Stone Layer Research Articles

Soil moisture and the distribution of giant Andean rosettes on talus slopes of a desert paramo

The distribution of giant Andean rosettes and soil moisture content during the dry season were studied in blocky and sandy talus slopes of the high Venezuelan paramo between 4335 and 4400 m. Rosette plants were virtually restricted to blocky talus and to areas downslope from isolated boulders embedded in sandy talus. Plant roots always grew upslope and beneath stones. Water content at the soil surface was 10 to 20 times greater under blocky talus and beneath boulders than in contiguous, bare sandy talus. The soil surface in the latter was very dry (< 1 'O water) when sampled both in 1987 and 1989. Soil moisture increased sharply with depth in all locations sampled, but always remained substantially higher below stones even at 20 cm depth. The amount of water available for plant growth above the permanent wilting point [PWP -1500 kPa) was also significantly greater under stones and boulders. Soil texture was similar (sand to loamy sand) in both talus types. Organic matter content was slightly higher in blocky talus, but its effects on water retention at PWP were minor, and could not be used to explain the observed differences in field moisture. Soil profiles in sandy talus were of a Typic Cryorthent, while the blocky talus was underlain by a fragmental Entic Cryumbrept. Several dry-season records of soil temperature show that both the maxima and minima were sorne\vbat lower under stones, but the differences with sandy talus were minor, and probably did not affect soil moisture. The higher water content found under stones and blocks could result from 3 processes. During precipitation, water readily flows over the inlpervious stone surfaces, and becomes concentrated in the sandy soil matrix found between and beneath stones. Afterwards, reduced water losses by evaporation occur due to the insulation provided by the superficial openwork layer of stones, which prevents capillary rise to the talus surface. In addition, falling temperatures at sunset could result in condensation in the hollow spaces between stones. Andean rosettes colonize blocky talus areas, and their roots grow under the stones, because soil there remains moist during the dry season, allowing plants to survive it more readily than in the desiccated bare sandy talus areas.

Internal and external pressure measurements in reshaped breakwaters

A series of hydraulic model tests was carried out to investigate the mechanisms by which reshaped breakwaters, that is breakwaters in which the initial profile is adjusted into a more stable profile as a result of wave action, gain their stability. This type of structure has been used frequently in the past decade, particularly in areas where a good supply of rock is available, and has been shown for these circumstances to have better stability characteristics and a much lower cost than conventional multi-layered designs. The breakwater models were instrumented with miniature stainless-steel diaphragm pressure transducers placed along the outer slope of the structure and along the core/filter interface. The motion of the phreatic surface within the internal porous matrix was determined using a set of specially designed capacitance gauges. A substantial reduction in the magnitude of the internal and external pressure fields was found for the reshaped structure compared with a conventional structure. The wave height at which the initiation of armour stone movement occurred was 60% higher for the reshaped structure than for a conventional breakwater armoured with two layers of the same size stone placed on a 1 : 2 slope.

Stonelines and landscape development on the laterized craton of Madagascar

Research Article| May 01, 1990 Stonelines and landscape development on the laterized craton of Madagascar NEIL A. WELLS; NEIL A. WELLS 1Geology Department, Kent State University, Kent, Ohio 44242 Search for other works by this author on: GSW Google Scholar BENJAMIN ANDRIAMIHAJA; BENJAMIN ANDRIAMIHAJA 2Ministère de l'Etablissement d'Enseignement Supérieur des Sciences, B.P. 4163, Tsimbazaza, Antananarivo, Madagascar Search for other works by this author on: GSW Google Scholar H.F.S. RAKOTOVOLOLONA H.F.S. RAKOTOVOLOLONA 3Musée d Art et d'Archéologie, 17, Rue Dr. Villette, Isoraka, Antananarivo, Madagascar Search for other works by this author on: GSW Google Scholar Author and Article Information NEIL A. WELLS 1Geology Department, Kent State University, Kent, Ohio 44242 BENJAMIN ANDRIAMIHAJA 2Ministère de l'Etablissement d'Enseignement Supérieur des Sciences, B.P. 4163, Tsimbazaza, Antananarivo, Madagascar H.F.S. RAKOTOVOLOLONA 3Musée d Art et d'Archéologie, 17, Rue Dr. Villette, Isoraka, Antananarivo, Madagascar Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1990) 102 (5): 615–627. https://doi.org/10.1130/0016-7606(1990)102<0615:SALDOT>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation NEIL A. WELLS, BENJAMIN ANDRIAMIHAJA, H.F.S. RAKOTOVOLOLONA; Stonelines and landscape development on the laterized craton of Madagascar. GSA Bulletin 1990;; 102 (5): 615–627. doi: https://doi.org/10.1130/0016-7606(1990)102<0615:SALDOT>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract In Madagascar, stonelines (horizons of quartz pebbles in laterites) are buried colluvial and alluvial lag gravels that outline former hill and valley surfaces. Their fabrics, especially rare multiple stone layers, identify the stonelines as old surface lags, and the immature geochemical compositions of their over-burdens relative to their substrates demonstrate burial by colluvium. Hill-mantling stonelines are convex upward and less well developed, whereas those lining valleys are concave to irregular, thicker, deeper, better packed and sorted, and have more rounded stones. Local differences in position between former and modern landforms demonstrate that, in a complexly and tightly folded metamorphic terrain, hills and valleys are likely to shift as the landscape is lowered by weathering, thus implying that the landscape is held at a relatively submature stage of development. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

The use of chlorine, bromine and fluorine in detecting a buried Cu-Zn orebody along the zinc-line in the Murchison Range, South Africa

A multi-element orientation study including the use of the halogen elements, was undertaken on transported soils overlying an Archaean copper-zinc deposit in the Lowveld area of the Northern Transvaal, with the view to evaluating the optimal sampling parameters. This hydrothermal copper-zinc orebody formed along a large shear zone in a sequence of quartz-muscovite schists. Apart from evaluating sampling parameters, the study also addresses the selection of suitable analytical techniques for detecting and locating a buried orebody. The total concentrations of elements such as Cu, Zn, Ni, Co, Fe, Mn, Au and Pd were determined in bulk soil samples, in addition to the distilled-water-soluble concentrations of Cl, Br and F. The results for the traverses where a thick soil cover is developed, showed that elements such as Cu, Zn, Ni, Co, Au and Pd did not reflect the presence of the orebody, but rather the bedrock concentrations of these elements in the rock-types up slope. The low rainfall in this area causes limited chemical weathering and prevents the formation of hydromorphic Cu and Zn anomalies above the ore zone. The halogen elements yielded concentration profiles which are relatively independent of the background compositions of the transported soils, primarily because water-soluble concentrations were analyzed. Along profiles where a thick soil cover is present, the Br anomalies show consistent narrow single peaks above the orebody. Both Cl and F yielded broader, double-peak anomalies with a typical “rabbit ear” shape and a prominent low above the ore zone. In general, the fluorine anomalies are broader than the chlorine anomalies indicating a probable halogen element zonation around the orebody. In traverses along areas where the soil cover is thinly developed, or where the residual soils below the “stone layer” (Lecomte, 1988) are exposed on surface, elements such as Cu, Zn and Au adequately reflect the presence of the ore zone. In the latter instance, the halogen elements also yielded peaks above the ore zone, but in this case both chlorine and bromine yielded sharp, single-peak anomalies. The possible mechanism whereby these epigenetic halogen haloes form in the soils above the ore zone are discussed and it is concluded that they could possibly be ascribed to the seasonal migration of groundwater rather than being driven by electrochemically enhanced migration.

ケルン大聖堂内陣の平頭ヴォールトの実物大模型によるフリーハンド施工実験と施工法の検討

In the last paper an experiment was carried out on each full-scale model of the domical vault in the case of Saint-Serge Church. And in this present paper the flat-ridge-like vault in the case of the Cologne Cathedral which was constructed by the method of the Amien Cathedral. As the specific gravity of Ohya Stone is relatively light and similar limestone, I formed the Ohya Stone into the size of the vault stone of Saint-Serge and Amien. We used mortar of the ratio of slaked lime: Sand: Water= 1: 4: 1 (ratio of weight) to lay stones. I come to the following conclusion as a result of this experiment: 1. Since both ends of the French stone layer of the flat-ridge-like vault are almost equal in height, the construction is less advantageous than the domical vault. But in the vault of the Cologne Cathedral, the bedding of the stone layer has the maximum horizontal angle of 70°. And so the vault can be built freehand by using a supplementary construction tool. 2. From the results of the experimental constructions of the domical vault and of the flat-ridge-like vault, I found that in the case of the flat-ridge-like vault the English stone layer is more advantageous in construction than the French stone layer since the former has more different hight on both ends of the stone layer. 3. In this experiment, I used three kinds of supplementary tool: Stone-rope, prop and cerce mobile. These simple supplementary construction tools are effective in freehand construction, but it is assumed that the other various skillful tools were used. 4. The freehand construction of a vault is generally considered to be a construction method of the East, such as the Orient or Byzantine architecture, but it was also a basic construction method for a vaulting in Western Europe in the middle ages.

DESIGN AND CONSTRUCTION OF BERM TYPE BREAKWATERS

The standard design for a rubble-mound breakwater as reported in recent text books and manuals has consisted of a core of rubble quarry-run that is protected from wave action by two layers of relatively large quarried stone or concrete units. Filter layers of intermediate size stone are recommended beneath the armour layer to prevent loss of the core material through the armour. The pioneering work of Hudson provides coefficients for a formula that allowed widespread use of this design concept throughout the world. A breakwater of this form tends to require the smallest volume of stone; however, it may not represent the least cost structure for a specific location because of the cost and availability of local materials. Recently, design engineers and hydraulic laboratories have given considerable attention to alternative forms of rubble mound structures. The objective of this work has been to minimize cost while maintaining the same or improved level of stability when the breakwater is subjected to extreme wave conditions. Principally, emphasis has been given to the utilization of locally available quarried stone and to maximizing the use of the full yield of a local quarry. This has required the design of breakwaters using smaller armour stone and a wider range of sizes than was used in the more conventional breakwater. These designs have also given consideration to the realities of construction and the limitation of construction equipment on the assumption that cost savings will be achieved with relatively simple construction methods. Clearly the use of smaller armour stones requires a change in other properties or characteristics of the armour layer, compared to a conventional design, in order to achieve the same stability. The principal characteristics of a berm breakwater are the high permeability of the armour-layer and the significantly larger volume of armour. Berm breakwaters generally consist of a relatively large and permeable mass of armour stone (of smaller size than required for a conventional design).

Limitations in microwave holographic synthetic aperture imaging over a lossy half-space

Experimental results are presented which illustrate the capabilitity of a single-frequency microwave holographic scheme to image both metallic and plastic pipes at a depth of 0.33 m in wet soil with a covering layer of concrete paving stones. The data acquisition system utilises a crossed dipole antenna scanning above the interface recording two orthogonal polarisations at each point on a two-dimensional grid, from which improved surface rejection is obtained. Maximum imaging depth is limited primarily by the ratio of soil attenuation to surface and environmental effects on the antenna response, thereby preventing any significant increase in the conditions quoted. Theoretical investigation into the influence of the lossy dielectric half-space on the synthetic aperture in a one-dimensional model has illustrated that scan height is an important consideration for resolution and antenna system design. It is shown that scanning in close proximity (≤0.1 λ) to the interface increase both lateral and depth resolution. To take advantage of this effect, it is concluded that a noncontacting antenna operating in close surface proximity must be insensitive to height fluctuations.

Instrumental neutron activation analysis of urinary calculi

Five kinds of urinary stones from 42 patients have been determined for a total of 19 elements by instrumental neutron activation analysis. Of these elements, Ca, Mg, Sr, Na, and Cl are found to be present in the core of all kinds of stones. The differences in elemental composition among the different kinds of stones as well as across the layers of stone are statistically evaluated.

A two-pour technique for investing interim partial dentures

A technique for the use of two stone layers to invest an interim partial denture has been presented. Holding all components on the master cast ensures accuracy

THE DESIGN OF BREAKWATERS USING QUARRIED STONES

The majority of rubble mound breakwaters built in North America that use quarried stones in their armour layer contain either one or two layers of armour stone, one or two filter layers and a core of quarry run. Preparation of a design normally involves use of the Hudson equation and may be supported by physical model tests. Once the design wave conditions are defined the size of armour stones are only a function of the outer slope of the breakwater. In this paper an alternative approach to the design of quarried stone breakwaters is discussed. The basic principal involved in this concept is the use of locally available materials. It is established that the greater the thickness of the armour layer, the smaller the stones that are required to provide stable protection against wave action. Therefore, the thickness of the armour layer for a specific breakwater is determined by the gradation of the available armour stones and the incident wave climate. The final cross-section makes allowance for the practical considerations of breakwater construction. New concepts for breakwaters that have resulted from the use of this alternative design procedure are described. Construction of these breakwaters in 1983-84 has demonstrated that significant cost savings are obtained.

TSUNAMI PRONE FRICTION FACTORS FROM WIND MEASUREMENTS

The long wave equations, used for tsunami run-up and flood wave calculations, have an unknown friction term. As an alternative to hydraulically determined friction factors, an adjustable three-level anemometer staff system is used for making wind profile measurements over typical Hawaii terrain. Results from measurements taken during trade wind conditions are given for three types of terrain: (1) golf course, (2) large flat knoll covered with 2 to 2 1/2 feet tall grass thin to medium dense, and (3) a large rock farm covered with several layers of stone 2 1/2 to 3 feet or more in diameter. Average values of Manning's "n" determined approximately from the von Karman friction length, n = .06 z ' vary from 0.028 over the golf course, 0.046 over the grass knoll, and 0.051 over the rock farm. The top level anemometer for both systems is at elevation 10.6 meters (35.8 feet) and the remaining anemometers are equally spaced on the log scale, with the bottom level anemometer at 1.3 meters (4.28 feet) above the support base. We are presently repeating the experiments using an adjustable five-level anemometer staff system. It is pointed out that the results obtained from wind experiments have not yet been correlated with hydraulic experiments, and it is known that the friction factor decreases with increase in the Froude number, given by F = V//gR, where V is the mean velocity over the vertical distance of the hydraulic radius, R. The question seems to be, what is the equivalent hydraulic radius for the adiabatic atmosphere that would give the same friction factor for the same roughness for the von Karman velocity profile in hydraulic experiments? The wind experiments do show that there is a tendency for the friction factor to decrease with increase of mean wind speed. It would be of scientific interest to determine an equivalent hydraulic radius for wind profile experiments, making it possible to correlate the data with hydraulic experiments. This needs further investigation.

Characterization of a protein isolated from pancreatic calculi of men suffering from chronic calcifying pancreatitis

A major protein was extracted by 0.15 M sodium chloride from human pancreatic calculi. It was found immunologically identical in ten different calculi and was present in different layers of the same stone. Its molecular weight was estimated to 13,500 daltons and its isoelectric point was found to be 5.5. This protein is present in normal and pathological human pancreatic juices as demonstrated by gel filtration of pancreatic juice on Sephadex G 100.

Beispiele für holozäne flächenbildung in Nord- und West afrika

Beispiele für holozäne flächenbildung in Nord- und West afrika

Cobble Lined Drop Structures

This paper describes the concept and the experimental study made to determine the design criteria for a drop structure comprised entirely of loose dumped rock. The three principal components of the design were: (1) the weir at the top of the slope, (2) the sloping portion downstream from the weir, and (3) the horizontal apron at the bottom. The rock weir was intended to prevent excessive drawdown and control upstream velocities. The sloping portion was a hydraulically steep reach, on which supercritical velocity occurred. The apron was intended to accommodate the transition back to subcritical flow at the end of the drop structure.The initial investigation involved study of the structure in two-dimensional flow. It was determined that the critical area for stability was in the terminal velocity region of the steeply sloping portion of the structure. The stone size and layer thickness required for channel stabilization was found to be a function of the channel slope and flow depth at terminal velocity. Eight combinations of variables were tested and included four different slopes, three different stone sizes, and two different layer thicknesses. Each combination was tested to failure.The failure process was unique in that there was an initial failure and an ultimate failure. Initial failure occurred when some stone at the lower end of the slope was displaced, exposing the subgrade. The exposed area was rapidly filled in by downstream migration of stones from further up the slope. The migration process continued until it was arrested at the top of the slope by the rock weir, and the structure became stable once again. A further large increase in discharge was required to precipitate a second or ultimate failure.Design criteria were formulated, including a recommended factor of safety based on initial failure, and the design was verified on a three-dimensional model.

Soils of Takapau agricultural research farm, Hawke’s bay, New Zealand

Abstract Soils of Takapau Research Farm have been mapped on a scale of 1:3168 (1 in. to 4 chains). The soils are derived from a layer of loess (with some volcanic ash) and greywacke stones overlying a layer of sandy alluvium which in turn overlies older greywacke stones. Three soil types are recognised: Takapau silt loam formed on loess and stones; Takapau mottled silt loam formed on the same parent material in small areas with imperfect drainage; and Takapau fine sandy loam formed in a small, slightly elevated area where the loess thins out and the underlying alluvium is thick enough to be a dominant part of the soil parent material. Morphological, chemical, physical, and mineralogical properties of the three soil types are described, and differences are related to differences in parent material and drainage. Soils from loess are silt loams with low to medium dry bulk densities and medium to high phosphorus retentions. Soils from alluvium are fine sandy loams with high dry bulk densities and low to medium phosphorus retentions. The differences in soil type and in distribution of stones are sufficiently important to be considered in research programmes on the farm. The soils have been related to soils of the Takapau series previously mapped in the area.

DISCONTINUOUS COMPOSITE WAVE ABSORBER STUDIES

An experimental study was conducted to determine the energy dissipation characteristics of a discontinuous wave absorber consisting of an impervious lower slope and a stone-filled upper slope. The purpose was to determine the wave energy absorption as a function of the incident wave parameters and the wave absorber geometry. Parameters varied were wavelength, wave height, lower and upper absorber slopes, berm depth and width, and stone size. For virtually all test conditions, a minimum wave reflection was found when the discontinuity (berm) depth was at one-quarter to one-half the water depth below the water surface. The overall wave absorption increased under the following conditions: an increase in horizontal berm width of up to five layers of stone; a decrease in the angle of the upper (stone-filled) slope when the berm depth is below one-fifth the water depth; and a decrease in the angle of the lower (impervious) slope when the berm depth is above one-half the water depth. The results should be useful where water wave reflections must be minimal and space is limited, such as in harbor walls or for hydraulic models.

Grave med teltformet overbygning fra tidlig-neolitisk tid

Grave med teltformet overbygning fra tidlig-neolitisk tid

Thermodynamics and stones

In New England each spring most gardeners are faced with clearing their plots of a multitude of varying sized stones. These same plots were cleared of stones during the spring planting of the previous year. Now the reappearance of surface stones is not without merit, for the phenomenon gives rise to some much needed exercise and the stones make walls of lasting practical and aesthetic value. It has also been suggested that the layer of stones that appear each spring upon the surface of tilled fields protects the soil from erosion by heavy spring rains. It is recommended that these surface stones be crushed and returned to the field. This process allows the use of farm machinery, and it still maintains a protective stone shield [Epstein et al., 1966] Even the most indolent observer should eventually begin to inquire as to the fundamental mechanism behind the phenomemon.

Drift stratigraphy and buried morphology beneath the Forth at Rosyth

Synopsis During work under contract to the Institute of Geological Sciences, over 500 old bore records have become available for a small area at Rosyth, the majority relating to the area below low water mark. They show that till and patchy fluvioglacial deposits are covered by fine late-glacial marine sediments whose maximal recorded thickness exceeds 60 m. In the western parts of the area a glacial readvance or halt stage is indicated particularly by ‘boulder clay’ inter-bedded with the late-glacial marine sediments. Sea-level when glacier ice last extended into the Rosyth area was about 35 m above present. Later in late-glacial times the sea fell below its present level and marine sediments deposited earlier were extensively planated, the coarser (ice-rafted) constituents of these sediments and the coarser constituents of the interbedded ‘boulder clay’ (where present) being left as a layer of stones and boulders sloping gently seawards. This coarse stratum now lies beneath a layer of silt and shells. The drift sequence in the Rosyth area can be correlated with that at Bo’ness and Grangemouth, enabling the gradient of the shoreline limiting the main period of late-glacial marine erosion to be provisionally calculated as between 0.20 and 0.25 m/km.

Dolktidsgrav med ravsmykker

Late Neolithic grave with amber pendantsIn 1966, a stone packing-grave was excavated at Nim in eastern Jutland (fig. 1). As the bottom of the grave was trough-shaped, the corpse must have lain in a bole­coffin, of which nothing remained. On the lowest layer of stones in the west end of the grave were two trapezoidal ear-rings of amber (fig. 4). In the centre of the grave lay a surface-flaked, triangular, flint arrow-head with two barbs (fig. 3). South of this lay the cremated bones of a small child, and a few fragments of animal bones (sheep?), and one potsherd. Higher up in the Stone heap was another flint point (fig. 3). The flint arrow-heads permit the grave to be dated to the Late Neolithic.Bent Sylvest