Deep Boundaries Research Articles

Lateral variation of aeromagnetic anomaly in South China and its tectonic implications

We present a series of images from the aeromagnetic data observed in South China areas, and reveal the detailed structures of the South China Block. By using lateral variation of the aeromagnetic anomalies, we characterize individual geological blocks and suggest the deep boundaries of the blocks. The Yangtze Block and Jiangnan orogenic belt are characterized by low aeromagnetic anomalies, whereas high values of the aeromagnetic anomaly are observed in the Cathaysia Block. The boundary between the Yangtze and Cathaysia blocks, which remains unclear to date, can be plotted along the large magnetic gradients. The high magnetic anomalies significantly relate to volcanic distributions in South China areas. These aeromagnetic observations seem to be useful to investigate the intracontinental tectonic evolution in this region.

Deep Crisp Boundaries: From Boundaries to Higher-Level Tasks.

Edge detection has made significant progress with the help of deep convolutional networks (ConvNet). These ConvNet-based edge detectors have approached human level performance on standard benchmarks. We provide a systematical study of these detectors' outputs. We show that the detection results did not accurately localize edge pixels, which can be adversarial for tasks that require crisp edge inputs. As a remedy, we propose a novel refinement architecture to address the challenging problem of learning a crisp edge detector using ConvNet. Our method leverages a top-down backward refinement pathway, and progressively increases the resolution of feature maps to generate crisp edges. Our results achieve superior performance, surpassing human accuracy when using standard criteria on BSDS500, and largely outperforming the state-of-the-art methods when using more strict criteria. More importantly, we demonstrate the benefit of crisp edge maps for several important applications in computer vision, including optical flow estimation, object proposal generation, and semantic segmentation.

Underground hydrosphere and geofluids of the Earth’s crust and upper mantle

The physicochemical state of the water at various temperature and pressure conditions of the Earth’s interior has been characterized. Two groups of geofluidic systems for water have been established: subcritical ( T 374 ¸ 450 °C), which together with the hydrogeological system of structured waters constitute hydrophysical, hydro- and fluid-geological lithosphere zonation. Based on the systematization of data on the decrepitating of gas-liquid inclusions in minerals of rocks of various facies of metamorphism, as well as fluid manifestations in zones of global rifting, a high content of mineral substances in the composition of dense supercritical fluids and a high electrical conductivity of such fluids is established. Recognition of high “salt content” and high electrical conductivity of supercritical fluids opens new possibilities in interpreting local high-speed anomalies and anomalies of electrical conductivity in the Earth’s crust, revealed from deep seismic and magnetotelluric sounding data. It is shown that with the water condensate — a kind of liquid-phase “restite” from the sphere of supercritical fluids separation — the genesis of highly mineralized waters and brines is connected in the crystalline basement of ancient platforms. On the example of the lithosphere of Belarus, for the first time, deep boundaries of localization of both structured water and supercritical geofluids have been determined. The hydro- and fluid-geological zonation of the lithosphere and upper mantle has been established as a basis for solving the scientific and practical problems of tectonophysics, mineralogy, hydrogeology, genesis and distribution of different type’s minerals, including hydrogenogenic minerals. A thermophysical method for determining the depth and thickness of a zone of underground structured waters is proposed. The method is based on comparison of seismic and thermal characteristics of rocks with sub- and supercritical temperatures for water.

Deep Morphology and Connectivity Determination of Late Triassic Shuangdinggou and Xinling Rock in Qingchengzi, Eastern Liaoning

The late Triassic Outstanding and Xinling rock exposed adjacently and both belonged to late Triassic grannitic magmatic events in Qingchengzi mining area of Liaoning-Jilin rift belt. The deep boundaries were determined and deep distribution morphology were explored. Hence, we found out the deep connectivity condition between the two rock. Applying the gravity and magnetic anomaly datas of 1:200000 scales in Dan dong area, and the processing interpretation of high-precision gravity magnetic survey datas and MT measured non seismic geophysical datas of two comprehensive profiles, simultaneously combined with measured density data of the samples, we performed comprehensive analysis on the basis of various anomalous signs , constrained rock morphology to control the profile and selected reasonable inversion parameters to carry out the gravity and magnetotelluric sounding joint inversion constraint by basic geological information. On basis of the work above, the deep geological structure inversion of 4 auxiliary profiles were completed, the rock spatial distribution geometrical morphology were found out, besides, the connectivity of the concealed rock underground between the two rock were determined. These provide reference for studying spatial distribution, ways the rock occurred and relationship between the mineral distribution and spatial distribution.

Common features of the tectonosphere deep structure in the Western Pacific Margins (Northeast Asia Region and Australia)

This paper analyses the spatial distributions of gravity sources and density contrast of geological media between the centers of mass of density heterogeneities and surfaces of some layers, which is reflected by the values of parameter μz, in the Northeast Asia Region and Australia. Statistical images of complex distributions of density heterogeneities are generally consistent with the shallowest tectonic structures, wave velocity, and electric anomalies. The correlation of μz minimums with high heat flow suggests melted magmas beneath the crust base and in the asthenosphere. In the lower crust layer, large μz maximums correlate with major continental megaelements, which are divided by extended linear μz minimums, high conductivity anomalies, and Vp/Vs maximums marking zones of lower viscosity. Deep boundaries and a thickness of lithospheric plates and asthenosphere lenses have been defined in the Northeast Asia Region. In Australia, two roughly NS-striking low-viscosity zones crossing the continent reflect the deep setting of the Lasseter (in the west) and the Tasman (in the east) lines. These zones are displayed in a wide depth range (15–120 km) and are confined to the Archean–Proterozoic and Proterozoic–Phanerozoic boundaries in the Australian lithosphere. Statistical gravity models derived without external (relatively to gravity) geological and geophysical information prove the multilayered tectonosphere structure of both continents and the similar deep structure features of their margins.

Effectiveness of a deep-water coral conservation area: Evaluation of its boundaries and changes in octocoral communities over 13 years

Over the past 15 years, multiple areas in the North Atlantic have been closed to destructive fishing practices to protect vulnerable deep-water coral ecosystems, known to provide habitat for diverse associated fauna. Despite the growing number of conservation measures, long-term studies on the recovery of deep-water coral communities from fisheries impacts remain scarce. In the Gulf of Maine, the Northeast Channel Coral Conservation Area (NECCCA)11NECCCA: Northeast Channel Coral Conservation Area. was established in 2002 to protect dense aggregations of the two numerically dominant octocoral species in the region, Primnoa resedaeformis and Paragorgia arborea. To evaluate the effectiveness of the conservation measures, we monitored shifts in abundance and size of these two coral species in the shallow section (400–700m) of the NECCCA for 12 years after the fisheries closure. We also evaluated the appropriateness of the location of the deep boundaries of the NECCCA that were placed based on a precautionary approach with limited information on coral distribution at depths >500m. Video transects were conducted with ROV “ROPOS” in 2001, 2006, 2010 and 2014. We found potential signs of recovery from fisheries impact at some of the shallow locations in 2014: higher coral abundance and the presence of some very large colonies as well as recruits compared to 2001 and 2006. However, spatial heterogeneity was pronounced and small colonies (<20cm) indicative of successful recruitment were not found at all sites, underscoring the need for long-term protection measures to allow full recovery of impacted coral communities. At 700–1500m different coral taxa were dominant than at the shallow locations and coral abundance peaked between 700 and1200m. High abundance and diversity of corals at this depth range, 8–10km southwest of the NECCCA, suggest that an extension of the southwest boundary should be considered. Comparably low coral abundance was found at depths of 1200–1500m inside the NECCCA indicating an appropriate initial placement of the southeast boundary. These are the first long-term observations of protected deep-water octocoral communities which are needed for the effective management of deep-water coral conservation areas.

Piezoelectric response enhancement in the proximity of grain boundaries of relaxor-ferroelectric thin films

The influence of surface morphology on the local piezoelectric response of highly (100)-textured 0.70PbMg2/3Nb1/3O3-0.30PbTiO3 thin films is studied using piezoresponse force microscopy in band-excitation mode. The local electromechanical response is mostly suppressed in direct proximity of the grain boundaries. However, within 100–200 nm of the grain boundary, the piezoresponse is substantially enhanced, before decaying again within a region at the center of the grain itself. Nested piezoresponse hysteresis curves confirm the influence of topography descriptors on parameters affecting the hysteresis loop shape. The enhancement of the electromechanical response is rationalized through reduced lateral clamping in the grains with deep trenched boundaries, as well as an expected lower energy for complex domain wall structures, due to curved ferroelectric surfaces. The lower piezoresponse at the center of the grain is assigned to the lateral clamping by the surrounding piezoelectric material.

Broken Character Image Restoration Using Genetic Snake Algorithm: Deep Concavity Problem

Active contours also known as snakes became a familiar and widely used in the field of image segmentation and restoration of historical documents in last few decades. Gradient Vector Flow (GVF) snake successes in overcome of converge to boundary concavities which represents the drawback of traditional snakes. Deep concavity problem it has become Obstacle faced GVF snake when restoring broken characters of historical documents. In this study we proposed algorithm to use genetic algorithm with GVF snake algorithm in order to optimize snake points to get right positions in deep concavity boundaries, also adding a Divergence factor as the third force to enhance the restoring and recognizing results. The experimental results show that our proposed algorithm has more capture than GVF alone.

The structural evolution of Cu(In,Ga)Se2 thin film and device performance prepared through a three-stage process

Cu(In,Ga)Se2 (CIGS) absorber layer is grown on Mo-coated soda-lime glass (SLG) substrates using co-evaporation deposition technique. The growth characteristics of the CIGS films deposited through a three-stage process are examined by interrupting the deposition along the reaction pathway. In the three-stage process, the absorber layer undergoes several phase transformations with Cu content. The γ-(In,Ga)2Se3 layer is formed first and is then converted to α-Cu(In,Ga)Se2 via β-Cu(In,Ga)3Se5. When α-Cu(In,Ga)Se2 stoichiometry is reached, Cu2−xSe segregation at the surface and at grain boundaries begins to occur. The Cu2−xSe improved the densification and grain growth of the absorber layer. Then, as the absorber layer reverts to substoichiometric composition, the Cu2−xSe phase disappears and the depleted server Cu near the surface instead. This paper reports several types of defects found in absorber layers that act as non-radiative recombination centers, such as impurity phases (Cu2−xSe and Cu(In,Ga)3Se5), deep point defects (InCu), grain boundaries, and voids. The highest efficiency at 10.97% was achieved when the bulk [Cu]/([In]+[Ga]) ratio was 0.98 at the third stage of the process. This result is attributed to the low-concentration deep-level defects that act as recombination centers and to the denser structure with larger grain size.

Ritualization and the Process of Knowledge Transfer

We analyze interactions among members of rural communities in Ghana and agriculture development specialists. We find that these participants in the knowledge transfer process are separated by deep knowledge boundaries, as well as by diverging worldviews (one centered on community relations, the other on market relationships). In this context, knowledge transfer is enabled through ritualized interactions and in particular by the use of two types of ritualization strategies: marking strategies (visiting dignitaries and events, praying, gift-giving) and recurring strategies (performing, fabletelling, affirming community values). These findings show that ritualization – understood as a way of acting that distinguishes particular situations from other, usually more mundane, activities – allows encounters between opposing orders and thus enables knowledge transfer. We suggest that this is the case because ritualization speaks to people’s aspirations to change; it is morally redemptive; and it bridges across groups. Ritualized interactions facilitate knowledge transfer by creating a context for learning during mundane interactions, by fostering mechanisms for peer-learning and teaching and by triggering reverse learning on behalf of knowledge workers from rural communities. Our study contributes to the literature on organizational rituals, learning in strong culture contexts, and economic sociology.

Deep structures and surface boundaries among Proto-Tethyan micro-blocks: Constraints from seismic tomography and aeromagnetic anomalies in the Central China Orogen

The Qinling–Qilian orogen preserves the records of Early Paleozoic convergence among the Proto-Tethyan micro-blocks. In this study, we analyze the seismic velocity structure and the aeromagnetic anomalies in the Qinling–Qilian orogen and its adjacent areas, showing that the northernmost boundaries of these Proto-Tethyan micro-blocks are defined by the Guyuan–Longshoushan Fault in the Qilian orogen and by the Luonan–Luanchuan Fault in the Qinling orogen, respectively. The lithosphere north of the Qinling–Qilian orogen subducted southward under the Qinling–Qilian orogen. The boundaries of the micro-blocks in the Qinling–Qilian orogen of the Proto-Tethys domain are mostly EW- or NE-trending. Combined with Early Paleozoic geological records, our results indicate that the south-dipping low-velocity anomaly under the Alxa block and the south-dipping high-velocity ones under the North Qilian orogen and the North China block might indicate that the Alxa block, the North Qilian Oceanic slab and the North China block subducted southward. The south-dipping high-velocity anomaly under the North Qilian orogen is interpreted as the remnant of the Proto-Tethys Ocean in that area. However, the north-dipping low-velocity anomaly under the South Qinling and the North Qinling orogens, the Qaidam block and the north-dipping high-velocity one under the Yangtze and the Bikou blocks suggest that the South Qinling and the North Qinling orogens, the Qaidam, the Yangtze and the Bikou blocks subducted northward. The present spatial framework of the Qinling–Qilian orogen is related to Early Paleozoic convergence among the Proto-Tethyan micro-blocks.

Orogenic gold mineral systems of the Western Lachlan Orogen (Victoria) and the Hodgkinson Province (Queensland): Crustal metal sources and cryptic zones of regional fluid flow

Orogenic gold mineral systems in the Western Lachlan Orogen (Victoria) and the Hodgkinson Province (Queensland) produced gold provinces characterised by vastly different scales of gold endowment and strongly uneven distribution of gold mineralisation within each province. The volume of hydrous pyrite-bearing rocks undergoing metamorphic devolatilisation during thermo-tectonic events driving orogenic gold mineral systems represents a fundamental first-order constraint on the total gold endowment and its broad spatial distribution, both between and within the provinces. Most of the largest gold deposits in both regions occur in linear, richly-endowed metallogenic zones, oblique to the dominant regional structures and related to deep crustal domain boundaries. These boundaries, with only subtle surface expressions, were the major regional structural controls which promoted focused near-vertical flow of mineralising metamorphic fluids above the outer margins of cratonic blocks in the lower crust. Recognised major faults represented only more local scale and often indirect controls on the focused fluid flow, particularly effective above the deep cratonic block boundaries overlain by relatively thick crustal source rocks.

Spatial data analysis of mineral deposit point patterns: Applications to exploration targeting

Systematic spatial analysis of mineral deposit point patterns can reveal significant spatial properties of mineral systems, with major implications for regional mineral prospectivity modelling. For valid results, a study area needs to be clearly defined, taking into account permissiveness of the geological units for a particular mineral system and effects of cover. Standard statistical tests assuming an isometric contiguous study area with regionally homogeneous distribution of deposits are likely to produce invalid results. Analysis of regional uniformity of spatial deposit density is required for adequate design and interpretation of tests for clustering. Spatial distribution of orogenic gold deposits in the Hodgkinson Province in Queensland and the Western Lachlan Orogen in Victoria (Australia) indicates the presence of significant regional linear metallogenic zones, probably controlled by deep crustal domain boundaries oblique and not related to any recognised major faults. Within the metallogenic zones in both regions, individual gold occurrences are strongly clustered into ore fields, but the distribution of ore fields is random.

The nature of the Conrad discontinuity with respect to the results of kola superdeep well drilling and the data of a deep geoelectrical survey

The problem of superdeep drilling of the continen� tal crust was stated for the first time at a meeting in Paris in 1962; the necessity of direct study by drilling of the physical nature of the deep geophysical boundaries found by surfacebased methods, first of all, by seismic survey, became clear. Approximately at the same time, two projects started in the United States—Moho and Apollo. The Moho project was aimed at reaching the most ancient rocks of the basaltic layer by drilling the oceanic crust from the R/V Glomar Challenger. The other project, the Apollo program, as is known, was related to landing humans on the Moon, lunar core sampling, and transportation back to the Earth. In turn, the Soviet Union launched two programs: the Lunokhod automated missions, which was intended to collect lunar core samples, and the superdeep conti� nental drilling program that included drilling of ten superdeep wells on the territory of the country. The Kola Superdeep Well SG�3 was part of this extensive research into the composition and structure of the Earth's interior. The location of the SG�3 drilling was determined by two points. The first point was the location of the ancient Archean rocks of the Earth's crust in the northeastern Fennoscandian Shield resulting from a deep erosional cut; these rocks were exposed to a depth of about 10 km; they are represented, in partic� ular, by granitic gneisses of the Kola Series and Mur� mansk block (Fig. 1, 1 and 3, respectively). The sec� ond point, based on deep seismic sounding (DSS) data and the anomalously high position of the Conrad dis� continuity (K1), was identified in the area of Pech� enga, Kola Peninsula. The Conrad discontinuity was believed to be where the chemical (substantial) com� position of the Earth's crust changes: the upper gra� nitic gneiss layer of aluminumsilicate (siallic) rocks is replaced with a lower lying magnesian, basaltic (simaic) layer. The position of this boundary is usually attributed to a sharp growth of seismic wave velocity from 6.1 to 6.5 km/s. According to the DSS data, the K1 depth in the area of Pechenga is about 7 km (2)

Growth of epitaxial Pt thin films on (001) SrTiO3 by rf magnetron sputtering

Abstract The growth of platinum thin film by rf magnetron sputtering on SrTiO3(0 0 1) substrates for oxide based devices was investigated. Platinum films grown at temperatures higher than 750 °C were epitaxial ([1 0 0]Pt(0 0 1)//[1 0 0]STO(0 0 1)), whereas at lower temperatures Pt(1 1 1) films were obtained. The surface morphology of the Pt films showed a strong dependence on the deposition temperature as was revealed by atomic force microscopy (AFM). At elevated temperatures there is a three-dimensional (3D) growth of rectangular atomically flat islands with deep boundaries between them. On the other hand, at low deposition temperatures, a two-dimensional (2D) layered growth was observed. The transition from 2D to 3D growth modes was observed that occurs for temperatures around 450 °C. The obtained epitaxial thin films also formed an atomically sharp interface with the SrTiO3(0 0 1) substrate as confirmed by HRTEM.

The Falkland Basins: new structural model and hydrocarbon bearing prospects (by remote sensing and geoelectric data)

New results of geoelectric measurements were obtained during the season works of 17 Ukrainian Antarctic Expedition (XVII UAE, 2012). New data on the deep structure of the tectonic zone between the Falkland Islands and the South Shetland Islands make it possible to estimate the probable nature of geodynamic processes in this region. Deep geoelectric boundaries position and nature of their contacts near the South Shetland Islands and the Falkland Islands show a fundamentally different distribution of crustal and mantle layers in the Strait structures with continental and oceanic rock complexes.&nbsp;Some anomalous zones of “hydrocarbon deposit” type were detected in the South Falkland Basin shelf by the special technology of satellite data processing and interpretation using. The "deposit" type anomalies were mapped by FSPEF survey and anomalous polarized layers of "hydrocarbon deposit" type were studied by VERS sounding in the South Falkland Basin. These results are new and additional to oil and gas potential data for the South Falkland Basin shelf zone.

Gravity models of two-level collision of lithospheric plates in northeastern Asia

Structural forms of emplacement of crustal and mantle rigid sheets in collision zones of lithospheric plates in northeastern Asia are analyzed using formalized gravity models reflecting the rheological properties of geological media. Splitting of the lithosphere of moving plates into crustal and mantle constituents is the main feature of collision zones, which is repeated in the structural units irrespective of their location, rank, and age. Formal signs of crustal sheet thrusting over convergent plate boundaries and subduction of the lithospheric mantle beneath these boundaries have been revealed. The deep boundaries and thickness of lithospheric plates and asthenospheric lenses have been traced. A similarity in the deep structure of collision zones of second-order marginal-sea buffer plates differing in age is displayed at the boundaries with the Eurasian, North American, and Pacific plates of the first order. Collision of oceanic crustal segments with the Mesozoic continental margin in the Sikhote-Alin is characterized, as well as collision of the oceanic lithosphere with the Kamchatka composite island arc. A spatiotemporal series of deep-seated Middle Mesozoic, Late Mesosoic, and Cenozoic collision tectonic units having similar structure is displayed in the transitional zone from the Asian continent to the Pacific plate.

AN ANALYTIC RADIATIVE-CONVECTIVE MODEL FOR PLANETARY ATMOSPHERES

We present an analytic 1-D radiative-convective model of the thermal structure of planetary atmospheres. Our model assumes that thermal radiative transfer is gray and can be represented by the two-stream approximation. Model atmospheres are assumed to be in hydrostatic equilibrium, with a power law scaling between the atmospheric pressure and the gray thermal optical depth. The convective portions of our models are taken to follow adiabats that account for condensation of volatiles through a scaling parameter to the dry adiabat. By combining these assumptions, we produce simple, analytic expressions that allow calculations of the atmospheric pressure-temperature profile, as well as expressions for the profiles of thermal radiative flux and convective flux. We explore the general behaviors of our model. These investigations encompass (1) worlds where atmospheric attenuation of sunlight is weak, which we show tend to have relatively high radiative-convective boundaries, (2) worlds with some attenuation of sunlight throughout the atmosphere, which we show can produce either shallow or deep radiative-convective boundaries, depending on the strength of sunlight attenuation, and (3) strongly irradiated giant planets (including Hot Jupiters), where we explore the conditions under which these worlds acquire detached convective regions in their mid-tropospheres. Finally, we validate our model and demonstrate its utility through comparisons to the average observed thermal structure of Venus, Jupiter, and Titan, and by comparing computed flux profiles to more complex models.

Influence of Alkyl Chain Length on the Structure of Dialkyldithiophosphinic Acid Self-Assembled Monolayers on Gold

We report the formation and characterization of self-assembled monolayers (SAMs) based on dialkyldithiophosphinic acid adsorbates {[CH(3)(CH(2))(n)](2)P(S)SH (n = 5, 9, 11, 13, 15)} on gold substrates. SAMs were characterized using X-ray photoelectron spectroscopy, reflection-absorption infrared spectroscopy, contact angle measurements, and electrochemical impedance spectroscopy. Data show that there is a roughly 60:40 mixture of bidentate and monodentate adsorbates in each of these SAMs. The presence of monodentate adsorbates is due to the numerous and deep grain boundaries of the underlying gold substrate, which disrupt chelation. Comparing the characterization data of dialkyldithiophosphinic acid SAMs with those of analogous n-alkanethiolate SAMs shows that both SAMs follow a similar trend: The alkyl chains become increasingly organized and crystalline with increasing alkyl chain length. The alkyl groups of dialkyldithiophosphinic acid SAMs, however, are generally less densely packed than those of n-alkanethiolate SAMs. For short alkyl chains (hexyl, decyl, and dodecyl), the significantly lower packing densities cause the alkyl chains to be liquid-like and disorganized. Long-chain dialkyldithiophosphinic acid SAMs are only slightly less crystalline than analogous n-alkanethiolate SAMs.

Deep structure of the crust beneath the Sea of Okhotsk inferred from 3D seismic density modeling

Potential field anomalies of the Sea of Okhotsk region are analyzed for compiling a map of the basement’s tectonic structures. A 3D density model of the Earth’s crust is constructed using seismogeological and experimental-petrophysical data, which made it possible to obtain a visual image of main structures of the region reflecting the observable geophysical anomalies. The obtained data allow a domain located in the central part of the Sea of Okhotsk beyond the limits of the exclusive economic zone of the Russian Federation to be considered as a natural continuation of the continental shelf since the latter is structurally similar to western Kamchatka. The deep structural boundaries rise beneath the large sedimentary Deryugin and Tinro basins, which is characteristic of petroliferous basins.