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	Lamprophyre - Wikipedia, the free encyclopedia
		Lamprophyres are uncommon, small volume ultrapotassic igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks and small intrusions.
		Lamprophyres are not amenable to classification according to modal proportions, such as the system QAPF due to peculiar mineralogy, nor compositional discrimination diagrams, such as TAS because of their peculiar geochemistry.
		Lamprophyres are a group of rocks containing phenocrysts, usually of biotite and amphibole (with bright cleavage surfaces), and pyroxene, but not of feldspar.
	en.wikipedia.org /wiki/Lamprophyre (1374 words)

	Isotope and Trace Element Geochemistry of Cretaceous Damaraland Lamprophyres and Carbonatites, Northwestern Namibia: ...
		Pb (15·705) of all the Okenyenya lamprophyres (Fig.
		0) in the genesis of the Damaraland lamprophyres or carbonatites.
		The Okorusu lamprophyre and carbonatite magmas and the Okenyenya lamprophyres all have Pb isotope compositions broadly similar to the calculated composition of the Tristan plume at 124 Ma (assuming a plume µ = 15 and [kappa] = 4; Fig.
	library.iem.ac.ru /j-petr/6-3998/html/egb027_gml.html (9460 words)

	Meta (?) lamprophyre dikes
		The strikes of the lamprophyre dikes varied from north-south to east-west, but a north-northwest trend was by far the dominant strike.
		Secondly, the lamprophyre dikes in the Alabama Hills were confined to the felsic hypabyssal rocks which places these dikes as part of a pre-plutonic hypabyssal sequence.
		Compositionally, the lamprophyric dikes of the Alabama Hills are characterized by two generations of mafic minerals.
	www.angelfire.com /extreme4/lkrwork/x114.htm (637 words)

	Lamprophyre from the Rossland gold camp, British Columbia, Canada
		Lamprophyres of varied compositions do nevertheless occur in the Rossland area, so we should conclude with a note on the wider significance of such rocks.
		For decades lamprophyres, like more abundant constituents of dykes and sills, such as diabase, were somewhat neglected in terms of economic geology, their occurrence serving more often to diminish the efficiency of mining operations in cases where the dykes cross-cut and offset older "pay rocks".
		ROCK,NMS and PAUL,DK (1988) `Lamprophyres', `lamproites' and `kimberlites' in India: a bibliography and preliminary appraisal.
	www.turnstone.ca /lampro.htm (1273 words)

	CNW Group
		The three microdiamonds, weighing a total of 0.02 milligrams, were recovered from a lamprophyre dike on the property The Company has an option to earn a 100% interest on a block of 11 contiguous mining claims covering 1,536 hectares (3840 acres) in Burt, Dunmore and Holmes townships, Ontario, Canada.
		The Company believes that there are at least two lamprophyre dikes on the property, as they are visible at surface after being exposed by stripping a small portion, approximately one acre of one claim unit.
		Lamprophyre in other parts of the world is being mined for diamonds.
	www.newswire.ca /en/releases/archive/October2005/18/c2571.html (903 words)

	Olympus Microscopy Resource Center: Polarized Light Microscopy Gallery - Camptonite
		Lamprophyre is a term that is usually applied to seven different rocks.
		Most lamprophyres are dark gray to fl in color and occur as tabular bodies located in fissures of other rocks.
		Lamprophyres readily erode and may decompose into a number of materials, including serpentine, limonite, and chlorite.
	www.olympusmicro.com /galleries/polarizedlight/pages/camptonitesmall.html (236 words)

	Apparent polar wander paths and the close of late Archean crustal transpression, northern Ontario
		Lamprophyre dikes of the southern Superior Province of the Canadian Shield crosscut Archean structures, including a late Archean unconformity and its overlying younger Archean Timiskaming sedimentary and volcanic rocks.
		Nevertheless, the lamprophyre dikes show a weak internal tectonic fabric that is approximately parallel to the schistosity in the bedrock and oblique to dike walls.
		Unfortunately, our previous attempts to compare the lamprophyre paleopoles with those of the age-calibrated apparent polar wander path (APWP) failed because it was not possible to isolate separate young and old components of magnetization.
	www.agu.org /pubs/crossref/2003/2002JB002379.shtml (431 words)

	Alkali Basalt and Lamprophyre-Hosted Sapphire and Ruby - Mineral Deposit Profiles, B.C. Geological Survey
		The lamprophyre dykes, such as Yogo, may consist of several en echelon segments from less than a metre to several metres thick and hundreds of metres in length.
		In lamprophyre hypabyssal rocks, pyroxene, phlogopite, ± calcite (mainly in veins), ± olivine, ± analcime are major constituents.
		Primary controls are sapphire and ruby-bearing alkali basalt, lamprophyre, nephelinite, basanite or phonolite dikes, flows, pyroclastics or possibly diatremes.
	www.em.gov.bc.ca /mining/GeolSurv/MetallicMinerals/MineralDepositProfiles/profiles/q10.htm (1746 words)

	Sr–Nd isotopic composition of lamprophyre dykes from Queen MaudLand, East Antarctica
		Zr/Nb ratio for the coarse-grained lamprophyre dykes is higher (16.4) than the fine grained dykes (4.5) due to higher Zr contents in the former.
		The leaching of biotite macrocrysts from lamprophyres prior to their Rb–Sr analysis removes trace amount of carbonate that may be entrained in cleavage planes or grain boundaries of biotite grains.
		The geochemical characteristics of these lamprophyre dykes suggest that the source magma has been generated by partial melting of upper mantle that was metasomatized prior to/or during melting by crustal component.
	www.ias.ac.in /currsci/dec251999/articles26.htm (1568 words)

	[No title]
		Both the lamprophyre and breccia are intercalated with 2700 Ma felsic to intermediate metavolcanics, intermediate to mafic metavolcanics, and mafic intrusive rocks (Fig.
		The lamprophyre may be weakly foliated as defined by faint alignment of actinolite and biotite grains.
		Lamprophyric volcaniclastic rocks may be considered a potential target for diamond exploration in the future.
	www.eos.ubc.ca /research/diamonds/kopylova/8IKCLONGABSTRACT03.doc (2489 words)

	Arkansas
		There is a spatially-related variation from lamproites (Prairie Creek) at the southwestern end through several carbonatite complexes (Magnet Cove and Potash Sulfur Springs), a lamprophyre dike swarm Benton), and at the northeastern end several large syenite bodies (Saline County and Granite Mountain).
		Lamprophyre and syenite dikes outcrop at the V-intrusive and carbonatite dikes are found at Perryville and Morrilton.
		There is a spatially-related variation from lamproites at the southwestern end through several carbonatite complexes, a lamprophyre dike swarm, and then at the northeastern end several large syenite bodies.
	faculty.uml.edu /Nelson_Eby/Research/Arkansas/arkansas.htm (548 words)

	Search MINFILE Database (Site not responding. Last check: 2007-10-30)
		At the Comstock mine, mineralized quartz veins occur predominantly along the contact of a biotite lamprophyre body and quartz monzonite, both of the Nelson intrusions.
		The biotite lamprophyre is dark grey to fl, medium grained with local coarse biotite crystals; magnetite is common.
		Several east striking lamprophyre dikes and quartz veins intersect the main zone.
	www.em.gov.bc.ca /cf/minfile/search/search.cfm?minfilno=082FNW077 (475 words)

	USGS: The River and The Rocks (Trail Log-Bear Island)
		The prominent levee constructed of rock debris to the left of the trail was designed to divert floodwaters from the canal bed and return them to the main channel of the Potomac.
		Lamprophyre dikes (indicated by white dots) on the Virginia side of the river as seen from Stop G5 on the Maryland side.
		These clefts are the continuation of the lamprophyre dikes on which you are standing.
	www.cr.nps.gov /history/online_books/grfa/sec8.htm (1399 words)

	USGS Professional Paper 1151-H: The Geology of Kentucky: Permian System
		The igneous intrusives are of two types: lamprophyre and peridotite dikes and sills in Caldwell, Crittenden, and Livingston Counties of the western Kentucky fluorspar district and three small peridotite intrusions in Elliott County, northeastern Kentucky (fig.
		The lamprophyre and peridotite dikes and sills (PI) in the western Kentucky fluorspar district, which are discussed in a summary report by Trace and Amos (1984), are shown on seven geological quadrangle maps (table 1).
		The Elliott County peridotite (Pp), represented by three small red outcrop areas on sheet 3 of the State geologic map, is shown on the Willard quadrangle (Brown, 1977).
	pubs.usgs.gov /prof/p1151h/permian.html (851 words)

	Dianor Resources Inc. (Site not responding. Last check: 2007-10-30)
		Dianor's base camp is strategically located a few hundred meters east of the paved Matagami-Radisson highway on the shores of Lake Ekomiak, approximately 65 kilometers south of the town of Radisson and 40 kilometers south of a commercial airport.
		The diamond discovery in a xenolithic lamprophyre dyke occurred on the Yasinsky North claim and fieldwork during 2001 was focused here.
		Field checking of a number of lamprophyre dyke/breccia locations on the P.E.M. 1404 and in close proximity to the P.E.M. was also undertaken.
	www.nafinance.com /Listed_Co/English/dianor_e.htm (2971 words)

	CobaltCampNews2.htm
		For years it has been recognized that there are many showings of lamprophyre in the Kirkland Lake, New Liskeard and Cobalt areas, but the only real significance given to it was a special relationship between lamprophyre and gold mineralization.
		Grabowski went on a field trip earlier this year to Wawa and observed that visually the lamprophyre in Wawa is very similar to lamprophyre in Timiskaming.
		Another positive for diamond exploration is the fact that there are diamond bearing kimberlite pipes, and the lamprophyre dikes are similar to the kimberlite pipes in that they are found in cross structures to the main structural zone.
	www.canadianminingnews.com /CobaltCampNews2.htm (417 words)

	Dumont Nickel
		All of the Wawa diamond occurrences are in mica-rich lamprophyre, containing fragments of the lower crust.
		It is my opinion that the Furnival Lake lamprophyre is a 'lahar', a rock-type found in the crater environment of kimberlite and lamproite pipes, in which diamonds are often found.
		To date, Dumont has identified 35 lamprophyres on its 77 square km property in Knicely, Lalibert and Menzies Townships, 25 km N of Wawa.
	www.dumontnickel.com /news/archives/pr20000821.htm (500 words)

	Mineralogy and Geochemistry of Kimberlites and Related Rocks from Finland
		Because there are a great number of lamprophyric dikes in the area, the rock was connected to them although the possibility of it being a kimberlite was also considered.
		Roughly 1 km long and 5 m wide, this dike rock is composed mostly of dark brown phlogopite crystals and subordinate serpentine pseudomorphs (after olivine?), in a olive green matrix of serpentine and carbonate containing accessory ilmenite, titanomagnetite, rutile and apatite.
		Phlogopite microphenocrysts occur as brown to reddish brown, tabular plates that are weakly pleochroic and zoned to reversely pleochroic tetraferriphlogopite.
	www.gsf.fi /explor/webdocs/kimberlite/finnish_kimberlites.htm (5420 words)

	CobaltCampNews1.htm
		Ministry of Northern Development and Mines District Geologist Gary Grabowski takes a close look at a local sample of lamprophyre, which is similar to the Wawa lamprophyre in the foreground.
		The bottom line is that lamprophyre is relatively common in the Kirkland Lake and n the Cobalt areas.
		Even if they do not find diamonds, or economic diamonds, the historic fact that lamprophyre often has a spatial relationship with gold mineralization still holds true, and the search for diamonds could lead to the discovery of more gold.
	www.canadianminingnews.com /CobaltCampNews1.htm (487 words)

	Adams & Cooper--Lamprophyre ages, Wanaka
		Abstract Lamprophyres, occurring as dikes and high-level diatremes, intrude greenschist facies Haast Schist in the southern part of the Alpine Dike Swarm, near Wanaka, western Otago.
		Of 12 lamprophyres dated by conventional K-Ar techniques, 10 give whole-rock ages ranging between 25.2 and 31.9 Ma, with kaersutites separated from four samples forming a tighter group at 22.9-27.8 Ma.
		Similar anomalous ages have been determined previously from lamprophyres and associated intrusives of the northern part of the swarm, at Haast River, and are attributed to incorporation of excess argon into the lamprophyre magma, especially during the later, intratelluric, stages of crystal-lisation.
	www.rsnz.org /publish/nzjgg/1996/96.php (242 words)

	Rhodes eResearch Repository - Evidence for Archaean lamprophyre from the Kaapvaal Craton, South Africa
		REE and trace element values for Set 1 dykes are similar to those for calc-alkaline lamprophyres.
		The Set 2 dykes have similar trace element distributions, but are significantly less enriched in general, and are broadly tholeiitic in composition, with enriched MgO (>11 wt.%) indicative of an olivine–phyric tholeiitic basaltic protolith.
		Prevec, Stephen A. and Anhaeusser, Carl R. and Poujol, Marc (2004) Evidence for Archaean lamprophyre from the Kaapvaal Craton, South Africa.
	eprints.ru.ac.za /107 (393 words)

	Kirkland Lake District- Summary of Monthly District Activity
		The three microdiamonds, weighing a total of 0.02 milligrams, were recovered from a 40 cm wide mica and amphibole-bearing lamprophyre dike cutting intermediate metavolcanic rocks.
		The purpose of the study was to determine whether lamprophyre dikes in the Kirkland Lake, Timiskaming and Timmins areas hosted diamonds.
		The samples collected, which were small by industry standards, and the lateral distribution of the locations indicate that further exploration of lamprophyres for diamonds is warranted and may yield more positive results.
	www.mndm.gov.on.ca /mndm/mines/resgeol/northeast/kirkland_lake/reports/2005/oct_e.asp (1149 words)

	[No title]
		The bulk of the intrusion is represented by the concentrically zoned North Fork tonalite-granodiorite, which ranges in composition from biotite-hornblende tonalite to biotite-hornblende quartz diorite to hornblende-bearing, biotite granodiorite.
		A concentrically zoned lamprophyre body comprising lamprophyre, orbicular lamprophyric tonalite, and hornblende tonalite pegmatite is spatially associated with the North Fork intrusion.
		The North Fork stock and its surrounding country rocks are unconformably overlain by younger rocks of the Clarno Formation and the Columbia River Basalt Group.Xenoliths derived from wallrocks and from earlier intrusives are common in the tonalite-granodiorite rocks which suggests stoping to be the dominant emplacement mechanism.
	nwdata.geol.pdx.edu /Thesis/Abstract.php?Th_ID=36 (489 words)

	[No title] (Site not responding. Last check: 2007-10-30)
		During its intrusion, the magma which gave rise to the layered body engulfed a large block of rock consisting of banded iron formation and thin lamprophyre dikes.
		Both the iron formation and the lamprophyre show evidence of high-temperature metamorphism followed by a retrograde event.
		Chemical compositions of the layered rocks and the lamprophyre are indicative of both having been derived from a primitive to slightly depleted mantle source.
	www.igsb.uiowa.edu /pubs/abstract/ias_91-1.htm (175 words)

	University of Wisconsin-Eau Claire: Geology
		Our study has characterized the geochemical fingerprint of this continental alkaline lamprophyre province and matches it with the geochemical signature of the seamounts.
		We are continuing the study of these rocks in order to compare the chemical and age progressions along each of the three magmatic lineaments within the New England province with the observations along the Hawaiian volcano trends.
		This study depicts the degassing history of the alkaline magmatic system and constrains the fractionation factor that governs melt-vapor carbon isotope partitioning in the CO -saturated magmatic system.
	www.uwec.edu /geology/meetTheFaculty/ihinger.htm (2296 words)

	CALCITE STRAIN ANALYSIS ON LAMPROPHYRE DIKES: STRESS-STRAIN ORIENTATIONS DURING EMPLACEMENT (Site not responding. Last check: 2007-10-30)
		Oriented samples were taken from two perpendicularly oriented ultramafic lamprophyre dikes in Little Presque Isle near Marquette, Michigan.
		The dikes intrude Archean metamorphic rocks and are presumed to be of Keweenawan age.
		Inferred differential stresses for the dikes and veins are ~50MPa.
	gsa.confex.com /gsa/2001AM/finalprogram/abstract_25750.htm (346 words)

	LAMPROPHYRE AND KIMBERLITE INTRUSIONS FROM THE GRASSRANGE FIELD, CENTRAL MONTANA (Site not responding. Last check: 2007-10-30)
		The Grassrange intrusion field of central Montana consists of more than thirty Eocene age dikes, plugs, diatremes, and sills scattered over an area of 42 x 27 km.
		The least-altered, primary igneous rock type in most intrusions is aillikite, a carbonate-bearing ultramafic lamprophyre.
		All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.
	gsa.confex.com /gsa/2001AM/finalprogram/abstract_26354.htm (465 words)

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