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Topic: Coccolith

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	Coccolith - Wikipedia, the free encyclopedia
		Coccoliths are individual plates of calcium carbonate formed by coccolithophores (single-celled algae such as Emiliania huxleyi) which are arranged around them in a coccosphere.
		The coccoliths are either dispersed following death and breakup of the coccosphere, or are shed continually by some species.
		Coccoliths are composed of calcium carbonate as the mineral calcite and are the main constituent of chalk deposits such as the white cliffs of Dover.
	en.wikipedia.org /wiki/Coccolith (299 words)

	Phycologia: A review of the coccolithophorid Emiliania huxleyi (Prymnesiophyceae), with particular reference to growth, ... (Site not responding. Last check: 2007-10-22)
		The spatial separation between the proximal and distal shields is relatively greater in type B coccoliths; the length: width ratio of the central area tends to be smaller; the distal shield elements are thinner; and there are differences in the structure of the central area (Young & Westbroek 1991).
		The coccolith vesicle and the reticular body are present in noncalcifying N cells as well, though in a somewhat reduced and deformed state and less closely associated with the nucleus (Klaveness & Paasche 1971; van der Wal et al.
		Coccolith formation in E. huxleyi differs in several ways from that in other coccolithophorids such as C. pelagicus (Manton & Leedale 1969) or P. carterae (Marsh 1994, and references therein), which lack a reticular body and in which the coccoliths are formed in vesicles directly derived from the Golgi apparatus.
	www.findarticles.com /p/articles/mi_qa3850/is_200111/ai_n9013591/pg_5 (1334 words)

	Seasonal and interannual variation of coccolithophore fluxes and species composition in sediment traps north of Gran ...
		Coccolith and coccosphere fluxes at both trap depths were characterized by a strong seasonality.
		Highest coccolith fluxes of 4538e6 coccoliths m-2 d-1 occurred at the beginning of March 1996, whereas lowest values of 19.8e6 coccoliths m-2 d-1 were recorded in June 1994.
		However, total coccolith flux peaks at 3000 m were about 2-4 times higher compared to the upper traps, probably due to horizontal advection from phytoplankton material from north of the study site.
	www.awi-bremerhaven.de /Publications/Spr2000b_abstract.html (337 words)

	IINA: Terminology - main text
		The division between coccoliths and nannoliths varies between authors and is liable to revision as new data becomes available.
		These are the fundamental components of coccoliths and their identification is a key objective of ultrastructural research.
		N.B. A coccolith or part of a coccolith can only appear non-birefringent in one orientation (when the c-axis is vertical), so these terms should not be used without explicit description of specimen orientation; e.g.
	www.nhm.ac.uk /hosted_sites/ina/terminology/maintext.htm (2608 words)

	coccolith -- Britannica Concise Encyclopedia - The online encyclopedia you can trust! (Site not responding. Last check: 2007-10-22)
		When the organisms die, the coccoliths are deposited (at an estimated 60,000,000,000 per square m [10 square feet] annually) onto the ocean floor and form, along with organic debris, a gray sediment.
		Fossil forms of coccoliths date from as far back as the Cambrian Period (540 to 505 million years ago).
		Chalk is composed of the shells of such minute marine organisms as foraminifera, coccoliths, and rhabdoliths.
	www.britannica.com /ebc/article-9024556 (438 words)

	Figure 3. (Site not responding. Last check: 2007-10-22)
		Coccoliths that fall within a grid-cell were counted using program Grid.f, which resulted in coccolith frequencies per grid-cell.
		The coccolith frequencies were the slight smoothing algorithm in Surface III and contour intervals of two coccoliths per grid-cell.
		Note, that some shaded grid-cells contain no coccoliths which is due to smoothing and boundary effects (a coccolith, that falls onto a grid-line is encountered as half a coccolith).
	www.ga.gov.au /paleo/2001_1/k2/fig_03.htm (161 words)

	[No title]
		The calcite platelets forming their skeleton — the coccoliths — make a significant contribution to the oceanic sedimentation, particularly in those regions where oligotrophic conditions prevail for most of the year, as is the case for the pelagic eastern Mediterranean Sea.
		Coccolith fluxes through the last 10 ky are also investigated from a selected sediment core.
		Coccolith fluxes from sediment traps show wide seasonal and interannual variations and are quite diverse from site to site; species composition varies on a seasonal scale and specific patterns in the assemblages are observed.
	www.geo.unimib.it /Elisa/Abstracts/2003_abstEGS_Malinv.doc (276 words)

	Emiliania huxleyi Coccoliths
		Coccoliths are one of the more remarkable types of biominerals owing to the very precise control by the organic system of every aspect of inorganic mineral growth.
		The concave side of the coccolith is nearer to the cell and is termed the proximal or lower surface, as opposed to the upper or distal surface.
		Coccolith structure and growth: coccolith formation occurs inside the cell and has been studied both by looking at sections through cells with coccoliths at various stages of growth and by looking at isolated incompletely formed coccoliths.
	www.soes.soton.ac.uk /staff/tt/eh/coccoliths.html (855 words)

	coccolith (Site not responding. Last check: 2007-10-22)
		Coccoliths are the individual plates formed by coccolithophores such as Emiliana Huxleyi
		The coccoliths are shed continually during the coccolith's lifetime, as well as following the breakup of the coccosphere on death.
		They sink through the water column to form an important part of the sediments (depending on the water depth), where they were first identified by Thomas Huxley.
	www.yourencyclopedia.net /Coccolith.html (193 words)

	INA: Terminology - Coccolith shape and size
		It also is in large part a reflection of the coccolithogenesis process; growth outward and upward from the proto-coccolith ring forms the rim whilst growth inward forms the central area.
		Coccolith size is normally given as maximum dimension in plan view, i.e.
		For instance most authors would agree that the term helicolith should be restricted to coccoliths of the Helicosphaeraceae, and not to any unrelated homoeomorphs.
	www.nhm.ac.uk /hosted_sites/ina/terminology/3coccoliths.htm (664 words)

	Implications for Biomineralization - 2001GB001408
		Attached to this coccolith vesicle is a reticular body, which is thought to pass matrix material and calcium, supplied by Golgi vesicles, to the forming coccolith.
		Once the coccolith is formed, the reticular body detaches and degenerates while the coccolith vesicle moves to the surface of the cell and exocytoses the mineralized body onto the surface to form an interlocking sphere of coccoliths.
		We propose that strontium incorporation into coccoliths is controlled by a rate-dependent discrimination by the cell against the biological pumping of the larger ions.
	www.agu.org /pubs/sample_articles/bg/2001GB001408/5.shtml (1187 words)

	Coccolith -- Facts, Info, and Encyclopedia article (Site not responding. Last check: 2007-10-22)
		Coccoliths are individual plates of (A salt found in nature as chalk or calcite or aragonite or limestone) calcium carbonate formed by (additional info and facts about coccolithophore) coccolithophores (such as (additional info and facts about Emiliania huxleyi) Emiliania huxleyi) which are arranged around them in a coccosphere.
		They sink through the water column to form an important part of the deep-sea (Matter deposited by some natural process) sediments (depending on the water depth).
		(English biologist and a leading exponent of Darwin's theory of evolution (1825-1895)) Thomas Huxley was the first to observe and name coccoliths in sedimentary samples.
	www.absoluteastronomy.com /encyclopedia/c/co/coccolith.htm (129 words)

	Emiliania huxleyi Home Page
		Thomas Henry Huxley ("Darwin's bulldog") was one of the first to examine sea-bottom mud and to detect coccoliths within it, and the first to use the term "coccolith".
		The construction of huge numbers of coccoliths from calcium and carbon, and their subsequent sinking to the ocean floor, also perturbs the ocean carbon system and eventually makes a difference to the amount of CO2 that can be stored in the atmosphere to contribute to the CO2 greenhouse effect.
		As well as exerting an impact on climate change, the long-term flux of coccoliths to the ocean floor goes to form chalk and limestone rocks - for instance the white cliffs of Dover are in large part made up of coccoliths that fell to the sea bed many millions of years ago.
	www.noc.soton.ac.uk /soes/staff/tt/eh/index.html (952 words)

	Determination of absolute coccolith abundances in deep-sea sediments by spiking with microbeads and spraying (SMS ... (Site not responding. Last check: 2007-10-22)
		However, until now it was not possible to apply this simple concept to coccolith counts because a) no uniform tracer particles were available in the size range of coccoliths and b) it was difficult to calculate the number of tracer particles that had to be added to a sample with an acceptable standard deviation.
		Coccolith counts obtained by the random settling method applying the formula given by Williams and Bralower (1984) are three times higher than the values obtained by the SMS-method and the filtration method.
		coccoliths per gram when the number of coccoliths is calculated assuming a total water column height of five centimetres instead of two centimetres in formula 4.
	www.geology.ethz.ch /mp/data/microbeads/paper.html (3465 words)

	[No title] (Site not responding. Last check: 2007-10-22)
		Fluctuations in bulk carbonate content at the core location are primarily driven by the coccolith fraction.
		The observed overall correlation between bottom flow speed, as given by the `sortable silt' mean size index, and the bulk coccolith concentration (abundance/g dry sediment) suggests that the accumulation of this fine carbonate fraction is, as a first order, controlled by processes of sediment redistribution by bottom current.
		These long-term reorganisations of the surface hydrology are interpreted as the response of the North Atlantic to the combined force of the solar insolation and the waning Laurentide ice sheet.
	www.elsevier.com /cdweb/journals/0012821X/articles/179/2/S0012821X0000113.abstract.en (348 words)

	Can Flood geology explain thick chalk beds?
		The two major microorganisms whose remains are thus fossilised in chalk are foraminifera and the spikes and cells of calcareous algæ known as coccoliths and rhabdoliths.
		The brown algæ that produce tiny washer-shaped coccoliths are known as coccolithophores, and these also float in the upper section of the open seas.
		Once the explosive blooms had generated the voluminous foraminiferal shells and coccoliths, these would then sink and be swept away by the Flood currents before being deposited in the alternating bands of the chalk beds.
	www.answersingenesis.org /tj/v8/i1/chalk.asp (3348 words)

	Phycologia: Five new species of the coccolithophorid genus Alisphaera (Haptophyta), with notes on their distribuion, ... (Site not responding. Last check: 2007-10-22)
		Kamptner (1941) mentioned that the structure of its closely packed coccoliths seemed to differ from that of the 'calyptrolith-like' coccoliths of the other Acanthoica species and suggested that it needed to be studied in more detail; he even suggested that it should be placed in a new genus.
		Therefore, we will compare its coccolith structure with that of the caneolith, the elliptical coccolith characteristic of the Syracosphaeraceae, and we will examine the relationship between Alisphaea and the other, possibly related genera that were included in the Syracosphaeraceae by Jordan & Green (1994).
		Since coccolith morphology is still the most reliable basis for coccolithophorid taxonomy, we have compared the coccolith structures of Alisphaera, Canistrolithus, and Syracosphaera, in order to study their phylogenetic interrelationships.
	www.findarticles.com /p/articles/mi_qa3850/is_200111/ai_n9013582 (1280 words)

	nanoeukaryotes (Site not responding. Last check: 2007-10-22)
		The coccoliths are formed inside of the cell in the coccolith vesicle through a process called coccolithogenesis.
		When each coccolith is fully formed, it is transferred to the outside of the cell and the vesicle membranes fuse with the cell membranes and the external parts of the membrane are reabsorbed so that the coccolith is outside of the cell.
		All of the carbon that they drew out of the water, to make their coccoliths, now sinks to the bottom of the ocean, meaning that the atmosphere and the top of the ocean are no longer in equilibrium with the other CO levels.
	biology.kenyon.edu /Microbial_Biorealm/eukaryotes/emiliania/emiliania.htm (676 words)

	Description of an Emiliania huxleyi Cell (Site not responding. Last check: 2007-10-22)
		Coccolith formation: the most distinctive feature of the cell is the covering of coccoliths.
		As shown, only one coccolith at a time is formed in Ehux and they develop within a coccolith vesicle close to the nuclear membrane.
		When the coccolith is fully formed the coccolith vesicle migrates toward the edge of the cell, the vesicle mebranes fuse with the cell membrane and the external parts of the membrane are resorbed so that the coccolith is extruded to the outside of the cell.
	www.soc.soton.ac.uk /soes/staff/tt/eh/cell.html (322 words)

	Journal of the Geological Society: White Stone Band of the Kimmeridge Clay Formation, an integrated high-resolution ...
		1) is a 1.2 m thick composite of coccolith limestone, oil shale and mudstone that lies within the generally homogeneous mudstone interval of the Pectinatites pectinatus Zone of the Upper Kimmeridge Clay.
		Analysis of the calcite content shows that the upper and lower boundaries to this coccolith limestone are transitional with some 20 cm of calcareous mudstone (about 60% calcite).
		The TOC and calcite analyses show that this is, in fact, a composite of discrete oil shale and coccolith limestones with some four 30-40% TOC oil shales c.
	www.looksmartcollege.com /p/articles/mi_qa3721/is_200407/ai_n9453021 (1479 words)

	Roth, A. A. --- Are Millions of Years Required to Produce Biogenic Sediments in the Deep Ocean?
		One coccolithophore may secrete 12 to 100 coccoliths which form a sheath around the outside of the organism.
		We are not dealing on an average with kilometers of foraminiferal sediments as has been conceived; nevertheless, considering how small these skeletal remains are, an average of 100 m of foraminiferal shells and 100 m of coccoliths can appear as a challenge to any model of rapid sedimentation.
		In other words it is possible to produce the average 100 m thickness of coccoliths proposed for the sea floor in less than 200 years.
	www.grisda.org /origins/12048.htm (3236 words)

	Literature Review
		The coccolith blooms have a profound affect on the global temperature.
		This light scattering causes remaining heat to be trapped at the surface of the ocean.
		When the salinity was decreased (34 to 24), calcification was increased in parts of the coccolith, but other components were formed incompletely.
	www.cvgs.k12.va.us /research/Final/sresch02/boman/litreview.htm (377 words)

	Satoh Abstract (Site not responding. Last check: 2007-10-22)
		In Emiliania huxleyi, the coccolith production process that proceeds intracellularly is a genetically controlled organic matrix-mediated calcification and the rate of production is regulated by some environmental factors.
		In this study, we found that the amount of coccolith production was strongly stimulated at low temperature although the lag time for initiation of calcification was elongated.
		The lag period was shortened when the cells were transferred to 10°C at the late logarithmic growth phase.
	www.biology.duke.edu /chlamy/abstracts/satoh.html (227 words)

	Marine Micropaleontology. (Site not responding. Last check: 2007-10-22)
		H.M. Stoll, P. Ziveri, Separation of monospecific and restricted coccolith assemblages from sediments using differential settling velocity, Marine Micropaleontology 46 (1-2) (2002) pp.
		Knappertsbusch, M.Y. Cortes, H.R. Thierstein, Morphologic variability of the coccolithophorid Calcidiscus leptoporus in the plankton, surface sediments and from the Early Pleistocene, Marine Micropaleontology 30 (4) (1997) pp.
		Xinrong, W. Pinxian, Controlling factors of coccolith distribution in surface sediments of the China seas: marginal sea nannofossil assemblages revisited, Marine Micropaleontology 32 (1-2) (1997) pp.
	www.elsevier.com /cdweb/journals/03778398/viewer.htt?viewtype=keywords&rangeselected=6 (778 words)

	Fossils, Coccoliths, and the BK Boundary, CARM
		An alternative model of coccolith accumulation is now presented in order to reflect the fact that coccolith accumulation is not steady-state but highly episodic.
		In response to my coccolith challenge to Karl, a chap who calls himself Tommy Hellfighter copied a bunch of material from a Woodmorappe paper that claimed that enough pre-flood coccolith deposits could have formed prior to Noah's flood to account for the extensive chalk layers that we see now.
		I also found that the specific gravity of calcium-carbonate (the primary consituent of coccoliths) is 2.7,and that chalk deposits typically consist of 90-99% coccoliths.
	www.carm.org /evolution_archive/fossils_coccoliths.htm (6124 words)

	Sedimentary Accumulation Rate
		Many nannofossil biostratigraphers believe that coccolith size evolution is important to nannofossil biostratigraphy (e.g., Perch-Nielsen, 1985; Backman and Hermelin, 1986; Takayama, 1993).
		coccolith size does not simply increase upward throughout the sedimentary sequence but is characterized a gradual increase in coccolith size followed by an abrupt decrease in maximum size.
		This may suggest an increase in coccolith size corresponding to more recent age in the sequence.
	www-odp.tamu.edu /publications/171B_SR/chap_07/c7_5.htm (331 words)

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