天姆尖破火山机构——潜在的富大铀矿找矿远景区

本文通过对天姆尖地区地质、遥感、重磁、地化等资料的综合分析和野外地质调查，初步查明了天姆尖破火山机构的成生及展布特征，识别出该区大面积分布的碎斑熔岩体系。认为该火山盆地经历了热隆起和破火山机构形成两个演化阶段，该区存在大型隐伏富铀花岗岩体；区内岩浆在垂向演化过程中，铀表现为下部富集而上部贫化带出的特点，大量成矿物质随岩浆热液向上进入破火山机构中成矿。此外，查明了该区以北东向断裂为主导的北东－北西向菱格状基底构造格局，强调了基底断裂对本区岩浆活动、火山盆地形成和铀成矿的控制作用。在对天姆尖地区铀成矿地质条件进行综合分析的基础上，指出该破火山机构具有形成富大铀矿床所必备的“源、运、聚、保”等各项条件和有利的多元成矿信息显示，是寻找富大铀矿床极为有利的远景区。     

Olympus Mons volcano,Mars: A photogeologic view and new insights

The volcano Olympus Mons is probably the best known extraterrestrial volcano. In the past decade, an unprecedented selection of high-resolution images with a spatial resolution of up to 25?cm/pixel has been collected, and these images now allow detailed morphologic analysis of the entire volcano. The summit comprises a nested caldera with six overlapping collapse pits. There are numerous wrinkle ridges and graben on the caldera floor, and topographic data indicate that the location of these features is controlled by subsidence of the central portion of the floor. Examination of the caldera walls reveals numerous layers interpreted to be lava flows. No clear evidence for eruption sites on the flanks of the volcano exist; rather, many previously identified sources of lava appear to be break-outs from flows up-slope which are controlled by local breaks in slope. The vents for these eruptions were most likely within the summit caldera but have been removed by the set of six large collapse events that have produced the 60?×?80?km diameter caldera, which are collectively called the “Olympus Paterae”. The origin of the basal escarpment surrounding the volcano remains enigmatic, but it is probably related to the origin of the surrounding lobate materials collectively called the Olympus Mons aureole. In places, this escarpment is >5?km high, but the elevation of the back-wall varies from ～1?km to ～8?km relative to the Mars datum. Inspection of kilometer-scale blocks within the aureole indicates that this material is not composed of lava flows, suggesting that the base of Olympus Mons consists of fragmented material comparable to the hyaloclastite material forming the base of Hawaiian volcanoes. Numerous additional features on Olympus Mons are discussed, including two large impact craters near the summit of the volcano, glacial deposits on the lower western flanks, channels and small shields around the base of the volcano, and ridges north of the escarpment which may have formed via the emplacement of dikes into ice-rich materials. Comparison with other Martian volcanoes may also help the analysis of Olympus Mons; the morphology of the basal escarpment of Apollinaris Patera suggests that erosion by wind or water may be restricted to the lowest elevations on Mars. If the basal materials of Olympus Mons are unconsolidated, then Olympus Mons may have been similar to Alba Mons or Tyrrhena Mons during the early phases of volcano growth. Certain basaltic volcanoes on Earth may serve as good analogs for features seen on Olympus Mons; the summit of Masaya volcano, Nicaragua, displays similar features to Olympus Patera at the summit caldera of Olympus Mons.     

Electric structure of the Copahue Volcano (Neuquén Province,Argentina), from magnetotelluric soundings: 1D and 2D modellings

Four magnetotelluric soundings were carried out in 1993 in the region of the Copahue active volcano located at the border between Chile and Argentina (37°45′S, 71°18′W). Three soundings were located inside the caldera of the ancient stratovolcano (east of Copahue) and the fourth outside it. The soundings inside the caldera were situated at about 6, 11, and 14 km from the volcano. Digital data were obtained covering the range of periods from 1 sec to 10,000 sec using induction coils and a flux-gate magnetometer to obtain the magnetic data and Cu-SO₄Cu electrodes for electric field measurements. The apparent resistivity curves corresponding to principal directions were analyzed in conjunction with the geological background in order to eliminate distortion — which is very important in this hot volcanic region. Then, 1D modellings were performed using the “normal” curves — i.e., curves without distortions. Using the apparent resistivity curves with distortions, 2D modelling was also performed along a profile perpendicular to the regional tectonic trend suggested by MT soundings into the caldera. Results show low resistivity values of about 3-15 Ωm between 9 km to 20 km depth in the crust, suggesting high temperatures, with minimum values of about 700°C with partially melted zones in the upper crust between 9 km to 20 km depth under the caldera. The presence of a possible sulphide-carbonaceous layer (SC layer) in the upper basement could play an important role in lowering the electrical resistivities because of its high electronic conductivity.     

THE SPILITE-KERATOPHYRE FORMATION IN THE REGION OF THE BLYAVA DEPOSIT IN THE URAL MOUNTAINS (PART 2 OF 2)

The article deals with a new vein deposit of kyanite in Bulgaria and some considerations concerning the origin of kyanite veins in general. The kyanite is found in quartz veins within garnetiferous staurolite schists of probable Jurassic age. The kyanite crystals are up to ten centimeters long along the c-axis and form parallel rodlike aggregates perpendicular to the selvages of the veins. The origin of the kyanite in the quartz veins is due to mobilization of silicon and aluminum under the action of boron and small quantities of alkalies, contained in pneumatolitic-hydrothermal or hydrothermal solutions. The temperature and the pressure are thought rather low but should be taken into consideration. It is suggested that the terms “stress” and “antistress minerals” be dropped and the terms “piezogene” and “thermogene” be introduced, depending on whether pressure or temperature plays the prevalent role in the formation of the mineral. — auth. English Summ.     

PROGRESS OF GEOLOGICAL STUDIES AT THE ACADEMY OF SCIENCES OF THE U.S.S.R.

Progress report deals with: 1) Geochronology — potassium-argon — principally Precambrian. Gives dates on Precambrian of Baltic Shield including eastern Sweden, Northeastern Norway, Finland, Karelia, and Kola Peninsula. Gives a correlation of the Precambrian for the entire European U.S.S.R. 2) Depth and origin of magmatic ore deposits using reconstructed erosion surfaces for the major periods of mineralization. The depth zones of ore formation of American and European theories is questioned. 3) Tectonic mapping in crustal studies. And in this conjunction 4) Bathy-metric map of the Pacific has been prepared, conspicuous features are major tectonic and volcanic forms of the ocean bottom, as well as minor detail. Brief mention is made of ore deposits from the ocean. 5) “Weathering Crust” studies of subaerial weathering erosion and deposition, mainly of ancient crusts. 6) Study on the origin and distribution of “agricultural areas”, mainly phosphates. 7) Compilation of a Manual of Minerals now underway.--M.A. Klugman.     

The anthracite smokers of eastern pennsylvania:P_{S_2 (g)} -T stability diagram by TL analysis

Coal seams and culm banks associated with mine fires in the anthracite region of eastern Pennsylvania have been burning for decades. Many of the fires may have ignited by spontaneous combustion or by the burning of trash. Minerals associated with the combustion of anthracite form by the condensation of gas exhaled through surficial gas vents or “anthracite smokers.” A Pressure-Temperature (P-T) stability diagram is constructed for the condensation of orthorhombic sulfur from anthracite gas using “Thermodynamic Loop Analysis” (TL analysis). This method of analyzing chemical systems incorporates Kirchhoff's Law into a four step procedure structured around a closed thermodynamic cycle or “thermodynamic loop.” The four steps, referred to us “The Four S ′S of Thermodynamic Loop Analysis,” include: (1) “Set Up”—graphical characterization of the problem. (2) “Sum”—the application of thermodynamic principles. (3) “Substitute”—the use of materials data available from the literature, and (4) “Solve”—computation of one or more variables. The example presented demonstrates that thermodynamic loops can incorporate any number of polymorphic phase transformations. In addition, thermodynamic loop analysis is applicable to any geologic process involving the condensation of minerals from a gas. The stability diagram derived by TL analysis may have applicability in monitoring the release of sulfur gas into the atmosphere.     

Effect of petrophysical properties and deformation on vertical zoning of metasomatic rocks in U-bearing volcanic structures: A case of the Strel’tsovka caldera,Transbaikal region

The development of vertical zoning of wall-rock metasomatic alteration is considered with the Mesozoic Strel’tsovka caldera as an example. This caldera hosts Russia’s largest uranium ore field. Metasomatic rocks with the participation of various phyllosilicates, carbonates, albite, and zeolites are widespread in the ore field. In the eastern block of the caldera, where the main uranium reserves are accommodated, hydromica metasomatic alteration gives way to beresitization with depth. Argillic alteration, which is typical of the western block, is replaced with hydromica and beresite alteration only at a significant depth. Postore argillic alteration is superposed on beresitized rocks in the lower part of the section. Two styles of vertical metasomatic zoning are caused by different modes of deformation in the western and eastern parts of the caldera. Variations of the most important petrophysical properties of host rocks—density, apparent porosity, velocities of P- and S-waves, dynamic Young’s modulus, and Poisson coefficient—have been determined by sonic testing of samples taken from different depths. It is suggested that downward migration of the brittle-ductile transition zone could have been a factor controlling facies diversity of metasomatic rocks. Such a migration was caused by a new phase of tectonothermal impact accompanied by an increase in the strain rate or by emplacement of a new portion of heated fluid. Transient subsidence of the brittle-ductile boundary increases the depth of the hydrodynamically open zone related to the Earth’s surface and accelerates percolation of cold meteoric water to a greater depth. As a result, the temperature of the hydrothermal solution falls down, increasing the vertical extent of argillic alteration. High-grade uranium mineralization is also localized more deeply than elsewhere.     

Multi‐kilometre long pathway of geofluids migration: Clues concerning an ophiolite serpentinization setting possibly responsible for the inferred abiotic provenance of methane in thermal water outflows of the South‐West Carpathians (Romania)

Methane occurrences displaying signatures of a possible abiotic origin had previously been reported in the South‐West Carpathians (Romania). Such an accumulation, at Tisovi?a, was intercepted by a well drilled in an ophiolitic rocks massif, whereas in two other localities—situated tens of kilometres faraway—the concerned methane is released via thermal groundwater outflows that are apparently not associated with any ultramafic products. By using groundwater ionic compositions, corroborated with previously published isotopic (¹³C‐CH₄, ²H‐CH₄, ³He/⁴He) and molecular gas analyses, we assessed in more detail the conjectured abiotic provenance of methane, and quantitatively investigated the hypothesis of a progressive mixing between two, abiotic and thermogenic, methane end‐members. The corresponding geofluids behaviour was modelled by hypothesizing a “concealed” ophiolite serpentinization setting (largely similar to that at Tisovi?a), whose abiotic methane production was “diverted” towards remote discharges at ground surface, via a ~20‐km‐long flowpath supposedly generated by recently operating extensional tectonics.     

松辽盆地白垩系营城组再搬运火山碎屑与相模式

以松辽盆地东南缘营城组二段两类火山碎屑岩(沉凝灰岩、凝灰质砂岩)为研究对象, 进行了火山碎屑粒度特征、碎屑组成和火山碎屑岩相研究.结果显示, 火山碎屑搬运除受火山作用激发控制外, 还受牵引流、重力流以及牵引流和重力流的双重机制影响.火山碎屑微观特征、成因分析和岩相分析认为, 本区火山碎屑堆积主体为热基浪堆积和热碎屑流堆积, 部分为空落堆积.火山碎屑组成特征为晶屑含量多, 玻屑和岩屑含量少, 且岩屑仅在较粗粒级颗粒组成中存在.研究认为, 本区发育的火山碎屑为沉积环境中的再搬运火山碎屑, 共识别出4种火山碎屑岩相, 河流故道上的热基浪, 河流故道上的热碎屑流, 冲积平原上的热基浪和空落相.建立了松辽盆地东南缘露头区营城组二段河流-冲积平原沉积环境的再搬运火山碎屑岩相模式.      

Fluid inclusion and carbon isotope study from bamble granulites (South Norway)

The carbon isotopic composition of CO₂ from fluid inclusions in granulite facies rocks has been determined. The “primary” carbonic fluid — most probably being of Upper Mantle origin — appears to have δ ¹³C-values around ?15%. or even lighter up to ?20%. During the late stages of retromorphosis an enrichment in the heavy carbon isotope seems to occur resulting in δ-values between ?5 and ?7%. which, on the basis of ¹³C/¹²C ratios of carbonatites, kimberlites and diamonds have been taken up till now as representative for juvenile carbon. The implications of these findings are discussed.     

生物标志化合物在地层划分与对比中的应用——以塔里木盆地下古生界为例

生物标志化合物是指沉积岩或原油和煤中碳—碳骨架稳定的特征化合物 ,它通常是用于油源对比和古沉积环境的恢复。本次研究在地层划分与对比中尝试利用正常甾烷分布的差异 ,研究表明 ,塔里木盆地寒武系—下奥陶统和中上奥陶统的甾烷分布特征完全不同 :前者的 C2 8甾烷含量高于后者 ,正常甾烷的分布是 C2 9>C2 8>C2 7,呈反“L”型分布 ;后者的 C2 7甾烷含量高于前者 ,甾烷的分布是 C2 9>C2 7>C2 8,呈“V”字型分布。寒武系—下奥陶统和中上奥陶统甾烷分布由反“L”型变为“V”型 ,说明生物在演化过程中 ,有机质的来源及化学结构组成发生了明显变化 ,据此可用于塔里木盆地下古生界的地层划分与对比。     

Principles of major classification of natural waters

The article presents some interesting, highly controversial, but well documented, ideas on the genesis of natural waters and their subsequent evolution. “Endothegenic” is embraced as a better name for what has long been called “juvenile” water. “Biogenic” waters include all other waters of various origins, except “cosmic” waters which are extra-global. Subclasses of water should be defined on basis of principal anion(s) and on physical criteria such as temperature or isotopic composition. — B.N. Cooper.     

从塔里木盆地看中国海相生油问题

塔里木盆地厚达 5～ 7km的海相寒武、奥陶系 ,可划分出下、中寒武统和中、上奥陶统两套工业性烃源岩。油源对比证实 :盆地目前保存下来的海相成因工业性油藏 ,主要来源于中上奥陶统泥灰岩。正是因为塔里木盆地比四川、鄂尔多斯盆地多了一套中等成熟的中上奥陶统油源岩 ,所以能够找到海相油田。笔者认为 :海相工业性烃源岩不必很厚 ,但w (TOC)应≥0 .5% ,碳酸盐岩要含泥质 ;海相源岩往往并不发育在凹陷中心 ,而发育在 4种有利沉积相带上 ;碳酸盐岩具有“双重母质”的特点 ,浮游藻类偏油 ,底栖藻类偏气。海相源岩的形成模式有“保存模式”和“生产力模式”两种 ,分别对应于塔里木寒武系和中上奥陶统烃源岩。塔里木古生代克拉通早期活动、晚期稳定、持续降温的演化史 ,有利于海相油气的多期成藏和晚期保存。     

Temperatur-Änderungen in der Erdgeschichte

This paper on “Temperature changes in earth-history” is an extension of a lecture given as an introduction to a section of equal title on the annual meeting of the Geologische Vereinigung, March 1976, in Hannover. The general development of paleoclimatological research in the last 300 years is represented on two diagrams (fig. 1–2) showing also the part of different climatic indicators. Otherwise, however, mostly new results and problems of the last years are treated (mainly papers since 1973; references of older literature are to be found in the 3^rd edition of the author's book on “Climates of the Past” = “Klima der Vorzeit”, Enke/Stuttgart 1974). This paper refers a) to some short comments on certain climatic indicators as diamictites (a similar term isSchermerhorn's “mixtite”, but “diamictite” is 6 years older and has therefore priority to “mixtite”) and “stellate nodules” (in the chapter “Mesozoic”) indicating perhaps cool climate in the Arctic. - b) Some great ice-ages are briefly discussed: Huronian (very important because of its old age); Late Proterozoic (“Eocambrian”) with many problems on account of its pretended worldwide extension. but with many uncertainities (partly pseudotillites, inconsistent paleomagnetic poles, combination of tillites with dolomites etc.); Permo-Carboniferous (many hypothesises up to 1975 try to explain the pretended “equatorial” position of tillites); Cenozoic ice-age (once “Quaternary” ice-age), with table 1 indicating some possibilities to evaluate the beginning of glaciations in Tertiary time (fig. 4). Why does glaciation start in Antarctica in the Tertiary? (Not or not only on account of drift via South Pole, but perhaps because of high relief and changes in global paleogeography). — c) Diagram of the great ice-ages in earth-history (fig. 6 b): it probably shows not all ice-ages but only the known ones indicating their maxima (i. e. times when inlandice extended to middle latitudes). This curve is probably essentially correct back to 300–400 m. y. yet especially the Precambrian time is still mostly paleoclimatic noman's-land. It is not possible to fix beginning and end of the Pre-Tertiary ice-ages exactly but at any rate the “akryogene” climates lasted longer than the “kryogene” ones (“kryogene” defined as climate with “much ice” [“pleistokryogene”], “akryogene” not as climate “without ice” but as climate with “a little ice” [“oligokryogene”]). - d) Periodicities in the temperature history: before exact dates were available (especially for Late Proterozoic and Huronian ice-ages) and before the Sahara glaciation of the Old Paleozoic was known, a periodicity of 250–300 m. y. was likely to exist. Therefore relations to the “Galactic year” were reasonable, stimulating attempts to find out plausible mechanisms for such a relation. But now, such a periodicity seems unlikely to exist (and much more one of 155 m. y., supposed byWilliams). The relative constancy of global earth temperatures over at least more than 2 billion years is more striking than their variations, though regionally the depressions may be very conspicious (in the middle, “sensitive” latitudes). Such depressions, however, are triggered by very small climatic changes on account of the existence of a hydrosphere with temperatures very favorable for a transformation of water into ice and vice versa. No other celestial body of our solar system has these optimal conditions with the consequences of occasional initiation of ice-ages. Ice ages, so to speak, are an inherited pecularity of the earth. The earth is the only “Ice-age Planet”. Under these circumstances, relatively small factors may cause ice-ages: multilateral origin of climatic changes. The most efficient parameters may be paleogeographic variations (relief etc. inclusive continental drift). Some comments are made on the radiation curves reflecting not the direct cause of glacials and interglacials but perhaps shorter climatic variations as they appear possibly in the curves of ocean temperatures (Emiliani etc.). Volcanic ashes seem not to have any farreaching influence on global temperatures; at least it is geologically impossible to support appropriate hypothesises by observations on continental volcanic sequences. The number of ash-layers in deep-sea cores may reveal sounder arguments though much more observations are needed to corroborate this supposition. — Table 2 gives a summary of the primary (planetary), secondary (multilateral) and — in special situations — tertiary “autocyclic” causes of climatic changes. Table 3 focuses on autocycles i. e. mechanisms which run. off automatically and could have caused the regular climatic variations in the Late Pleistocene with the classic glacialinterglacial sequence (not known from the older Quaternary or Pre-Tertiary ice-ages). In my opinion the most probable hypothesises on autocycles are those which were founded on wide extending subarctic continents of the northern hemisphere (qualified for the formation of large inlandice) in combination with mighty oceanic heat storage (Stokes, D. P. Adam, R. E. Newell).     

DUST-2: Towards a more efficient (interactive) documentation and validation of scientific information demonstrated with ozone,water vapour and other selected data of the Earth's atmosphere

The exponential growth of geophysical information must lead inevitably to a better access to geophysical information for science and education, especially if the resources shrink and the cost-efficiency ratio needs to be improved predominantly for the (non commercial and insufficient rich) users, who suffer from the fast rising information retrieval costs, now charged by nearly all major information systems. (This is, however, different in the U.S.A. because of the “freedom of information act”). That a better access means essentially more than just faster and more information is demonstrated with the DUST-2 CD-ROM (Data Utilization Software Tools). As a result of an international MPAe pilot project (FKZ.: 50 EE 98038) this CD-ROM has been published in September 2000 under ISBN 3-9804862-3-0. It was conceived predominantly for scientific technical purposes and can be regarded as a continuation of the work which was started in 1985 at MPAe to edit a Landolt-Börnstein data handbook “The Upper Atmosphere”. The DUST-2 concept is an example for an interactive, flexible interface and qualifying filter, although only a first step-matching several different non uniformly formatted data sources. The DUST-2 CD provides graphical methods of qualified information retrieval. It allows a synergetic combination of selected information of the Earth's atmosphere, texts and relevant numerical data for the topics ozone and water vapour. The software tools can be applied in principle to any data base. In the first chapter of this introductory paper 9 other papers are briefly described that show the scientific-technical background of the new and upgraded classical information processing DUST-2 “tools”. They still need to be stronger interrelated. The “joint retrieval method” allows an optimal, value added, data validation. This is demonstrated with a combination of temperature data from the Millimeterwave Atmospheric Sounder (MAS) with corresponding ones from a GRAS sensor (GRAS: Combined GPS-GLONASS receiver). The impressively good results strongly support the concept of a relevant technologically feasible MAS Followon/GRAS experiment on the International Space Station (ISS). See paper 4. The (dynamic) DUST-2 concept will contribute — from a qualitative and temporal aspect — to a reduction of the insufficient supply of (general, actual) understandable geophysical information. It has been successfully demonstrated with 8 posters at the 25th General Assembly of the European Geophysical Society (EGS). The DUST-2 CD-ROM can be ordered via Copernicus Gesellschaft e.V., Max-Planck Str. 13, D-37191 Katlenburg-Lindau, Germany; shipping & handling 12 EUR or via URL: www.copernicus.org. The ADLATUS concept — still in the planning and fundraising phase — supplements the DUST-2 concept and puts special emphasis on educational aspects. It will also provide links to the Geographic Information System (GIS). In context with this enlarged ADLATUS concept an essential continuation of the earlier discontinued Landolt-Börnstein “ Upper Atmosphere” activities is possible and should lead to an “ADLATUS Atmosphere”.     

滇西新生代富碱斑岩的岩石特征与成因

对滇西金沙江-墨江缝合带中段新生代富碱斑岩的岩石地球化学和同位素组成的研究表明,这一套岩石形成在板内造山后的剪切和拉张构造环境,是壳-幔混合层物质部分熔融,快速上升浅部定位所形成。本区壳-幔过渡带可能是先期生成的一种富集源区。文中还讨论了壳-幔过渡带的成因及富碱斑岩岩浆活动与岩石圈演化的关系。     

On the formation of the vein-type uranium „Yellow Ores“ from the Schwarzach Area (NE-Bavaria,Germany) and on the behaviour of P,As, V and Se during supergene processes

Most of the U occurrences situated at the western edge of the Bohemian Massif show in their upper parts secondary U minerals. The immigration (P, V, As and Se) from the country rocks and the ore body, via saprolite and paleosoils into the secondary ore minerals is investigated. The P content is suggested to be closely related to hydromorphic paleosoils. From those intermediate stages it may have been brought into the upper parts of the vein structures. No laterogenic impoverishment in the wall rocks with respect to phosphorus or apatite could be determined. The arsenic distributions is also governed as at other sulfide deposits by underlying sulfides and reducing conditions of a primary hypogene ore zone, whereas vanadium content in U secondary minerals is closely related to the enclosing country rocks. Granites, on account of their low content in mafic minerals, have low V contents in U secondary minerals. Besides the Schwarzach Area, U ore mineralisations from other U occurrences have been investigated. Some of the U deposits are certainly of “per ascensum” origin and their secondary U mineralisation can well be interpreted as having been derived from the underlying primary “black ores”. However, some mineralisations cannot be classified with certainty as being “per ascensum”. They include some properties pointing to “per ascensum” (e. g. sulfide association) as well as characteristics typical for “per descensum” (small depth, large amounts of U-VI minerals). The mode of formation may in some cases be as follows: Variscan or Alpine ore mineralisations of no economic significance may have formed a reducing environment and caused U to be concentrated. Younger redistribution processes influenced by modern tectonics (uplifting) and the fluviatile drainage pattern have taken place and in some cases destroyed the primary deposits or enhanced the ore mineralisation. These processes roughly resemble those described from sandstone — hosted roll front deposits.     

The Bashilsky swell: an Upper Pleistocene extrusion in the Verkhnechegemskaya caldera (Northern Caucasus)

This work describes a young extrusive massif in the uppermost reaches of the Chegem River (Bashilauzu-su River), which had been considered as a feeder of the great sequence of Upper Pliocene rhyolite ignimbrites of the Verkhnechegemskaya caldera. The Upper Pleistocene age of the stratum, extrusive origin of automagmatic breccias and fluidolites, as well as its difference from rhyolites of the caldera are proven. The Bashilsky swell, located in the Late Pleistocene glacial trough, is evidence of young volcanism in this area, which has not been previously proposed.     

Vancouver’s newest Chinese diaspora: settlers or “immigrant prisoners”?

This study seeks to reground concepts of “diaspora” and “transnationalism” in the realities of everyday life through examining the lived experiences of immigrants. Based on in-depth household interviews and focus groups, it examines the newest Chinese diaspora in Vancouver—skilled immigrants from the People’s Republic of China. It explores the challenges that they face in an unfamiliar city, including employment and language barriers as well as domestic anxieties surrounding childcare, education and marital difficulties. The strategies that they adopt to counter these problems are at times transnational—in the form of astronaut families or transnational childcare—but almost always familial. Ultimately, the settlement challenges that they face, coupled with the available transnational possibilities, raise the question of whether they are settlers or “immigrant prisoners”, temporarily serving their time in Vancouver before a further relocation.