
	Where results make sense

Topic: Global Standard Stratigraphic Age

Related Topics

Geologic timescale

Eocene

In the News (Tue 29 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Global Standard Stratigraphic Age - Wikipedia, the free encyclopedia (Site not responding. Last check: 2007-09-18)
		A Global Standard Stratigraphic Age, often abbreviated GSSA, is an internationally agreed upon chronological age used to define the boundaries between different periods or epochs on the geologic time scale.
		GSSAs are defined by the International Commission on Stratigraphy and are only used for time older that 630 million years ago.
		In contrast to GSSAs, GSSPs are based on important events and transitions within a particular stratigraphic section.
	en.wikipedia.org /wiki/Global_Standard_Stratigraphic_Age (150 words)

	Overview
		The formal definition of the Global Boundary Stratotype Section and Point (GSSP) is: The selected type or standard for the definition and recognition of a stratigraphic boundary between two named standard global chronostratigraphic units.
		The definition of a boundary by its linear age is the consequence of the fact that the the Proterozoic now recognizes units of global stratigraphic subdivision, where the boundaries are defined in terms of the age in millions of years.
		Since the Cambrian by stratigraphic consensus is considered to be the lowest Period in the Paleozoic Era and the Paleozoic the lowest major unit in the Phanerozoic Eon, the Fortune Head GSSP also defines the lower boundary of these major chronostratigraphic unit.
	www.stratigraphy.org /over.htm (2078 words)

	Geologic time scale - Wikipedia, the free encyclopedia
		The table of geologic periods presented here is in accordance with the dates and nomenclature proposed by the International Commission on Stratigraphy, and uses the standard color codes of the United States Geologic Survey.
		The "Devonian" was named for the British county of Devon, and the name "Carboniferous" was simply an adaptation of "the Coal Measures," the old British geologists' term for the same set of strata.
		For over 100 years, the age of the Earth and of the rock strata was the subject of considerable debate until advances in the latter part of the 20th century allowed radioactive dating to provide relatively firm dates to geologic horizons.
	en.wikipedia.org /wiki/Geologic_age (1684 words)

	Stage boundaries, global stratigraphy, and the time scale: towards a simplification
		The stratigraphic Committee of the Geological Society of London (Zalasiewicz et alii, 2004) proposes to eliminate a dual stratigraphic terminology because the concept of a Global Stratotype Section and Point (GSSP) allows the succession of time to be defined in its entirety using a succession of stages (Fig.
		Units of older rocks are best defined by numerical ages because measurements of physical age using rates of isotope decay and their interpretation constitute the most commonly applicable unequivocal tool for correlation.
		A stratigrapher easily comprehends a moment as lower or upper; in fact, he understands immediately: the moment (which is represented-recorded in a) lower or upper deposit.
	paleopolis.rediris.es /cg/CG2004_A02/index.html (7798 words)

	AGE MODEL AND MASS ACCUMULATION RATES
		For the "Leg 208 Summary" chapter age plots, ~300 cyclostratigraphic tie points derived from the MST data were used to align the individual sites and thereby increase the precision of the age-depth models.
		In cases of conflicting microfossil datums, we also took into account the reliability of individual datums as global dating tools, the stratigraphic reliability of fossil groups or specific datums, abundance, preservation, and reworking, if indicated, and the uncertainties associated with the first or last occurrence of a datum (first occurrence datums are generally preferred).
		For the age plots in Table T2, in the "Leg 208 Summary" chapter, ~300 cyclostratigraphic tie points derived from the MST data were used to align the individual sites and thereby increase the precision of the age model.
	www-odp.tamu.edu /publications/208_IR/chap_02/c2_10.htm (1127 words)

	[No title]
		Ash (1992) suggested that a K-Ar age on a biotite of 239±9 Ma is the age of a Middle Triassic tuff that was subsequently reworked during Late Triassic time to form the Black Forest bed.
		Furthermore, an age of 207 Ma for the early Norian Black Forest Bed seems unlikely, unless all previous calibration of the Late Triassic timescale is incorrect (Lucas, 1994, 1997).
		Therefore, neither of the published numerical ages of the Black Forest Bed is a reliable syndepositional age, and abundant biostratigraphic evidence constrains deposition of both the Sonsela Member and the Black Forest Bed to the early- to mid-Norian.
	www2.nature.nps.gov /grd/geology/paleo/pub/grd3_3/pefo3.htm (2641 words)

	k09 The geologic column is transformed into a geologic time scale
		For example, J. Jolly’s famous estimate in 1899 of the age of the earth from the chemical analyses of river waters and the salinity of the sea.
		Sollas himself had seen no reason to change this rate for his calculation of the age of the earth even as the reported maximum thickness of sedimentary rocks increased from 164,00 feet in 1895, to 265,00 feet in 1900, to 335,000 feet in 1909.
		Precambrian chronostratigraphic boundaries are formally defined in terms of absolute ages: Global Standard Stratigraphic Age (GSSA) – Remane, J., Bassett, M.G., Cowie, J.W., Gohrbandt, K.H., Lane, R., Michelsen, O. and Naiwen, W. (1996): Revised guidelines for the establishment of global chronostratigraphic standards by the International Commission on Stratigraphy.
	geowords.com /histbooknetscape/k09.htm (1109 words)

	[No title]
		The early middle Eocene age is suggested by a series of K-Ar age dates on a tuff (known as the "K-spar tuff" by Buchheim, 1994) in the uppermost part of the middle unit.
		Further taxonomic and stratigraphic resolution of the Fossil Butte palynoflora, new tuff samples for age dating utilizing new analytical techniques, and additional study of the mammal fossils in Fossil Basin is needed to resolve this confusing situation.
		Potassium-argon age determinations of 49.1 + 1.8, 50.2 + 1.9, and 52.2 + 2.0 Ma on a potassium-feldspar tuff near the top of the middle unit suggest that the upper part of the Green River Formation in Fossil Basin may be early middle Eocene in age.
	www2.nature.nps.gov /geology/paleontology/pub/grd3_3/fobu3.htm (2377 words)

	Nat' Academies Press, Active Tectonics: Impact on Society (1986)
		As few as 10 yr ago, estimates of the age of Quaternary deposits were commonly in error by sev- eralfold, and it was not uncommon for age estimates to have been off by a factor of 10.
		For marine mollusks from the North At- lantic, the age of CO2 in ocean water increases ages by 400 to 750 yr (Mangerud and Gulleksen, 1975~.
		Late Pleistocene loess in Germany yielded TL ages that are stratigraphically consistent and concordant with carbon-14 ages of an associated ash (Wintle and Brun- nacker, 1982; Figure 13.7~.
	www.nap.edu /books/0309036380/html/195.html (10779 words)

	Palaeos Cenozoic: Holocene: The Holocene Epoch - the modern age
		All other ages, epochs, and eras are represented by natural evolutionary and geological phenomena.
		The Holocene in contrast is distinguished by being the Age in which human activities have had a marked, and for the most part extremely detrimental, effect on the rest of the biosphere.
		The beginning of the Singularity could be taken as the starting point for a totally new phase of Gaian evolution, the Technozoic (age of artificial life) or Nooarchic (reign of mind).
	www.palaeos.com /Cenozoic/Holocene/Holocene.htm (614 words)

	[No title]
		One commenter on proposed sec.3.94 suggested that the worker protection standards of subsection (c) apply only to an employer of persons engaged in activities involving the disposal of oil and gas waste that is known to be oil and gas NORM waste.
		However, an employer whose workers are exposed to oil and gas NORM waste cannot avoid complying with the worker protection standards of this section by failing to make a determination as to whether or not a particular oil and gas waste meets NORM exemption criteria established by TDH.
		One commenter on proposed sec.3.94 suggested eliminating the requirement of subsection (e)(1)(A) that surface owner consent be obtained prior to disposal of oil and gas NORM waste generated on one lease in a well on another lease that is being plugged and abandoned.
	texinfo.library.unt.edu /texasregister/text/1994/1227adop.txt (12837 words)

	ES 331/767 Glossary
		Paleosol: ancient or buried soil, often used as a stratigraphic marker for interglaciation.
		SMOW: stands for "Standard Mean Ocean Water", used as a chemical and isotopic reference standard, for example in oxygen-isotope analysis.
		Stratotype: A specific sequence of sediment or rock, in which a stratigraphic unit or boundary is defined.
	academic.emporia.edu /aberjame/ice/gloss.htm (2277 words)

	cynthia burek / history of stratigraphy and the age of the earth (Site not responding. Last check: 2007-09-18)
		Secondly, the geological stratigraphic column is used to illustrate the history of how scientists debated the age of the earth and how that relative timescale can be used to put an age on earth materials.
		Two people who are obviously different in age, are chosen and then the audience is asked to either write down why one is older or younger than the other and then to discuss with the person next to them or to share this with the whole audience.
		The chronostratigraphic scale is a summation of all stratigraphical knowledge and as such there is no one cliff or quarry section on the Earth at which all units are exposed.
	nti.educa.rcanaria.es /penelope/uk_confburek.htm (3813 words)

	GEOLOGIC TIME SCALE FACTS AND INFORMATION (Site not responding. Last check: 2007-09-18)
		The table of geologic_periods presented here is in accordance with the dates and nomenclature proposed by the International_Commission_on_Stratigraphy, and uses the standard color codes of the United_States_Geologic_Survey.
		When William Smith and Sir_Charles_Lyell first recognized that rock_strata represented successive time periods, there was no way to determine what time scale they represented.
		For over 100 years, the age of the Earth and of the rock strata was the subject of considerable debate until advances in the latter part of the 20th century allowed radioactive_dating to provide relatively firm dates to geologic horizons.
	www.dontpayyourtaxes.com /Geologic_time_scale (1239 words)

	USGS Open-File Report 99-559, Stratigraphic Framework Maps of the Nearshore Area of Southern Long Island from Fire ...
		The fourth unit comprises Holocene age deposits that were not well defined in seismic profiles collected by Williams (1976), probably due to their limited vertical resolution.
		Most of the Chirp data were acquired at a 1/4-second fire rate (this translates to a horizontal distance of 4 meters between traces because of trace decimation and an average ship speed of 5 knots) and sweep lengths, except for some 1/8-second fire rate data off Fire Island.
		The stratigraphic framework together with sidescan-sonar imagery (Schwab and others, 1997and 1999a,b) constitutes a detailed data set from which the depositional history of the area can be interpreted.
	pubs.usgs.gov /of/1999/of99-559/report.htm (3704 words)

	[No title]
		Ganymede is one of the key members of the Galilean satellite system, is an important element in determining the nature and evolution of outer planet satellites, and was the focus of acquisition of significant new data during the Galileo mission.
		Refining the inferred surface age and resurfacing rate of the polar layered deposits using imaging and altimetric data Mars Global Surveyor and (if available) 2001 Mars Odyssey THEMIS data will be used to study the geomorphology and stratigraphy of the PLD.
		In particular, we will use standard thermodynamic techniques to understand the mineral forms in which phosphorus will occur in martian aqueous and hydrothermal environments, the mobility of different species, and the availability and accessibility at the surface and in the crust.
	research.hq.nasa.gov /code_s/nra/current/NRA-01-OSS-01-PGG/winners.html (15882 words)

	Rouse, I. E. --- Paleomagnetism II
		To obtain an "absolute" age for the rocks and thus for their primary remanence, either standard stratigraphic correlation techniques or radiometric methods, typically potassium-argon dating, are used.
		In studying rocks of early Pleistocene age, or older, these scientists discovered that a large proportion of the samples were magnetized in a direction nearly 180º from the present field direction.
		The "standard" evolutionary geological and geophysical interpretation of paleomagnetic data is that reversals of the earth's field occurred many times during the last several hundred million years.
	www.grisda.org /origins/10066.htm (7922 words)

	Sn-Sz
		A proposed globally standardized stratigraphy whose chronostratigraphic units will eventually be delimited by boundary stratotypes.
		The purpose of the network is to develop and coordinate research on the specific regional origins and impacts of global environmental change that contribute to the objectives of the three aforementioned parent organizations.
		The conductance varies with the age of the leaf, its position in the canopy, and the availability of water in the soil.
	stommel.tamu.edu /~baum/paleo/paleogloss-old/node38.html (7268 words)

	- A Reply to Dr. Henke and Others -
		For example, Plaisted’s “explanation” for the correlation of isotopic age with vertical position in the geologic column is essentially that excess argon would have existed in lavas in greater quantity early in the Flood, and decreased as it was outgassed over time.
		K/Ar ages from these minerals are often published to better understand the types of conditions that cause them to produce unreliable dates rather than to assign actual ages.
		We can assume that as a result of a global catastrophe, the oceans were highly enriched in argon 40 in the past, and that the concentration of argon 40 gradually decreased over time, due to its diffusion into the atmosphere and due to a smaller amount being released into the seawater.
	www.trueorigin.org /henke1.asp (8379 words)

	CD-ROMs and DVDs at the Earth Sciences & Map Library-University of California, Berkeley
		Global gridded upper air statistics, 1980-1995 ASCII data files of long-term monthly means and standard deviations of the period, represented on a 2.5 degree global grid at 15 standard pressure levels.
		The data are accessible by geographically panning and zooming to a given area on a global display or by directly selecting a station from one of seven identifiers, such as name, WMO no., or country.
		Contains historical global climate data including: mean monthly surface air temperature for both stations and aggregate averages for 5 x 5-degree grid boxes, monthly precipitation totals, mean monthly sea-level pressure, and global topographical relief data.
	www.lib.berkeley.edu /EART/cdrom.html (15884 words)

	Earth-Pages Archive News, Planetary
		Analysis of historic, global seismograph records using sophisticated software allows far more than the detection of various discontinuities in the deep mantle and core that figure in most textbooks.
		The authors speculate that a major unconformity in the Archaean of the Pilbara province in Australia, which is around the same age, may be the result of tsunamis induced by the impact.
		Their ages, obtained by methods based on the build up of lead isotopes from decayed uranium and thorium reached back to 4.27 billion years.
	www.earth-pages.com /archive/Planetary.asp (13242 words)

	A Reply to Dr. Henke and Others
		However, this does not remedy the situation, and the ages are still too high." This indicates that there may be a systematic difference between U-Pb ages and K-Ar ages, which could be a further evidence of a change in decay rates.
		If a catastrophic event increased Pb-Pb ages by 600 million years and K-Ar and Rb-Sr ages by 550 million years, then this would produce the observed one percent discrepancy in meteorites, but also invalidate ages on Cambrian and later strata.
		Other than a true age for the meteorites, this could indicate a mixing process, which does not seem likely, or an increase in decay rates, for which a mechanism would need to be found.
	www.cs.unc.edu /~plaisted/ce/henke.html (9726 words)

	Global Stratotype Sections and Points
		Astrochronology age of 7.251 Ma; middle of magnetic polarity chronozone C3Br.1r; lowest regular occurrence of the Globorotalia conomiozea planktonic foraminifer group.
		Pacific spreading model for magnetic anomaly ages (variable rate), using placement at M14r.3 (base T. pertransiens).
		Age suggested by Ediacaran Subcomm.; bracketed by radiometric ages of 600 and 635 Ma
	www.stratigraphy.org /gssp.htm (2656 words)

	talk.origins newsgroup
		The fossils are arranged in standard stratigraphic order - oldest at the bottom, youngest at top.
		Metazoans are commonly found in an interval known as the Ediacaran, named for the location in Australia where fossils of this age were first found.
		An evaluation of Ed Conrad and Ted Holden's claims of the discovery of Carboniferous age human bones in Pennsylvania.
	www.geo.ucalgary.ca /~macrae/talk_origins.html (1923 words)

	Global Engineering Documents - Your source for standards and specifications (Site not responding. Last check: 2007-09-18)
		This standard contains information for GM engineers and suppliers pertaining to material inputs that are prohibited or subject to declaration requirements.
		We are pleased to announce that we are now the exclusive distributor for the Aerospace Industries Association (AIA) National Aerospace Standards.
		Also, visit our Aerospace page to see the most popular standards for the aerospace industry.
	global.IHS.com (402 words)

	IngentaConnect Status of Divisions of the International Geologic Time Scale (Site not responding. Last check: 2007-09-18)
		Each chronostratigraphic unit of the International Geologic Time Scale will be defined at its base by a Global Stratotype Section and Point (GSSP) or Global Standard Stratigraphic Age (GSSA).
		However, in order to utilize global correlation horizons, the international stage divisions of other systems, such as the Ordovician or Permian, have required assembling new stage nomenclatures or hybrids of different regional stages.
		A reference table by the International Commission on Stratigraphy itemizes the current or potential GSSP and GSSA definitions of all international geologic time units.
	ingentaconnect.com /content/tandf/slet/2004/00000037/00000002/art00006 (210 words)

	Stratigraphy of the Permian
		A standard global correlation of the Permian period has been undertaken only in recent years (Jin et al., 1994), since there are difficulties in correlation, especially within relatively newer strata.
		Since the upper strata of various locations lack numbers of fossils, correlation via index fossils must involve different fossils that are in some cases native only to the local regions where they were found, and older work had to use assumptions that have changed in more recent years (Menning, 1995; Jin et al., 1994).
		Permian fossils that have been used as index fossils include brachiopods, ammonoids, fusilinids, conodonts, and other marine invertebrates (Menning, 1995), and some genera occur within such specific time frames that strata are named for them and permit stratigraphic identification through the presence or absence of specified fossils.
	www.ucmp.berkeley.edu /permian/permstrat.html (571 words)

Try your search on: Qwika (all wikis)