Small Basement Research Articles

Depositional models for fluvial sediments in an intra-arc basin: an example from the Upper Cenozoic Tokai Group in Japan

The Upper Cenozoic Tokai Group is an example of fluvial sedimentation in the Japanese intra-arc region. The sedimentary basin, in which the group was deposited, consiss of several small basement blocks. The depositional models and their controlling factors of the Tokai Group around the east coast of Ise Bay are clarified on the basis of facies analysis. Five sedimentary facies associations are recognized in the group. They represent deposits from gravelly low sinuosity trunk streams, gravelly to sandy low sinuosity streams, sandy low to middle sinuosity streams, sandy high sinuosity streams with a muddy flood plain, and sandy tributary high sinuosity streams with an extensive flood plain. Spatial and termporal facies distributions within the stratigraphic framework of the group show depositioal processes with a resolution of 0.5 to 1 m.y. Synthesizing tectonic movements and volcanism, depositional models were mainly controlled by syndepositional movement of small basement blocks, involving collapse, subsidence, and tilting. In particular, the change in tilt direction of a block resulted in high sinuosity streams, instead of low to middle sinuosity streams. Fluvial sedimentation controlled by volcanism is also recognized in the group. Thus, fluvial depositional models in this intra-arc basin are controlled by the interaction of tectonism and volcanism.

Mitigation of Indoor Radon in an Area with Unusually High Radon Concentrations

In an area of unusually high indoor radon concentrations of up to 270,000 Bq m-3, four houses were selected for mitigation of indoor radon. Methods used were basement sealing, soil depressurization, a mechanical intake and outlet ventilation system with heat exchanger in the basement, and a multilayer floor construction using a fan to suck radon from a layer between bottom slab and floor. Basement sealing proved unsuccessful, the radon concentration remained unchanged after the mitigation attempt. The most successful remedial measure was soil depressurization using two fans and loops of drainage tubes to withdraw radon from the region under the floor and outside the walls of the basement and from soil under the part of the house without a basement. This method reduced the basement radon level in winter by about a factor of 200, i.e., from 100,000 Bq m-3 to 500 Bq m-3, and the ground-floor level by about a factor of 400. As regards the mechanical intake and outlet ventilation system with heat exchanger in the basement, it is essential to ensure that ventilation provides increased air pressure in the basement compared to outdoors. Unbalanced mechanical intake and outlet ventilation may decrease the air pressure indoors compared to outdoors, leading to increased radon concentrations. Optimization of this method reduced radon concentrations from 200,000 Bq m-3 to 2,000-3,000 Bq m-3 in winter. In one house with only a very small basement, a multilayer floor construction using a fan to suck radon from a layer between the bottom slab and floor was found to reduce radon concentrations on the ground floor from 25,000 Bq m-3 to about 1,700 Bq m-3 in winter. The results show that even in areas with extremely high radon concentrations, effective mitigation of indoor radon can be accomplished if suitable techniques are used. The evaluation of the different mitigation methods shows good coincidence with the ICRP 65 report.

Basement slivers within the New Britain Accretionary Wedge: Implications for the emplacement of some ophiolitic slivers

Using multichannel seismic data from the western Solomon Sea we have imaged several 2.5 to 3‐km‐thick oceanic basement slivers within the New Britain accretionary wedge which may serve as a modern analogue for the detachment of some ophiolitic slivers. The most recently accreted basement sliver is located just over 5 km from the thrust front. An approximate area balance indicates the subjacent section of the downgoing plate from which this sliver originated is between 11 km and 15 km arcward of its present position. Though we have not imaged the basement ramp, sedimentary strata beneath the basement sliver pinch out between 9 and 12 km from its seaward edge, suggesting that detachment occurred in that vicinity. Normal faults reactivated in response to the flexural bending of the downgoing oceanic plate are a prominent feature of this region. Significantly, almost all basement normal faults near the recently accreted basement sliver, including those imaged beneath the toe of the wedge, dip arcward. Based on these data, we suggest that small (1–3 km thick) basement slivers are decoupled along favorably oriented, preexisting zones of weakness formed by normal fault detachments within the oceanic basement.

FlankFlux: an experiment to study the nature of hydrothermal circulation in young oceanic crust

The sediment-buried eastern flank of the Juan de Fuca Ridge provides a unique environment for studying the thermal nature and geochemical consequences of hydrothermal circulation in young ocean crust. Just 18 km east of the spreading axis, where the sea-floor age is 0.62 Ma, sediments lap onto the ridge flank and create a sharp boundary between sediment-free and sediment-covered igneous crust. Farther east, beneath the nearly continuous turbidite sediment cover of Cascadia Basin, the buried basement topography is extremely smooth in some areas and rough in others. At a few isolated locations, small volcanic edifices penetrate the sediment surface. An initial cruise in 1978 and two subsequent cruises in 1988 and 1990 on this sedimented ridge flank have produced extensive single-channel seismic coverage, detailed heat flow surveys co-located with seismic lines, and pore-fluid geochemical profiles of piston and gravity cores taken over heat flow anomalies. Complementary multichannel seismic reflection data were collected across the ridge crest and eastern flank in 1985 and 1989. Preliminary results of these studies provide important new information about hydrothermal circulation in ridge flank environments. Near areas of extensive basement outcrop, ventilated hydrothermal circulation in the upper igneous crust maintains temperatures of less than 10–20 °C; geochemically, basement fluids are virtually identical to seawater. Turbidite sediment forms an effective hydrologic and geochemical seal that restricts greatly any local exchange of fluid between the igneous crust and the ocean. Once sediment thickness reaches a few tens of metres, local vertical fluid flux through the sea floor is limited to rates of less than a few millimetres per year. Fluids and heat are transported over great distances laterally in the igneous crust beneath sediment however. Heat flow, basement temperatures, and basement fluid compositions are unaffected by ventilated circulation only where continuous sediment cover extends more than 15–20 km away from areas of extensive outcrop. Where small basement edifices penetrate the sediment cover in areas that are otherwise fully sealed, fluids discharge at rates sufficient to cause large heat flow and pore-fluid geochemical anomalies in the immediate vicinity of the outcrops. After complete sediment burial, hydrothermal circulation continues in basement. Estimated basement temperatures and, to the limited degree observed, fluid compositions are uniform over large areas despite large local variations in sediment thickness. Because of the resulting strong relationship between heat flow and sediment thickness, it is not possible, in most areas, to detect any systematic pattern of heat flow that might be associated with cellular hydrothermal circulation in basement. However, an exception to this occurs at one location where the sediment thickness is sufficiently uniform to allow detection of a systematic variation in heat flow that can probably be ascribed to cellular circulation. At that location, temperatures at the sediment–basement interface vary smoothly between about 40 and 50 °C, with a half-wavelength of about 700 m. A permeable-layer thickness of similar dimension is inferred by assuming that circulation is cellular with an aspect ratio of roughly one. This thickness is commensurate with the subbasement depth to a strong seismic reflector observed commonly in the region. Seismic velocities in the igneous crustal layer above this reflector have been observed to be low near the ridge crest and to increase significantly where the transition from ventilated to sealed hydrothermal conditions occurs, although no associated reduction in permeability can be ascertained from the thermal data.

Immunological and molecular approaches to the study of basement membrane proteoglycan diversity

It has been appreciated for some time that all mammalian basement membranes contain type IV collagen, laminin, entactin/nidogen and proteoglycans [ 11, but more recently it has become clear that there may be a high degree of tissue specificity in the expression of various forms of these molecules. For example, a chain of laminin known as s-laminin [2], is restricted to basement membranes which are present between two tissues, such as the kidney glomerular loop and the neuromuscular junction. In a similar way, it now appears that many forms of proteoglycan may be present in basement membranes, varying not only in core protein but also carbohydrate characteristics. Basement membrane heparan sulphate proteoglycan (HSPG) was first isolated from the murine transplantable Engelbreth-Holm-Swarm (EHS) tumour matrix [3, 41, and was found to have comparatively low buoyant density (approx. 1.3 g/ml), because of a high protein/carbohydrate ratio, the core protein being 400 kDa. As reported by us and others [ 3, 5, 61, antibodies against this HSPG showed widespread and uniform basement membrane staining of all tissues so far examined, including those of the human. Howcvcr, immunohistochemical analysis with polyclonal antibodies raised against a small HSPG with low protein/carbohydrate ratio and high buoyant density (approx. 1.5 g/ml), indicated this had a heterogeneous distribution in rat basement membranes 171. Although synthesized by most epithelia, including those of the skin and mammary gland, the small HSPG was apparently absent from visceral smooth muscle and cardiac muscle basement membranes. It is currently debated whether small basement membrane HSPGs are derived from the large HSPG by limited proteolysis. Evidence from the EHS tumour and studies on the kidney in vivo have lent support to this view [8, 91. Equally, other evidence has indicated that small HSPGs may be unique [6]. Our studies with antibodies support the case for at least some unique small HSPGs, but the problem can only clearly be resolved by protein sequence data. This is partially available for the large HSPG [lo], and we are currently cloning cDNAs from a mammary epithelial l g t l 1 library, screening with the antibodies against a small basement membrane HSPG [7]. So far, our sequence data do not coincide with those available for the large HSPG, and further important information has emerged from Northern blots. The mRNA encoding the small HSPG was found to be approximately 2.6 kb, whereas that for the large HSPG is 10I 1 kb. Therefore, we now have some evidence for the distinct nature of at least one small HSPG core protein. However, as we and others have indicated [6, 71, there may be some conservation of epitopes between members of this class of basement membrane component which can be detected immunologically. Whether these are protein or carbohydrate determinants is presently unknown. The complexity of basement membrane proteoglycans does not end with HSPGs. We have now identified a chon-

Basement membrane continuity in benign, premalignant and malignant epithelial conditions of the uterine cervix

The pattern of basement membrane deposition in the uterine ectocervix was assessed in benign, premalignant and malignant conditions, using an indirect immunoperoxidase technique to detect laminin, an intrinsic basement membrane component. A semi-quantitative approach was used to assess the frequency of small breaks in the basement membrane. The cervical squamous epithelium in benign epithelial conditions has an almost completely continuous basement membrane, but the development of viral atypia or cervical intraepithelial neoplasia (CIN) is associated with the appearance of small basement membrane breaks. There is a correlation between increasingly severe CIN and increasing numbers of breaks, and there is a concurrent increase in the numbers of subepithelial inflammatory cells. The development of invasive neoplasm is associated with a sudden change to a fragmented pattern of basement membrane deposition, a finding which is of potential diagnostic use.

Tholeiitic, calc-alkaline and (?)alkaline igneous rocks of the Shortland Islands, Solomon Islands

The Shortland Islands lie in a northeast-southwest line across the western end of Solomon Islands, immediately adjacent to Bougainville. Three major islands dominate the group. Fauro and surrounding islands, in the northeast, have an altered basement suite comprising tholeiite, icelandite and tholeiitic dacite. This is intruded by a high-level calc-alkaline assemblage of microdiorite, hornblende andesite and rhyodacite and overlain by volcanogenic sandstones derived from an andesitic to dacitic volcano. Pyroclastics comprising high-alumina basalt and pyroxene andesite overlie the volcanogenic sandstones. The tholeiitic basement lavas may be of Late Oligocene to Early Miocene age, and the calc-alkaline rocks are probably also pre-Pliocene in age. Alu, in the centre of the group, also has an altered tholeiitic lava basement, which is intruded by a quartz diorite body and overlain by hypersthene-augite basaltic andesite. Pliocene siltstone and Quaternary shallow marine carbonates cover these igneous rocks over much of the island. Mono, in the southwest, has a small basement exposure of altered pillowed hawaiite, overlain by Miocene pelagic limestone, Pliocene siltstone and Quaternary reef limestone. Isolated clasts of pyroxene andesite and ?benmoreite occur in streams and on beaches. The younger, calc-alkaline suites on all islands were formed in an island arc environment, possibly related to subduction from the southwest beneath the New Britain Trench. The basement lavas on Alu are probably early island arc tholeiites, and both these lavas and the calc-alkaline rocks of Alu share a common trend on variation diagrams. The two igneous suites of Fauro, however, have distinctly different trends. The basement lavas have some chemical similarities with oceanic tholeiites, but an early island arc origin for these lavas cannot be ruled out. The altered hawaiite and benmoreite on Mono probably originated in an oceanic island environment.

Geology of Norton Basin and Continental Shelf Beneath Northwestern Bering Sea, Alaska

The rocks that floor the Norton basin and the northwestern Bering Sea are most likely of Precambrian and Paleozoic age, like those rocks that crop out around the basin. A maximum of 6.5 km of mainly Cenozoic strata lie over basement in the basin. On the basis of the geometry of reflections in seismic data, we believe alluvial fans to be present deep in the basin and to border major basement fault blocks. These fans are the lowest units of the basin fill in many areas and consist of uppermost Cretaceous or lower Paleogene, possibly coal- and volcanic-rich rocks. Mainly clastic nonmarine sedimentary rocks overlie the fan deposits. The Neogene and Quaternary basin rocks apparently were deposited in a marine environment. The basement of the northwestern Bering Sea, west of Norton basin, is 1 km below sea level for the most part, but local structural lows are filled with at most 2 km of strata of probable late Neogene and Quaternary age. The continental shelf in this area is separated structurally from the Seward Peninsula by a zone of small basement antiforms, over which relatively high gravity values have been measured. The Norton basin comprises two structural areas that are separated by a major northwest-striking horst. The first structural area lies west of this horst, where major normal faults strike northwest to form local areas where the basin is as deep as 5 km. The second area, east of the horst, includes major normal faults that strike east and northeast. The deepest part of the Norton basin (6.5 km) lies there. During the Late Jurassic and Early Cretaceous, basement rocks now beneath the Norton basin were affected by the orogeny that formed the Brooks Range. These basement rocks were metamorphosed and thrust, and then eroded deeply nearly 50 m.y. before the basin began to form. In the middle Late Cretaceous, the area of the eastern Seward Peninsula and eastern Norton Sound was subjected to east-west compression and consequent eastward thrusting. The strike-slip Kaltag fault probably formed at this time. If Norton basin formed as a pull-apart basin along this fault, then the basin may be as old as middle Late Cretaceous. However, during the latest Cretaceous and early Paleogene, the compression gave way to regional extension that formed northeast-trending grabens onshore, east of Norton basin We believe that the extensional Norton basin most likely formed in response to this regional extension. Initial deepening of the basin was controlled by major normal faults and occurred rapidly, whereas subsidence was slower and more regional in scale.

Hydrogen Sulfide Poisoning in a Hospital Setting

TOXICITY from hydrogen sulfide (H₂S) has been experienced in industries involving petroleum refining, manufacturing of heavy water, tanning, vulcanization of rubber, manufacturing of rayon, and also in the fishing and refuse industries.^1,2An episode of H₂S poisoning occurred in an acute-care hospital, where H₂S gas resulted from the reaction of a strong acid in an industrial cleaner with plaster of paris sludge in a cast room drain. <h3>Report of a Case</h3> A previously healthy 45-year-old man set out to clean the cast room drain trap of a community hospital with 90% sulfuric acid (H₂SO₄) solution. Previous efforts to clean the drain had been limited to mechanical means (snaking) because of the high sludge content. As the H₂SO₄solution was poured into the drain in a small basement cubicle, noxious fumes spread through the hospital and the workman

Centro parroquial - Eching - Munich - Alemania federal

To stand out among the scattered urbanization in which it lies, this Parish Centre was designed as a group of independent buildings, distributed around a court-yard or atrium, and built on a rectangular design, intented, respectively, for the church, parish home and children's nursery. The church, due to its height, is the dominating feature of the whole. It has a main aisle, encircled by a less high passage, a small side chapel and the vestry. The parish home which is made up of a ground floor and semibasement, has, in the latter, a room for table tennis, two for groups and an area for heating the whole building. In the ground floor there is a parish hall with a stage and library. The children's nursery has the ground floor and a small basement, in which there are three stores and a workshop. The ground floor houses: the children's area, with two large rooms and a rest room; the teachers' area, with two rooms, toilets and kitchen; the services area, and finally, to complete the floor, an office and meeting room. The whole building has been made of whitewashed brick walls, contrasting with the large window panes.

Structural Framework of Sunda Shelf

The Sunda Shelf is one of the most extensive continental shelves of the world. In June-July 1971 a geophysical survey was conducted over the southern part of the shelf (Java Sea). Water depth, sediment thickness, and the gravity and magnetic fields were measured continuously. Expendable radiosonobuoys permitted seismic refraction measurements. These geophysical data, supplemented by data from earlier studies of the northern Sunda Shelf and geologic data from land areas, provide a comprehensive picture of the structural framework of the entire Shelf. The seismic reflection profiles show that the Sunda Shelf consists of three major units: the northern Sunda Shelf basinal area, the Singapore platform, and the Java Sea basinal area. In the northern unit are two large sedimentary basins (the Brunei and Gulf of Thailand basins) separated by the Natuna Ridge. In the Java Sea are several other basins separated by uplifts. The basins in the western Java Sea are approximately circular and seem to result from tensional forces, whereas those in the eastern Java Sea are narrow and long and appear to be the result of compressional forces. Radiosonobuoys revealed small basement features and resolved many strata having different seismic velocities. Faults are abundant throughout the Sunda Shelf and clearly control the distribution and shapes of the basins. The faults strike north-south in the western Java Sea and northeast-southwest in the eastern Java Sea. A major discontinuity trending north-south (termed here the Natuna rift in the northern Sunda Shelf and the Billiton depression in the western Java Sea) cuts the structures of the entire Sunda Shelf and continues southward across central Java to the deep-ocean floor. Analysis of magnetic anomalies shows that the region can be divided into several distinct magnetic provinces that do not everywhere follow the major structural units mapped by the seismic reflection data. These magnetic provinces coincide with corresponding provinces of lithic units. The gravity field over the central and southern Sunda Shelf averages about +30 mgal. Local gravity anomalies with relative amplitude of 10-25 mgal are superimposed on the regional background level. Although the local gravity anomalies were helpful in resolving the upper crustal structures, the cause for the high regional gravity is unknown. All of the geophysical studies serve to outline the distribution pattern of sediment-filled basins and intervening ridges and platforms beyond the level of understanding reached by early workers through inferences based upon the geology of the land areas, and beyond the scant publications of oil companies within the restricted areas of their concessions. These regional results may be helpful both for understanding the general structure of the Sunda Shelf and for denoting the areas with the greatest future oil potential. The main structural elements are interpreted as the result of past interaction between lithospheric plates.

DECOMPRESSION CRANIOTOMY IN BULLET WOUND OF BRAIN AND HEMIPLEGIA

Associate Neurologic Surgeon, Polyclinic Medical School and Hospital <h3>History.</h3> —D. M., man, aged 74, born in Ireland, of small stature, weight 120 pounds, was brought to the Polyclinic Hospital in the evening of Jan. 16, 1916. He was perfectly conscious, and gave his history frankly without showing any great excitement or any evidences whatever of shock. He said that two men entered his small basement store and at the point of a revolver demanded money. He gave them what he had, and in leaving, one of them fired at him, striking him in the face just below the left eye. Almost immediately he lost the sight of the left eye. <h3>Examination.</h3> —Just below the left eye was a small ragged wound, the size of a bullet, from which blood was freely oozing. There was also considerable hemorrhage from the left nostril. This was controlled by packing the nose with gauze,