
	Where results make sense

Topic: Hornfels

In the News (Sat 22 Nov 08)

Norm Coleman

Benji Madden

Freddie Mac

Puerto Rico

Vladimir Putin

Treasury Department

Mitt Romney

Giovanni Trapattoni

Steve Ballmer

James Bond

	Hornfels - LoveToKnow 1911
		HORNFELS (a German word meaning hornstone), the group designation for a series of rocks which have been baked and indurated by the heat of intrusive granitic masses and have been rendered massive, hard, splintery, and in some cases exceedingly tough and durable.
		Most hornfelses are fine-grained, and while the original rocks (such as sandstone, shale and slate, limestone and diabase) may have been more or less fissile owing to the presence of bedding or cleavage planes, this structure is effaced or rendered inoperative in the hornfels.
		They are excessively variable in their mineralogical composition, and very often alternate in thin seams with biotite hornfels and indurated quartzites.
	www.1911encyclopedia.org /Hornfels (1240 words)

	Hornfels: World of Earth Science
		Hornfels is a fine-textured metamorphic rock formed by contact metamorphism.
		The term hornfels is often restricted to rocks produced by contact metamorphism of shale, slate, or mudstone.
		Hornfels may be chemically altered by the magma that metamorphoses them, but generally reflect the chemical composition of their parent rocks; thus, quartz, feldspar, biotite, muscovite, pyroxenes, garnet, and calcite are common ingredients of hornfelses.
	science.enotes.com /earth-science/hornfels (330 words)

	Hornfels (Site not responding. Last check: 2007-09-11)
		Hornfels are rocks that form by contact metamorphism in the inner parts of the contact zone around igneous intrusions.
		All of the rocks called hornfels--a hard, fine-grained, flinty rock--are created when heat and fluids from the igneous intrusion alter the surrounding rock, changing its original mineralogy to one that is stable under high temperatures.
		The minerals of the hornfels facies depend largely upon the composition of the parent rock.
	geology.csupomona.edu /alert/metamorphic/hornfels.htm (90 words)

	Hornfels
		Hornfels can have any of a wide diversity of microscopic minerals, all too small to see or identify without thinsection and a specialized microscope.
		Hornfels is a nondescript rock which varies widely in appearance.
		Hornfels results from the contact metamorphism of shales or other clay rich rocks in the viscinity of an igneous intrusion.
	csmres.jmu.edu /geollab/Fichter/MetaRx/Rocks/hornfels1.html (117 words)

	Hornfels - Wikipedia, the free encyclopedia
		Hornfels (German, meaning "hornstone") is the group designation for a series of contact metamorphic rocks that have been baked and indurated by the heat of intrusive igneous masses and have been rendered massive, hard, splintery, and in some cases exceedingly tough and durable.
		When perfused with boric and fluoric vapors from the granite they may contain much axinite, fluorite and datolite, but the altiminous silicates (andalusite, andc.) are absent from these rocks.
		Among these may be mentioned cordierite and sillimanite gneisses, andalusite and kyanite mica-schists, and those schistose calcite-silicate rocks that are known as cipolins.
	en.wikipedia.org /wiki/Hornfels (1290 words)

	ROCK LANDFORMS of Australia & NZ - METAMORPHIC LANDFORMS - Case Study (A)
		It is believed that the hornfels derived from phyllite which had recrystallised through heat from the nearby intrusion.
		The phyllite was altered into hornfels as a results of heat from a granite intrusion (this process is referred to as contact metamorphism; heat rather than pressure was the main agent of recrystallisation).
		The hornfels occurs in a relatively narrow band between the granite intrusion and the original phyllite.
	www.vnc.qld.edu.au /enviro/landform/landf-mc.htm (963 words)

	CHAPTER 8 (Metamorphic Rocks)
		The hornfels comprise the series of rocks that result from contact metamorphism under low pressures and a wide range of temperatures.
		Hornfels are generally products of heated recrystallization of the original rock (typically sedimentary rock), coupled with chemical reactions involving hot fluids from the nearby magmatic intrusion.
		Hornfels are essentially cooked in place by the adjacent magmatic intrusion without deformation.
	www.uh.edu /~geos6g/1330/meta.html (1634 words)

	Lab#7 (Site not responding. Last check: 2007-09-11)
		Hornfels: A massive (no foliation, lineation, etc.) rock composed of a mosaic of equidimensional grains without preferred orientation.
		In a spotted hornfels there are porphyroblasts of one or more minerals such as biotite or andalusite.
		Spotted hornfels have been blamed recently for the decline in the logging industry in the Pacific northwest.
	www.mines.utah.edu /~jrbowman/gg3090/Labs3090/lab07_MetRocks1.html (1209 words)

	All about skarns
		Calc-silicate hornfels is a descriptive term often used for the relatively fine-grained calc-silicate rocks that result from metamorphism of impure carbonate units such as silty limestone or calcareous shale.
		Genetically, skarnoid is intermediate between a purely metamorphic hornfels and a purely metasomatic, coarse-grained skarn.
		Thus, the term biotite hornfels is not strictly appropriate, but has been retained as a field term because biotite is an essential component and the alteration typically is fine grained and granular.
	www.wsu.edu:8080 /~meinert/aboutskarn.html (19814 words)

	[No title]
		The different environments are the following: hornfels, igneous breccias, marble xenoliths, miarolitic cavities, pegmatites (altered and unaltered), sodalite syenites and sodalite xenoliths.
		Two types of hornfels are present, on formed some distance from the magma that contains more carbonates, and the second formed near the magma containing mostly silicates.
		This is due in part to the current activities of the quarry following the hornfels for the asphalt shingles material.
	www.chez.com /mineralzine/ancien/info3-4-b.htm (1707 words)

	Prehistoric site near blasting, construction
		Hornfels breaks cleanly and predictably, which makes it a shapeable material prehistoric people prized for making tools, Boisvert said.
		Only up to 10 other prehistoric quarries have been discovered in New Hampshire, and the hornfels quarry is especially valuable, he said.
		He said he believes the site is eligible for inclusion on the National Register of Historic Places, but he called the process of having it included time consuming and often costly.
	www.focustamworth.org /Citizen_11_06_05.htm (612 words)

	NH Scrap
		The primary goal of the fieldschool was to locate the bedrock source of hornfels, a workable stone used predominantly for lithic artifacts at sites in the area.
		Hornfels is produced by the contact metamorphism of volcanic ash by subsequent intrusions of igneous material.
		Based on the density of hornfels in the area, it has long been suspected that the source lies in the ring dike which forms distinct circular shape of the Ossipee Mountains.
	mysite.verizon.net /ddboisvert/FS2000/Fs00sum.htm (1093 words)

	Open-File Report 03-056 -- Deep structure Rapidan
		In detail, the body is a concave-up intrusive that cradles in it's interior a massive inlier of Balls Bluff siltstone, grading into it's contact metamorphosed equivalent hornfels.
		hornfels screens, which are characteristically more intensely fractured, more susceptible to weathering, and would be much lower in bulk electrical resistivity than their diabase neighbors.
		The body is believed not to be monolithic but, however, to have significant three-dimensional character in it's upper contact surface and in it's interrelationships with the hornfels above it.
	pubs.usgs.gov /of/2003/of03-056/html/DSRapidandesc.htm (578 words)

	EWU \| Current Research
		This field course is one way in which we get our students out in the field for a trip longer than a day trip or weekend trip to learn about the interaction of geology and biology on both small and large scales in the scenic Pacific Northwest.
		In particular, the drill core was investigated to characterize the mineral assemblages and their textures, search for evidence of partial melting, and to determine mineral and whole-rock geochemistry to provide an understanding of the petrogenesis of the hornfels close to the contact with the Stillwater Complex.
		Average T-P conditions of hornfels genesis is 786Â°C and 4 kbar.
	www.ewu.edu /x17429.xml (711 words)

	Particle and Fibre Toxicology \| Full text \| Different particle determinants induce apoptosis and cytokine release in ...
		Thus, the data for hornfels and porphyr did not confirm the difference in apoptosis observed for quartz-2 and quartz-10 in Fig.
		An important observation in the present study is that for the examined stone particles/mineral particles surface reactivity seemed important for the ability to induce cytokine responses, whereas the surface reactivity seemed of less importance for the reduction in cell viability and apoptosis.
		With respect to aging of the particles the hornfels and porphyr particles were produced and the experiments conducted at a later time point than for the other particles.
	www.particleandfibretoxicology.com /content/3/1/10 (6199 words)

	TALLAROOK WINES
		Chardonnay -The fruit, sourced from multiclonal plantings on hornfels and ironstone gravel, is hand harvested,
		Shiraz - Hornfels, ironstone and granite all contribute to the soils of the Tallarook Shiraz vineyards.
		The fruit is gently destemmed and crushed, followed by fermentation with Marsanne and Viognier in small open vats.
	www.tallarookwines.com.au /winemaking/W1.htm (107 words)

	Dawson Lab Research - Alpine Research
		In addition hornfels and marble, the two metamorphic rocks, have greater nitrogen availability than granite and diorite.
		Micronutrient availability is variable, but in general hornfels have the highest concentration of all cations except Ca and Mg, which are very abundant on marble.
		These measures imply that hornfels is the most hospitable environment for plants, and indeed species show the greatest biomass on hornfels.
	ib.berkeley.edu /labs/dawson/research_alpine.php (543 words)

	Temperature and pressure of metamorphism
		The shaded area represents the ranges in temperature and pressure thought to have controlled the mineral assemblages in the metamorphic rocks in the Alabama Hills.
		Figure 35b shows the ranges for the three hornfels facies and the granite melting curve.
		When the field relationships between the metamorphic facies are applied to this diagram, some important conclusions can be made concerning the pressure and temperature during contact metamorphism.
	www.angelfire.com /extreme4/lkrwork/x348.htm (212 words)

	TRANS-ROAD MOUNTAIN
		The hornfels layers are generally green to fl and are mud rich layers.
		The limestones and muds now exist as marbles and hornfels, respectively, because they were baked to approximately 600o C by the surrounding granites.
		This baking was responsible for changing the Castner carbonates and muds to marble and hornfels, the Lanoria sandstones to quartzites and the Thunderbird conglomerates and rhyolites to meta-conglomerates and meta-rhyolites.
	www.geo.utep.edu /loca/Precambrian/transmtn.htm (5249 words)

	Particle and Fibre Toxicology \| Abstract \| Different particle determinants induce apoptosis and cytokine release in ...
		The crystalline particles of the different stone types mylonite, gabbro, basalt, feldspar, quartz, hornfels and fine grain syenite porphyr (porphyr), with a relatively equal size distribution (≤ 10 μm), but different chemical/mineral composition, all induced low and relatively similar levels of apoptosis.
		Furthermore, hornfels (≤ 2 μm) was more potent than the corresponding hornfels (≤ 10 μm) and quartz (≤; 2 μm) to induce cytokine responses.
		Pre-treatment of hornfels and quartz particles ≤ 2 μm with aluminium lactate, to diminish the surface reactivity, did significantly reduce the MIP-2 response to hornfels.
	www.particleandfibretoxicology.com /content/3/1/10/abstract (404 words)

	Understanding Planet Earth 186-201C: Field trip 2
		In fact, it is only within the innermost 100 m of the contact metamorphic aureole that we can observe the effects of thermal change with the naked eye.
		The results are "bleaching" of the dark grey limestone to form white marble, and metamorphism of the soft and fissile shale to a slightly coarser-grained and harder hornfels.
		Name two ways in which the hornfels differs from the shale samples we bring.
	www.eps.mcgill.ca /~venetia/201c/trip2.html (2823 words)

	RI8084
		The most common types are hornfels, believed to be recrystallized greenstone or Virginia Formation (argillite), and xenoliths of recrystallized Biwabik Iron Formation (figs.
		The thick 100-foot zone of hornfels centered at 700 feet in figure 2 is a zone of recrystallized iron formation and fine-grained metasediments.
		The remaining hornfels are small intersections that are usually dense, fine-grained rocks with some relic structures.
	www.tc.umn.edu /~mboucher/mikebouchweb/pubs/ri8084.htm (10321 words)

	Contact Metamorphism
		The area surrounding an igneous intrusion that has been metamorphosed as a result of the heat released by the magma is called a contact aureole.
		The outer zone contains metapelites in the Hornblende Hornfels Facies, and the zone adjacent to the pluton contains metapelites in the Pyroxene Hornfels Facies.
		The facies of contact metamorphism progress in temperature at relatively low pressure from the Albite-Epidote Hornfels Facies to the Hornblende Hornfels Facies, to the Pyroxene Hornfels Facies.
	www.tulane.edu /~sanelson/geol212/contactmeta.htm (1354 words)

	Metamorphic Rocks: Types and Facies
		Because of the shallow depth there is almost no confining pressure and no differential stresses are applied to the rock leaving most rocks formed by contact metamorphism to be non-foliated.
		Types of rocks that are formed by contact metamorphism are those that have no foliation like hornfels, marble, and quartzite.
		Regional metamorphism is responsible for most of the metamorphic rocks found on earth and is the result of both high temperatures and confining pressure.
	www.suite101.com /article.cfm/everyday_geology/97584 (566 words)

Try your search on: Qwika (all wikis)