
	Where results make sense

Topic: Chert

Related Topics

Lithic flake

Stone tool

Lithic analysis

Hornfels

Flint

Igneous rock

Rock (geology)

Sedimentary rock

Geology of the Grand Canyon area

Shale

RTS

Luster

Siltstone

Phyllite

Chalcedony

	Chert gravel
		Chert gravels are abundant along the main valley and most tributary valleys of the Cottonwood system in Chase and Lyon counties--see chert map and study region.
		Chert gravel is preserved in vicinity of the Missouri-Arkansas drainage divide in central Anderson County at elevations of 350-360 m.
		Upland chert gravel is abundant in upper portions of the basin in southern Lyon and northeastern Greenwood counties--see chert map and
	www.emporia.edu /earthsci/chert/chert.htm (5031 words)

	Chert
		In prehistoric times, chert was often used as a source material for stone tools.
		The partial Hertzian cones produced during lithic reduction are called flakes, and exhibit features characteristic of this sort of breakage, including striking platforms, bulbs of force, and occasionally eraillures, which are small secondary flakes detached from the flake's bulb of force.
		A primary historic use of chert was as flints for flintlock firearms, in which flint or chert striking a metal plate produces a spark that ignites a small reservoir containing fl powder, igniting it and discharging the firearm.
	www.ebroadcast.com.au /lookup/encyclopedia/ch/Chert.html (307 words)

	Rock Types \| Chert
		Chert is a common surface rock that is often a headache to farmers and gardeners as they try to work the soil.
		Chert is especially abundant within the dolomite layers of the Roubidoux Formation and at times forms continuous layers or ledges of chert (Figure 4) that may be as much as twelve inches thick.
		Chert nodules are formed due to chemical migration of silica during diagenesis: the process of creating rock from sediment.
	www.watersheds.org /earth/chert.htm (436 words)

	Chert - Presidio of San Francisco
		In the Franciscan Complex, chert is a silica-rich rock formed from the altered shells of microscopic radiolaria, which slowly rained down onto the ocean bottom.
		Chert is also typically formed under areas of high productivity in the oceans, which promotes the growth of radiolaria relative to other types of plankton.
		Franciscan cherts are formed from the tiny (0.5 to 1.5 mm) silica shells of radiolaria.
	www.nps.gov /prsf/geology/chert.htm (247 words)

	Rock Kits/Chert (Site not responding. Last check: 2007-10-20)
		Chert and flint are so similar that there is no sharp distinction between them.
		Chert has a conchoidal fracture, a hardness of around 7, a dull luster, and a colorless streak.
		The chert sample in the Texas Rock Kit was collected in Bexar County and is Cretaceous in age.
	www.beg.utexas.edu /mainweb/publications/graphics/chert.htm (217 words)

	Chert: World of Earth Science
		Chert is just one of the many types, or polymorphs, of quartz, a mineral composed of three-dimensionally bonded silicate tetrahedra.
		Chert is very fine-grained, so it does not occur as the 6-sided, prismatic crystals typical of such coarsely crystalline varieties of quartz as rock crystal, amethyst, smoky quartz and citrine.
		Chert usually occurs as bands or nodules in limestone, a marine sedimentary rock that forms by the same mechanism of biological mineral precipitation.
	science.enotes.com /earth-science/chert (341 words)

	Alaskan Chert
		The term "chert" is also sometimes broadly and loosely used by geologist to describe other dense siliceous rocks that fracture with as dull and somewhat granular appearance, but these rocks are more properly considered Silicified mudstone or limestone and do not yield as high a quality of material for tool making.
		Chert is found dominantly associated and inter-bedded with fine grained sedimentary rocks that were deposited slowly on the ocean floor and occasionally is found inter-bedded with fine grained igneous rock such as basalt that was extruded in the oceans of long ago.
		Chert is not present in sandstone or conglomerate, except sometimes as pebbles or cobbles recycled from older rocks, because sandstone and conglomerate are deposited rapidly in settings in which the slow rain of silica-bearing organisms is diluted by the abundance of coarse detritus.
	www.alaskanartifacts.com /Lithics/Ak_Typology_Lithic.html (1332 words)

	GemRocks: Chert
		Two examples are the Fort Payne Chert of the southern Appalachians and the Huntersville Chert of West Virginia, Tennessee, Kentucky, and Virginia.
		Mozarkite - a multicolored chert that occurs sporadically in Missouri and in the Ozark Mountains of Arkansas.
		Although flint is chert is flint is chert.
	www.cst.cmich.edu /users/dietr1rv/chert.htm (959 words)

	Past lives: Chronicles of Canadian Paleontology - Gunflint Chert
		The red chert, or jasper, is particularly diagnostic of the Gunflint.
		When he examined thin-sections of this chert under a petrographic microscope, he was astonished to find that it was infused with thousands of minute spheres, flasks and long segmented filaments; all less than 10 microns across.
		Barghoorn, E.S. and Tyler, S.A. Microorganisms from the Gunflint Chert.
	gsc.nrcan.gc.ca /paleochron/05_e.php (527 words)

	assemblage 4 -- Chert Use in the Mesolithic (Site not responding. Last check: 2007-10-20)
		Chert is generally understood to be of inferior quality to flint for knapping, though dark, fine-grained chert from the Bakewell area of the Peak District knaps considerably better than some of the coarse, white Wolds flint of North Yorkshire.
		Derbyshire chert is represented (though not geochemically identified) on the gritstone uplands of the South Pennines, as well as in the coal measures and magnesian limestone of South Yorkshire and North Derbyshire, but it has not been recorded to the south of the White Peak in the Trent Valley.
		Chert is rarely, if ever, found in the Trent Valley into which the White Peak drains (Manby 1963), but it is frequently found in upland areas to the north, over the most mountainous terrain in England.
	www.assemblage.group.shef.ac.uk /4/4hind.html (3882 words)

	DRAM, FGS, Chert (Site not responding. Last check: 2007-10-20)
		Identification: Chert, also known in Florida as flint or flint rock, is an extremely fine-grained variety of the mineral quartz.
		It is characterized by its extreme hardness (7.0), glass-like fracture, and the sharpness of the edges of broken fragments, Florida's cherts are generally gray in color, though some are bright shades of blue, red, yellow and orange.
		Chert is found at the surface of the ground in many of the northern and western counties of the State, especially Wakulla, Marion, and Citrus counties.
	www.dep.state.fl.us /geology/geologictopics/rocks/chert.htm (184 words)

	Ancient Uses of Ramah Chert: Newfoundland and Labrador Heritage
		Archaeologists have identified Ramah chert amongst all of the indigenous cultures of the province.
		Archaeologists investigating Newfoundland and Labrador prehistory have identified Ramah chert amongst all of the indigenous cultures of the province.
		Chert is workable, but often Ramah chert was used to the exclusion of other more accessible materials of similar quality, such as the cherts from Cape Mugford.
	www.heritage.nf.ca /environment/landscape_ramah.html (1191 words)

	Chert
		Chert is resistent to weathering and so tends to stand out of the ourcrop.
		Cherts typically form in places where clastic influx is low (i.e.
		Two broad types of chert form, nodular and bedded, with abundant variations in between.
	csmres.jmu.edu /geollab/Fichter/SedRx/Rocks/chert1.html (203 words)

	98 CHERT
		CHERT recommendations and other communications from the operators, their consultants, and agencies were compiled in numerous electronic mailings generated throughout the mining season.
		CHERT recommendations were to realign the landward extraction edge to provide a greater buffer between the extraction area and a side channel along the landward edge of the bar.
		CHERT recommended that the skim be flat in the cross stream direction, but slope in a downstream direction parallel to the river’s slope, and that the downstream end be feathered out to avoid leaving an upstream-facing berm.
	www.calawnet.com /environmental/98report.html (8237 words)

	USC Sequence Stratigraphy Web
		These cherts are composed of microcrystalline quartz that contains abundant water that is dispersed interstitially between the crystals.
		Chert nodules in limestones have been linked interstitial anoxia, soft-sediment deformation, when the secondary replacement of carbonate by silica can occur.
		Thus deep-sea cherts are found both in the central Atlantic and the Pacific Oceans.
	strata.geol.sc.edu /thinsections/caco3-chert.html (292 words)

	PRESS RELEASE Birim Goldfields Inc.: Positive Drill Intersection at Chert Ridge Target Area (Site not responding. Last check: 2007-10-20)
		The Chert Ridge Prospect is a 9-kilometer long northeast trending contact zone of sheared and folded phyllitic metasediments and metavolcanics.
		Chert Ridge is situated on a regional structural lineament that is readily traceable for over 50 kilometers to the southwest and a further 20 kilometers to the northeast.
		The Chert Ridge Prospect represents an exciting drill target due to its spatial coincidence with a major crustal structure and the intensity of the hydrothermal alteration in the sheared corridor.
	www.marketwire.com /mw/release_html_b1?release_id=159011 (736 words)

	Rhynie Chert, Scotland
		The Rhynie Chert beds in Aberdeenshire in the north of Scotland are important fossil sites that reveal much about the evolution of life from the Early Devonian, approximately 408-360 million years ago.
		The result is a preservation in chert, a kind of finely crystalline quartz, which occurs in veins throughout the rest of the surrounding rocks.
		Other significant discoveries from the fossils of the Rhynie Chert are the diverse fossils of fungi and record of their interactions with the surrounding plants.
	www.ucmp.berkeley.edu /devonian/rhynie.html (1102 words)

	Chert & Chalcedony
		Cherts found in the bedrock of Pennsylvania are of Paleozoic (Ordovician and especially Devonian) ages.
		Chert may form from siliceous sea-floor ooze, incorporating the remains of millions of individual organisms such as plankton and sponges that secrete silica.
		Whatever the origin of the silica in chert, the usual connotation is of a chemical precipitate, as opposed to more abundant clastic sediments composed of fine sand particles, such as siltstone or quartzite.
	www.turnstone.ca /chert.htm (612 words)

	Flint vs. Chert....whats the difference? (Site not responding. Last check: 2007-10-20)
		Chert is composed of larger crystal particles and has a specific gravity similar that of pure quartz.
		Chert is duller and more opaque than chalcedony and its luster ranges from non-existant to very waxy, depending on the individual rock formation.
		The reality of the flint verses chert debate is that in most cases it is something like "splitting hairs", there really is very little difference, chemically speaking.
	www.theaaca.com /Learning_Center/flintvs.htm (509 words)

	Jurassic chert from Liel on Flintsource.Net
		The material in an unaltered state is quite similar to the banded, light-grey chert from the prehistoric flint mine of Kleinkems.
		The Liel chert has been found in archaeological contexts in Switzerland and west of Lake Constance(Affolter 2002), but this publication is the only one in which this raw material is mentioned.
		As the chert from Liel is quite typical, it should be possible to differentiate it from the Kleinkems chert, and similar materials from the southernmost part of the Alsace.
	www.flintsource.net /flint/D_liel.html (1556 words)

	Neighborhood Rocks: White Chert
		Chert is made mostly of extremely tiny crystals of the mineral, quartz.
		Chert often breaks to form sharp or scalloped edges, but dolostone usually does not.
		Chert is sometimes classified as a chemical sedimentary rock, because it often forms when limestone or dolostone is chemically changed.
	saltthesandbox.org /rocks/chertwhite.htm (376 words)

	Chert (Site not responding. Last check: 2007-10-20)
		Chert is a sedimentary rock in the class known as chemical sedimentary rocks.
		Flint is dark-colored chert that contains organic matter to contribute the dark color.
		Chert occurs in banded forms that are commonly called agate.
	hyperphysics.phy-astr.gsu.edu /Hbase/Geophys/Chert.html (59 words)

	Chert (Site not responding. Last check: 2007-10-20)
		Chert Chert is a fine-grained silica-rich cryptocrystalline sedimentary rock that may contain small fossils.
		The Gunflint Chert of western Ontario (1.9 to 2.3 By) preserves not only bacteria and cyanobacteria but also organisms believed to be ammonia-consuming and some that resemble green algae and fungus-like organisms.
		The Devonian Rhynie Chert (400 My) of Scotland has the oldest remains of land flora, and the preservation is so perfect that it allows cellular studies of the fossils.
	chert.iqnaut.net (533 words)

	(GCPAE8) Grand Falls Chert Bed Earthcache by Mimi & Pa (Site not responding. Last check: 2007-10-20)
		Chert is made from Slicia and Oxygen and a few other things mixed in.
		The chert was more than likely formed from tiny sea creatures shells or sponges that have Slicia in them.
		To the south of the falls is a sheet of Chert.
	www.geocaching.com /seek/cache_details.aspx?wp=gcpae8 (505 words)

	AERA - Stone Age Tools in the Bronze Age
		Chert can be shaped into very effective tools and its presence in huge quantities on the desert surface made it a natural resource for the pyramid builders.
		Chert is perhaps so common that archaeologists sometimes ignore this simple material in favor of artifacts like pots, which are familiar because we still use pottery, and inscribed sealings because hieroglyphic texts speak more directly than material like chert.
		It is worth noting that almost no chert of the good, imported type occur north of the Wall of the Crow, where a scrappy local chert assemblage predominates.
	www.aeraweb.org /spec_flint.asp (1129 words)

	Chert (Site not responding. Last check: 2007-10-20)
		Chert is a rock type composed mostly of...
		Taphonomy is the study of the various overlapping, consecutive processes which can affect organic remains prior to burial and their inclusion in the fossil record.
		Alluvial deposits of chert gravel of presumed Neogene age are widespread and abundant on hill tops and high terraces...
	www.toprocks.net /MineralList/18/Chert.asp (576 words)

	Neighborhood Rocks: Brown Chert
		Chert is one of the most common rocks in our neighborhood.
		Brown chert gravel fills in the narrow space between sidewalk and fence.
		This variety of chert is usually brown or creamy white, and it sometimes looks smooth and waxy.
	www.saltthesandbox.org /rocks/chertbrown.htm (369 words)

Try your search on: Qwika (all wikis)