hydrothermal alteration of amphibolites

  • The Werner Lake Co-Cu-Au deposit, Ontario: Evidence for ...

    The δ³⁴S values of sulphides and sulpharsenides in the ores of the Werner Lake deposit are uniformly close to O‰, similar to those sulphides in the alteration assemblages (-0.5 to +2.3‰) and amphibolites (+0.3 to +1.8‰), suggesting a juvenile source for the S.

  • Petrochemistry of Two Magnetite Bearing Systems in the ...

    The Binga and Djadom iron ore prospects are located in the Precambrian Belt of southern Cameroon, and form part of what is locally termed the Central African Iron Ore Emerging Province, which is known to host several world class deposits, such as; Mballam, Nkout, Ntem, Ngovayang and the Mamelles in southern Cameroon, and Boka Boka, Belinga ...

  • Geochemistry of hydrothermally altered rocks from the ...

    Geochemistry of hydrothermally altered rocks from the Asarel porphyry copper deposit, Central Srednogorie Atanas Hikov ... Abstract. The distribution of major and trace elements in hydrothermal alteration zones (propylitic, argillic, sericitic and advanced argillic) from the Asarel porphyry copper deposit is studied. ... amphibolites, slates ...

  • Distribution and Origin of Clay Minerals During ...

    The hydrothermal alterations associated with uranium mineralization are represented particularly by the removal of quartz, chloritization, albitization, hematitization and origin of younger generations of chlorite and white mica

  • Chloritization | Article about Chloritization by The Free ...

    Hydrothermal alteration zones, quartz-pegmatite veins and veinlets and dykes of sub-volcanic origins with intensive silicification, pyritization, and chloritization occur around the granodiorite stock body.

  • Hydrothermal alkali metasomatism in the Salobo iron oxide ...

    ABSTRACT: Hydrothermal alteration effects on host amphibolites of the Archean iron oxide Cu (-Au) deposit of Salobo, northern Brazil, have been investigated. Preliminary results indicate that the ...

  • The Carolina terrane in northwestern South Carolina ...

    The Carolina terrane is one of several exotic terranes rec-ognized in the southern Appalachian hinterland (Fig. 1; Willi- ... amphibolites are interpreted to represent massive basaltic or ... sent hydrothermal alteration contemporary with volcanism. It

  • Hornblende alteration and fluid inclusions in Kärdla ...

    Alteration is believed to have resulted from convective flow of hydrothermal fluids through the central areas of the crater. Chloritic mineral associations suggest formation temperatures of 100-300 °C, in agreement with the most frequent quartz fluid inclusion homogenization temperatures of 150-300 °C in allochthonous breccia.

  • Radioisotope Dates for Precambrian Amphibolites in Grand ...

    Any sericitic alteration of the plagioclase would represent post-formation hydrothermal alteration with introduced K 2 O, so the K 2 O in these amphibolites is, thus, of the primary in situ origin required for valid K-Ar radioisotope dating. Equally significant are the wide variations in the contents of Rb, Sr, Sm, Nd, U, and Pb in these ...

  • Metasomatism - Wikipedia

    Metasomatism is the chemical alteration of a rock by hydrothermal and other fluids. It is the replacement of one rock by another of different mineralogical and chemical composition. The minerals which compose the rocks are dissolved and new mineral formations are deposited in their place.

  • Geotectonic significance of gneissic amphibolites from the ...

    Previous article in issue: Hydrothermal activity at the Trans-Atlantic Geotraverse Hydrothermal Field, Mid-Atlantic Ridge crest at 26°N Previous article in issue: Hydrothermal activity at the Trans-Atlantic Geotraverse Hydrothermal Field, Mid-Atlantic Ridge crest at 26°N Next article in issue ...

  • 11. Hydrothermal Alteration - USGS

    The geochemical reactions that produce hydrothermal alteration in host rocks of VMS deposits are critically important for a number of reasons.

  • Hydrothermal mineral alteration patterns in the Mount Isa ...

    Abstract. High-resolution mineral maps derived from hyperspectral imaging (4.5 m pixel) enable the recognition of various types of hydrothermal alteration and the identification of fluid pathways.

  • MINERALOGICAL AND PETROGRAPHICAL CHARACTERISTICS OF …

    A strong zoning structure is determined in plagioclase (An 48 and An94) of the amphibolites by SEM studies. The andesine is indicated to be earlier than anorthite by existence of linear compositional variations in the amphiboles, lack of widespread metasomatic, hydrothermal alterations and migmatisation in the the amphibolites.

  • Geologic and mineralogic controls on acid and metal-rich ...

    The surface and subsurface geology, hydrothermal alteration, and mineralogy of the Handcart Gulch area was studied using map and drill core data as part of a multidisciplinary approach to understand the hydrology and affects of geology on acid-rock drainage in a mineralized alpine watershed. Handcart Gulch was the locus of intense hydrothermal alteration that affected an area of nearly 3 ...

  • Paleozoic Amphibolites, Kreuzeck Mountains, Austria ...

    Paleozoic Amphibolites, Kreuzeck Mountains, Austria: ... Amphibolites were chosen for this purpose because in the western Kreuzeck Mountains they always occur in the immediate ore environment. In addition, they are easy to ... original hydrothermal alteration should be readily detected.

  • Nuvvuagittuq Greenstone Belt - Wikipedia

    The Nuvvuagittuq Greenstone Belt [needs IPA] (NGB) is a sequence of metamorphosed mafic to ultramafic volcanic and associated sedimentary rocks (a greenstone belt) located on the eastern shore of Hudson Bay, 40 km southeast of Inukjuak, Quebec. These rocks have undergone extensive metamorphism, and represent some of the oldest rocks on Earth.

  • Types of Metamorphism - Tulane University

    The hydrothermal metamorphism results in alteration to such Mg-Fe rich hydrous minerals as talc, chlorite, serpentine, actinolite, tremolite, zeolites, and clay minerals. Rich ore deposits are often formed as a result of hydrothermal metamorphism.

  • Amphibolite - Wikipedia

    Amphibolite (/ æ m ˈ f ɪ b ə l aɪ t /) is a metamorphic rock that contains amphibole, especially the species hornblende and actinolite, as well as plagioclase.. Amphibolite is a grouping of rocks composed mainly of amphibole and plagioclase feldspar, with little or no quartz.It is typically dark-colored and heavy, with a weakly foliated or schistose (flaky) structure.

  • Geotectonic significance of gneissic amphibolites from the ...

    A large collection of gneissic amphibolites was recovered by two close dredge hauls from the deepest part of the north facing slope of the transverse ridge forming the south wall of the Vema Fracture Zone. ... Hydrothermal alteration studies of gabbros from Northern Central Indian Ridge and their geodynamic implications, Journal of Earth System ...

  • Preliminary studies of the alteration of a granite by an ...

    Solution channels in quartz, microcline, and plagioclase of a granite were produced by exposure of the rock to an artificial hydrothermal system. Electron microprobe analyses, beam-scanning photographs, and element profiles show that the mineral grains are homogeneous and unaltered within a few ...

  • HORNBLENDE ALTERATION IN IMPACT-INFLUENCED …

    HORNBLENDE ALTERATION IN IMPACT-INFLUENCED BASEMENT ROCKS AT THE KÄRDLA IMPACT ... alteration in amphibolites at the Kärdla crater. It is likely, that stable tectonic and thermal history of the ... metamorphism and hydrothermal alteration of the intermediate to …

  • Hydrothermal alkali metasomatism in the Salobo iron oxide ...

    Hydrothermal alteration effects on host amphibolites of the Archean iron oxide Cu (-Au) deposit of Salobo, northern Brazil, have been investigated.

  • hydrothermal alteration of amphibolites - gigsgh.org

    Hydrothermal mineral alteration patterns in the Mount Isa ... Four different types of hydrothermal alteration were ... The MgOH and Fe 2+ mineral maps were also used to distinguish various mafic rocks from amphibolites, ...

  • Amphibolite - Titi Tudorancea

    Amphibolite Facies. Amphibolites define a particular set of temperature and pressure conditions known as the amphibolite facies.However, caution must be applied here before embarking on metamorphic mapping based on amphibolites alone.

  • Paragenesis of Hydrothermal Mineralization in Amphibolites ...

    A specimen of adularia from Dean quarry, which appeared to have suffered hydrothermal alteration, gave an apparent age of 147 ± 3 Ma. If partial overprinting is present, it would have taken place in Cretaceous or Tertiary times (Seager et al., 1975, 1978).

  • Hydrothermal alteration studies of gabbros from Northern ...

    Alt J C, Honnorez J, Laverne C and Emmermann R 1986 Hydrothermal alteration of a 1 km section through the upper oceanic crust, Deep Sea Drilling Project hole 504B: Mineralogy, chemistry, and evolution of seawater-basalt interactions; J. Geophys.

  • Cooling of the Kärdla impact crater: I. The mineral ...

    evidence of hydrothermal alteration is mainly found both in and around the crater central uplift, for example in the Kärdla, ... quartz-feldspar gneisses with amphibolites, biotite gneisses, ... Cooling of the Kärdla impact crater 5

Copyright ©2019 Company Deer All rights reserved. sitemap