Spatial and Temporal Patterns Associated with Permitted Tree Removal in Austin,Texas, 2002–2011

A wide-ranging set of physical, urban, demographic, socioeconomic, and policy characteristics determines the spatial distribution of urban forests. Information on the characteristics surrounding tree removals on both public and private properties has received less attention in the literature. The purpose of this research was to analyze the spatiotemporal trends and geographic patterns of tree removals in Austin, Texas, between 2002 and 2011 in an effort to understand how site-specific characteristics influence urban tree removal and affect the overall distribution of Austin's urban forest. We examined permitted tree removals using a geographic information system (GIS) as well as spatial and statistical analyses. Specifically, we evaluated the degree to which variables related to various physical, urban, and socioeconomic conditions predicted tree removals. The results indicate that permitted tree removals and their associated characteristics in Austin have varied over the ten-year study period. Permitted tree removals increased over the study period and took place in the urban core and along the urban periphery. Permitted tree removals were more likely to be undertaken by college graduates and owner-occupants and to occur in more densely populated areas, closer to major streets, and on properties with older structures. The results of this research provide urban forest professionals with information on the location and intensity of permitted tree removals and the significant characteristics driving urban tree loss.     

Young eclogite from the Greater Himalayan Sequence,Arun Valley,eastern Nepal: P–T–t path and tectonic implications

Garnet geochronology was used to provide the first direct measurement of the timing of eclogitization in the central Himalaya. Lu–Hf dates from garnet separates in one relict eclogite from the Arun River Valley in eastern Nepal indicate an age of 20.7 ± 0.4 Ma, significantly younger than ultra-high pressure eclogites from the western Himalaya, reflecting either different origins or substantial time lags in tectonics along strike. Four proximal garnet amphibolites from structurally lower horizons are 14–15 Ma, similar to post-eclogitization ages published for rocks along strike in southern Tibet. P–T calculations indicate three metamorphic episodes for the eclogite: i) eclogite-facies metamorphism at ～ 670 °C and ≥ 15 kbar at 23–16 Ma; ii) a peak-T granulite event at ～ 780 °C and 12 kbar; and iii) late-stage amphibolite-facies metamorphism at ～ 675 °C and 6 kbar at ～ 14 Ma. The garnet amphibolites were metamorphosed at ～ 660 °C. Three models are considered to explain the observed P–T–t evolution. The first assumes that the Main Himalayan Thrust (basal thrust of the Himalayan thrust system) cuts deeper at Arun than elsewhere. While conceptually the simplest, this model has difficulty explaining both the granulite-facies overprint and the pulse of exhumation between 25 and 14 Ma. A second model assumes that (aborted) subduction, slab breakoff, and ascent of India's leading edge occurred diachronously: ～ 50 Ma in the western Himalaya, ～ 25 Ma in the central Himalaya of Nepal, and presumably later in the eastern Himalaya. This model explains the P–T–t path, particularly heating during initial exhumation, but implies significant along-strike diachroneity, which is generally lacking in other features of the Himalaya. A third model assumes repeated loss of mantle lithosphere, first by slab breakoff at ～ 50 Ma, and again by delamination at ～ 25 Ma; this model explains the P–T–t path, but requires geographically restricted tectonic behavior at Arun. The P–T–t history of the Arun eclogites may imply a change in the physical state of the Himalayan metamorphic wedge at 16–25 Ma, ultimately giving rise to the Main Central Thrust by 15–16 Ma.     

The Major Element Variation of the Layered Series of the Skaergaard Intrusion and a Re-estimation of the Average Composition of the Hidden Layered Series and of the Successive Residual Magmas

Using variation diagrams for the major elements in the layeredrocks, estimates are made of the average amounts of the variouselements in the total rock separating at successive stages.From the analyses of the chilled marginal gabbro, taken to representthe composition of the initial magma, and with the further likelyassumption that the Skaergaard intrusion is a closed system,at any rate for most of the elements, various hypotheses onthe relative volumes of the different parts of the intrusionare tested to find the one best fitting the known distributionof the elements in the observable rocks. Estimates are thenmade of (1) the overall composition of the hidden part of theintrusion by subtracting the amounts of an element in the observedrocks from the total in the initial magma, and (2) the compositionof the successive residual magmas formed as a result of thecrystal fractionation.     

Neogene gravity folds at the Yegor’evsk phosphorite deposit

At the Yegor’evsk phosphorite deposit, the beds lie horizontally, although peculiar folds are observable locally. Close to the present-day and Neogene river valleys, the phosphorite-bearing succession and the Lower Cretaceous beds acquire an appreciable tilt toward the river valley floor. Folds occur only in those places where the river valley downcuts Oxfordian clay to a considerable depth (down to 10 m or deeper). In such cases, the plastic clay is squeezed out under the load of overlying sediments into the valley wall and is removed with water. The overlying beds subside as a strip parallel to the river valley and make up a border that is folded down.     

Role of the Radiation Factor in Global Climatic Events of the Late Holocene

Izvestiya, Atmospheric and Oceanic Physics - On the basis of calculations of insolation and insolation characteristics, taking into account changes in solar activity, the causes of global climatic...     

Fattening of wild short‐finned eels,Anguilla Australis schmidtii Phillipps

Short‐finned wild eels fed an artificial diet containing either a low (5%) or a high (20%) oil content were found to increase their mass by an average of more than 30% after a 34‐day feeding period; the lipid content of the eels’ muscle was also increased from about 10% to around 20%.     

Robertson-Walker Lyttleton-Bondi universe with cosmological constant

It is shown that contortion and gravity are not interacting in the lowest possible order. The most convenient pairs of materials in the new Eötvös' experiments are also proposed.     

2.5 Ga gabbro-anorthosites in the Belomorian Province,Fennoscandian Shield: Petrology and tectonic setting

The Vorochistoozersky, Nizhnepopovsky, and Severo-Pezhostrovsky gabbro-anorthosite massifs have been studied in the central part of the Belomorian Province, Fennoscandian Shield. The similarity of geological setting and rock composition of these massifs suggests their affiliation to a single complex. The age of the gabbro-anorthosites was determined by U-Pb (SHRIMP II) zircon dating of gabbro-pegmatites from the Vorochistoozersky massif at 2505 ± 8 Ma. The studied massifs were overprinted by the high-pressure amphibolite facies metamorphism. Relicts of magmatic layering and primary magmatic assemblages preserved in the largest bodies. The massifs consist mainly of leucocratic gabbros but also contain rocks of the layered series varying in composition from olivinite to anorthosite. The presence of troctolites in the layered series indicates the stability of the olivine–plagioclase liquidus assemblage and, respectively, shallow depths of melt crystallization. Despite the composition differences between gabbro-anorthosites of the Belomorian and peridotite–gabbronorite intrusions Kola provinces, these simultaneously formed massifs presumably mark a single great igneous event. It also includes the gabbronorite dikes in the Vodlozero terrane of the Karelian province, the Mistassini swarm in the Superior province, and the Kaminak swarm in the Hearne Craton, Canadian Shield. The large igneous province of age ~2500 Ma reflects the oldest stage of within-plate magmatism after a consolidation of the Neoarchean crust of the Kenorland Supercontinent (Superia supercraton).