
	Where results make sense

Topic: Dolerite

In the News (Tue 2 Dec 08)

Damian Green

Sumner Redstone

Crimson Tide

Tommy Tuberville

Bill Clinton

Wayne Rooney

Vilasrao Deshmukh

Wake Forest

Grand Slam

Oklahoma State

	Dolerite gemstone. Description, wares from dolerite.
		Dolerite - (from Greece "doleros" - deceptive), magmatic effusive or intrusive rock (on small depth), having structure of basalt.
		It is characterized by holocrystalline, coarse-grained dolerite (or ophite) structure (the unit of pyroxene, it is frequent together with olivine, as isometric grains carries out angular sites between prisms of plagioclase).
		Also dolerite is used as ornamental gemstone with combinations with other colored gemstones such as jasper, charoite, rhodonite and so on for accenting the pattern of these gemstones.
	www.gemstonesgift.com /dolerite.html (137 words)

	Black Granite Slabs
		Other notable occurrences of dolerite dykes are those of Talpara, Bishrampur, Khori and Chhatterpur areas of Palamau; Ranka, Ramuna and Nagar Untari areas of Garhwa as well as Jingi area of Lohardaga district.
		The dolerite dykes of the areas around Talpara in Chainpur P.S. occur almost on ground level, are thin varying in thickness - from 10m to 30 m and extending along strike from 300 m to 500 m.
		The newer dolerites of Singhbhum occur in form of a number of dykes extending for miles together.
	www.sellgranite.com /black-granite-slabs.html (0 words)

	dolerite - Hutchinson encyclopedia article about dolerite (Site not responding. Last check: )
		Igneous rock formed below the Earth's surface, a form of basalt, containing relatively little silica (mafic in composition).
		Dolerite is a medium-grained (hypabyssal) basalt and forms in shallow intrusions, such as dykes, which cut across the rock strata, and sills, which push between beds of sedimentary rock.
		When exposed at the surface, dolerite weathers into spherical lumps.
	encyclopedia.farlex.com /dolerite (109 words)

	Hydrogeology of Fractured-Rock Aquifers and Related Ecosystems within the QoQodala Dolerite Ring and Sill Complex, ...
		Dolerite ring systems also control to a very large extent the morphology, the recharge and the drainage pattern at surface and influence the emergence of many springs and seepages.
		Dolerite sill and ring systems of the Great Kei catchment control to a large extent the morphology, the rain fall, the drainage pattern, the occurrence of many springs and therefore the geographic distribution of the local communities and their economic and social life.
		When the results of the seep mapping are compared with the slope analysis and dolerite elevation classes, it was seen that in general, the density of seeps decreases with elevation and with slope steepness.
	www.fwr.org /wrcsa/1238104.htm (1782 words)

	Minerals of the Tasmanian Dolerites
		Dolerite is an intrusive igneous rock closely related to basalt and gabbro that generally forms as dykes and sills.
		Pigeonite and augite are the primary pyroxenes in Jurassic dolerites.
		It is found in Jurassic dolerites as small cubes at a quarry on Proctors Road, and on calcite at Longley mainly as modified cubes, and as coarse aggregates with magnetite at Pelverata.
	www.crocoite.com /locations/tasdolerite.htm (4939 words)

	Vestfold Hills (Site not responding. Last check: )
		In its turn, the dolerite is cut in the centre of the photograph by a ductile shear zone, recognisable by the finely laminated internal structure.
		The curious hourglass shape of the dolerite dyke is due to the fact that there are TWO dykes; the segments at top left and bottom right were part of one dyke, which has been cut by a younger horizontal one.
		Because of the misalignment created by the dolerite intrusion, only the branches of the pseudotachylyte that happened to be in line were reactivated, and the dyke was deformed into a typical curved geometry.
	www.uni-mainz.de /FB/Geo/Geologie/tecto/perth_workshop/vestfold_hills/vestfoldhillsint.html (558 words)

	Neighbours
		Dolerite is both intrusive and an igneous rock, meaning it has cooled and crystallised from high temperature magma.
		In a regular dolerite profile, elemental composition, crystal size and texture are considered and the compositional range may include rocks such as gabbro, pegmatite, granophyre and glass.
		Locating dolerite below the surface seems to require some sort of a divining rod although geologists tend to use slightly more scientific methods such as seismic refraction, magnetic models, electric resistivity, and the gravity method to an area in the hope of gaining an insight into this buried treasure.
	www.tasmaniantimes.com /jurassic/tania.html (3033 words)

	Scawt Hill (Site not responding. Last check: )
		Dolerite crags of Scawt Hill, Co. Antrim; the curving vertical joints parallel the plug margin; Cretaceous Ulster White Limestone adheres to the plug contact in the NE gully; foreground shows part of main scree.
		Dolerite plug in contact with Cretaceous Ulster White Limestone in SE gully; a thin tongue of limestone extends along the base of the dolerite crag above the grass-covered scree and is cut by pyroxenite rock.
		The normal olivine dolerite merges within a metre of the contact into pyroxene-rich dolerite which carries vesicles lined chiefly with thomsonite associated with analcime, stilbite, natrolite, scawtite, and calcite.
	www.habitas.org.uk /escr/site.asp?Item=1130 (1720 words)

	A devil in disguise
		Dolerite is an intrusive igneous rock; that is, one which has "invaded older rock and may displace or dilate the pre-existing rock", contrasting with "extrusive", where magma reaches the Earth's surface and erupts from a volcano as lava flows which then cool.
		Darwin was able to separate dolerite (greenstone is his word) from basalt or lava on the basis of texture, mineralogy or field evidence such as gas vesicles and crystal size at Sandy Bay.
		This is the first recorded geophysical observation related to the dolerite although it is likely that de Rossel, a fine scientist travelling with D'Entrecasteaux who made observations of the magnetic field, must have noted similar responses at Recherche Bay.
	www.leatherwoodonline.com /history/2005/leaman/index2.htm (1251 words)

	Attraction - Mesosaurus Fossil Site & Quiver Tree Dolerite Park
		The Mesosaurus is probably one of the most convincing examples to prove the drifting of continents.
		At the Quiver tree Dolerite Park we do not have 100, 200 or 300 trees but over 5000 specimens, which makes it the densest concentration of Quiver trees in Namibia...
		They are mainly kept for the production of pelts, and because this farming method is often shrouded with controversy, its rich and colourful history, and its particular economic role in Southern Namibia, is often overlooked...
	www.mesosaurus.com /pages/attractions.htm (0 words)

	Shropshire Rocks : Shaping of Shropshire - Rocks and Their Descriptions
		Dolerite is a coarse fl or dark greenish crystalline rock.
		Dolerite is an intrusive igneous rock, cooled slowly beneath the ground.
		Dolerite Dykes are found at the foot of the Wrekin in Forest Glen and the summit of Brown Clee and Titterstone Clee where it is quarried for road stone.
	www.shropshirerocks.org /rock_descriptions (448 words)

	Banks, M. R. and D. Leaman eds. 1999. Charles Darwin's Field Notes on (Site not responding. Last check: )
		Dolerite in the Domain approaches a granophyre in composition and texture and, in the state of knowledge at the time, could appropriately have been called syenitic Greenstone.
		The western spur of the Hill is capped by siltstone and the contact between dolerite and siltstone is now visible on the northern slope of the hill in the face of Mornington Quarry.
		From the dolerite point immediately south of the fossiliferous beds, he may well have looked south along the coast or even walked as far south as the point immediately south of the mouth of Riverview Rivulet and then looked south.
	darwin-online.org.uk /content/contentblock?itemID=F1821&basepage=1&viewtype=side&hitpage=1 (14869 words)

	The Egyptian Prophecy walkthrough
		The dolerite papyrus is missing in his house.
		Standing in front of the circle stand use the banner spell on square dolerite to move it to the center of altar.
		Standing by triangle stand, use banner spell on square dolerite to move it to square stand by exit.
	www.gameboomers.com /wtcheats/pcTt/TEP.htm (4845 words)

	Shiant Isles Geology Paper (Walker 1929) Page 1
		These islands also consist of dolerite, the sill or sills of which they are composed dipping southwards at a variable angle.
		The 'dunite', picrite, and the augite from the dolerite are figured in plates.
		The pyroxene in the dolerite assumes a very marked ophitic habit, and encloses numerouslaths of the plagioclase, but the size of the crystals and their optical properties remain unchanged, apart from a tendency towards zonary banding.
	www.shiantisles.net /geology/g04_1.htm (6464 words)

	Kattenhorn, S.A. (1994) (Site not responding. Last check: )
		The intrusion of fine-grained dolerite into older sills is demonstrated by abrupt variations in the whole-rock and mineral geochemistry profiles across the sills.
		The fine-grained dolerite is associated with xenolithic dolerite which represents a contaminated magma propagation front of the fine-grained dolerite.
		The higher viscosity of the xenolithic dolerite hindered propagation, and was thus overtaken and engulfed by the main magma pulse.
	www.webpages.uidaho.edu /~simkat/msc.html (483 words)

	pg 009: Second annual report of the Geological and Agricultural Survey of Texas Publication 25425061 (Site not responding. Last check: )
		All the igneous rocks that we saw north of the Pecos are either of upper cretaceous or tertiary age, shown by the uptilted strata of the cretaceous rocks amid and bordering the mountains.
		About four miles east of Fort Clark, in Kinney county, on the San Antonio road, are dolerite and basaltic rocks, extending fifteen to twenty rods along the road, and covering much of the hill over which the road passes.
		On the eastward from the Frio, I saw dolerite rocks in the road and near it quite often.
	www.lib.utexas.edu /books/landscapes/publications/txu-oclc-25425061/txu-oclc-25425061-b-009-print.html (370 words)

	Ant. Jou. of the U. S.: Etch Pits in Dolerite
		As part of a study of geomorphic processes in the ice-free areas of Victoria Land, solution etch pits occurring on dolerite cobbles are being investigated in the Allan Hills and dry valleys.
		The ultimate objective is to model the formation mechanisms of these pits and use the calculated rates of development to determine the exposure ages of various ice-free surfaces in Victoria Land.
		Refinement of this first approximation requires recalculation of the rates from Helgeson, Brown, and Leeper (1969) for the dolerite under antarctic conditions, and direct measurements of the water flux at these surfaces as well as the solution chemistries of the water.
	www.msss.com /earth/antarctica/AJUS_papers/AJUS86.html (1089 words)

	Blackslee Dyke (Site not responding. Last check: )
		Blocks of sandstone up to 3m in size were seen suspended in the dolerite (solidified lava), broken from the wall and transported as xenoliths, then frozen into position as the rock solidified.
		In the same quarry, the dolerite of the dyke was seen to be crushed into a breccia - clear evidence of movement along the fault after intrusion.
		The limestone quarry at the north west limit shows a dolerite full of small quartz inclusions, demonstrating tridymite pseudomorphs perfectly.
	www.habitas.org.uk /escr/summary.asp?item=81 (476 words)

	Geology - Van Zijl Guesthouses at Nieuwoudtville
		Sills and dykes of dolerite are plentiful in the eastern half of the area where they are intruded in all the formations, but mainly in the Karoo sediments.
		Dykes are from 1 ft to 50 ft wide with exceptional ones of 250 ft that extend for 28 miles.
		A few relatively small faults, in which there are dolerite dykes, displace the Karoo sediments and dolerite sheets.
	www.nieuwoudtville.co.za /information19.html (971 words)

	Research on Karoo Igneous Rocks by D.L. Reid
		Potassium-argon dates of four dykes from the False Bay dolerite swarm yield a mean age of emplacement of 132 ± 6 Ma.
		Dolerite dykes associated with the post-Karoo continental flood basalt provinces occur near the Atlantic coast in the northern Richtersveld and neighbouring southern Namibia.
		The age data reinforce the recognition of two distinct periods of late Mesozoic basaltic igneous activity in Namibia, namely the older Karoo province (represented by the Jurassic sills) and younger Etendeka province (represented by the coastal dyke swarms).
	web.uct.ac.za /depts/geolsci/dlr/karoo.html (927 words)

	CSIRO Petroleum - Proterozoic oil inclusions
		Inclusion oils in both the dolerite feldspar and in the transgranular fractures in the Bessie Creek Sandstone are pristine, non-biodegraded fluids with a great similarity to other bitumens, oils and sediment extracts from the Roper Superbasin.
		Based on migration distance, organic richness, geochemistry and similarity of source rock maturity, the Velkerri Formation, which directly overlies the dolerite sill and the Bessie Creek Sandstone, is the most likely source rock for the higher molecular weight hydrocarbons preserved in the fluid inclusion oils.
		Geochemical data indicate that the oil inclusions in clusters in albitised zones of labradorite crystals in the dolerite matrix represent a different migration event from oil inclusions in transcrystalline fractures in vein calcite in the dolerite sill and in transgranular fractures in quartz in the Bessie Creek Sandstone.
	www.dpr.csiro.au /ourcapabilities/petroleumgeoscience/organicgeochemistry/projects/proterozoicoilinclusions (425 words)

	dolerite
		Dolerite is a medium-grained, mafic, intrusive, igneous rock with a chemical composition similar to that of basalt and gabbro.
		The rock usually forms as dykes and sills in basaltic provinces.
		This piece of Olivine Dolerite was kindly sent to me by a fellow S260 student.
	www.francesjane.com /dolerite.html (0 words)

	Hard Stone Quarries
		Such is the case with the extraction of granite, where dolerite balls were pounded against the rock's surface in order to cut into it.
		After the trench had reached its desired depth (a bit deeper than the depth of the block being quarried), workers had to cut out enough rock from underneath the block so that it could be broken free by massive wooden levers.
		The incessant noise of dolerite balls pounding, knee damage due to kneeling all the time, and other factors led to what would seem to be a rather miserable existence for quarry workers.
	www.duke.edu /~jpw5/quarries/hardstone.html (623 words)

	The Stones Comprising Stonehenge - Archaeo Forums (Site not responding. Last check: )
		Opaque mineralogy of the dolerites supports the conclusion of a Preseli source, while modal analysis of a sandstone fragment excavated at Stonehenge shows that it is not from the Cosheston or Senni Beds of South Wales, as has been suggested.
		A small number of spotted dolerite implements have previously been shown to have chemical compositions atypical of and marginal to Preseli, suggesting the possibility of a source of spotted dolerite outside Preseli.
		There are other sources of dolerite ahd rhyolites in the Uplands (Pennines, Cumbria and Scotland), and they have Not been subjected to the tests that would tell us whether they are the source of the bluestones at Stonehenge.
	www.stonepages.com /forum/index.php?act=findpost&pid=4680 (5373 words)

	Tasmanian Treasures-Index
		TASMANIA is one of Australia's better kept secrets, cradled by the Roaring Forties (winds) and as old as Time.
		Ancient sedimentary rocks were intruded by dolerite, which was later exposed and sculpted by glacial ice to create a rugged landscape of bare mountains with a characteristic "organ pipe" design.
		Temperate rainforests, abundant with ferns, mosses, lichens and colourful fungi, hide in sheltered mountain folds.
	www.apstas.com /sgaptas-treas1.htm (0 words)

	INTRODUCTION (Site not responding. Last check: )
		This contribution seeks to illuminate the possible affinities of these dolerites with respect to the regional geology using new geochemical and age data.
		The almost ubiquitous presence of dolerite and gabbro in Leg 180 holes shows the importance of this rock type in the regional context and suggests that the basement may be of ophiolitic character.
		The two other sites are on the footwall and have experienced net uplift; the dolerite at Site 1114 was encountered at 295 mbsf, whereas the gabbro at Site 1117 at ~85 mbsf was found to underlie a fault gouge that passes gradually downward into fresh quartz gabbro.
	www-odp.tamu.edu /publications/180_SR/155/155_2.htm (445 words)

	Peperite contacts in dolerite - Jarama River. (Site not responding. Last check: )
		These photos are from the lowermost dolerite but this time as exposed on the west bank.
		Mudrock veins can be traced through the lowermost dolerite at right angles to the lower contact for up to 39 metres - see right-hand photo above for part of one of these zones.
		A feature of the lower dolerite is the mudrock-filled vesicles which show that the mud was fluidised at the time the dolerite was vesiculated.
	www.soton.ac.uk /~cab1/ldwbnk.htm (114 words)

	Celt World Stonehenge Bluestone Info Page
		On the one hand are those who believe that spotted dolerite was sufficiently important to the Ancient Britons to inspire them to carry so many large stones to the Wiltshire Downs.
		It is likely that some of the stones would have been lost on such a journey and the Realists argue that the numbers would probably have been made up with other stones along the way.
		The fact that the small number of Welsh stones at Stonehenge that are not of spotted dolerite were all taken from Southern Wales, along the most logical route, supports this idea.
	www.celtworld.supanet.com /blst2.htm (723 words)

Try your search on: Qwika (all wikis)