Pretražite po imenu i prezimenu autora, mentora, urednika, prevoditelja

Napredna pretraga

Pregled bibliografske jedinice broj: 601012

Pseudomorphs of low microcline after adularia fourlings from the Alto da Cabeça (Boqueirão) and Morro Redondo pegmatites, Brazil


Bermanec, Vladimir; Horvat, Marija; Žigovečki Gobac, Željka; Zebec, Vladimir; Scholz, Ricardo; Škoda, Radek; Wegner, Reinhard; de Brito Barreto, Sandra; Dódony, István
Pseudomorphs of low microcline after adularia fourlings from the Alto da Cabeça (Boqueirão) and Morro Redondo pegmatites, Brazil // Canadian mineralogist, 50 (2012), 4; 975-987 doi:10.3749/canmin.50.4.975 (međunarodna recenzija, članak, znanstveni)


CROSBI ID: 601012 Za ispravke kontaktirajte CROSBI podršku putem web obrasca

Naslov
Pseudomorphs of low microcline after adularia fourlings from the Alto da Cabeça (Boqueirão) and Morro Redondo pegmatites, Brazil

Autori
Bermanec, Vladimir ; Horvat, Marija ; Žigovečki Gobac, Željka ; Zebec, Vladimir ; Scholz, Ricardo ; Škoda, Radek ; Wegner, Reinhard ; de Brito Barreto, Sandra ; Dódony, István

Izvornik
Canadian mineralogist (0008-4476) 50 (2012), 4; 975-987

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
low microcline; adularia; pseudomorph; granitic pegmatite; Brazil

Sažetak
Potassium feldspar crystals from the Alto da Cabeça (Boqueirão), Rio Grande do Norte (sample BQ) and the Morro Redondo. Minas Gerais (sample MR) pegmatites in Brazil have a typical adularia fourling habit consisting of a combination of Baveno and Manebach twins. Crystal morphology suggests a monoclinic symmetry, but XRPD measurements and TEM experiments show that the samples are low microcline. Calculated values of triclinicity [Δ = 0.915 (BQ) and Δ = 0.9225 (MR)], cell parameters [a 8.587(4), b 12.969(4), c 7.223(2) Å, α 90.66(3) β 115.97(4), γ 87.69(3)° for BQ and a 8.584(3), b 12.970(3), c 7.225(2) Å, α 90.66(3) β 115.97(3), γ 87.74(3)° for MR), t1o occupancy of Al [0.99 (BQ) and 0.98 (MR)], order index [ΔSM= 0.97 (BQ) and ΔSM = 0.99 (MR)] and ΣAl at the T1 sites [98.6% (BQ) and 99.5% (MR)] reveal a triclinic symmetry and a high state of order for the samples of potassium feldspar. Transmission electron microscopy and selected-area electron-diffraction investigations of the crystals show that they are compositionally homogeneous, without exsolution lamellae of other phases. The electron-diffraction patterns show no splitting of any reflection and no streaking, and thus indicate ideal order in both samples. According to crystal morphology and the results on submicroscopic scale, we conclude that in this case adularia samples have a completely ordered structure. The measurements and calculations demonstrate that they are highly ordered, i.e., maximum microcline. Adularia pseudomorphs are highly ordered triclinic feldspar developed through transformation of a monoclinic parent.

Izvorni jezik
Engleski

Znanstvena područja
Geologija



POVEZANOST RADA


Projekti:
098-0982934-2742 - Nanočestice u biogeokemijskim procesima u okolišu
119-0000000-1158 - Međudjelovanje minerala i okoliša (Bermanec, Vladimir, MZOS ) ( POIROT)

Ustanove:
Institut "Ruđer Bošković", Zagreb,
Prirodoslovno-matematički fakultet, Zagreb,
Hrvatski geološki institut,
Hrvatski prirodoslovni muzej

Poveznice na cjeloviti tekst rada:

doi www.canmin.org

Citiraj ovu publikaciju:

Bermanec, Vladimir; Horvat, Marija; Žigovečki Gobac, Željka; Zebec, Vladimir; Scholz, Ricardo; Škoda, Radek; Wegner, Reinhard; de Brito Barreto, Sandra; Dódony, István
Pseudomorphs of low microcline after adularia fourlings from the Alto da Cabeça (Boqueirão) and Morro Redondo pegmatites, Brazil // Canadian mineralogist, 50 (2012), 4; 975-987 doi:10.3749/canmin.50.4.975 (međunarodna recenzija, članak, znanstveni)
Bermanec, V., Horvat, M., Žigovečki Gobac, Ž., Zebec, V., Scholz, R., Škoda, R., Wegner, R., de Brito Barreto, S. & Dódony, I. (2012) Pseudomorphs of low microcline after adularia fourlings from the Alto da Cabeça (Boqueirão) and Morro Redondo pegmatites, Brazil. Canadian mineralogist, 50 (4), 975-987 doi:10.3749/canmin.50.4.975.
@article{article, author = {Bermanec, Vladimir and Horvat, Marija and \v{Z}igove\v{c}ki Gobac, \v{Z}eljka and Zebec, Vladimir and Scholz, Ricardo and \v{S}koda, Radek and Wegner, Reinhard and de Brito Barreto, Sandra and D\'{o}dony, Istv\'{a}n}, year = {2012}, pages = {975-987}, DOI = {10.3749/canmin.50.4.975}, keywords = {low microcline, adularia, pseudomorph, granitic pegmatite, Brazil}, journal = {Canadian mineralogist}, doi = {10.3749/canmin.50.4.975}, volume = {50}, number = {4}, issn = {0008-4476}, title = {Pseudomorphs of low microcline after adularia fourlings from the Alto da Cabe\c{c}a (Boqueir\~{a}o) and Morro Redondo pegmatites, Brazil}, keyword = {low microcline, adularia, pseudomorph, granitic pegmatite, Brazil} }
@article{article, author = {Bermanec, Vladimir and Horvat, Marija and \v{Z}igove\v{c}ki Gobac, \v{Z}eljka and Zebec, Vladimir and Scholz, Ricardo and \v{S}koda, Radek and Wegner, Reinhard and de Brito Barreto, Sandra and D\'{o}dony, Istv\'{a}n}, year = {2012}, pages = {975-987}, DOI = {10.3749/canmin.50.4.975}, keywords = {low microcline, adularia, pseudomorph, granitic pegmatite, Brazil}, journal = {Canadian mineralogist}, doi = {10.3749/canmin.50.4.975}, volume = {50}, number = {4}, issn = {0008-4476}, title = {Pseudomorphs of low microcline after adularia fourlings from the Alto da Cabe\c{c}a (Boqueir\~{a}o) and Morro Redondo pegmatites, Brazil}, keyword = {low microcline, adularia, pseudomorph, granitic pegmatite, Brazil} }

Časopis indeksira:


  • Current Contents Connect (CCC)
  • Web of Science Core Collection (WoSCC)
    • Science Citation Index Expanded (SCI-EXP)
    • SCI-EXP, SSCI i/ili A&HCI
  • Scopus


Uključenost u ostale bibliografske baze podataka::


  • Chemical Abstracts, Mineralogical Abstracts, American Geological Institute GeoRef, Institute for Scientific Information


Citati:





    Contrast
    Increase Font
    Decrease Font
    Dyslexic Font