Archive
The editorial board of the "MSTU Vestnik" journal supports the «Open Access» policy which enables users to have free and unlimited access to scientific articles (to read, download, copy, distribute) in case the author is indicated when further quoted.
Warning: file_get_contents(http://doi.crossref.org/servlet/getForwardLinks?usr=murmansk&pwd=4_mstu&doi=): failed to open stream: HTTP request failed! HTTP/1.1 400 Bad Request in /var/www/old/sites/vestnik/php/find_ref.php on line 2
Skufin P.K., Lyutoev V.P., Yakovlev Yu.N., Smirnov Yu.P., Glukhov Yu.V., Kotova E.N.
Properties and structural peculiarities of rock forming minerals and Early Proterozoic sedimentary rocks in the SG-3 section and their homologues at the surface
Abstract. Actinolites and hornblendes from the SG-3 Archaean rocks and from the surface Archaean complex (Allarechka block) have been studied. The Allarechka block used to be considered a surface analogue of the SG-3 Archaean complex. The mineral structure, the nature and degree of structural defects have been investigated by X-ray powder diffractometry, infrared and Mossbauer spectroscopy. The chemical composition was determined by the wet chemistry and microprobe methods. The comprehensive investigations resulted in establishing composition stoichiometry of deep and surface amphiboles. Vacancies are present only in rare samples and in minor amounts. The majority of the studied amphiboles had a high degree of the unit cell deformation and its elongation along the c axis. A high and about the same degree of Fe2+ and other cations was observed in both groups of specimens. At the same time the patterns of the site occupation by Fe2+ are slightly different: Fe(M3)>Fe(M2)?Fe(M1) – for deep samples and Fe(M3)>Fe(M1)>Fe(M2) – for surface ones. The degree of iron oxidation is established to be similar (from 5 to for 20 %) for both surface and deep samples. Actinolite and low-alumina hornblende have no marked difference in their structural state at a depth of 7900-11350 m and at the surface. The data on the crystalline substance state at the crust deep zones may be useful for reliable interpretation of geophysical measurements, development of correct models of the crust structure and for choosing the proper sites for disposal of radioactive wastes. The structural state of amphibole (actinolite, low-alumina hornblende) from amphibolite and crystalline schist of the SG-3 Archaean complex and their surface homologues has been studied. The aim was to elucidate whether the structural state of those amphiboles differs and whether the amphiboles from the SG-3 Archaean rocks preserve any information about the physical state of the crystalline substance at great depths during their extraction to the surface. We have studied the composition, degree of iron oxidation, nature and degree of structural defects and the availability of various forms of water in the structure of amphiboles from the SG-3 Archaean rocks (7930-11330 m) and their surface homologues from the Allarechka block (southern framing of the Pechenga structure). According to the modern nomenclature (Leake, 1997), the actinolite and hornblende pertain to the calcic amphibole group.
Printed reference: Properties and structural peculiarities of rock forming minerals and Early Proterozoic sedimentary rocks in the SG-3 section and their homologues at the surface / P.K. Skufin, V.P. Lyutoev, Yu.N. Yakovlev, Yu.P. Smirnov, Yu.V. Glukhov, E.N. Kotova // Vestnik of MSTU. 2007. V. 10, No 1. P. -.
Electronic reference: Properties and structural peculiarities of rock forming minerals and Early Proterozoic sedimentary rocks in the SG-3 section and their homologues at the surface / P.K. Skufin, V.P. Lyutoev, Yu.N. Yakovlev, Yu.P. Smirnov, Yu.V. Glukhov, E.N. Kotova // Vestnik of MSTU. 2007. V. 10, No 1. P. -. URL: http://vestnik.mstu.edu.ru/v10_1_n26/articles/05_skufjin.pdf.
