Factbites
 Where results make sense
About us   |   Why use us?   |   Reviews   |   PR   |   Contact us  

Topic: Lysocline


  
  LYSOCLINE - Métacycline - Doctissimo
LYSOCLINE est utilisé pour traiter certaines infections spécifiques et l'acné.
LYSOCLINE est contre-indiqué en cas d'allergie aux tétracyclines.
LYSOCLINE peut interagir avec d'autres médicaments, en particulier les anticoagulants oraux.
www.doctissimo.fr /medicament-LYSOCLINE.htm   (236 words)

  
  Lysocline
The lysocline is a term used in geology, geochemistry and marine biology to denote the depth in the ocean below which the rate of dissolution of calcite increases dramatically.
At the lysocline, the rate of dissolution increases dramatically.
Furthermore, it is not constant over time, having been globally much shallower in the Cretaceous through to Eocene.
www.ebroadcast.com.au /lookup/encyclopedia/ly/Lysocline.html   (169 words)

  
 Kids.Net.Au - Encyclopedia > Lysocline
The lysocline is a term used in geology, geochemistry and marine biology to denote the depth in the ocean below which the rate of dissolution of calcite increases dramatically.
At the lysocline, the rate of dissolution increases dramatically.
Below this, there exists a depth known as the carbonate compensation depth (CCD) below which the rate of supply of calcite equals the rate of dissolution, such that no calcite is deposited.
www.kids.net.au /encyclopedia-wiki/ly/Lysocline   (194 words)

  
 586   (Site not responding. Last check: 2007-09-26)
Since the lysocline has always been deeper than 3,500m during the last 200 ka (1ka † 1000 years) (Curry and Lohmann, 1990), we assume that the CaCO3-flux supplied to the deeper locality EW9209 1JPC is comparable to the one into the shallower sediment of GeoB 1523-1.
Supposing that the degree of CaCO3 dissolution increases linearly with depth below the lysocline level and that the CCD has remained constant at 4,600m depth (Berger, 1977), we evaluated the variations of the depth of the lysocline for the last 200 ka.
The observed periodicity of the lysocline variation at the Ceará Rise exhibits a correlation with the variability of the Composite Preservation Index of the CaCO3 in the Southern Ocean (Howard and Prell, 1994).
www.the-conference.com /JConfAbs/1/586.html   (514 words)

  
 "OS51B-04" in sm97
Carbonate saturation horizons and lysoclines have been calculated for the western Indian Ocean from dissolved inorganic carbon and titration alkalinity data collected shipboard as part of the WOCE/DOE survey I7N transect during the southwest monsoon of July/August 1995.
Of specific interest are the results within the Arabian Sea where calcite saturation horizon and lysocline depths were found to be approximately 3100 and 4500 meters, respectively.
Samples for the determination of dissolved calcium concentration were also collected throughout the water column as an additional parameter of the marine inorganic carbon system useful in providing evidence for the dissolution and precipitation of calcium carbonate.
www.agu.org /cgi-bin/wais?c=OS51B-04   (307 words)

  
 EarthRef.org Reference Database (ERR) -- Archer 1991
A numerical model of calcite dissolution in contact with sediment pore water is used to predict the depth and shape of the calcite lysocline in the deep sea.
The model lysocline shape is sensitive to the calcite dissolution rate constant, the calcite, organic carbon, and refractory material rain rates, and the rates of oxic versus anoxic organic carbon degradation in the sediment.
Lysocline data from the western equatorial Atlantic are anomalous to the rest of the data; this anomaly may be explained by high rates of refractory material sedimentation from the Amazon River.
earthref.org /cgi-bin/err.cgi?n=48475   (286 words)

  
 coretop_mudmap3-galleys
Thus, each square on the maps represents one regional plot of the calcite lysocline, and the lysocline plots are tiled together like a sheet of stamps to show the areal distribution of the shape of the lysocline and the coverage of available data.
The lysocline in the Pacific was somewhat deeper than today, especially near the equator [Farrell and Prell, 1989]; the Atlantic was somewhat shallower [Balsam and McCoy, 1987] but relative to a scale of 1500 m the glacial-interglacial changes in the depth of the lysocline were small.
The lysocline is thicker (has a greater contrast in [[Delta]]CO between the high- and low-calcite sediments) in the western Pacific and in the Atlantic Oceans than it is in the eastern equatorial Pacific.
geosci.uchicago.edu /~archer/reprints/gbc96/coretop_mudmap3-.html   (7021 words)

  
 Limestone
Limestone is a sedimentary rock, mainly composed of mineral calcite.
The primary source of the calcite is usually marine organisms, which settle out of the water column and are deposited on the ocean floors as pelagic[?] ooze (but see lysocline for information on calcite dissolution).
Secondary calcite may also be deposited in super-saturated meteoric[?] waters, as is evidenced by the creation of stalagmites and stalactites.
www.ebroadcast.com.au /lookup/encyclopedia/li/Limestone.html   (117 words)

  
 INTRODUCTION
Thus, the behavior of the lysocline and CCD in different parts of the ocean can be used to constrain the source of carbon during the PETM and its distribution through the atmosphere and oceans (Zachos et al., 2005).
As CO is removed from the system, primarily through weathering of silicates and organic carbon burial, the concentration of bicarbonate begins to rise, and the lysocline and CCD deepen, resulting in a transient supersaturation of bicarbonate in the deep sea.
The extent and rate of lysocline and CCD shoaling during the PETM can be approximated in closely spaced sites along a depth transect in middle to lower bathyal water depths using visual observations of foraminiferal preservation and a suite of other preservational proxies.
www-odp.tamu.edu /publications/198_SR/112/112_2.htm   (974 words)

  
 "PP23A-1726" in fm06
AF: University of Minnesota, Department of Geology and Geophysics, 310 Pillsbury Drive SE, Minneapolis, MN 55455 United States
AB: The response of calcite lysocline to idealized thermohaline circulation changes is examined using Grid ENabled Integrated Earth system model (GENIE).
Under simulation of the present conditions, sedimentary calcite content in the Pacific appears to be more strongly controlled by deep ocean carbonate ion concentration than in the Atlantic.
www.agu.org /cgi-bin/wais?hh=PP23A-1726   (245 words)

  
 Carbonate Preservation in Deep and Intermediate Water Masses in the South Atlantic: Evaluation and Geological Record (a ...
In the western South Atlantic, the sedimentary calcite lysocline is encountered by the BDX~ at the transition between AABW and LNADW.
However, in the western South Atlantic the LDX displayas a double lysocline for aragonite, the upper lysocline at a water depth of 750 m and the lower at 2500 m.
With 3200 m, the position of the calcite lysocline is encountered at the same level in the southern parts of eastern and western basins dropping to 4000 m near the equator.
www.mpimet.mpg.de /en/wissenschaft/ueberblick/ozean-im-erdsystem/physik-des-ozeans/carbonate-preservation-in-deep-and-intermediate-water-masses-in-the-south-atlantic-evaluation-and-geological-record-a-review.html   (587 words)

  
 586   (Site not responding. Last check: 2007-09-26)
Since the lysocline has always been deeper than 3,500m during the last 200 ka (1ka † 1000 years) (Curry and Lohmann, 1990), we assume that the CaCO3-flux supplied to the deeper locality EW9209 1JPC is comparable to the one into the shallower sediment of GeoB 1523-1.
Supposing that the degree of CaCO3 dissolution increases linearly with depth below the lysocline level and that the CCD has remained constant at 4,600m depth (Berger, 1977), we evaluated the variations of the depth of the lysocline for the last 200 ka.
The observed periodicity of the lysocline variation at the Ceará Rise exhibits a correlation with the variability of the Composite Preservation Index of the CaCO3 in the Southern Ocean (Howard and Prell, 1994).
www.esc.cam.ac.uk /Library/Journals/J.Conf.Abs./1/586.html   (514 words)

  
 ABSTRACTS   (Site not responding. Last check: 2007-09-26)
Processes that increase alkalinity in the upper water column facilitate the sequestration of anthropogenic CO2.
However, such anaerobic processes as sulfate reduction in the sediments on the continental shelves do generate alkalinity which is unrelated to the dissolution of calcium carbonate.
In fact, shelf-generated alkalinity may almost be as important as that generated by dissolution in the open oceans above the chemical lysocline.
co2.ihas.nagoya-u.ac.jp /jgofs/page008.html   (164 words)

  
 Oceanic Sediments
The lysocline is the depth at which the rate of dissolution increases markedly.
(the depth of the lysocline and CCD) is influenced by a number of interrelated factors including water temperature, pressure, biological activity, calcite crystal size, and dissolved CO concentration.
Both the lysocline and the CCD are shallower in the Pacific than the Atlantic due to the fact that there is more CO in the Pacific water.
www.odp.usyd.edu.au /odp_CD/oceplat/opindex.html   (3725 words)

  
 Climate Audit - by Steve McIntyre » HAnsen and Schmidt: Predicting the Past - Continued
They lysocline is not the same as the CaCO3 saturation horizons (there are usually two referred to, because the two polymorphs of CaCO3, calcite and aragonite, have different solubilities in seawater).
The lysocline was first noted in CaCO3 solubility studies using balls of calcite suspended in the water column as a region over which the rate of dissolution increased rapidly.
The lysocline is a physical observation of dissolution “intensity” that is correlated with the carbonate ion concentration and CaCO3 saturation state in seawater.
www.climateaudit.org /?p=652   (9553 words)

  
 Ocean 540: Control of Carbonate Preservation
When the effect of organic carbon is not included, the lysocline is at the saturation horizon and the separation between the lysocline and the CCD is about 300 meters.
When the effect of organic carbon is included, the lysocline can be kilometers above the saturation horizon and the saturation horizon and the CCD are coincident.
At a depth of about 3700 m, roughly equivalent to the lysocline, the rate of dissolution of the spheres increased rapidly and continued to increase to the sea floor (Figure C-12).
www2.ocean.washington.edu /oc540/lec01-20   (2309 words)

  
 Biogenic Sediments
Pelagic sediments from relatively shallow depths in low latitudes are often dominated by pteropods shells, at intermediate depths by foraminiferal tests, below the lysocline and above the CCD by coccoliths, and below the CCD by red clays.
In modern oceans, deep ocean circulation is driven by formation of bottom waters during the freezing of sea ice.
The result is substantial shoaling of the lysocline and CCD in these regions.
geology.uprm.edu /Morelock/GEOLOCN_/dpseabiogenic.htm   (2701 words)

  
 Ccd (Carbonate Compensation Depth) | World of Earth Science
The water depth at which the sea water carbonate ion content and the concentration of carbonate ions in equilibrium with sea water for calcite or aragonite mineral phase intercept is called hydrographic calcite or aragonite lysocline, respectively.
Below the lysocline, calcium carbonate dissolution begins and becomes progressively more intense in proportion to the fourth power of carbonate ion undersaturation.
An undersaturation of about 10 μmol/kg is enough to dissolve almost all the calcite descending to the sea floor.
www.bookrags.com /research/ccd-carbonate-compensation-depth-woes-01   (672 words)

  
 Equatorial Pacific Sediments and Paleoceanography
Varied dissolution with depth was also accounted for using published trends in dissolution rates derived from the DSDP cores and paleodepths from a new subsidence calculation.
A westerly deepening of the carbonate compensation depth (CCD) and a sedimentary lysocline evolution were proposed, which improved the model for seafloor 30 Ma and older.
Carbonate dissolution and sharpness of the lysocline Differences in deposition rate at a common latitude should reflect mostly differences in carbonate dissolution because the primary sediment input (pelagic biological productivity) is relatively uniform east-west.
www.ocean.cf.ac.uk /people/neil/eqpac/eqpac.html   (1122 words)

  
 Just spit it out
lysocline 300 mg gél lysocline 300 mg gél
Note: Your message body is limited to 2000 characters.
lysocline 300 mg gél lysocline 300 mg gél" />
www.pliner.net /appmb/boardpost.aspx?id=14921&key=49824ECF77EF455A&page=1&thread=250861&msgpage=1   (61 words)

  
 Ocean 540: Marine Sedimentation
Two important horizons are the lysocline, where the proportion of solution-resistant tests increases abruptly, and the calcite compensation depth (CCD) which is the boundary between carbonate-bearing and carbonate-free sediments (Figure MS-3)
Carbonate concentration versus depth showing lysocline and CCD (right) created by simple linear dissolution with depth of carbonate in a carbonate-opal mixture (left).
The sea floor distributions of both carbonate and opal tests reflect the evolution of bottom water chemistry as it makes the "grand tour" from the North Atlantic via the Southern Ocean to the northern Pacific and Indian Oceans.
www2.ocean.washington.edu /oc540/lec01-16   (1027 words)

  
 California Space Grant Consortium
Berger’s contributions to understanding carbonate sedimentation in the oceans began with his Ph.D. thesis on the production and preservation of calcium carbonate shells in planktonic foraminifera, microscopic organisms that are widespread in the upper ocean waters.
He developed the concept of the lysocline – the depth level on the seafloor that separates well preserved from poorly preserved calcareous fossils.
Fluctuations of this level through geological time go parallel with major changes in the carbon dioxide content of the atmosphere.
calspace.ucsd.edu /casgc/bio_wolf.html   (379 words)

  
 Energy Citations Database (ECD) - - Document #244058
CaCO{sub 3} concentrations in global deep sea sediments were compiled from published data and compared to a gridded field of seawater carbonate ion concentration to determine regional variations in the calcite lysocline.
The thicker calcite lysocline in the Atlantic, as compared to the Pacific, is attributed to the delivery rate of terriginous material.
A gradient in calcite preservation with latitude was found to be smaller than the glacial/interglacial shift, implying that a rain ratio type of model requires a uniform application of perturbation conditions during glacial time which do not correspond to current conditions.
www.osti.gov /energycitations/product.biblio.jsp?osti_id=244058&query_id=0   (282 words)

  
 ۞ Lysocline - Encyclopédie, information et définition sur www.apropos-france.fr   (Site not responding. Last check: 2007-09-26)
La lysocline, en géologie, géochimie et biologie marine, est la profondeur dans l'océan à partir de laquelle la solubilité du calcaire augmente fortement.
La pression augmentant avec la profondeur dans la colonne d'eau, la saturation de l'eau de mer en calcite diminue, et la coquille commence à se dissoudre.
À la lysocline, la vitesse de dissolution augmente rapidement.
www.apropos-france.fr /Lysocline   (239 words)

  
 DISCUSSION
However, in Hole 1183A the shift corresponds to the level at which the quality of preservation changes, and in Hole 1186A the shift corresponds to the level at which the foraminiferal lysocline was crossed (P. Sikora and J. Ogg, unpubl.
Further, the shift is in the opposite direction from what would be expected if dissolution preferentially removed material precipitated in warm surface water and was, thus, most out of equilibrium with bottom water.
That said, the correlation between preservational evidence for Maastrichtian changes in the depth of the lysocline and carbonate compensation depth on OJP (J. Ogg et al., unpubl.
odp.pangaea.de /publications/192_SR/108/108_5.htm   (1070 words)

  
 Oceanographic Setting
The typical depth of the lysocline is between 3700-4500m and varies are a result of the carbonate ion concentration in the deep and intermediate water masses.
Factors that affect the depth of the lysocline and the compensation depth include
The depth of the lysocline (dotted line) and the CCD (solid line) in the Equatorial Pacific, along with the amount of water column saturation by carbonate (
strata.geol.sc.edu /MARINESEDIMENTS/CarbonateSlopes/webpage-oceanset.htm   (381 words)

Try your search on: Qwika (all wikis)

Factbites
  About us   |   Why use us?   |   Reviews   |   Press   |   Contact us  
Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.