BELGIAN SETTLEMENT AND SOCIETY IN THE INDIANA RUST BELT*

ABSTRACT. At first glance the industrial city of Mishawaka, near the northern border of Indiana, appears to be ethnically homogeneous. Closer examination, however, reveals the rich ethnic heritage of Mishawaka, as it does in so many other Rust Belt cities from Pittsburgh to Chicago. One of the most fascinating of these immigrant stories is the rise of Belgian Town, on Mishawaka's southwest side. This study examines residential, commercial, and social patterns of this evolving ethnic community during the first three decades of the twentieth century. Although industrial jobs attracted immigrants to the city, creation of a Flemish Catholic church provided the foundation on which to build a tightly knit Belgian community.     

云南腾冲-潞西金成矿带地质特征与成矿预测

腾冲-潞西金成矿带是云南省重要金成矿带之一。通过分析其地质特征，解剖矿带内典型金矿床，讨论矿带成矿模式及找矿方向，进而提出了矿带内两个重要矿化集中区(段)。     

Late Caledonian Ductile Thrusting Deformation in the Central East Kunlun Belt, Qinghai, China and Its Significance: Evidence from Geochronology

A high-angle ductile thrusting deformation with top-to-the-north movement penetratively developed in the Proterozoic-Early Paleozoic metamorphic rocks along the Central East Kunlun belt. The deformed rocks suffered epidote-amphibolite facies metamorphism. On the basis of our previous study, we present more data in this paper to further support that the ducdle thrust deformation occurred in the later Caledonian and more detailed information about the deformation. A zircon U-Pb concordant age of 446±2.2 Ma of a deformed granodiorite in the ductile thrust zone was obtained and can be interpreted as the lower limit of the deformation. A syntectonically crystallized and also strongly deformed hornblende Ar/ Ar dating gives an Ar/Ar plateau age of 426.5±3.8 Ma, which represents the deformation age. A strongly orientated muscovite gives an Ar/Ar plateau age of 408±1.6Ma, representing the cooling age after the peak temperature, constraining the upper limit of the ductile thrust deformation. This ductile thru     

滇中震旦系碳酸盐岩破碎地层的钻探护孔新技术

破碎地层中钻探，采用有效的护孔技术是避免孔内事故发生的重要手段，同时也是保证完成钻探各项技术经济指标的先决条件。本文阐述了在具代表性的磷矿破碎地层中钻进所遇到的护孔难题及其所采用的护孔新技术、新方法。     

Monsoonal precipitation variation in the East Asia since A.D. 1840 ——Tree-ring evidences from China and Korea

The main characteristic of the East Asian climate is the monsoon system. Plenty of studies have demonstrated that the Asian monsoon system plays a crucial role in the global climate sys- tem [1-4]. The Asian summer monsoon can be divided into two parts, t…     

吐哈盆地中央构造带正反转演化特征

吐哈盆地中央构造带由火焰山构造和七克台构造组成。中央构造带形成于三叠纪晚期至侏罗纪早期,表现为伸展构造特征,生长断层上盘地层厚度明显大于下盘,并于断层上盘所在的台北凹陷形成沉降中心。晚侏罗世,由于拉萨陆块与欧亚大陆的碰撞作用导致吐哈盆地由伸展盆地转变为挤压盆地,中央构造带也于此时发生构造反转,由早期的伸展正断层转变为挤压逆断层。发生于55Ma的喜山构造事件对天山地区产生了深刻的影响,但影响时间略有滞后,大致发生在晚渐新世至早中新世,中央构造带即在此次构造事件中强烈变形,逆冲出露于地表。     

Characterisation of the Dabla Granitoids, North Khetri Copper Belt, Rajasthan, India: Evidence of Bimodal Anorogenic Felsic Magmatism

The Palaeoproterozoic Dabla granitoid pluton of the North Khetri Copper Belt is located to the east of a NNE-SSW trending lineament with numerous albite-rich intrusives, the intraplate ‘albitite line’. The Dabla pluton is essentially made up of calcic amphibole-bearing granitoids, displaying a concentric bimodal distribution of alkali-feldspar granites, comprising a microcline-albite granite and an albite-granite. The dominant rock type is pink-coloured granite, which is characterised by quartz, microcline, albite and hastingsitic hornblende, and occurs in the marginal parts of the pluton. The volumetrically subordinate albite-granite in the central part of the pluton is invariably white in colour, non-foliated and is mainly composed of quartz, albite and amphibole of actinolite to ferro-actinolite composition. The albite-granite is characterised by low K₂O (0.06-0.09%), Rb (<5 ppm) and Ba (<20 ppm), high Na₂O (7.19-7.36%) and high Na/K ratios (122.4-185.2) as compared to the granite. These rocks are not subjected to any metamorphic overprint, especially the albite-granite, which shows pristine abundances of major and trace elements. The rocks are highly evolved as reflected in their high SiO₂ (72 to 78%) contents and high DI (89.5-97) values. The Dabla granitoids are characterised by similar REE and spider patterns, displaying LREE enriched slopes, flat HREE profiles and strong negative Sr, P, Ti and Eu anomalies suggesting their comagmatic nature. Nevertheless, the granite is relatively more fractionated [(La/Yb)_N = 3.89-8.19] and show higher REE abundances (466-673 ppm) as compared to the albite-granite [(La/Yb)_N = 1.97-2.96; REE = 220-277 ppm]. Distinctive features of these rocks are their low Ca (0.21-1.53%), Mg (<0.02-0.19%), Al (11.84-12.96%) and Sr (12-46 ppm) abundances, high Zr (155-631 ppm), Y (67-156 ppm), Nb (14-91 ppm), and Ga (20-31 ppm) concentrations and high Fe*-number, high Ga/Al ratio and high agpaitic index (AI) values. These features, coupled with their ferroan, alkaline and metaluminous nature, are typical of within-plate aluminous A-type granites. The geochemical data further indicate that the Dabla magma was generated at fairly high temperature, apparently in an upper mantle region, under relatively low H₂O activities and reduced conditions and emplaced at a shallow depth in an extensional tectonic environment.     

Hazard Zoning for Landslides Connected to Torrential Floods in the Jerte Valley (Spain) by using GIS Techniques

The Jerte Valley is anortheast-southwest tending graben located in the mountainous region of west central Spain (Spanish Central System). Mass movements have been a predominant shaping process on the Valley slopes during the Quaternary. Present day activity is characterized as either `first-time failure' (shallow debris slides and debris flows) or `reactivations' of pre-existing landslides deposits.A delineation of landslide hazard zoningwithin the Valley has been carried out by using the detailed documentation of a particular event (a debris slide and a sequel torrential flood, which occurred on the Jubaguerra stream gorge), and GIS techniques. The procedure has had four stages, which are: (1) the elaboration of a susceptibility map (spatial prediction) of landslides; (2) the elaboration of a map of `restricted susceptibility' in the particular case of slopes that are connected to streams and torrents (gorges); (3) the elaboration of a digital model which relates the altitude to the occurrence probability of those particular precipitation conditions which characterized the Jubaguerra event and (4) the combination of the probability model with the `restricted susceptibility map', to establish `critical zones' or areas which are more prone to the occurrence of phenomena that have same typology as this one.     

Effect of the chemical composition of the crust on the metamorphic evolution of orogenic wedges

Petrological data provide a good record of the thermal structure of deeply eroded orogens, and, in principle, might be used to relate the metamorphic structure of an orogen to its deformational history. In this paper, we present two‐dimensional thermal modelling of various subduction models taking into account varying wedge geometry as well as variation of density and topography with metamorphic reactions. The models clearly show that rock type accreted in the wedge has important effects on the thermal regime of orogenic wedges. The thermal regime is dominated by radiogenic heat production. Material having high radioactive heat production, like the granodioritic upper crust, produces high temperature metamorphism (amphibolitic conditions). Material with low radioactive heat production results in low temperature metamorphism of greenschist or blueschist types depending on the thickness of the wedge. Application of this model to seemingly unrelated areas of the Central Alps (Lepontine Dome, Grisons) and Eastern Alps (Tauern Window) explains the coexistence and succession of distinct Barrovian and blueschist facies metamorphic conditions as the result of a single, continuous tectonic process in which the main difference is the composition of the incoming material in the orogenic wedge. Accretion of the European upper continental crust in the Lepontine and Tauern Domes produces Barrovian type metamorphism while accretion of oceanic sediments results in blueschist facies metamorphism in the Valaisan domain.     

Paleozoic terranes of eastern Australia and the drift history of Gondwana

Critical assessment of Paleozoic paleomagnetic results from Australia shows that paleopoles from locations on the main craton and in the various terranes of the Tasman Fold Belt of eastern Australia follow the same path since 400 Ma for the Lachlan and Thomson superterranes, but not until 250 Ma or younger for the New England superterrane. Most of the paleopoles from the Tasman Fold Belt are derived from the Lolworth-Ravenswood terrane of the Thomson superterrane and the Molong-Monaro terrane of the Lachlan superterrane. Consideration of the paleomagnetic data and geological constraints suggests that these terranes were amalgamated with cratonic Australia by the late Early Devonian. The Lolworth-Ravenswood terrane is interpreted to have undergone a 90° clockwise rotation between 425 and 380 Ma. Although the Tamworth terrane of the western New England superterrane is thought to have amalgamated with the Lachlan superterrane by the Late Carboniferous, geological syntheses suggest that movements between these regions may have persisted until the Middle Triassic. This view is supported by the available paleomagnetic data. With these constraints, an apparent polar wander path for Gondwana during the Paleozoic has been constructed after review of the Gondwana paleomagnetic data. The drift history of Gondwana with respect to Laurentia and Baltica during the Paleozoic is shown in a series of paleogeographic maps.