Alpine metamorphism in the south-east Tauern Window, Austria: 1. P–T variations in space and time

Abstract The Pennine rocks exposed in the south-east Tauern Window, Austria, contain mineral assemblages which crystallized in the mid-Tertiary ‘late Alpine’regional metamorphism. The pressure and temperature conditions at the thermal peak of this event have been estimated for rocks at four different structural levels using a variety of published and thermochemically derived geobarometers and geothermometers. The results are: (a) In the garnet+chlorite zone, 2–5 km structurally above the staurolite+biotite isograd: T= 490.50°C, P= 7° 1 kbar; (b) Within 0.5 km of the staurolite+biotite isograd: T= 560±300C, P=7.1 kbar; (c) In the staurolite+biotite zone, c. 2.5 km structurally below the staurolite+biotite isograd: T= 610±30°C, P=7.6±1.2 kbar; (d) In the staurolite+biotite zone, 3–4 km structurally below the staurolite+biotite isograd: T= 630±40°C, P= 6.6±1.2 kbar. The pressure estimates imply that the total thickness of overburden above the basement-cover interface in the mid-Tertiary was c. 26.4 km. This overburden can only be accounted for by the Austro-Alpine units currently exposed in the vicinity of the Tauern Window, if the Altkristallin (the ‘Middle Austro-Alpine’nappe) was itself buried beneath an ‘Upper Austro-Alpine’nappe or nappe-pile which was 7.4 km thick at that time. The occurrence of epidote + margarite + quartz pseudomorphs after lawsonite in garnet, indicates that part of the Mesozoic Pennine cover sequence in the south-east Tauern experienced blueschist-facies conditions (T<450°C, P<12 kbar) in early Alpine times. Evidence from the central Tauern is used to argue that the blueschist-facies imprint post-dated the main phase of tectonic thickening (D¹_A) and was thus a direct consequence of continental collision. Combined oxygen-isotope and fluid-inclusion studies on late-stage veins, thought to have been at lithostatic pressure and in thermal equilibrium with their host rocks during formation, suggest that they crystallized from aqueous fluids at 1.1±0.4 kbar and 420.20°C. Early Alpine, late Alpine and vein-formation P–T constraints have been used to construct a P–T path for the base of the Mesozoic cover sequence in the south-east Tauern Window. The prograde part of the P–T path, between early and late Alpine metamorphic imprints, is unlikely to have been a smooth curve and may well have had a low dP/dT overall; the decompression (presumably due to erosion) which occurred immediately before the thermal peak and possibly also earlier in the Tertiary, was probably partly or completely cancelled by the effects of early- to mid-Tertiary (D²_A) tectonic thickening. The thermal peak of metamorphism was followed by a phase of almost isothermal decompression, which implies a period of rapid uplift in the middle Tertiary. The peak metamorphic P–T estimates are compared with the solutions of England's (1978) one-dimensional conductive thermal model of the Eastern Alps, and are shown to be consistent with the idea that the late Alpine metamorphism was caused by tectonic burial of the Pennine Zone beneath the Austro-Alpine nappes in the absence of extraneous heat sources, such as large intrusions, at depth.     

Metamorphic P–T Paths from pelitic schists and greenstones from the south-west Tauern Window, Eastern Alps

Abstract Petrological data from intercalated pelitic schists and greenstones are used to construct a pressure–temperature path followed by the Upper Schieferhülle (USH) series during progressive metamorphism and uplift in the south-west Tauern Window, Italy. Pseudomorphs of Al–epidote + Fe-epidote + albite + oligoclase + chlorite after lawsonite and data on amphibole crystal chemistry indicate early metamorphism in the lawsonite-albite-chlorite subfacies of the blueschist facies at P ± 7–8 kbar. Geothermometry and geobarometry yield conditions of final equilibration of the matrix assemblage of 475±25°C, 5–6 kbar; calculations with plagioclase and phengite inclusions in garnet indicate early garnet growth at pressures of ∼ 7.5 kbar. Garnet zoning patterns are complex and reversals in zoning can be correlated between samples. Thermodynamic modelling of these zoning profiles implies garnet growth in response to four distinct phases of tectonic activity. Fluid inclusion data from coexisting immiscible H₂O–CO₂–NaCl fluids constrain the uplift path to have passed through temperatures of 380 + 30°C at 1.3 + 0.2 kbar.
There is no evidence for metamorphism of USH at pressures greater than ∼ 7.5 kbar in this area of the Tauern Window. This is in contrast to pressures of ± 10 kbar recorded in the Lower Schieferhülle only 2–3 km across strike. A history of differential uplift and thinning of the intervening section during metamorphism is necessary to reconcile the P–T data obtained from these adjacent tectonic units.     

C–O–H–N fluids in quartz segregations from a major ductile shear zone: the Berzosa fault, Spanish Central System

Abstract The Berzosa fault is a major ductile shear zone, the Berzosa Shear Zone (BSZ), which separates the ‘Ollo de Sapo’anticline from the inner higher-grade crystalline axis of the Iberian Hercynian Belt. This shear zone is the site of abundant early kinematic quartz (± Al-silicates) segregations, rich in fluid inclusions. Host rocks are medium-grade staurolite schists and sillimanite gneisses. Fluid inclusions in selected quartz segregations across the Berzosa shear zone have been studied by microthermometric methods as well as, in some instances, by Raman analysis. The recorded fluid inclusion history begins at the end of an intense secondary recrystallization period during late-peak metamorphic conditions and lasts until late in the uplift history of the zone. Three types of inclusions have been found, which in a time sequence are: CO₂± H₂O; H₂O+salt (B-type); and, N₂+CH₄. Three types of B inclusion may be distinguished in turn, depending on whether they were trapped during an earlier dynamic-recovery phase (B₁-type), formed later as intergranular trails (B₂-type), or were trapped apparently along with N₂+CH₄ in clusions from a heterogeneous fluid (B₃-type). Considerations from isochores confirm that CO₂± H₂O inclusions were trapped during late-peak and high-T retrograde metamorphic conditions (in the range 650–500°C and 5–2 kbar), whilst N₂+CH₄ inclusions, along with the B₃-type of inclusions, formed at low-pressures (<1 kbar) and temperatures (± 300°C). B₂-type inclusions were trapped chronologically between these two in a period in which strong inverse lateral thermal gradients developed in the zone. Inferred P-T paths for the area are convex to the T-axis.     

感知技术在文化遗产研究中的应用与展望

感知技术的发展为文化遗产的探测、保护、利用和传承带来了机遇和挑战。鉴于当前文化遗产研究中应用的感知技术的复杂性及多样性,本文对感知技术及其在文化遗产研究中的应用进行系统梳理。首先,对感知技术的概念进行总结,重点介绍在文化遗产研究中发挥重要作用的多源遥感平台、社交媒体、移动通讯、智能交通等多源传感器的特点,以及关键信息处理技术,包括数据挖掘和知识发现、可视化技术以及虚拟现实技术;其次,梳理了感知技术在物质文化遗产、非物质文化遗产以及群体对于文化遗产的体验和评价等方面的应用进展;最后,探讨了文化遗产研究中感知技术在数据精度、多源数据融合、信息处理等方面存在的问题,指出其数据共享化、平台网络化和应用社会化的发展趋势。     

Integrating social network data into GISystems

Today, online social media outlets provide new and plentiful sources of data on social networks (SNs) and location-based social networks (LBSNs), i.e., geolocated evidence of connections between individuals. While SNs have been used to show how the magnitude of social connectivity decreases with distance, there are few examples of how to include SNs as layers in a GISystem. If SNs, and thus, interpersonal relationships, could be analyzed in a geographic information system (GIS) setting, we could better model how humans socialize, share information, and form social groups within the complex geographic landscape.

Our goal is to facilitate a guide for analyzing SNs (as derived from online social media, telecommunications, surveys, etc.) within geographic space by combining the mature fields of social network analysis (SNA) and GISystems. First, we describe why modeling socialization in geographic space is essential for understanding human behavior. We then outline best practices and techniques for embedding SN nodes and edges in GISystems by introducing terms like ‘social flow’ and ‘anthrospace’, and categorizations for data and spatial aggregation types. Finally, we explore case study vignettes of SNA within GISystems from diverse regions located in Bolivia, China, Côte d’Ivoire, Singapore, the United Kingdom, and the United States, using concepts such as geolocated dyads, ego–alter relationships, node feature roles, modularity, and network transitivity.     

从地震信息看新生代郯庐断裂带的展布与活动

郯庐前新近纪断裂带为中国东部滨太平洋地区一条巨型张扭走滑构造带。利用地震信息分析地质结构,可将其分为南、中、北三大段和七亚段。按其影响范围的规模可划分为广义和狭义两类:广义郯庐前新近纪断裂带地质结构是“两凹夹一隆”,狭义郯庐前新近纪断裂带则指高垒带与两侧(邻)的断层组合。断裂带内外都发育有反转、花状构造。狭义郯庐前新近纪断裂带走向为NNE,仅在嘉山以南为NE向,其两侧的前新近纪断层大体上都为EW、NE和NEE走向,与狭义郯庐断裂呈锐角相切。古近纪构造层中,由南到北郯庐断层两侧箕状断陷边界都由生长断层所组成,说明郯庐断裂两侧的古近纪断陷应属拉张盆地,并非拉分盆地,郯庐古近纪断裂动力学是拉张而非拉分构造应力场。古近纪构造层在拉张翘倾运动中叠加了右旋走滑地质应力,这种右旋走滑应力是太平洋板块向西俯冲至欧亚板块之下的结果。中生代郯庐断裂的动力学表现为库拉板块向北俯冲至欧亚板块之下形成的左旋平移现象。郯庐断裂NE向平移走滑与北西向隐蔽断裂的相交处是发生破坏性地震的构造部位,因此,应特别重视对高丽营北东向生长断层与渤中-孙河-南口北西向隐蔽断层相交处地震动向的监控。     

乡村聚落地理研究的国外动态与国内趋势

本文根据国内外乡村聚落地理研究的内容变化和理论进展，初步划分了乡村聚落地理研究的主要发展阶段。在此基础上，结合国外乡村聚落地理研究的动态及我国乡村地区发展的现实，对我国乡村聚落地理研究进行了回顾与评价，并提出若干重点研究内容与趋势。     

我国实施大洋钻探工程的初步设想

约占地球面积71%的海洋里蕴藏着海量的地质、生物、气候等信息和丰富的资源,我国“十三五”国家科技创新规划中,将“深海、深地、深空、深蓝科学研究”列为战略性前瞻性重大科学问题,并将“国际大洋发现计划（IODP）列为5项国际大科学计划和大科学工程之一。但在深海钻探,作业环境和条件都较陆地上更加复杂,对钻探船、钻探工艺、环保措施、施工组织管理等都是严峻的考验。本文在概述大洋钻探的意义和成果,回顾世界大洋钻探的演进史和工程实施概况以及我国参加大洋钻探情况的基础上,针对大洋钻探的钻井特点和地层条件,探讨了海洋科学钻探取心技术、超深水条件的重入钻孔技术、跟管钻进下套管技术、超深水条件的泥浆循环等关键技术问题,提出了我国实施大洋钻探工程的初步设想。     

古尔班通古特沙漠南缘近40年大雾变化特征分析—蔡家湖区域

利用新疆蔡家湖气象站1971-2010年大雾天气现象观测资料,分析了该地区近40a大雾天气的年际、年代际、日变化特征以及大雾天气的持续时间特征。研究表明：蔡家湖近40a大雾的年日数年际变化不明显;秋季雾日增多趋势明显,春季和冬季雾日呈减少的趋势;大雾主要出现在冬季,其次为秋季;一日中大雾主要发生在02-08时,其次为8-14时;大雾持续时间大多在3h之内;40a雾的最长持续时间为46．88h,出现在2010年11月;各月平均最长持续时间为14．49h,也出现在11月;最长持续时间季节分布呈秋末和冬季较长,夏季较短;大多月份雾的最长持续时间呈增长的趋势;当出现2d及以上的高湿天气,且日平均气温在一7．O～O℃、日最高气温在一6．0～0℃时,有利于雾的持续。