Yaskawa, Katsumi

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RIGHT:URL:CITATION:AUTHOR(S):ISSUE DATE:TITLE:Paramagnetism of Some Kinds ofCrystalline SchistsYaskawa, KatsumiYaskawa, Katsumi. Paramagnetism of Some Kinds of Crystalline Schists. Memoirs of theCollege of Science, University of Kyoto. Series B 1962, 28(4): 485-4881962-03-20http://hdl.handle.net/2433/258226MEMOIRS OF       Vol.THE COLLEGEXXVIII, No. 4OF SCIENCE,Geology andUNIVERSITYMifieralogy, oF KyoTo, SERIEs B,Article 2, 2962Paramagnetism of SomeKindis oi Cxystalline SchistsGeologieal and           ByKatsumi YAsKAwAMineralogiÅëal Institute, University of  (Received Nov. 1, 1961)I<yote                                    Abstract    In this paper it is mentioned that except several specimens almost al! samples of Sambagawacrystalline schists have no clear indication showing existence of ferro or ferrimagnetic mineralstherein. Their susceptibility, all being nearly inverseiy proportional to temperature in therange from OOC to 6000C, indicates paramagnetic nature. On the other hand, it was foundthat the susceptibility of those paramagnetic rocks is anisotropic, that is, the susceptibilitymeasured paralle! to the lineation oi the crystalline schist and that measured perpendiculargenerally differ from each other.    The rock samples on which the measurements were made are those takenfrom the soÅíalled Sambagawa crystalline schists in southwestern Japan Theywere collected from the vicinity of Mt. KoTsu and the places aiong the RiverYoshino in the eastern Shikoku. Tlte crystalline schists from these regionshave such minera} compositions as shown in Tabie 1.    Table 1. Showing the numbers and constituents of every kind of the rock samples.GrouplIGreen schistBlack sehistQuartz schistSandstone schistNumbers ActinoHte-green l  schist ]Glaucophane-green  schist15Mineral composition81ack  AIbite, actinoiite, epidote, titanite    (sericite, quartz)*IschistIl       GIaucophane, chlorite, epidoiE, 3 titanite, (albite, quartz, Iawso-         nite)     I       Sericite, quartz, brownish-blackli         mineral, albite (garnet, chlorite)     1Piedmontite-quartz  schistStilpnomelane-  quartz schistSericite-quartz  schistSandstone schist52716Piedmontite, quartz, sericite  (garnet, braunite)s  Stilpnomelane, quartz, calcitek..mEllematiteLmag..n.WIEg/lwwwh_Sericite, quartz (garnet)Quartz, microcline, albite, pyroxe- ne, Åëlinozoisite, sericite  (titanite)* The rninerals in the brackets are rarely found,486 I<atsumi YAsi<AwA   Table 2 skows the mean va}ue of intensity of magnetization and of sus-ceptibilitiy in all kinds of the crystalline schists. The intensity of magBetiza-tion and its temperature dependeRcy of each specimen (powder sample containedin a small quartz tube with a voiume of 0.2cc) was determined uRder appliedmagnetic field ef about 3000 Oe at room temperature (200C) and the meansusceptibility, Z,n := M/ JI, was obtained.   Several curves show!ng variat2on of magnetization with temperature up to8000C are shown in Fig. 1. These curves are obtained by using spring baiancemagnetometer under the field of about 3000 Oe in vacuum about 10fi2mmKg.   In Fig. 2, the values of magnetic susceptibility of the schists are plottedas afunction of the reciprocal of the temperature. The values obey the Curie-Weiss' LawZ =- C/(T-e),where Z is susceptibilky per gramme, C the Curie constant, T absoiute tem-peratui"e and e the transition temperature. This indicates the fact that almostali of the crysta!line schi$ts are paramagnetic.   Next, by means of KRisHNAN's oscillation methed'), anisotropy in suscep-tibMty was determined. Tke results show that the susceptibllity parallel tothe direction of the lineation <Zi) is laTgest and that perpendicular to tke s--surfaceslj` (Z3) the smallest.   The difference may be explained to be due to tke statistical alignmeRt ofconstkuent minerais in rock whose susceptibilitles along their crystal axesdiffer ffom each other. The magnetic study of siiicate minerals is, tkerefore,important to understand the observed anisotropy.Table 2. Intensity of magnetization and mean susceptibility under       room temperature and 26eO Oe.NameParamagnetie actinolite-green schistGIaucophane-green schistBlack schistPiedmontite-quarzt schistStilpnomelane-quartz schistSericite-quarts schistSandstone schist Intensity of Meanmagnetization susceptibility (c.g.s./gr) (c.g.s.t'gr)5.62Å~10nt3 l 2.lsxle-67.94 Å~, le --3 l 3.68Å~10 -e1.85 Å~. le-3 I e.71 Å~ 10-6         l3.35Å~10-3 I 1.26Å~10-62.s6Å~lo--3 I o.gsxlo-6         12.05Å~10-3 l 0.79Å~10-e         l.1.29xiO-3 i 0.50Å~10--S''v'''''_ -L---_mum. mu.* The term "s-surfaces" is used by SAÅ}NDER to denote sets of parallel planes of mechanical inhomogeneity in deformed rocks.Pararnagnetism of Some Kinds of Crystalline Schists 487e76gskeets 4ggts 3lzg2to   2oo 400 600         TEMPERATURE {O cl           Fig. 1.(1) Glaucophane green schist(2) Actinolite green schist(3) Stilpnomelane quartz schist(4) Sericite quartz schist(5) Black schist(6) Sandstone schistseoTable 3. The values of magnetic susceptibility in different directions. 1 : The susceptibility parallel to the direction of the lineation. 2 : The susceptibility perpendicular to the direction of the lineaiion    and parallel to s--surfaces. 3 : The susceptibtlity perpendicular to the s-surfaces.Name   (1)(c.g.s.,fgr)Paramagnetic actinolite-green schistGlaucophane-green schistBlack schistPiedmontite-quartz schistStilpnomelane-quartz schistSericite-quartz schistSandstone-schistli3.02xlO--65.02Å~10-61.30Å~10-G2.36Å~10-61.96 Å~ 10-6l.47Å~10-60.80Å~10-6  (2)(c.g.s./gr)1.81Å~10--64.59xle-60.67Å~10-6!.31Å~10-G1.27Å~10--G0.65Å~10-60.48Å~10-6t  (3)(c.g.s./gr)Ll.72Å~10-6l.43Å~lo-60.15Å~10-60.43Å~10-60.61Å~10-G0.24Å~10-fi0.23Å~10--6488and1)'trÅípaFS88s:gx]osr i76s4]2I<atsumi YASKAWACl)                 Ot 234                                                     T#                                   "IT) xio'                               Fig. 2.                     (1) Glaucophane green schist                     (2) Actinolite green schist                     (3) Stilpnomelane quartz schist                     (4) Sericite quartz schist                     (5) B}ack schist                     (6) Sandstone schist                         AckRowledgmentI wish to express my hearty thanl<s to Dr. Naoto KAwAisuggesSioBs given throughout this werk.                            RefereMceK. S. KRismxTAN, B. C. GuHA and S. BANERmE: Phil. Trans., 231,for his235,direction(1933)e

Paramagnetism of Some Kinds of Crystalline Schists

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Paramagnetism of Some Kinds of Crystalline Schists

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