Aurion identifies 3 to 9 m wide zone over 450 m at launi. The geology of hydrothermal quartz veins that are gold bearing. Abitibi in canada, serpentine veins from the san andreas system in california and. The belt contains over 200 goldquartzvein deposits with production nearing 7,000,000 ounces 200,000,000 g of gold.
The microstructures developed in an example of a syntectonic crackseal vein. Quartz mines are found and worked in a great many counties in california, from siskiyou on the north to san diego on the south. The most common forms of gold mineralization are as free gold in fine films near crackseal laminae, along veinwall contacts, as coarsegrained aggregates in the white quartz, within sericitic fractures, and as smears within quartz veins. Aurion resources drills highgrade, near surface intercepts. Quartz vein morphology and implications for formation. This paper presents the results of a combined structural and fluid inclusion study on three goldquartz vein deposits of the val dor area abitibi, quebec consisting of subhorizontal extensional veins and ew steeply dipping shear veins. Samples were collected in three different areas, goldbearing quartz veins from. Dec 09, 2019 other previously drilled crack seal textured quartz veins in the mcz which carried lower amounts of gold can be explained by high variability in the gold distribution nugget effect. This happens swiftly by geologic standards, because pressures and deformation mean that large open spaces cannot be maintained. Only minor amounts of invisible gold were detected. Gold and base metal mineralization, hydrothermal alteration. Aurion drills multiple, highgrade, near surface intercepts.
Nondirectional quartz veins are composed of granular quartzcarbonate pyrite tourmaline sphalerite galena chalcopyrite tetrahedrite gold and record. Oman these are calcite veins standing out against a darker limestone. As the hot quartzrich fluids cooled, gold was precipitated out into quartz veins. Many mesothermal goldquartz deposits are localized along highangle reverse or. The structurally deeper ores of the adjoining prestea concession are associated with brittleductile deformation and consist of extensive crackseal quartzveins and graphitic shear zones. Other previously drilled crack seal textured quartz veins in. Samples were collected in three different areas, goldbearing quartz veins.
Historically, handmining of gold ores permitted the miners to pick out the lode quartz or reef quartz. Massive gold bearing quartz vein with mineralization. The formation of these veins can be explained by a growth mechanism involving many repeated small increments, the crackseal process ramsay 1980. Vein geology the reader wiki, reader view of wikipedia. Pdf mechanics of formation of the goldbearing quartz. Quartz vein morphology and classification of archaean goldvein deposits 41 1 fig. Syntectonic calcite or quartz veins with a crackseal structure are common in rocks at low metamorphic grades and high fluid pressure beach 1977. As the hot quartz rich fluids cooled, gold was precipitated out into quartz veins.
Diamond drilling of 64 holes extended the gold bearing structure to a vertical depth of 30 metres. This page is dedicated to the gold thats still attached to quartz, or a host rock. Gold also occurs along selvages within the argillite and as inclusions, fracture fillings or attached to. The crack seal principle applies for them just the same. The periodically fractured rocks crack seal veins would have been ideal hosts for mineralizing fluids. Both of these quartz vein intercepts exhibit crackseal textures which are typical for highgrade veins at aamurusko. Aurion drills highgrade, near surface intercepts extending.
Both of these quartz vein intercepts exhibit crack seal textures which are typical for highgrade veins at aamurusko. Rich gold bearing quartz from the mother lode of california. Crackseal patterns home geological society, london, special. The quartz in these bodies ranges widely in texture from coarsely crystalline to crackseal and crack. When the confining pressure is too great, or when brittleductile rheological conditions predominate, vein formation occurs via crackseal mechanisms. Fractures and cracks in the bedrock form ideal pathways for superheated water and steam under pressure to flow and to precipitate out their dissolved mineral and heavy metal loads. In other cases there is an obvious pattern in the orientations of the veins. A quartz vein, prominent from the surrounding weathered rock in geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. The maisie is a fairly complex vein system of laminated and banded crack seal type quartz to massive bull quartz. Am191 and am19114 intersected significant widths of quartz veins core lengths of 3.
A microstructural study of a crackseal type serpentine vein using. The crackseal principle applies for them just the same. Other previously drilled crackseal textured quartz veins in the mcz which carried lower amounts of gold can be explained by high variability in the gold distribution nugget effect. Mechanics of formation of the goldbearing quartzfuchsite vein at.
The giant quartzbreccia veins of the tyndrum dalmally area. The geology of hydrothermal quartz veins that are gold bearing when you first look at a quartz vein in a rock it looks like a very narrow vein but in reality a quartz vein develops into a sheet like body of quartz or other mineral that is carried in the cracks and fissures in the rock by a hot aqueous solution that is deposited through. Many mesothermal gold quartz deposits are localized along highangle reverse or reverse. Statistical analyses are performed on several crackseal patterns containing several hundreds successive cracks from three areas goldbearing quartz veins from abitibi in. Quartz veins, indicated by the red lines, formed between and within the layers of rock. Faultvalve behaviour in optimally oriented shear zones. Drill hole am19103, drilled 20 m below am19102, intersected a zone of 10% disseminated pyrite and extensional quartz veining, with vg, adjacent to a 1. This heat caused hot, quartz rich fluids to ooze through the folding rocks, dissolving and concentrating gold. The effect of the crackseal mechanism on the morphology of vein forming. Goldquartz specimens are in a completely different league of their own. Rocks are sometimes cut by quartz veins at random orientations, with or without crystals. The maisie is a fairly complex vein system of laminated and banded crackseal type quartz to massive bull quartz. The periodically fractured rocks crackseal veins would have been ideal hosts for mineralizing fluids. Gold is deposited by precipitation along the fracture edges.
In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Their formation and the gold they contain are of interest. Antitaxial crackseal vein microstructures and their relationship to. This paper presents the results of a combined structural and fluid inclusion study on three gold quartz vein deposits of the val dor area abitibi, quebec consisting of subhorizontal extensional veins and ew steeply dipping shear veins. Crackseal structures, tourmaline fibres, stretched quartz crystals and openspace filling textures. I really liked the mircoblaster so i wanted to pass on some info. Veins form when mineral constituents carried by an aqueous solution within the rock mass are. Goldbearing quartz veins, blue ribbon mine, alaska for this reason, veins within hydrothermal gold deposits are no longer the exclusive target of mining, and in some cases gold mineralisation is restricted entirely to the. Palaeoseismic events recorded in archaean goldquartz vein.
Aurion identifies 3 to 9 m wide zone over 450 m at launi east. When the confining pressure is too great, or when brittleductile rheological conditions predominate. Although most lode gold is found in quartz veins where the gold is precipitated out of solution in the formation of a deposit. This is the primary way in which lode gold is found, but there are also lode deposits that are associated with pyrite in this case the gold is either dissolved into the pyrite as an impurity, or forms as thin films between the crystal faces. The giant quartzbreccia veins of the tyndrum dalmally. The 3 aces project is host to high grade quartz veins, some with visible gold. Video taken with permission of the mineral rights claim holder of the site.
Crackseal veins are thought to form quite quickly during deformation by precipitation of minerals within incipient fractures. Large, mscale quartz veins have been extensively studied because they commonly host gold mineralisation, in the form of lodegold deposits. The hanging wall contact of the main gold zone at knoll is marked by a late, mafic to ultramafic dyke that has exploited the extensional structure hosting the intense alteration and quartz veining. Vein gold two types of gold deposits gold in nature. The geology of hydrothermal quartz veins that are gold bearing when you first look at a quartz vein in a rock it looks like a very narrow vein but in reality a quartz vein develops into a sheet like body of quartz or other mineral that is carried in the cracks and fissures in the rock by a hot aqueous solution that is deposited through precipitation. Crack seal structures, tourmaline fibres, stretched quartz crystals and openspace filling textures.
Was looking specifically for this quartz vein, which is known for having visible gold. Ek7nff the company or rainy mountain is pleased to report that drilling is now underway on the companys optioned gold exploration property the brunswick property or. Syntectonic calcite or quartz veins with a crackseal structure are. Statistical analysis of crackseal patterns request pdf. Oct 19, 2015 earlier this summer i purchased a microblaster system to do some prospecting and high grading of some gold bearing quartz viens. The systematic association of high grade ore with ribbon quartz suggests a genetic link whereby gold.
As a consequence, gold complexes were probably destabilized in the hydrothermal fluid and deposited with quartz in crackseal veins. How to clean quartz kitchen countertops granite gold. The program is designed to drill at least 5 holes to test this vein system to a potential depth of 100 m. Other previously drilled crackseal textured quartz veins in. The majority of the previous studies concerned quartz or calcite veins in. This heat caused hot, quartzrich fluids to ooze through the folding rocks, dissolving and concentrating gold. Drilling commenced on rainy mountains brunswick gold exploration property. The inclusion bands can be straight or gently undulating parallel to the vein margins fig. In most of todays mines, ore material is primarily composed of the veins and some component of the wall rocks which surrounds the veins the difference between 19thcentury and 21stcentury mining techniques and the type of ore sought is based.
Other previously drilled crack seal textured quartz veins in the mcz which carried lower amounts of gold can be explained by high variability in the gold distribution nugget effect. Pdf on the arrangment of solid inclusions in fibrous veins and the. Lead isotope studies of whole rocks and galenas associated with gold in the quartzfuchsite vein suggest a genetic link between the gold mineralization and the quartzfeldspar porphyries of the dome mine. Evidence for crackseal growth processes is common in antitaxial veins, where trails and bands of small 210. Gold mineralization in asrich mesothermal gold ores of the. Sep 22, 2011 rocks are sometimes cut by quartz veins at random orientations, with or without crystals. Drilling commenced on rainy mountains brunswick gold. Look for gold in quartz veins in areas where the bedrock is fractured by tectonic and volcanic activity.
Gold mineralization in asrich mesothermal gold ores of. Most gold occurs as micrometresize particles in arsenian pyrite, and as invisible gold in arsenian pyrite and arsenopyrite. More than threequarters of alaskas lode gold was mined from the juneau gold belt. This type of gold is highly desired in the mineral collecting community. Statistical analyses are performed on several crack seal patterns containing several hundreds successive cracks from three areas gold bearing quartz veins from abitibi in canada, serpentine veins. Within this area are a countless number of gold bearing quartz veins, commonly following the strike and dip of the strata, occasionally crossing them.
Mar 07, 2011 the geology of hydrothermal quartz veins that are gold bearing when you first look at a quartz vein in a rock it looks like a very narrow vein but in reality a quartz vein develops into a sheet like body of quartz or other mineral that is carried in the cracks and fissures in the rock by a hot aqueous solution that is deposited through. Crackseal veins are thought to form quite quickly during deformation by precipitation of. Aurion identifies 3 to 9 m wide zone over 450 m at. Surface exploration since august, 2016 has been highly successful with the discovery of over 25 new quartz veins. Veins of gold bearing quartz are well known in california, and historically they have produced millions of dollars worth of gold. At bernadette, crack and seal style quartz veins returned significant gold values drill hole bk1403. If youre in the usa, the geological survey lists locations where significant amounts have been recorded. Quartz vein morphology and implications for formation depth. The great mother lode vein system is the largest group of veins in california. Earlier this summer i purchased a microblaster system to do some prospecting and high grading of some gold bearing quartz viens. Natural gold and quartz mineral specimens for sale.
Crack seal veins are thought to form quite quickly during deformation by precipitation of minerals within incipient fractures. Dec 09, 2019 am191 and am19114 intersected significant widths of quartz veins core lengths of 3. A massive gold bearing milky white quartz vein with gold values. Prior to 2016, exploration had focused primarily on just the ace of spades and ace of hearts zone.