pre-Quaternary volcanic arcs and back-arc basins. The geology of these features is less well characterized than that of the active Tonga-Kermadec and Vanuatu arcs. We report new major and trace element, and Pb, Hf, Sr and Nd isotope data for 27 lavas dredged from the Loyalty and Three Kings ridges during the 2015 VESPA cruise of R/V l&#039;Atalante. Low-K basalts were dredged from the seabed deeper than 3300 m, and high-K to shoshonitic suites from shallower ridge crests at 2000–3300 m. The samples are mainly basalts, with lesser trachybasalts, basaltic andesites, trachyandesites andesites, dacites, and one granite (anhydrous SiO2 and K2O + Na2O range from ∼47 to 64 and 1.5 to 11 wt% respectively). Trace element patterns allow discrimination of three geochemical signatures, identified as i) depleted, ii) transitional and iii) enriched, based on their light to heavy rare earth element (REE) ratios (with La/Sm ranging from 0.4 to 8). Depleted and transitional samples are basalts, featuring REE concentrations similar to MORB, but with high field strength element and large ion lithophile element contents, typical of back-arc basin basalts. The most enriched samples are basaltic andesites, andesites, trachyandesites and trachytes with island arc magma trace element signatures. Pb isotope ranges are limited (208Pb/204Pb ∼38 to 39.8, 207Pb/204Pb ∼15.51 to 15.64 and 206Pb/∼17.9 to 20.1), while Hf isotopes display more diverse compositions (εHf ranging from +7.7 to +14). Both Nd (εNd = 2.8–9.3) and Sr (87Sr/86Sr = 0.7026–0.7048) isotopes are correlated with Hf data. Trace element and isotopic compositions can be explained in terms of mixing between three distinct geochemical endmembers in the mantle resembling DMM, HIMU and EM-2 sources. Our study confirms voluminous subduction-related magmatism on the Loyalty and Three Kings ridges, mostly of Late Oligocene – Early Miocene age. The issue of polarity of subduction to generate these rocks remains open, but the composition-space-time distribution of the igneous rocks can be explained in the context of SW Pacific geodynamics using a west-dipping Pacific slab model