Groundwater isoscapes in a montane headwater catchment show dominance of well‐mixed storage

We conducted an integrated groundwater–surface water monitoring programme in a 3.2‐km² experimental catchment in the Scottish Highlands by sampling all springs, seepages, and wells in six, spatially extensive synoptic surveys over a 2‐year period. The catchment has been glaciated, with steep hillslopes and a flat valley bottom. There is around 70% glacial drift cover in lower areas. The solid geology, which outcrops at higher elevations, is granite and metamorphic schist. The springs and seepages generally occur at the contact between the solid geology and drift or at breaks of slopes in the valley bottom. Samples were analysed for stable isotopes, Gran alkalinity and electrical conductivity. Despite the surveys encompassing markedly different antecedent conditions, the isotopic composition of groundwater at each location exhibited limited temporal variability, resulting in a remarkable persistence of spatial patterns indicating well‐mixed shallow, groundwater stores. Moreover, line‐conditioned excess values derived from the isotope data indicated no evidence of fractionation affecting the groundwater, which suggests that most recharge occurs in winter. The alkalinity and electrical conductivity of groundwater reflected geological differences in the catchment, being highest where more weatherable calcareous rocks outcrop at higher altitudes in the catchment. Springs draining these areas also had the most variable isotope composition, which indicated that they have shorter residence times than the drift covered part of the catchment. The study showed that even in geologically heterogeneous upland catchments, groundwater can be characterized by a consistent isotopic composition, reflecting rapid mixing in the recharge zone. Our work, thus, emphasizes the critical role of groundwater in upland catchments and provides tracer data that can help constrain quantitative groundwater models.     

大厂矿区尾矿稀散资源分布规律与潜力评价研究

许多矿山开采和选矿排放的尾砂中蕴藏丰富的伴生金属资源,随着这类矿产资源价格上涨,尾砂伴生资源越来越受到人们的关注。本文对大厂矿集区茶山、车河、长坡和绿荫塘四个尾矿库中铟、镉、镓、锗等稀散元素分布特征与变化规律进行了调查,以期评价其潜在经济价值。调查结果表明,解放前修建的绿荫塘老尾矿库尾砂稀散元素铟、镉、锗均远超过工业品位,具有一定开采价值。70年代修建的长坡尾矿库铟、镉达到工业品位;90年代修建的车河、茶山尾砂库只有铟达到工业品位。四个尾矿库中稀散元素含量与尾砂来源和选矿水平密切相关,并发生次生淋滤富集作用。对环境有毒害的稀散元素镉尽管含量较高,但其主要赋存在闪锌矿中并没有释放到土壤环境中产生污染。这些调查研究结果将为政府部门和矿山企业决策提供依据。     

A new Late Triassic age for the Puesto Viejo Group (San Rafael depocenter,Argentina): SHRIMP U–Pb zircon dating and biostratigraphic correlations across southern Gondwana

The Puesto Viejo Group crops out in the San Rafael Block, southwest Mendoza, at approximately 35° S and 68°20′ W. It consists of the basal mainly grayish Quebrada de los Fósiles Formation (QF) overlying by the reddish Río Seco de la Quebrada Formation (RSQ). The basal unit includes both plant remains (pleuromeians and sphenopsids) and vertebrates (scattered fish scales, dicynodont synapsids and remains of an archosauriform). In contrast, the RSQ beds have yielded only tetrapods, although a more diverse fauna. The latter includes cynodonts as Cynognathus, Pascualognathus and Diademodon, and also dicynodonts (Vinceria and Kannemeyeria). Based on the assemblage of tetrapod taxa the bearing levels were correlated to the Cynognathus AZ of South Africa and thus referred to the Middle Triassic (Anisian). We obtained a SHRIMP ²³⁸U/²⁰⁶Pb age of 235.8 ± 2.0 Ma from a rhyolitic ignimbrite interdigitated between the QF and RSQ formations at the Quebrada de los Fósiles section. This new radiometric date for the Puesto Viejo Group suggests that the tetrapod fauna in the RSQ beds existed, instead, during the Late Triassic (early Carnian) some 10 Ma later than the currently accepted age. Two scenarios might explain our results: first, the Cynognathus AZ of South Africa is wrongly assigned to the lower Middle Triassic (Anisan) and should be considered younger in age, Late Triassic (Carnian); second, the relative age of the Cynognathus AZ of South Africa is correct but the inferred range of Cynognathus and Diademodon is incorrect as they were present during the Late Triassic (Carnian) at least in South America. In any case, this new date pose serious doubts about the validity of biostratigraphic correlations based solely on tetrapod taxa, a common practice for Triassic continental successions across Gondwana.     

Prediction of Impacts Caused by South-to-North Water Diversion on Underground Water Level in Shijiazhuang

After implementation of the South-to-North Water Diversion Project which has attracted worldwide attentions, new surface water sources would be added and, accordingly, mining of groundwater for industrial and living water would be reduced to ease the mining pressure of the underground water and abate the decline of the water level in the depression centers of Shijiazhuang and the whole intake area. Numerical model was established in this paper to respectively calculate the underground water level in 2020 based on three schemes including mining status of underground water, urban water resource planning of South-to-North water diversion in Shijiazhuang and Hutuo River infiltration with artificial regulation and storage. It is estimated that after implementation of the South-to-North Water Diversion Project, the buried depth of groundwater of depression centers in Shijiazhuang in 2020 will increase by 28.5~41.09 m comparing with that without water supply through South-to-North water diversion     

A Note on Extension Variances in IR2

Matheron (1971) proposed an approximation of the extension variance in IR. We propose in this note an extension of this formula in IR ² , based on a MacLaurin formula. Its application is shown in an example, the estimation of the maximum depressional storage of a soil surface.     

Palaeogene Sediment-hosted Pb–Zn deposits in SE Asia: the Uragen example

The strata-bound Pb–Zn deposits in western China share many similarities and are controversial in genesis. The large Uragen Pb–Zn deposit is located in the northwestern part of the Kashgar sag, southwest of Tarim Basin, Xinjiang, NW China. With the 980.9 Mt tons of Pb–Zn ores at 0.45%Pb and 2.61%Zn, it is the third largest known Pb–Zn deposits in China. The orebodies are stratiform and stratabound and are predominantly controlled by the Uragen syncline that has an E–W axial trend. Mineralization mostly occurs in sandstones and conglomerates of the Lower Cretaceous Kezilesu Group (K₁kz), with a small amount in the Palaeocene limestone. The main ore types consist predominantly of disseminated ore with minor massive ore, veined ore, and breccia ore. The primary metal minerals are composed of sphalerite, galena, pyrite, and minor arsenopyrite and chalcopyrite, and the supergene metal minerals include smithsonite, cegamite, beudantite, jarosite, limonite, and minor hemimorphite. The gangue minerals are composed of dolomite, calcite, quartz, celestite, and gypsium. Our new Rb–Sr isotopic analyses on the separated sphalerite, galena yielded an isochron age of 55.1 ± 1.6 Ma, coeval to an isochron age of 55.4 ± 2.2 Ma by Sm–Nd isotopic data. This age is much younger than the youngest ore-bearing strata (E₁¹, 65.5–61.7 Ma), arguing for an epigenetic origin. The calculated initial ⁸⁷Sr/⁸⁶Sr ratio of sulphides is 0.710322, which is much lower than those of basement formation, regional bituminous sandstone, and even the ore-bearing strata, but higher than the regional mantle-derived, alkaline volcanic rocks and marine carbonate. The calculated initial ¹⁴³Nd/¹⁴⁴Nd ratio of calcite and galena is 0.512081. These data suggest that the metals may be chiefly derived from crust, possibly from the minor contribution of mantle materials. Our new-age data, in combination with the previous data, suggest that there probably is a huge medium-low-temperature epigenetic stratabound Pb–Zn belt, which is possibly correlated to the India–Asia collision event.     

Provenance,tectonic setting and source of Archean metasedimentary rocks of the Browns Range Metamorphics,Tanami Region,Western Australia

This study combines U–Pb age and Lu–Hf isotope data for magmatic and detrital zircons, with whole-rock geochemistry of the Browns Range Metamorphics (BRM), Western Australia. The BRM are medium- to coarse-grained metasandstones that consist of angular to sub-rounded detrital quartz and feldspars with minor granitic lithic fragments. The sequence has undergone partial to extensive quartz–muscovite alteration and rare-earth-element mineralisation and has been intruded by mafic/ultramafic, syenitic and pegmatitic intrusive rock units. Uranium–Pb and Lu–Hf isotopic data on detrital zircons from the metasandstones and intruding granitic rocks yield a well-defined age of ca 3.2 to ca 3.0 Ga for all samples, with relatively radiogenic ?_Hf values (?_Hf = –1.7 to 5.1) indicating derivation from Mesoarchean granite basement of juvenile origin. This is consistent with geochemical and petrological data that support deposition from a granitic source in a continental rift basin setting. The timing of sediment deposition is constrained between the ca 3.0 Ga age of the source rocks and ca 2.5 Ga age of the granitic intrusive bodies that cross-cut the metasedimentary rocks. The ca 2.5 Ga zircons from the intrusive rocks have ?_Hf model ages of ca 3.4 to ca 3.1 Ga, which is consistent with formation via partial melting of the BRM, or the Mesoarchean granite basement. Zircons of the Gardiner Sandstone that unconformably overlies the BRM return detrital ages of ca 2.6 to ca 1.8 Ga with no trace of ca 3.1 Ga zircons, which discounts a significant contribution from the underlying BRM. The Mesoarchean age and isotopic signatures of the BRM zircons are shared by some zircon records from the Pine Creek Orogen, and the Pilbara, Yilgarn and Gawler cratons. Collectively, these records indicate that juvenile Mesoarchean crust is a more significant component of Australian cratons than is currently recognised. This work also further demonstrates that detrital minerals in Paleoproterozoic/Archean sedimentary rocks are archives to study the early crustal record of Earth.     

Carbon capture and storage, bio-energy with carbon capture and storage, and the escape from the fossil-fuel lock-in

Carbon capture and storage (CCS) is increasingly depicted as an important element of the carbon dioxide mitigation portfolio. However, critics have warned that CCS might lead to “reinforced fossil fuel lock-in”, by perpetuating a fossil fuel based energy provision system. Due to large-scale investments in CCS infrastructure, the fossil fuel based ‘regime’ would be perpetuated to at least the end of this century.In this paper we investigate if and how CCS could help to avoid reinforcing fossil fuel lock-in. First we develop a set of criteria to estimate the degree of technological lock-in. We apply these criteria to assess the lock-in reinforcement effect of adding CCS to the fossil fuel socio-technical regime (FFR).In principle, carbon dioxide could be captured from any carbon dioxide point source. In the practice of present technological innovations, business strategies, and policy developments, CCS is most often coupled to coal power plants. However, there are many point sources of carbon dioxide that are not directly related to coal or even fossil fuels. For instance, many forms of bio-energy or biomass-based processes generate significant streams of carbon dioxide emissions. Capturing this carbon dioxide which was originally sequestered in biomass could lead to negative carbon dioxide emissions.We use the functional approach of technical innovations systems (TIS) to estimate in more detail the strengths of the “niches” CCS and Bio-Energy with CCS (BECCS). We also assess the orientation of the CCS niche towards the FFR and the risk of crowding out BECCS. Next we develop pathways for developing fossil energy carbon capture and storage, BECCS, and combinations of them, using transition pathways concepts. The outcome is that a large-scale BECCS development could be feasible under certain conditions, thus largely avoiding the risk of reinforced fossil fuel lock-in.     

业务流程个性化和可视化的实现

引入面向对象设计的思想，提出了业务流程组件的概念，通过通用的业务流程组件的建模，并将其参数化而使得业务流程平台成为根据用户权限而可以自由进行可视化组装的工作平台。设计了新的会商流程，实现了天气预报会商的多媒体化，同时输出多媒体的天气预报幻灯片，作为台站之间交流的信息产品。