 | | Journal (article/letter/editorial) | | deeper water deposition as evidenced by alternate metachert and metabasalt layers, and emplacement of basaltic...associated with subduction setting in the oceanic realm. South of the Godavari rift in India, the Eastern Dharwar...Mukhopadhyay and Basak, 2009; Henderson et al., 2014; ). South of the Godavari graben, the EGB is known to extend...with thin metasedimentary slivers of ferruginous quartzite, garnet-kyanite bearing pelitic schist and occasional...different thrust slices bound by WNW trending, south dipping thrusts around Kandra, have been recognized |  | | Report (issue) | | Sketches showing: 3. Folding and cleavage in metachert, phyllite, and lensed phyllite of the Calaveras...a west-southwest-plunging axis in interbedded quartzite and muscovite-biotite schist, Shoo Fly Formation...bounded by the Melones fault on the east. Three new chemical analyses together with thirteen analyses...andesite-sodarhyolite suite. A belt consisting of metachert and phyllite derived from sediments typical on...continued southward to the area around the North, South, and Middle Forks of the Feather River (Hietanen |  | | Journal (article/letter/editorial) | | pages 804-818, i,993 Fluid infiltration through metachert layers at the contact aureole of the Bufa del...contact. Broad wollastonite rims occur around the metachert layers into the tremolite zone. Isobaric (P =...aqueous fluid infiltration. In contrast, the metachert beds acted as channelwaysfor HrO-rich fluids under...trapped in the two-fluid immiscibility field of the H,O-CO,-salt systemat peak metamorphicconditions of 500-580...generatedby the reaction calcite + quarlz : wollastonite * CO, at the two-fluid solvus during flow of magmatic |  | Mancini, F., Alviola, R., Marshall, B., Satoh, H., Papunen, H. (2000) THE MANGANESE SILICATE ROCKS OF THE EARLY PROTEROZOIC VITTINKI GROUP, SOUTHWESTERN FINLAND: METAMORPHIC GRADE AND GENETIC INTERPRETATIONS. The Canadian Mineralogist, 38 (5) 1103-1124 doi:10.2113/gscanmin.38.5.1103 | Journal (article/letter/editorial) | | of Technology – Sydney, P.O. Box 123, Sydney, Australia HISAO SATOH Geological Survey of Japan, 1-1-3...in southwestern Finland, are interbedded with metachert, and are associated with amphibolitic metavolcanic...silica-rich and carbonate-rich sediments. The metachert comprises a dominant Fe-rich silicate facies (with...Natural History, Central Park West at 79th Street, New York, N.Y. 10024-5192, U.S.A. E-mail address: mancini@amnh...concentrations of rhodonite and pyroxmangite within quartzite also were found nearby at Simpsiö (Hietanen 1938) |  | | Report (volume) | | Ordovician, undifferentiated___________________ Quartzite and colored slate____________________________...b)__-________________________ 10 Black slate, metachert, 10 and tuffaceous rocks of Snow Mountain,...metasedimentary rocks are metasiltstone, impure quartzite, slate, and quartzite metaconglomerate. Thin units of rhyolitic...rhyolitic metatuff, thin black metachert, limestone metaconglomerate, phyllite, and schist are present...across the southeastern part of the area and into New Brunswick for perhaps as much as 50 miles. The post-Pennsylvanian |  | | Journal (article/letter/editorial) | | essentially along the bedding lamination of the metachert are referred to as the metamorphosed chert-sulphide...Pyrite is characterised by high-Co values (262± 4524 ppm) and high±Co/Ni ratios (3.0±19.7). Rare earth...with minor pentlandite. These sulphides with low-Co/Ni ratios (0.87±1.80), have either a strong positive...Geological setting The cratonised block of the South Indian shield is known as the Dharwar craton and...metapelites. Within the mine area, metachert (mineralised metachert in Fig. 1d) is the only sedimentary |  | Amaral, Leandro, Caxito, Fabrício de Andrade, Pedrosa-Soares, Antonio Carlos, Queiroga, Gláucia, Babinski, Marly, Trindade, Ricardo, Lana, Cristiano, Chemale, Farid (2020) The Ribeirão da Folha ophiolite-bearing accretionary wedge (Araçuaí orogen, SE Brazil): New data for Cryogenian plagiogranite and metasedimentary rocks. Precambrian Research, 336. 105522 doi:10.1016/j.precamres.2019.105522 | Journal (article/letter/editorial) | | accretionary wedge (Araçuaí orogen, SE Brazil): New data for Cryogenian plagiogranite and metasedimentary...accretionary wedge (Araçuaí orogen, SE Brazil): New data for Cryogenian plagiogranite and metasedimentary...accretionary wedge (Araçuaí orogen, SE 2 Brazil): New data for Cryogenian plagiogranite and metasedimentary...graphite-rich schist (black shale), sulfide-bearing metachert, diopsidite with massive sulfide, 34 and banded...sulfide-bearing fine-grained ortho35 amphibolite with thin metachert intercalations (mafic volcanic unit). That formation |  | | Journal (article/letter/editorial) | | Abstract Impure limestones with interstratified metachert layers were contact metamorphosed and metasomatized...wollastonite (Wo)+CO 2, and were observed at distances of up to 400 m from the contact. The produced CO 2 exsolved...marble calcites measured perpendicular to two metachert bands reveal significant isotopic alterations...reaction was lost into overlying marble. The metachert aquifers did not leak with respect to water-rich...located in north-east Mexico. They found that metachert layers acted as aquifers for high salinity brines |  | | Journal (article/letter/editorial) | | Formation. The latter consists preponderantly of quartzite and a variety of schistose rocks containing quartz—i...domain 3 of Soares et al. (1988). It may either be a new unit of the Aquiri Group or part of the Rio Fresco...a clastic metasedimentary sequence, mostly of quartzite, which is assigned to the Cuxiú Formation of Soares...drill core intercepted a sequence of hornblende quartzite in which chalcopyrite, pyrite and pyrrhotite are...diabase and granitic pegmatite. The hornblende quartzite also hosts some 10-cmthick layers of chert-like |  | | Journal (article/letter/editorial) | | the Harris Greenstone Domain, Gawler Craton, South Australia Wen-Long Zang ∗ Geological Survey, Department...Industries and Resources of South Australia, Adelaide, South Australia 5000, Australia Received 9 October 2006;...Greenstone Domain, central Gawler Craton, South Australia are interpreted to have been deposited at ∼2520...Orogeny at ∼2440 Ma. Microfossils are preserved in metachert layers that had been boudinaged into lenses. These...biological origin. The microfossils in foliated metachert lenses, either from original deposition or from |  | | Report (issue) | | Metamorphic. 4. Petrology-California-Butte Co. 5. Geology-California-Butte Co. I. Title: Paleozoic-Mesozoic Boundary...................................... 6 Quartzite and metachert ....................................................................... 7 Phyllite unit south of the Big Bend fault ............................metamorphic belt of the Sierra Nevada have yielded new information that helps in distinguishing between...western metamorphic belt of the Sierra Nevada yield new information concerning the nature of differences |  | | Report (issue) | | ................. 5 Phyllite and interbedded quartzite.................. 5 Orthoquartzite ....................................................... 7 Metachert ..................................................................-......................:.. Quartzite and marble interbedded with 17 18 metavolcanic............................................... Quartzite ................................................showing structures and compositional variations in metachert of the Calaveras Formation .................. |  | | Report (issue) | | rocks on the south. The belt is commonly interpreted as a suture along which rocks to the south were accreted...Proterozoic crystalline rocks of Colorado and Wyoming south of the Cheyenne belt have been referred to as the...province and the post1700 Ma Mazatzal province to the south. The Early Proterozoic metamorphic rocks are chiefly...Proterozoic rocks are extensively exposed along and south of the Gunnison River, especially in the valleys...to the north and the San Juan Mountains to the south. The general character of the Proterozoic rocks |  | | Journal (article/letter/editorial) | | Australian National University, Canberra, ACT 0200, Australia a r t i c l e i n f o Article history: Received...terranes is a strongly tectonised, thin unit of metachert, BIF and carbonate-bearing rocks with minor detrital... In the southern 3800 Ma terrane, a fuchsite-quartzite has 3900–3810 Ma zircons. Three samples of the...dividing sedimentary unit and the southern fuchsite quartzite shows that the southern ca. 3800 Ma terrane, although...genuine sedimentary layering combined with growth of a new magnetite foliation around the margins of rare low |  | Argapadmi, Windeati, Toth, Eniko R., Fehr, Manuela A., Schönbächler, Maria, Heinrich, Christoph A. (2018) Silver Isotopes as a Source and Transport Tracer for Gold: A Reconnaissance Study at the Sheba and New Consort Gold Mines in the Barberton Greenstone Belt, Kaapvaal Craton, South Africa☼. Economic Geology, 113 (7) 1553-1570 doi:10.5382/econgeo.2018.4602 | Journal (article/letter/editorial) | | Sheba and New Consort Gold Mines in the Barberton Greenstone Belt, Kaapvaal Craton, South Africa* Windeati...Barberton greenstone belt of the Kaapvaal craton in South Africa. Published structuralgeologic and geochronological...variably tectonized former chert. Observations at New Consort (higher temperature, close to granitoid contact)...all hydrothermal silver samples. Gold samples from New Consort have negative ε109Ag values, whereas samples...granitoids is isotopically light, as observed at New Consort. Residual silver reaching the interior of |  | | Report (volume) | | NORTHEASTERN BROOKS RANGE, ALASKA View looking south across Lake Schrader in foreground, and Lake Peters...Domain 1 showing superposition of second folds with south-dipping axial planes on both limbs of first fold...phyllite with subordinate p,mounts of metachert and quartzite. Underlying, and gradational with, the...subordinate amounts of phyllite, metaconglomerate, a:nd metachert. Rocks of the Neruokpuk Formation have a well-developed...thicknes from 0 to 350 feet and collS!Lsts of quartzite, pebble and cobble conglomerate, and minor siltstone |  | Whitney, Donna L., Fornash, Katherine F., Kang, Patricia, Ghent, Edward D., Martin, Laure, Okay, Aral I., Vitale Brovarone, Alberto (2020) Lawsonite composition and zoning as tracers of subduction processes: A global review. Lithos, 370. 105636pp. doi:10.1016/j.lithos.2020.105636 | Journal (article/letter/editorial) | | Analysis, University of Western Australia, Crawley WA 6009, Australia 5 Eurasia Institute of Earth Sciences...subduction and exhumation. In Jo this review, we use new and published data to document lawsonite composition...Analysis, University of Western Australia, Crawley WA 6009, Australia Eurasia Institute of Earth Sciences...subduction and exhumation. In this review, we use new and published data to document lawsonite composition...continental margin material, oceanic sediments (metachert, metacarbonate), Jo and metasomatic rocks (e |  | | Report (issue) | | GEOLOGICAL SURVEY The occurrence of gold in siliceous Co-Cu exhalite deposits of the Blackbird nining district...Denver, CO 80225 ^Noranda Exploration, Inc., Lakewood, CO (currently with Coca Mines, Inc., Denver, CO 80203).............~................... 5 Geochemistry of Co-Cu-Au Lodes........................................Geology of the Blackbird mine area showing location of Co-Cu-Au lodes and prospects..........................of the Sunshine lode showing the distribution of Co, Cu, and Au............................ 8 Figure |  | SPIER, C, DEOLIVEIRA, S, SIAL, A, RIOS, F (2007) Geochemistry and genesis of the banded iron formations of the Cauê Formation, Quadrilátero Ferrífero, Minas Gerais, Brazil. Precambrian Research, 152 (3) 170-206 doi:10.1016/j.precamres.2006.10.003 | Journal (article/letter/editorial) | | terrigenous sediments. These changes are expressed by the co-existence of dolomitic, quartz, and amphibolitic...alluvial coarse-grained quartzite, conglomerate, finegrained marine quartzite, and phyllite (Villaça...metamorphism (Pires, 1995). At the Águas Claras Mine, quartzite and phyllite of the Moeda and Batatal formations...between the stratigraphic units is gradational. Quartzite and phyllite occur at the southern wall of the...lenses of coarse and fine quartzite. Higher in the sequence, fine quartzite lenses are interlayered with |  | | Journal (article/letter/editorial) | | & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer...Geoscience Journal of the Geological Society of Australia Publication details, including instructions for...Geophysics , GPO Box 378, Canberra, ACT, 2601, Australia Published online: 09 May 2007. To cite this article:...Geoscience Journal of the Geological Society of Australia, 37:2, 147-167, DOI: 10.1080/08120099008727917...Geophysics, GPO Box 378, Canberra, ACT 2601, Australia. Rocks in the Brungle-Darbalara area of the Tumut |  | | Journal (article/letter/editorial) | | mica (f) by D = 0.728d(1/f)0.629. Key words: metachert; recrystallization. normal grain INTRODUCTION...ENE-WSW and dip moderately to the north or to the south (e.g. Kano, 1978). Gentle upright folds at macroscopic...and metapsammitic rocks (Kano, 1978). Fifty metachert samples were collected from 49 localities (Fig...pre-existing porphyroblasts and by the appearance of new porphyro- 1 I I C D Progressive metamorphism...complete microstructural sequence of quartzite at Mt Isa, Australia, from detrital grains to exaggerated |  | | Report (volume) | | ?) eugeosynclinal sequence of greenstone and metachert at its unconformable contact with the subjacent...oblong body of porphyritic granodiorite 5 miles south of Oroville and trending, like the Osoyoos, northwest...other is located alongside a magnesite deposit south of Chesaw (pi. 1, loc. K). The largest ultramafic...containing several interbeds 3-12 ft thick of quartzite in zone 80 ft thick. Overlain by 50 ft of grayish-green...exposed, 950-ft-long, dip slope, dipping gently south, with abundant minor folds and crenulations. Locally |  | | Report (issue) | | nomenclature. Menlo Park, CA Geological Survey, New South Wales, Australia 1983 2 -Stanford University TECTONOSTRATIGRAPHIC...KHR KOT KOY KUH KYK MGO NAY NOY OLO Aluchin (South Anyui subterrane?): Pre-Tr ophlolitic rocks Alazeya:...continental basement; accreted in Middle Jr(?) South Anyui: oceanic crust and deep sea sed rocks--eugeosyncline;...may be continental massif; in south, composed of island arc volcanics South Primor'e: middle Pz foldbelt;...accreted arc with ophiolite and blueschist border at south; age estimates of Jr and 100-130 my. Verkhoyansk: |  | | Report (issue) | | Area of enigmatic contact relations near the south end of the French Gulch pendant. Table 1. Summary...to quartzofeldspathic schist, pure to impure quartzite, and calcareous beds including relatively pure... and south, appearing to form a giant lens in an otherwise normal sequence of schist, quartzite, and...conspicuous chiastolite) and some metavolcanic rocks. quartzite are notably absent. Marble and In a large area...outcrop area to pendants in the plutonic rocks south of the Garlock fault, is in many respects a "normal" |  | | Report (volume) | | the current-year issues of the monthly catalog "New Publications of the U.S. Geological Survey." Prices...Reports Section, Federal Center, Box 25425, Denver, CO 80225. Reports released through the NTIS may be obtaine...Open-File Reports Federal Center, Box 25425 Denver, CO 80225 Subscriptions to periodicals (Earthquakes &...SALT LAKE CITY, Utah--Federal Bldg., Rm. 8105, 125 South State St. • SAN FRANCISCO, California--Customhouse...Map Distribution Federal Center, Box 25286 Denver, CO 80225 Residents of Alaska may order maps from Alaska |
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