Stony Layer Research Articles

Hidden soils and their carbon stocks at high-elevation in the European Alps (North-West Italy)

Alpine soils store large quantities of total organic carbon (TOC). Given their high sensitivity to climate change, they may release large amounts of CO2 in a warming climate scenario. Thus, it is important to know their C stocks in order to estimate its possible release. While C stocks of forest, dwarf shrub and alpine grassland soils are well documented, little is known about soils and C stocks in high-elevated periglacial environments dominated by frost-driven processes. The object of this study is the periglacial environment of the Stolenberg Plateau (LTER site Istituto Mosso, 3030 m a.s.l.), at the foot of the Monte Rosa Massif (NW Italian Alps). The plateau is mostly covered by a thick stony layer, organized in periglacial blockfields and blockstreams. The plant cover reaches only 3–5%. During the construction of a chair lift, open trenches revealed, unexpectedly, well-developed soils under the active periglacial stone cover. In particular, thick (30–65 cm) and dark TOC-rich A horizons were observed. Below these Umbric horizons, Cambic Bw ones were developed but discontinuous. Despite the lack of vegetation, C stocks were remarkably high (up to ~ 5 kg m−2), comparable to vegetated soils at lower elevation. Non-invasive geophysical methods revealed that these hidden soils were widespread on the plateau under the stony cover, with a mean thickness of around 50 cm. These TOC-rich soils, without vegetation and covered by periglacial landforms, represent a unique pedoenvironment suggesting new perspectives on the actual C-stocks at high-elevation sites, which are probably underestimated.

The stony phase as a differentiation factor in vineyard soils

espanolSe ha llevado a cabo un estudio en un area viticola cercana a Lezuza (Castilla-La Mancha, Espana) con el objetivo principal de vincular los efectos de la pedregosidad con la productividad y la calidad del vinedo. El area estudiada es singular debido a que tiene una pedregosidad muy alta (6 de los 11 perfiles superaron el 30% y otros 3 alcanzaron el 50%). Se ha realizado una discusion sobre la importancia de la capa pedregosa superpuesta en la meseta de piedra caliza, que produce un claro contraste en los suelos ya que se trata de dos tipos muy diferentes de sustratos quimicos y minerales (acidos en la superficie pero calcareos en el subsuelo). Este tipo especial de pedregosidad podria definir caracteristicas unicas que son altamente valoradas en el mercado actual del vino. Se ha definido que la importancia de la fase pedregosa reside en que, ademas del papel protector sobre la erosion del suelo, desempena una funcion definitiva en la conservacion de la humedad del suelo que seguramente sera relevante durante el periodo de crecimiento en el vinedo. Se debe tener en cuenta la experiencia acumulada durante muchos anos por los agricultores, en el sentido de que los fragmentos de roca mas pequenos no deben eliminarse de la superficie de los campos de cultivo, especialmente si el objetivo es conservar el suelo y el agua. EnglishA study has been conducted in a viticulture area near Lezuza (Castilla-La Mancha, Spain) with the main aim of linking the effects of stoniness on vineyard productivity and quality. The studied area is unique because of the very high stoniness (6 of the 11 profiles exceeded 30% and another 3 reached 50%). A discussion is provided on the importance of the stony layer superimposed on the limestone plateau, which produces a clear contrast in the soils since these are two very different types of chemical and mineral substrates (acidic at the surface but calcareous in the subsurface). This special type of stoniness could impart unique characteristics that are highly valued in the current wine market. It was found that the importance of the stony phase is that – apart from the protective role from soil erosion – it plays a definitive role in the conservation of soil moisture, which is relevant during the growth period in the vineyard. The experience accumulated over many years by farmers, in the sense that smaller rock fragments should not be removed from the surface of the agronomic fields, should be taken into consideration, especially if the aim is to conserve soil and water. portuguesFoi realizado um estudo em uma area de viticultura perto de Lezuza (Castilla-La Mancha, Espanha), com o objetivo principal de relacionar os efeitos da pedregosidade com a produtividade e qualidade da vinha. A area estudada e unica devido a elevada pedregosidade (seis dos 11 perfis excederam 30% e outros tres chegaram a 50%). E discutida a importância da camada pedregosa sobreposta a camada de calcario, o que produz um claro contraste nos solos pois estes sao dois tipos muito diferentes de substratos quimicos e minerais (acidos na superficie, mas calcarios na camada subsuperficial). Este tipo especial de pedregosidade poderia conferir caracteristicas unicas que sao altamente valorizadas no mercado atual do vinho. Verificou-se que a importância da fase pedregosa, alem do papel protetor da erosao do solo, e devida ao facto de desempenhar uma funcao positiva na conservacao da humidade do solo, o que certamente sera relevante durante o periodo de crescimento da vinha. Deve ser levada em consideracao a experiencia acumulada pelos agricultores ao longo de muitos anos, no sentido em que os fragmentos de rocha de menores dimensoes nao devem ser removidos da superficie dos campos de cultivo, especialmente se o objetivo e conservar o solo e a agua.

The emission of carbon dioxide from soils of the Pasvik nature reserve in the Kola Subarctic

The emission of carbon dioxide (CO2) from podzols (Albic Podzols (Arenic)) and the factors controlling its spatiotemporal variability in the forest ecosystems of the Pasvik Reserve in the Kola Subarctic are characterized. Relatively favorable climatic conditions beyond the polar circle in summer are responsible for intensive soil respiration. The type of forest affects the emission of CO2 from the soil surface. The lowest rate of the CO2 emission is typical of the soils under lichen pine forest (105–220 mg C/(m2 h) or 180 g C/m2 during the summertime). Higher rates are observed for the soils under green moss pine (170–385 mg C/(m2 h) or 360 g C/m2 during the summertime) and birch (190–410 mg C/(m2 h) or 470 g C/m2 during the summertime) forests. This may related to a higher contribution of root respiration (44, 88, and 67%, respectively). Soil respiration and the contribution of root respiration to it increase with an increase in the canopy density; mass of small roots; microbial biomass; depth of the stony layer; soil moistening; and the contents of available carbon, nitrogen, phosphorus, and potassium compounds. At the same time, they decrease with an increase in the portion of lichens in the ground cover. The seasonal dynamics are characterized by the CO2 emission maximums in the summer and fall and minimum in the spring. The daily dynamics are smoothed under conditions of the polar day.

Development and morphology of the fruit and seed of the hemiparasite genus <em>Jodina</em> (Cervantesiaceae)

The monotypic genus Jodina is endemic to central and southeastern South America, common in forests and scrubland environments. The fruit type in Jodina is controversial since it has been described at different stages of development. The main objective of this work was to analyze the morphology of the fruit of J. rhombifolia during its maturation to attain a consensus about its type. Also characteristics of seed development and anatomy were analyzed in detail. Material was processed according to conventional techniques for LM and SEM studies. The fruit of J. rhombifolia is a pseudodrupe since the ovary is half-inferior; the fleshy layer of the pericarp is constituted by an increase of the nectary disk whereas the stony layer is represented by the mesocarp. Participation of the nectary disk as part of the fruit wall has not been mentioned previously. The seed is “naked” —the integument disintegrates during development— and the resulting structure is a pyrene. The interpretations made by other authors on the fruit of Jodina are also discussed.

Intra- and inter-population polymorphism in Coletinia maggii (Grassi, 1887) (Zygentoma: Nicoletiidae), an inhabitant of soil, mesovoid shallow substratum (MSS) and caves--A challenge for the strict classification of subterranean fauna?

New locations of Coletinia maggii (Grassi, 1887) have been discovered in the center of the Iberian Peninsula in different types of subterranean environments, such as a stony layer in the subsoil of an alluvial plain, an alluvial Mesovoid Shallow Substratum or Milieu Souterrain Superficiel (MSS) and a gypsum cave. This is the first record of both an alluvial MSS in the center of the Iberian Peninsula and of a subterranean species living in it. The high number of specimens captured allowed the first detailed study of the morphological intra- and inter-population variations of this species. The implications of its presence in these different environments, its wide distribution area across Europe, and the relevance of the morphological variation in the characters for the taxonomy of this species are discussed. Based on the results, Coletinia hernandoi Molero, Bach & Gaju, 2013 is proposed as a new synonym of C. maggii.

Analysis of geomorphic dynamics in ancient quartzite landscape using phytolith and carbon isotopes, Espinhaço Mountain Range, Minas Gerais, Brazil

Although there are important landscapes developed on underlying quartzite in Brazil, there is still very little known about the processes and mechanisms involved in their formation. Some recent research has drawn attention to the presence of karstic features associated with silica dissolution in this lithology. However, there are other relief forms and materials commonly encountered in the domain of quartzite in the Espinhaco Mountain Range in the southeast region of Brazil. The main objective of this research is to analyze the geomorphic processes associated with the material overlying relatively flat surfaces of low inclination that always occur near quartzite outcrops in the study area. This is relevant in order to attempt to understand the development of landforms in quartzite domains in tropical humid areas. A Geomorphic approach for the analysis of the material was used, in which geomorphic sites were identified and two soil profiles were described and sampled for laboratory analysis. This was complemented with laboratory analysis of phytoliths found in the soil, 13C analysis and 14C-AMS dating. The relatively shallow profiles show a sequence of similar horizons, in which the material varies from sandy organic material at the top to stony immediately below. The superficial horizons have predominantly finer sand and also clay, which is expected in humid tropical environments. Both profiles present a stony layer formed of angular to subangular quartz pebbles lying just on the top of the weathered quartzite in the C horizons where the oldest SOM 14C dating values were found. Considering the mean residence time (MRT), it is possible to assume that the first depositions in P2 are more than 10.000 yrs old (10,506-10,230 yr cal BP) and that the first profile in P1, located on the upper slope, presents younger SOM (5,919-5,664 yr cal BP). This suggests that the erosive processes were either more intense or more recent on this portion of the slope and that these deeper horizons may have previously been on the surface, when the material was deposited. Also, the high amount of phytoliths which are unclassified due to their destruction, along with the presence of the most robust types, can be interpreted as evidence of intense erosion and transportation of the material by surface runoff, enabling the assumption that the material is colluvium and that its source is a nearby quartzite outcrop. After deposition along the gently inclined slope, identified as a “colluvial ramp”, the material was relatively undisturbed, which allowed pedogenic processes to take place, forming Quartz-sand Neosols. The ramp itself seems to be the result of very slow rates of weathering and removal of the material, together with strong control from relatively flat Mesoproterozoic depositional macro-structures of the underlying rock. This study is one of the first attempts to use phytoliths combined with carbon isotope analysis for geomorphologic purposes, with very interesting results. Their relevance points to their potential for geomorphic studies.

Embryology of the dioecious Woonyoungia septentrionalis (Magnoliaceae)

The embryological characteristics and ovular integument development of the dioecious species Woonyoungia septentrionalis (Dandy) Law (Magnoliaceae), which are poorly understood, were investigated under laser scanning confocal microscope (LSCM) and light microscope (LM). The embryological characteristics conform to most of the previously studied species in Magnoliaceae. The anther has 4 microsporangia, and the anther wall develops according to the dicotyledonous type. Cytokinesis at meiosis of the microspore mother cells follows a modified simultaneous type, giving rise to isobilateral or decussate tetrads, and a cell plate is absent, but a membrane was observed. Mature pollen grains are 2‐cellular and have high germination rates. The ovule is anatropous, crassinucellate and bitegmic, and meiotic result in linear tetrads of megaspores, the one at the chalazal end functions directly as an embryo‐sac cell. The development of the embryo sac is of the Polygonum‐type and endosperm formation is of the nuclear type. The outer integument of the ovule differentiates into an outer fleshy and an inner stony layer while the inner integument is reduced to a tanniniferous layer. The normal embryological development, high germination rates of pollen and high seed set indicate that the primary reason for the decline of the species is not to be found in these developmental processes.

Feasibility study of rainwater harvesting system in Sylhet City

In rural areas in Bangladesh, groundwater is the principal source of water supply. This underground water is available in considerable amount in shallow aquifers. It is free from pathogenic microorganisms and hence water-borne diseases. In plain lands, other than hilly areas, water supply to 97% rural population comes from tube-wells, which is regarded to be a phenomenal achievement in preserving public health. Besides, a dependable water supply system all throughout the country is offset by two factors: (a) high salinity in surface plus groundwater in coastal areas; (b) want of suitable groundwater aquifers in hilly areas and the high cost of setting up tube-wells due to deep underground water table and stony layers. However, presence of arsenic in underground water now poses a serious threat to the success once made in water supply by setting up of manually operated tube-wells in the village areas-the achievement is now on the brink of total collapse. In about 61 districts out of 64, presence of arsenic exceeds a quantity of 0.05mg/1, a permissible limit as per Bangladeshi water quality standard. Harvesting rainwater can be a pragmatic solution to this problem, which is common in many places in Sylhet especially in the hilly areas on the north eastern part of the city. This can be an alternative source of drinking water because of availability of rainwater from March to October. Heavy rain occurs from end of May till mid September, which is commonly known as the rainy season. This paper focuses on the possibility of harvesting rainwater in rural communities and thickly populated urban areas of Sylhet. It also demonstrates the scopes of harvesting rainwater using simple and low-cost technology. With setting up of a carefully planned rainwater storage tank, a family can have all of its drinking water from rain. Planned use of rainwater through rainwater harvesting in the roof catchments may fulfill the entire annual domestic water demand of a family in the rural areas of Bangladesh.

Temperature regime of some soil types in Georgia

The thermal regime of the different soil types of Georgia has been studied on the basis of soil temperature records obtained at 60 weather stations in 1947–1995. It is shown that the thermal conductivity and temperature gradients in the soil profiles depend on the soil type. In the upper 0–20 cm of the soils in the intermontane depressions, the lowest temperature gradients in the summer are typical of the red ferrallitic soils (0.5–1.1°C/dm), and the highest gradients are observed in the chernozems of eastern Georgia (1.0–1.3°c/dm). The soil temperature gradients are especially high in the late spring (1.4–1.8°c/dm), when the atmospheric convection is formed. In the mountains, the lowest gradients in the summer are observed in the cinnamonic soils (0.4–0.9°c/dm), and the highest gradients are established in the brown forest soils (0.5–1.3°c/dm). The redistribution of the temperatures in the deeper layers depends on the soil texture. The lowest temperature gradient is in the soils of Telavi (3.1°c/m), where a stony layer is found at the depth of 60 cm, which causes the good heating of the deep layers. The highest gradients are seen in the clayey and loamy soils of western (Chakva, 3.8°c/m) and eastern (Tbilisi, 3.9°c/m) Georgia. This is probably related to the high water content in the heavy-textured soils.

Cronología reproductora de Ceratozamia mexicana (Cycadales)

En Cemtozamia mexicana Brongn. el desarrollo de la semilla se cumple en 24 meses desde la iniciación de los óvulos en agosto hasta el desarrollo completo del cuerpo del embrión. Durante los tres primeros meses ocurre la megasporogénesis y la megagametofitogénesis. Al finalizar febrero el gametofito es cenocítico. La celularización del gametofito termina en mayo y comienzan otros cambios: endurecimiento del gametofito, lignificación de la capa pétrea, desaparición de tricomas y acumulación de almidón en el gametofito. La polinización probablemente ocurre entre febrero y marzo. Al inicio de septiembre, aparecen proteínas y gotas de aceite en el gametofito. La semilla se dispersa en septiembre; puede presentar arquegonios y ocasionalmente suspensores en desarrollo. La fertilización ocurre aproximadamente en el período de la dispersión fuera de la planta madre. Los suspenso res crecen durante cinco meses y el cuerpo del embrión se desarrolla en cuatro meses. Previo a la presencia de un embrión, esta semilla se dedica a proveerse de nutrimentos y protegerse.

Microzamia gibba (Reuss) Corda: a cycad ovulate cone from the Bohemian Cretaceous Basin, Czech Republic—micromorphology and a reinterpretation of its affinities

The ovulate cone Microzamia gibba (A.E. Reuss) Corda, from the Bohemian Cenomanian (Czech Republic, Central Europe) is described. The genus Microzamia Corda is newly emended and compared with the fossil genera Beania Carruthers, Zamiostrobus Endlicher and the extant genera Zamia L., Chigua Stevenson, Macrozamia Miquel, Ceratozamia Brongniart and Encephalartos Lehmann. The genus Cycadeostrobus Carruthers might be synonymous with Microzamia. The typification of Microzamia gibba is discussed resulting in the designation of a neotype. It is demonstrated that the stony layers of Beania gracilis and M. gibba have a similar anatomy. A reconstruction of the ovulate cone M. gibba is proposed, showing large cataphylls on the cone peduncle. The ovulate cones occur in association with the leaves Jirusia jirusii (Bayer) Domin.

Simulation of unsaturated water flow around obstructions: three-dimensional Rankine bodies

Sink and source combinations were used to simulate flow around barriers such as might exist within a stony, unsaturated soil system. Although more complicated than two-dimensional cases which were previously presented, the three-dimensional “Rankine bodies” are more appropriate for simulating flow around real objects. Generally, the appropriate potentials and velocity fields are easy to write down and evaluate, in fact, much easier than the alternative solutions based on scattering theory. Also, arrays of bodies can be arranged to simulate a repeated pattern rather than deal with only single barriers, cavities, etc. However, the shapes of the bodies are not known ahead of time and can only be roughly controlled. For the same Darcian flow, a simulated stony layer was shown to be wetter than that without stones and the effective saturated conductivity reduced somewhat less than 1 - f s where f s is the fraction of stones. Overall there is a qualitative agreement with previous theoretical and experimental results for both saturated and unsaturated flow.

Anatomy and Morphology of Araucaria sphaerocarpa Carruthers from the Jurassic Inferior Oolite of Bruton, Somerset

Anatomical study of the holotype of the ovulate cone Araucaria sphaerocarpa Carruthers reveals excellently preserved cone and seed tissues in spite of the fragmentary nature of the fossil remains. Large conescale complexes up to 4 cm long are helically arranged in the 13 x 15-cm cone. A ligular sulcus separates the strongly vascularized bract and scale. The pith of the cone axis is wide, and traces to the bract and scale diverge separately from the axis stele. One large inverted ovule is embedded in the tissue of each ovuliferous scale. The integuments are well developed, with slight lateral extensions. The wide band of elongate sclereids in the stony layer has a zigzag pattern in surface view. The nucellus, attached only at the chalazal end of the inner integumentary layer, does not appear to have the wavy apex characteristic of other araucarians. Thin-walled, isodiametric megagametophyte cells surround large, well-developed embryos that have two cotyledons. The cone structure most closely resembles that...

Seed Scarification to Speed Germination of Ornamental Cycads (Zamia spp.)1

Abstract Rate and percent germination of Zamia integrifolia Ait. and Z. furfuracea L.f. can be significantly improved by seed scarification. Reported germination times of up to a year or more can be reduced to 1 to 3 months under greenhouse conditions if the outer fleshy seed coat is removed and the inner stony layer scarified. Rate and percent germination vary with placement of scarification cut and species. Germination of 80 to 100% in 1 week were obtained for Z. integrifolia under laboratory conditions.

Runoff generative process and runoff yield from arid talus mantled slopes

AbstractPrevious works dealing with the influence of a stone cover on runoff yield showed that runoff, attributed to the sealing effect of the topsoil by raindrops impact, was negatively related to the per cent of stone cover and stone size. These works were conducted on gentle slopes (3–11·5 degree) with a per cent of stone cover generally lower than 50 per cent, and composed of gravels. The present study deals with the runoff yield of steep talus slopes (26–36 degree) whose per cent of stone cover is very high (90–100 per cent), composed of cobbles and boulders. Three stimulated rainstorms were performed at various rainfall. intensities and durations on each one of six plots representative of the North eastern sector of Sinai. Although the contiguous stony cover prevented surface sealing by raindrops impact, runoff developed quite quickly on most slopes, and reached at peak discharge, after approximately ten minutes, up to 56 per cent of the rainfall. Differences between plots, in time lag, peak discharge and other hydrological variables, could be attributed mainly to the properties of the upper stony layer, with stone size as the most influential factor. Contrary to previous works, a positive relationship, was obtained between stone size to runoff yield. The result is explained by the process of water concentration. Each cobble and boulder behaves, on a smaller scale, like a bare rocky surface and yields per unit area water amounts beyond the infiltration rate of the limited uncovered areas. For a given stony cover the effect of water concentration is quicker with the big blocks than with gravels. A series of graphs trying to relate theoretically the relative importance of sealing and water concentration processes in runoff generation, at various conditions of stone cover and stone size, is proposed. The graphs enable to reconcile the results of the present study with those of previous works.

Soils and Stratigraphy of a Portion of the Gola River Fan of Uttar Pradesh, India

AbstractThe Gola River fan, formed at the base of the Himalayan Mountains in Nainital District of Uttar Pradesh, India, is composed of strongly to moderately sloping, thin, coarse‐textured sediments over stony layers near the foothills and gently sloping, moderately thick to thick, medium‐textured sediments over sand and gravel beyond some 8 to 10 km below the foothills. The two portions of the fan are separated by a spring line.The soils of the upper portion of the fan, which is known as the bhabar, are thin and drouthy. Soils of the lower portion of the fan, which is called the tarai, have good moisture storage capacity and are highly productive. All soils are weakly developed with high pH values and high base saturation. Some leaching of bases, translocation of iron, and formation of structure has taken place in these soils, but clay movement has been very slight. Mineral alteration has not been great, the high chlorite and mica clay mineral content being inherited from the soil parent materials. Most of the soils in the tarai have mollic epipedons and cambic horizons and are Mollisols. Soils in the bhabar tend to have thinner, dark‐colored surface horizons than those in the tarai, and those near the apex of the fan and the foothills are Inceptisols and Entisols.

Jættestuen Jordhøj

Jættestuen Jordhøj

A Note on Wind-Stable Stone-Mantles in the Southern Sahara

Large areas of the Sahara, as well as other deserts, are covered with a mantle of ston s which, though surpri ing y restricte in size range in any one area, vary in different places from very coarse sand to stones several inches across. It has long been assumed that wind action has produced these stony surfaces by blowing away the smaller particles from a mixed deposit of stones and sandy soil until a stony layer is exposed at a somewhat lower level, and that this process of deflation continues until the constituents of the surface layer are either too large or too deeply embedded in the underlying soil to be moved by the wind. At the present time these surfaces are almost eertainly stable to wind erosion. The term wind-stable is here used to mean that the lowering of the surface by the wind has ceased, but not that the stone mantle contains no sand that can be moved by the wind. The movement of sand across the stone-mantle surface can in fact be observed frequently, and a surface which is windstable will nevertheless act 'as a reservoir in which sand is stored during periods of gentle wind, and from which it is removed by a sudden storm' (Bagnold, 1954)This note describes an attempt to demonstrate that such a surface might in fact have been produced by wind erosion, and to determine the depth of mixed stony soil from which the finer material would have been removed to produce it. The observations and an experiment were made in 1966 at In Abangharit (i7?58'N, 6?02/E), situated on the plain of Tamesna which is bounded by the mountains of Adrar des Iforas to the west, the Hoggar to the north and the mountains of Air to the east. The plain of Tamesna is crossed by an ancient shallow valley system draining to the south-west into the Azaouak valley which formerly drained into the River Niger.

Nonsorted Steps in the Mt. Kosciusko Area, Australia

Research Article| August 01, 1967 Nonsorted Steps in the Mt. Kosciusko Area, Australia A. B COSTIN; A. B COSTIN CSIRO1 Division of Plant Industry, Canberra, Australia 1Commonwealth Scientific and Industrial Research Organization Search for other works by this author on: GSW Google Scholar B. G THOM; B. G THOM Coastal Studies Institute, Louisiana State University, Baton Rouge, Louisiana Search for other works by this author on: GSW Google Scholar D. J WIMBUSH; D. J WIMBUSH CSIRO Division of Plant Industry, Canberra, Australia Search for other works by this author on: GSW Google Scholar MINZE STUIVER MINZE STUIVER Radiocarbon Laboratory, Yale University, New Haven, Connecticut Search for other works by this author on: GSW Google Scholar Author and Article Information A. B COSTIN 1Commonwealth Scientific and Industrial Research Organization CSIRO1 Division of Plant Industry, Canberra, Australia B. G THOM Coastal Studies Institute, Louisiana State University, Baton Rouge, Louisiana D. J WIMBUSH CSIRO Division of Plant Industry, Canberra, Australia MINZE STUIVER Radiocarbon Laboratory, Yale University, New Haven, Connecticut Publisher: Geological Society of America Received: 09 May 1966 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1967, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1967) 78 (8): 979–992. https://doi.org/10.1130/0016-7606(1967)78[979:NSITMK]2.0.CO;2 Article history Received: 09 May 1966 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation A. B COSTIN, B. G THOM, D. J WIMBUSH, MINZE STUIVER; Nonsorted Steps in the Mt. Kosciusko Area, Australia. GSA Bulletin 1967;; 78 (8): 979–992. doi: https://doi.org/10.1130/0016-7606(1967)78[979:NSITMK]2.0.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 The Mt. Kosciusko area of Australia contains a variety of soil and landscape features attributed to periglacial conditions. Among the features are several types of solifluction terraces, one of which is the nonsorted step. The steps occur in groups restricted to the tops of wind-exposed slopes of metasediment outcrops. The slopes range in declivity from 4 to 25 degrees and the vegetation is a mosaic of alpine herbfield and fjaeldmark (dwarf open heath).Nonsorted steps are more often lobate (width > length) than tongue-shaped (length > width), with 10–77-foot widths, 9–46-foot lengths, and risers up to 3 feet high. They consist of stony soil, a poorly sorted mass of silt to small stones, which overlies a layer of tabular rock fragments, up to 18 inches long and oriented downslope. This stony layer grades downward into fractured phyllite, schist, and slate with nearly vertical dip and cleavage. Between the stony soil and stony layer within several of the steps is an organically rich lens of stone-free soil.Radiocarbon analyses of this material indicate that steps 50–400 feet below the mountain crests are 2000–3000 years old and that further upslope, within 50 feet of the crests, episodic movement occurred during the last 300 years. Botanical and microtopographic data also support the view that downslope steps are relict features, whereas closer to the crests increased activity is apparent. Mass movement of an entire step requires the perennial or seasonal impedance of subsoil drainage, which permits the soils' frost susceptibility to promote active solifluction. Local variations in this susceptibility across a slope could account for differential slope movement leading to the development of steps. Frost penetration of the slope mantle, sufficient for the steps to form, could have been produced by either a decline of at least 4° F in mean annual temperature or by stronger winter winds blowing more snow off exposed sites. The convex land forms on which the steps occur are not due to glacial smoothing, as previously thought, but to periglacial frost shattering of bedrock followed by solifluction. The last main period of solifluction 2000–3000 years ago produced most of the steps. The mechanisms, however, by which the steps assumed lobe and tongue forms or asymmetry, are not understood. 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.

Geografia Distribuo de Tertremaj Domagoj kun Speciala Referenco al la Efikoj de la Nankaido Tertremo, la 21-an de Decembro, 1946, en Koti Prefektejo, Sikoku, Japanujo.

Concerning the relations between geomorphological ground conditions and earthquake damages throughout the Prefecture of Kochi, Shikoku, Japan, due to the Great Nankaido Earthquake of December 21st, 1946, we have noticed several interesting facts:i) On the sandy ground of beach ridges, damages were found only in those parts, where the basement bed rock lies deep, or where some kind of soft mud layers lies beneath sand, or where the ground consists of very soft sand, which has been deposited in very recent years or accumulated by wind blow. On the contrary, there was scarcely any damage, where the bed rock lies near the surface, or where hard materials such as pebbles or stones lie under the sandy ground, or where the surface sand are consolidated. Practically, of course, some of the above mentioned conditions coexist complicatedly combined in the same place.ii) There were severe damages on swampy low lands behind the beach ridge.iii) Even on alluvial plains, we found patches of rather slight damages among otherwise severe damages. Under those patches of slight damages stony layers were usually found as is the case on beach ridges.We have examined the hardness of the surface ground by a simple hand-boring stick of about 1m. length.Existence of the stony layers under the ground was conjectured by the distribution of Cl' contents in underground water. Where there are stony layers under the ground, underground water flows constantly and the Cl' contents must be small. On the contrary, underground water cannot flow easily in clay, mud or fine sand layers, and the Cl' contents must become great there. A typical example of the above two cases was encountered in the town of Nakamura, where the geographical distribution of earthquake damages clearly agrees with the Cl' contents distributions. (Fig. 10)