The Brittlestar Amphiodia urtica; A Candidate Bioindicator?

Abstract. The ophiuroid Amphiiodia urtica L yman is presently under study as a potential wastewater discharge indicator species from ocean outfalls in the Southern California Bight. On the San Pedro Shelf, the maximum abundance of A. urtica was found at depths from 30 to 100 m, and in sediment with a median grain size of 0.085 nim, 60–80% sand. 15–30% silt, 0–37% clay, and 0.2–0.5% TOC. The mean abundance of A. urtica fluctuated annually with a slight increase from 1977 through 1993.
The hypothesis was posed that the distribution and abundance of A. urtica is not influenced by an ocean outfall and its operation on the San Pedro Shelf. Based on long-term (1977–1994) and intensive (2860 samples) sampling. the hypothesis was rejected. However, the effect of the outfall is not clear because sediment bioassays from test stations and controls produced no significant differences in survivorship and growth of juveniles. Amphiodia presently occupies areas within the Zone of Initial Dilution (ZID) where it was not found during the mid-1970s and early 1980s. While recognizing that A. urtica abundance responds to proximity to the outfall, the mechanism for this response is still unclear. The application of a single species as a bioindicator is not recommended, and most certainly not without fully essing its role in community structure and function.     

Tephrostratigraphy of the late glacial and Holocene sediments of Puyehue Lake (Southern Volcanic Zone, Chile, 40°S)

We document the mineralogical and geochemical composition of tephra layers identified in the late Quaternary sediments of Puyehue Lake (Southern Volcanic Zone of the Andes, Chile, 40°S) to identify the source volcanoes and to present the first tephrostratigraphic model for the region. For the last millennium, we propose a multi-criteria correlation model based on five tephra layers identified at seven coring sites. The two upper tephras are thin fine-grained green layers composed of more than 80% rhyodacitic glass shards, and associated to the AD 1960 and AD 1921-22 eruptions of the Puyehue-Cordon de Caulle volcanic complex. The third tephra is a sandy layer dominated by orthopyroxene, and related to the AD 1907 eruption of Rininahue maar. An olivine-rich tephra was deposited at the end of the 16th century, and a tephra characterized by a two-pyroxene association marks the second half of the first millennium AD. In addition, we detail the tephra succession of an 11.22-m-long sediment core covering the last 18,000 yr. The results demonstrate that the central province of the Southern Volcanic Zone has been active throughout the last deglaciation and the Holocene, with no increase in volcanic activity during glacial unloading.     

Hypocenter migration of fluid-induced earthquake swarms in the Tjörnes Fracture Zone (North Iceland)

The Tjörnes Fracture Zone separates Iceland's North Volcanic Zone from Kolbeinsey-Ridge (Greenland-Sea). Seismicity mainly occurs in swarms, often 100 and more per day, with similar waveforms and frequently offshore.We analysed three earthquake swarms between June and September 2004, recorded by 35 stations, i.e. the permanent Icelandic SIL network and a temporary setup of land and ocean-bottom-seismometers, and 5 swarms of the years 1994-1997 only using the sparser SIL network. Events occurring in the same swarm often show similar waveforms at the same station. We cross-correlated these time series by using a new approach of three component cross-correlation in order to relocate the hypocenters relative within the swarms and to precisely determine the direction and velocity of migration. Our method delivered good relocations with small spatial and temporal errors. This allows the interpretation and characterisation of the observed earthquake swarms. We try to classify observed migration velocities by comparing them to typical fluid- and crack-propagation velocities and determine focal-mechanisms and orientation of the best fitting plane through the hypocenter distribution.We separate the investigated events into two types of earthquake swarms, supposedly dike-induced and hydrothermally- or gas-induced swarms, by pointing out typical characteristics of both types and by comparing them to similar events of other volcanic regions. Based on different migration velocities, we will discuss possible mechanisms and their triggers of all single clusters within a swarm. Hypothetic models will be established, trying to explain the processes during the swarm episodes and to derive possible pre-eruptive patterns from the character of seismicity.     

中国境外经贸合作区的“园中园”发展模式与案例研究

以发展较为成功的中国?印尼经济贸易合作区（简称“中印合作区”）为例,讨论“一带一路”背景下中国境外经贸合作区的成功发展经验与“园中园”发展模式。中印合作区是中国企业在印度尼西亚设立的第一批国家级境外经贸合作区之一,采用“园中园”发展模式。通过实地调研与访谈的方法,构建“园中园”发展模式分析框架,从构建多主体间的合作网络、根植地方的制度文化环境、提供优质的园区环境这3个维度重点分析了中印合作区的发展过程与特征。归纳总结境外经贸合作区发展的成功经验,为未来境外经贸合作区的建设提供案例借鉴与理论参考。     

Determination of the stress conditions of the ductile-to-brittle regime along the Asuke Shear Zone,SW Japan

The stress conditions of the ductile-to-brittle regime have been assessed along the Asuke Shear Zone (ASZ), which strikes NE–SW in the Cretaceous Ryoke granite terrain in SW Japan. Along the ASZ, pseudotachylyte and mylonitized pseudotachylyte are locally developed together with cataclasite. The simultaneous operation of dislocation creep and grain-size-sensitive creep, as indicated by the coexistence of the Z-maximum and relatively random c-axis lattice preferred orientations as well as the sizes of dynamically recrystallized quartz grains (6.40–7.79 μm) in the mylonitized pseudotachylyte, suggest differential stresses of 110–130 MPa at ∼300 °C. The e-twin morphology, twinning ratio, and distribution of the glide direction on the e-twin plane of the twinned calcite in the amygdules of the pseudotachylyte suggest the stress conditions of the σ₁ and σ₃ axes trend 228° and 320° and plunge 55° and 1°, respectively, and indicate differential stresses of 40–80 MPa at 150–200 °C. Based on kinematic indicators in the fault rocks, the stress conditions estimated from calcite twins, and the cooling history of the granitic protolith, the ASZ is inferred to have been activated under a stress state that caused sinistral normal movements before and after pseudotachylyte formation at 70–50 Ma.     

对外开放度与经济增长关系研究——以河南省为例

基于河南对外开放度与经济增长情况,采用指标分析和回归分析方法,利用SPSS13.0统计软件,对河南省的对外开放度与GDP的相关性进行分析。结果表明,对外开放度系数与GDP高度关联,即对外开放促进了河南经济增长,经济增长带动了河南的对外开放。进而提出充分利用中原经济区建设的机遇,在改善投资环境上实现新突破,加快河南经济的对外开放步伐等对策建议。     

Textural re-equilibration,hydrothermal alteration and element redistribution in Fe-Ti oxide pods,Singhbhum Shear Zone,eastern India

This study describes textures and mineral chemistry of magnetite-ilmenite-bearing pods/pockets in mineralogically diverse feldspathic schist near Pathargora in the Singhbhum Shear Zone, eastern India. The textural and geochemical characteristics of the magnetite-ilmenite assemblage are the results of a protracted geological history involving magmatic crystallization and oxidation-exsolution of titanomagnetite, deformation-induced recrystallization and textural re-equilibration and hydrothermal fluid-induced hematitization of magmatic magnetite. The magnetite grains contain characteristic trellis and sandwich ilmenite lamella, which are interpreted to be the products of oxidation-exsolution of ulvöspinel component of magnetite-ulvöspinel solid solution. The exsolution process was accompanied by preferential partitioning of spinel elements such as Cr, Al and V in magnetite and Ti, Mn, Mg, HFS elements (Nb, Ta), transition elements (Sc, Co, Cu and Zn) and granitophile elements (Mo, Sn and W) in ilmenite. The deformed sandwich lamella is locally recrystallized and transformed into granular ilmenite close to fractures, micro-shear planes and magnetite grain boundaries. Coarse granules of ilmenite, within or associated with magnetite, are of two textural types: one invariably contains Fe-rich exsolved phase and may be of magmatic origin, while the other mostly formed by strain-induced, fluid-mediated expulsion (from the interior of magnetite to its boundary) and dynamic recrystallization of existing ilmenite lamella in magnetite, and dynamic recrystallization of primary ilmenite containing Fe-rich exsolved phases. Magnetite is variably hematitized. The highly porous nature and trace element geochemistry of hematite and mass-balance calculations suggest the hematitization was mostly redox-independent and was caused by infiltration of metal-rich, reduced and acidic fluid. The hematitization process was associated with significant enrichment and immobilization of U, Th, Pb, REEs, Cu, Mo and W and depletion of Ni, Cr, V in hematite.     

福州永泰高盖山“农家乐”旅游开发构想

“农家乐”作为一种新兴旅游形式,在中国各地已如火如荼开展。“农家乐”旅游一般具有乡土味鲜明、平民性明显、原生美突出、参与性强的特点。因此,其持续、健康发展很大程度上取决于景区所提供的旅游产品。通过提出当前农家乐开发的一些问题,分析了永泰高盖山景区农家乐开发现状、可行性及外部环境与内部条件,最后提出符合高盖山具体情况的4种旅游产品即农业观光、田野人家、农事体验竞技及农业修学,同时提出开发原则。     

Structure and kinematics of the Louth-Eumarra Shear Zone (north-central New South Wales,Australia) and implications for the Paleozoic plate tectonic evolution of eastern Australia

The ～E–W-trending Olepoloko Fault and ～ENE-trending Louth-Eumarra Shear Zone in north-central New South Wales are approximately orthogonal to the dominant ～N–S-trending structural grain of Paleozoic eastern Australia. These structures have been interpreted to represent the boundary between the Thomson and Lachlan orogens, but their exact geometry and kinematics remain unclear owing to the scarcity of surface exposure. Using gridded aeromagnetic data and limited field mapping, we obtained new data on the tectonic history of the Louth-Eumarra Shear Zone, which seems to represent a broad zone of dextral shearing with a component of crustal thickening indicated by the recognition of kyanite growth in a mica-schist. The timing of deformation is relatively poorly constrained, but at least a component of the dextral shearing appears to be coeval or younger than the age of displaced late Silurian and Early Devonian granitoids. Additional indicators for dextral kinematics farther north, along the ～ENE-trending Culgoa Fault, suggest that the width of the zone that was subjected to dextral deformation is possibly >100 km. This raises the possibility that a large component of dextral displacement was accommodated in this region. In a broader geodynamic context, we discuss the possibility that the precursor of the Louth-Eumarra Shear Zone and Olepoloko Fault originated from segmentation between the northern and southern Tasmanides, perhaps during the Cambrian. The existence of such a discontinuity may have buttressed the process of oroclinal bending in the Silurian. The observed dextral kinematics has possibly resulted from reactivated deformation during the Tabberabberan and Alice Springs orogenies.     

Impacts of simulated M9 Cascadia Subduction Zone earthquakes considering amplifications due to the Georgia sedimentary basin on reinforced concrete shear wall buildings

Southwest British Columbia has the potential to experience large‐magnitude earthquakes generated by the Cascadia Subduction Zone (CSZ). Buildings in Metro Vancouver are particularly vulnerable to these earthquakes because the region lies above the Georgia sedimentary basin, which can amplify the intensity of ground motions, particularly at medium‐to‐long periods. Earthquake design provisions in Canada neglect basin amplification and the consequences of accounting for these effects are uncertain. By leveraging a suite of physics‐based simulations of M9 CSZ earthquakes, we develop site‐specific and period‐dependent spectral acceleration basin amplification factors throughout Metro Vancouver. The M9 simulations, which explicitly account for basin amplification for periods greater than 1s, are benchmarked against the 2016 BC Hydro ground motion model (GMM), which neglects such effects. Outside the basin, empirical and simulated seismic hazard estimates are consistent. However, for sites within the basin and periods in the 1‐5 s range, GMMs significantly underestimate the hazard. The proposed basin amplification factors vary as a function of basin depth, reaching a geometric mean value as high as 4.5 at a 2‐s period, with respect to a reference site located just outside the basin. We evaluate the impact of the M9 simulations on tall reinforced concrete shear wall buildings, which are predominant in the region, by developing a suite of idealized structural systems that capture the strength and ductility intended by historical seismic design provisions in Canada. Ductility demands and collapse risk conditioned on the occurrence of the M9 simulations were found to exceed those associated with ground motion shaking intensities corresponding to the 975 and 2475‐year return periods, far exceeding the ～500‐year return period of M9 CSZ earthquakes.