Lightweight Corer Designed for Sampling Very Soft Sediments

1979 ◽  
Vol 36 (3) ◽  
pp. 241-246 ◽  
Author(s):  
J. D. H. Williams ◽  
A. E. Pashley
Keyword(s):  
Key Words ◽  
Optical Sensor ◽  
Lacustrine Sediments ◽  
Water Interface ◽  
Soft Sediments ◽  
Fine Grained

An underwater corer has been developed capable of taking 10-cm diam cores up to 1 m long from unconsolidated, fine-grained fluvial and lacustrine sediments including organic-rich (gyttja-like) deposits. The corer is lightweight and compact for transport and hand operation from float planes and small boats. It is of the piston type and has a sphincter valve for core retention. A miniature optical sensor triggers the corer when the sediment–water interface is penetrated. The corer is compatible with a system to subdivide the cores by vertical extrusion. Key words: corer, sediment, piston, sampling

scholarly journals A key continental archive for the last 2 Ma of climatic history of the central Mediterranean region: A pilot drilling in the Fucino Basin, central Italy

2015 ◽  
Vol 20 ◽  
pp. 13-19 ◽  
Author(s):  
B. Giaccio ◽  
E. Regattieri ◽  
G. Zanchetta ◽  
B. Wagner ◽  
P. Galli ◽  
...  
Keyword(s):  
Central Italy ◽  
Lacustrine Sediments ◽  
Mediterranean Area ◽  
Central Mediterranean ◽  
Fine Grained ◽  
Xrf Scanning ◽  
History Of ◽  
Sedimentary Succession ◽  
Geochemical Analyses ◽  
Fucino Basin

Abstract. An 82 m long sedimentary succession was retrieved from the Fucino Basin, the largest intermountain tectonic depression of the central Apennines. The basin hosts a succession of fine-grained lacustrine sediments (ca. 900 m-thick) possibly continuously spanning the last 2 Ma. A preliminary tephrostratigraphy study allows us to ascribe the drilled 82 m long record to the last 180 ka. Multi-proxy geochemical analyses (XRF scanning, total organic/inorganic carbon, nitrogen and sulfur, oxygen isotopes) reveal noticeable variations, which are interpreted as paleohydrological and paleoenvironmental expressions related to classical glacial–interglacial cycles from the marine isotope stage (MIS) 6 to present day. In light of the preliminary results, the Fucino sedimentary succession is likely to provide a long, continuous, sensitive, and independently dated paleoclimatic archive of the central Mediterranean area.

scholarly journals Sedimentology and stratigraphy of the type section of the Pennsylvanian Boss Point Formation, Joggins Fossil Cliffs, Nova Scotia, Canada

2015 ◽  
Vol 51 (1) ◽  
pp. 001 ◽  
Author(s):  
Michael C. Rygel ◽  
Corinne Lally ◽  
Martin R. Gibling ◽  
Alessandro Ielpi ◽  
John H. Calder ◽  
...  
Keyword(s):  
Nova Scotia ◽  
Lacustrine Sediments ◽  
World Heritage Site ◽  
Fine Grained ◽  
Type Section ◽  
The North ◽  
Heritage Site ◽  
Unesco World Heritage Site ◽  
Floodplain Deposits ◽  
Fluvial Sandstone

<p style="margin: 0in 0in 0pt;"><span style="font-family: 'Minion Pro','serif';"><span style="font-size: medium;">The 1125-m-thick type section of the Pennsylvanian Boss Point Formation is well exposed along the shore of the Bay of Fundy in Nova Scotia. We provide the first comprehensive account of the entirety of this formation, which comprises nearly one-third of the stratigraphic thickness of the Joggins Fossil Cliffs UNESCO World Heritage Site. The basal Chignecto Bay Member (0–91.5 m) is composed of redbeds, single-storey channel bodies with northerly paleoflow, and thin palustrine limestones. The middle Ward Point Member (91.5–951.7 m) contains up to 16 megacycles composed of alternations between thick packages of braided fluvial sandstone and fine-grained deposits. Although regional studies of the Boss Point Formation suggest that the fine-grained deposits are largely composed of lacustrine sediments, these intervals consist largely of poorly drained and well-drained floodplain deposits in the type section. The facies variations and southeast-directed paleoflow in the Ward Point Member record modest uplift associated with the growth of the salt-cored Minudie Anticline. The North Reef Member (951.7–1125 m) is composed of redbeds and two distinctive multistorey channel bodies. This uppermost member records a shift to more arid, oxidizing conditions, was the precursor to a major phase of salt withdrawal, and represents a transition to the overlying Little River Formation. The sedimentological framework, revised stratigraphy, and detailed measured section and map will provide a foundation for future study of this remarkable Pennsylvanian exposure.</span></span></p>

scholarly journals Distribution of geological materials in Lower Hutt and Porirua, New Zealand

1992 ◽  
Vol 25 (4) ◽  
pp. 332-344 ◽  
Author(s):  
G. D. Dellow ◽  
S. A. L. Read ◽  
J. G. Begg ◽  
R. J. Van Dissen ◽  
N. D. Perrin
Keyword(s):  
Urban Areas ◽  
City Centre ◽  
Areal Extent ◽  
Near Surface ◽  
Ground Shaking ◽  
Geological Materials ◽  
Soft Sediments ◽  
Fine Grained ◽  
Maximum Thickness ◽  
The City

Geological materials in the Lower Hutt, Eastbourne, Wainuiomata, and Porirua urban areas are mapped and described as part of a multi-disciplinary assessment of seismic ground shaking hazards. Emphasis is mainly on the flat-lying parts of these areas which are underlain by variable Quaternary-age sediments that overlie Permian-Mesozoic age 'greywacke' bedrock. Within the Quaternary-age sediments, the two material types recognised on strength characteristics are: 1)  Soft sediments, typically composed of normally consolidated, fine-grained materials (sand, silt and clay), with typical standard penetration values (SPT) of <20 blows/300 mm; and 
 2)  Loose to compact coarser-grained materials (sand, gravel), with SPT values of >20 blows/300 mm. 
 The total thickness and nature of Quaternary-age sediments in the study areas is described, with particular emphasis on the thickness and geotechnical properties of near-surface sediments. Such sediments are considered likely to have a significant influence on the an1plification and attenuation of ground shaking intensity during earthquakes. In the Lower Hutt valley, near-surface soft sediments greater than 10 m thick have an areal extent of -16 km2. Such soft sediments underlie much of Petone and the Lower Hutt urban and city centres, and have a maximum known thickness of 27 m near the western end of the Petone foreshore. In the Wainuiomata area, near-surface soft sediments greater than 10 m thick have an areal extent of - 3 km2, and attain a maximum thickness of 32 m. In Porirua, near-surface soft sediments have a maximum thickness of 14 m, cover an area of -2km2, and underlie much of the city centre. In the Lower Hutt valley the total known thickness of Quaternary-age sediments, including near-surface soft sediments is 300 m. Quaternary-age sediments are very much thinner in other areas, with thicknesses of 60 m recorded in Wainuiomata, 10 m in Eastbourne, and 90 m in the Porirua area.

New insights on Illinoian deglaciation from deposits of Glacial Lake Quincy, central Indiana

2010 ◽  
Vol 73 (2) ◽  
pp. 374-384 ◽  
Author(s):  
J.R. Wood ◽  
S.L. Forman ◽  
J. Pierson ◽  
J. Gomez
Keyword(s):  
Oxygen Isotope ◽  
Sea Level ◽  
Lacustrine Sediments ◽  
Glacial Lake ◽  
Depositional Facies ◽  
Oxygen Isotope Stage ◽  
Fine Grained ◽  
Blue Excitation ◽  
Global Sea Level ◽  
Maximum Limit

The deposits of Glacial Lake Quincy overlie a diamicton associated with the classically defined Illinoian limit in central Indiana. This lake covered at least 180 km2 with a depth of > 20 m and developed when the Illinoian ice sheet retreated 15 km from the maximum limit, causing lake impoundment against Devore Ridge. Overflow from Glacial Lake Quincy eroded across the ridge forming a number of steeped-walled outlets. A section along Mill Creek exposes a sedimentologic sequence associated with Glacial Lake Quincy from a subglacial diamicton to ice-proximal to ice-distal glacial lacustrine sediments. We report new optical ages by multiple aliquot regenerative dose procedure for the fine-grained rhythmically bedded sediments presumed to represent the lowest energy depositional facies, dominated by suspension settling, which maximized sunlight exposure. In turn, optical ages were determined on the fine-grained (4-11 μm) polymineral and quartz fractions under infrared and blue excitation, which yielded statistically similar ages. Optical ages span from ca. 170 to 108 ka, with the average of 16 optical ages indicating deglaciation at ca. 135 ka, generally coincident with Marine Oxygen Isotope Stage 6-to-5 transition and rise in global sea level.

scholarly journals Late Miocene sedimentary record of the Danube/Kisalföld Basin: interregional correlation of depositional systems, stratigraphy and structural evolution

2016 ◽  
Vol 67 (6) ◽  
pp. 525-542 ◽  
Author(s):  
Orsolya Sztanó ◽  
Michal Kováč ◽  
Imre Magyar ◽  
Michal Šujan ◽  
László Fodor ◽  
...  
Keyword(s):  
Late Miocene ◽  
Pannonian Basin ◽  
Lacustrine Sediments ◽  
Structural Evolution ◽  
Fluvial Systems ◽  
Lake Pannon ◽  
Fine Grained ◽  
The North ◽  
Shelf Slope

AbstractThe Danube / Kisalföld Basin is the north-western sub-basin of the Pannonian Basin System. The lithostratigraphic subdivision of the several-km-thick Upper Miocene to Pliocene sedimentary succession related to Lake Pannon has been developed independently in Slovakia and Hungary. A study of the sedimentary formations across the entire basin led us to claim that these formations are identical or similar between the two basin parts to such an extent that their correlation is indeed a matter of nomenclature only. Nemčiňany corresponds to the Kálla Formation, representing locally derived coarse clastics along the basin margins (11- 9.5 Ma). The deep lacustrine sediments are collectively designated the Ivanka Formation in Slovakia, while in Hungary they are subdivided into Szák (fine-grained transgressive deposits above basement highs, 10.5 - 8.9 Ma), Endrőd (deep lacustrine marls, 11.6 -10 Ma), Szolnok (turbidites, 10.5 - 9.2 Ma) and Algyő Formations (fine-grained slope deposits, 10 - 9 Ma). The Beladice Formation represents shallow lacustrine deltaic deposits, fully corresponding to Újfalu (10.5 - 8.7 Ma). The overlying fluvial deposits are the Volkovce and Zagyva Formations (10 - 6 Ma). The synoptic description and characterization of these sediments offer a basin-wide insight into the development of the basin during the Late Miocene. The turbidite systems, the slope, the overlying deltaic and fluvial systems are all genetically related and are coeval at any time slice after the regression of Lake Pannon initiated about 10 Ma ago. All these formations get younger towards the S, SE as the progradation of the shelf-slope went on. The basin got filled up to lake level by 8.7 Ma, since then fluvial deposition dominated.

scholarly journals Benthic community analysis and the prediction of organic carbon content in Mesozoic black shale facies

1992 ◽  
Vol 6 ◽  
pp. 258-258
Author(s):  
Bradley B. Sageman ◽  
Erle G. Kauffman
Keyword(s):  
Water Column ◽  
Sea Level ◽  
Black Shale ◽  
Bottom Water ◽  
Water Interface ◽  
Short Term ◽  
Time And Space ◽  
Fine Grained ◽  
Water Oxygen ◽  
Preservation Potential

The burial and preservation of significant quantities of marine organic matter in epicontinental basins results from low bottom water oxygen levels, and moderate to low sedimentation rates of fine-grained siliciclastic sediment under at least moderately productive waters. Because benthic biotas are extremely sensitive to such factors as bottom water oxygen, grain size, substrate consistency and sedimentation rate, there is a potentially predictive relationship between biofacies and Corg potential of marine strata. High-resolution biological, sedimentological and geochemical studies of Mesozoic organic-rich black shale facies, comprising major hydrocarbon source rocks, allow characterization of this relationship: a) A series of recurrent, bivalve-dominated benthic communities are defined based on trends in diversity, abundance, equitability and trophic specialization. They comprise biofacies which reflect oxygen and substrate gradients in time and space, and thus the Corg preservation potential of marine sediments/strata. The biotas are surprisingly robust in terms of population size and inferred biomass, and demonstrably colonized the benthic zone (as opposed to pseudoplanktic origins). They include both resident communities of taxa specifically adapted to low oxygen (dysoxic) conditions through physiological and anatomical means (e.g., expanded oxygen adsorptive surfaces), or possibly through bacterial chemosymbiosis, and event communities of less tolerant taxa reflecting short-term improvements in benthic conditions; b) many organic-rich sequences contain common event biofacies, indicating a dynamic benthic environment with frequent short-term fluctuations in oxygen and substrate. These are attributable to mixing during large storms, productivity blooms, rapid deposition from mass flows, or reduced sedimentation during condensation/bypass events. However, increasing frequency of events is not necessarily correlated with decrease in Corg levels; c) comparison of trends in the quantity and quality of Corg to biofacies patterns indicate that the most favorable Corg preservation is associated with “benthic boundary biofacies.” These biofacies represent a redox boundary at or near the sediment-water interface and a predominantly dysoxic to episodically oxic water column. The “benthic boundary” may have been associated with the presence of microbial (mainly sulphur bacterial) mats on the substrate surface, which could have regulated its position and contributed to the pool of sedimented Corg; d) mapping of benthic boundary biofacies in time and space within a basin makes possible correlation of Corg preservation potential to paleogeography and sea level history. Although the results of such analyses from the Greenhorn Formation, Western Interior basin, suggest highest Corg burial and preservation in fine-grained shale facies of distal offshore environments during sea level rise, high Corg is not necessarily associated with an anoxic water column. This suggests the need for reappraisal of stagnant basin scenarios for source rock formation. The most important factors in Corg accumulation and preservation may be the development of benthic boundaries and consequent maintenance of anoxia below the sediment-water interface in fine-grained, organic-rich substrates, and the contribution of bacteria to the flux of Corg into the sediment.

Clay mineralogy and potassium status of selected soils in the glacial Lake Agassiz region of central Manitoba

1999 ◽  
Vol 79 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Michael T. Aide ◽  
Gary J. Cwick ◽  
Mark F. Cummings
Keyword(s):  
Lacustrine Sediments ◽  
Clay Mineralogy ◽  
Glacial Lake ◽  
X Ray Diffraction ◽  
Lake Agassiz ◽  
X Ray ◽  
Fine Grained ◽  
Potassium Fixation ◽  
Glacial Lake Agassiz ◽  
Reduced Intensity

The clay mineralogy of the soil is important in that it can affect potassium (K) availability, particularly if vermiculite is present. Large areas of Glacial Lake Agassiz in Manitoba contain fine-grained lacustrine sediments that support boreal forest vegetation. The purpose of this investigation was to identify the clay mineralogy of several commonly occurring soils and document its influence on soil fertility, particularly K availability. The soils were classified as either Eluviated Eutric Brunisols or Orthic Eutric Brunisols. X-ray diffraction analysis verified that vermiculite, hydrous mica and kaolinite were the principal clay minerals in these soils. Vermiculite was demonstrated to have hydroxy Al-interlayers and the amount of vermiculite decreased in the deeper soil horizons. Smectite was present in the Btj horizons of the Eluviated Eutric Brunisols, while trace amounts of chlorite were present in every inorganic horizon. Quantity/intensity curves for K and an experimental estimate of the K-fixation potential indicated that the Ae horizons of several Eluviated Eutric Brunisols supported higher K activities in the soil solution and that K-fixation was greater in subsurface horizons. Potassium fixation and the quantity/intensity curves for selected horizons of the Orthic Eutric Brunisols were nearly identical and each showed a reduced intensity to maintain the aqueous activity of K. Key words: Potassium fixation, vermiculite, quantity/intensity

scholarly journals Concentration levels and spatial distribution of sulphur and metals in fine-grained sediments in western Finland

2008 ◽  
Vol 14 (1) ◽  
pp. 14 ◽  
Author(s):  
M. ÅSTRÖM ◽  
K. RÖNNBACK
Keyword(s):  
Spatial Distribution ◽  
Lacustrine Sediments ◽  
Acid Sulphate Soil ◽  
Distribution Maps ◽  
Acid Sulphate ◽  
Fine Grained ◽  
Acidification Potential ◽  
Extensive Release ◽  
Concentration Levels ◽  
Mn Concentrations

On the coastal plains of Finland, widespread Holocene marine and lacustrine sediments have developed into acid sulphate soil as a result of extensive artificial drainage for agricultural purposes. This has caused a variety of environmental problems. The aim of this study was to determine the concentration levels and spatial distribution of sulphur, carbon and metals [titanium, vanadium, chromium, manganese (Mn), iron, cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn)] in these sediments, in order to increase the geochemical understanding of the parent materials from which acid sulphate soil develops. Sediment samples were collected at 317 sites from a depth of 1.5–3 m. While the sediments have high S (sulphide) concentrations (median = 0.54%) and thus a strong acidification potential, they carry transition metals mainly in smallsized silicates close to “background concentrations” far below contamination limits. The previously documented extensive release of Co, Cu, Mn, Ni and Zn from oxidised and acidified layers of these sediments (i.e. acid sulphate soil) is thus not explained by anomalously high natural or anthropogenic metal concentrations of the soils/sediments, but by an inherent highly mobile metal pool. Spatial-distribution maps highlight areas of elevated S and Mn concentrations, where it is likely that ditching and subsequent oxidation will result in an exceptionally large release of protons and Mn respectively.;

Three-dimensional consolidation of fine-grained sediments

1999 ◽  
Vol 36 (2) ◽  
pp. 355-362 ◽  
Author(s):  
David N Dewhurst ◽  
Joseph A Cartwright ◽  
Lidia Lonergan
Keyword(s):  
Formation Mechanism ◽  
Three Dimensional ◽  
Current Theory ◽  
Pore Fluid ◽  
Water Interface ◽  
Consolidation Process ◽  
Fine Grained ◽  
Porosity Reduction ◽  
Colloidal Properties ◽  
Gravitational Loading

Current theories of one- to three-dimensional consolidation are based on the concept of gravitational loading with concomitant expulsion of pore fluid as a result of mechanical rearrangements of particles and porosity reduction. However, the recent discovery of extensive networks of layer-bound fractures forming polygonal patterns in extremely fine grained smectitic clays and chalks suggests that current theory may not adequately explain the consolidation process in such sediments. These faults develop during shallow burial and often appear to have been active at the sediment-water interface. Radially isotropic strain suggests that the process of formation was nontectonic. Measured values of strain suggest that deformation resulted from volumetric contraction of the sediments. We argue that the formation mechanism for these fault systems is related to the colloidal properties of the constituent sediments and that, as such, stresses due to gravity may not be the only factor controlling pore-fluid expulsion during consolidation.Key words: polygonal faults, clay, smectite, shrinkage, colloidal.

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