Title Configuration of Migmatite Dome Comparative Tectonics of Migmatite in the Hidaka Metamorphic Belt
Author(s) Kizaki, Koshiro
Citation Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy, 15(1-2), 157-172
Issue Date 1972-03
Doc URL http://hdl.handle.net/2115/36009
Type bulletin (article)
File Information 15(1-2)_157-172.pdf
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Hokkaido University Collection of Scholarly and Academic Papers : HUSCAP CONFIGURATION OF MIGMATITE DOME COMPARATIVE TECTONICS OF MIGMATITE IN THE HIDAKA METAMORPHIC BELT by Koshiro KIzAKI (with 16 Text-Figures) (Contribution from the Department of Geology and Mineralogy, Faculty of Science, Hokkaido University, No, 1227 ) lntroduction The Hidaka metamorphic belt wliich represents the geological backbone of the Hokkaido is}and in northern Japan, is composed of various metamorphics and migmatites of pelitic and psamitic origin and a}so is characterizecl by thick sheets of basic intrusives which were metainorphosed to various aixtphibolites. Basic and ultrabasic plutonics as olivine gabbro, norite, gabbro and periodotite are significant in the belt. The core portion of the belt is occupied by the migmatites which are classified to biotite migmatite, cordierite migmatite and granitic migmatite of agmatitic, schollen, nebulitic and anatexitic natures, while sometimes of massive kind (Fig. I). The radiometric age of these migmatites indicates 30-40 my by K-A method (Kawano et al, 1967). So that with other geological informations, the age of the metamorphism and migmatization should be around from Cretaceous to Tertiary. The petrography of the metamorphic rocks and migmatites of the belt has been published by several authors (HiRoTA, l963, HuNAHAsHi, et al, l9S6, KizAKi, l964, ToNozAKi, 1965, etc.). The general picture on the Hidaka orogeiry in the Alpine period has been presented by HuNAHAsHi, and KizAKi, (HuNAHAsHi, l957, KizAKi, l964). The migmatite forming dome and arch along the core zone are divided into several tectonic units throughout the belt though some of the units are not clear yet. The irtajor units, however, have been investigated to classify from the tectonic facies view points. The conception of tectonic facies which is provided by the scale, shape and composition of the structure, has been originally defined by HARLAND (HARLAND, 19S6). The synclinal structure of the Pipairo complex and the Oshirabetsu dome dealt with in the present paper, reveal to be the identical tectonic facies nevertheless they might be seemed to be different in struck}re, because it shows that the synclinal structure of the Pipairo conaplex and dome of the Oshirabetsu body represent the different level of a l58 K, KIZAKI
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>kl NN )( Z/l] Htdaka supergroup .-.-Xx 'SL x v --I >5E : zag Nllii;E:fg.-=- ;"" Basic metamorphics N t & syn-kinematic gabbros / >srCSI / BIRO / 1･ NN . xN i . Late & post-kinematic gabbros N -N ,2 ･' x tf ' x ABETSU yul t..t :; Mt, aklslii"SN e tt..tt t Acid metamorphics J 'f / N , i? i]'i", ..t..x ma & migmatites /-- t ti "N lt t N ' .- N mo Late-kinematic gramtes SAMANI- xl NiNsl e ' .t x t N ts, /x -N s-N K- t t ng x N N [llll] post-kmematic granites 1 M zz s N x sX K t s t -s / Fold axis PAClFlC OCEAN HOROIZUMi- e ; 53i.1 630oeoe 1.Lmeation .
f 61e- 8of l CAPE ERIMO. o 10 20 KM f Thrust fault / Fault
Fig. 1 Tectonic map of tlie Hidaka metamorphic belt, A: Pipairo complex, B: Oshirabetsu dome. MIGMATITE DOME IN THE HIDA} Pipairo Complex (Fig. 2 and 3) The Pipairo complex has been seemed simply to be a mass of gneissose granite called the Pipairo gneissose granite. The complex is, however, composed of the biotite gneiss and biotite migmatite which form a synclinal basin structure of 9km long and 3km wide at the center and the coarse granitic miginatite of anatexitic itature revealing three sheet structures or steeply inclined phacoliths at the easterR side. The complex situated at the north-eastem part of the H[idaka metamorphic belt, contacts to tlie schistose biotite hornfels with faults or sheared zone in between. Further east it transits to the slates and sandstones of the Hidaka , supergroup, presumably of the lower Mesozoic in age. It is surrounded l)y the gabbros to north, west and south. [l]he eastern side of the H[idaka metamorphic belt generally represents a series of progressive metamorphism of the high temperature and low pressure type from the sediments of the Hidaka supergroup to be various types of migmatites via biotite hornfe}s, schistose biotite homfels and banded biotite gneiss. In the area in questioll, the zone of the banded biotite gneiss is missing and also the most graAitized portions, i.e. anatexites of the granitic migmatites, occur on the eRstern side. A iiumber of gabbro sheet in the migmatite aureole separates tliLe structural subunits which are tl'ie synclinal basin and phacolith structures. The gabbros are acidified tobediorjtic,graRodioritic rocks by migmatization and are scattered in the migmatites as paleosomes. The gabbros at the northern portion iiiterfinger and contaminate with the migmatites so that the boundary between tlaem is obscured. The schistose biotiie hornfels and banded biotite gneiss on the westeri] side of the syiiclinal structure are tlae cohtinuation of the septum between gabbro masses from the north and envelope tlie synclinal structure at the southern end. A small sheet ofgranite is observed on the eastem flank of the syncline and its petrographic natui'e is quite similar to that of the postkinematic granites which are seen at the northern region of the belt (Fig. 1). 160 K, KIzAKI f ltl/tiss Nfl N nx, Nf N l !N re N. eke ivfug fx if %,eie 2eo":a$i,il, o eq ag qta. I .)N ]; i elljl ig % eq fa e !.i eq igeq k Segie eee ee l< .. m..tttt ss,// x N vaigva ts %e 20 e - ig e igk 30 e l- die efits " e ig g eq s ktse e es ig va va ts fi eee yi N ta W$si¥,el.e e gx { ts". k e g ig 1 / -bets y eq eq % e 3oN / 50q ¢ hete' ek es "e ts G. Ge ee ts 3 N/ I)v"ti,}ilillli;ilXIIIIilliiilii)lllll)lililli(x-il$,$i:,:f}tg,i,,,i,ts ee te" g / N. 40 pt ts .e "x ig "s / treqS 6 O ets:s?eO,"eG e, X ! ",,g ¢ e w"sfu eESSIti K ts e" k. t. -.'''-r-- tw E,,{ / iN "" Nkt$ijIIN¥aj%y x /Nt .] 10 otso ooe'e N fu4 ee /t i ssM3o eB e N "e fi eeg"- i]l 1 pmptpt 5 e Xi5< !,i(i 3 Elii!ili Midaka N i l sssstwtwlscstsi bs 35 " gy Fig. 2 Tectonic map of Pipairo complex. MIGMATITE DOME IN THE HIDAKA METAMORPHIC BELT l61 .--tt tNiN SxN 1 ' i t-- S- t ' "te X sJ ' t lll;'i'/e';l'11i tt /f'/ ,'/"3i';,'1' t st tt it 1t lt ' Ilss$ss LIt x : t ! tt'.1'g..･J.IIIill･f.::1 sst ! 4 aooO m sw' "N f℃ 'ite,il,'i,,kfei:"iii."Ze'//i/liii;ell'II";"l:{zi";;" NE Nf ZZT)Z. "if fN y .kNtsSf sss o ptpm f K NNNkl X XxXNtNN "LsNsx-lts.N K Fig. 3 Cross section of Pipiro complex Structures Foliation: Foliation is signified by the p}anar arrangement of biotite flakes and tlie compositional alternation of biotite-rich layers and quartz - feldspathic layers emphasizes the foliation. The foliation is weakend in the migmatized portion and then the massive migmatites are observed in some locations. The general trend of the foliation indicates the direction ofN 200 W though the local variation is significant because of the complexed structure. The inclination of the schistose biotite hornfels and banded biotite gneiss on the western side changes from east on the north vertica; to south-west on the sot}thern end where the strike turns toward east-west enveloping the migmatite core. The migmatite core indicates a syRcline at the central portion, while a monoclinic structi.ire inclined to west sviggests a dome structure at the southern portion. The 6 diagram in Figure 4 shows an incomplete synclinal structure with monoclinic tendency. The 6 maximum coincides to the maximum in the orientation pattern of the lineati'on of the structure (Fig. 5), therefore, the lineation signifies the b-lineation. This structural pattern attributes to the same tectonic facies as that of the Oshirabetsu clome of the southern extreine region of the belt. Three phacolith structures occupy tlie eastern sicle of the srnclinal one which are separated by the narrow gabbro sheets. The phacolith sheets of granitic migmatite are overlapping one anothei' dipping gently toward west at the inside, while steeply at the outsicle and bounded by thrust faults associated with occasional gabbro sheets. These phacolith sheets, therefore, are seemed to be thrusting up toward east resulting in the str"cttire above mentioned. A granitic migmatite arch is found on the north-easterR side of the complex where the foliation inclines geRtly to west with monoclinic teRdency bet the distribution of the liBeation indicates the arch structure. Tlie 6 diagram of these phacolith structures (Fig. 6) shows the monoclinic and the presence of two maxinia suggests that these sheet structt}res should be arches basically as showR by the north-eastem arch (Fig. 2). g,4] (/ XXx･.lll/ttg7tli/il;iXti;asi:'(2t2'fl'-"'-X '---x. .--" . s･ Fig. 4 B diagram of the synclinai structure of Pipait"o complex /"ts-- N / 6tt5 .. (1-c-'SsL¢ S(l,. / R ,L'-"V' Fig. 5 Lineation diagram of the synclinal structure of Pipairo complex MIGMATITE DOME iN THE HIDAKA METAMORPHIC BELT l63 N '/vfJI;ii;t .:" ee --L. I - -- tt, Fig. 6 6 diagram of the phacolithic structure of Pipairo complex. txt ..<-7vt') !h-x X ?5 () (aj rf s Fig. 7 Llneation diagram of the pltacolithic structure of Pipairo complex. Lineation: Lineation is represented by the iinear arrangement of biotite fiakes oii the foliation and the axis of micro-undulation of the foliation both of which are generally parallel each other. It is clear that the lineation is the b-lineation from the 6 diagram as well as field obseivations (Fig. 5 and 7). The lineation inclines generally to south altho}}gh some to north in the arches. The principal direction of tectonic transport of the complex particularly on the synclinal structure, should be toward soutk upward. This movei'nent picture due to the lineation shows a good accordance with that by the pattern from the 164, K. KIzAKI fo1iation. Marked overthrust round the southern end of the synclinal structure where the mignaatites are crushed to reveal myloRitic texture under the microscope. This should be another evidence for the movement direction of the structure toward south. However, the directioil of the tectonic transport of the phacoliths are generally toward east upward accompanied with southward element. It is suggested by the 5 and lineation diagrams that the 5 maxima and lineation of the sliteets indicate the cooperation witlit the synclinal structure moving toward south, while they move up toward east associatecl with overthrusting. The Pipairo complex hence seems to show two sorts of different tectonic facies but the deformation history is more complicated in detail. The trend of N 200 W with the inclination to eastward which is the general trend of the metamorphic belt, is observed at the northern portion of the synclinal structure that forms "Falling star". Then, the acute syncline appears in the central portion and the monoclinic structure inclined toward west occupies the head of the "Falling star". The sequence of the deforiinations of the complex is divided into three stages as follows; 1) Synkinematic stage I. The general trend of the structure of N 200 W with eastward dipping. 2) Synkinematic stage II. The southwkrd flow forming "Falling star". 3) Latekinematic stage I. The eastward upthrusting phacolithic sheets of granitic migmatite and its anatexites. 0shirabetsu Dome (Fig. 8 and 9) The Oshirabetsu doirLe locates the eastern part of the southern extreme region of the Hidaka meatamorphic belt and show a characteristic shape like "Falling star" on the surface plane which indicates quite resemblance to the surface pattern of the synclinal structure of the Pjpairo comp}ex in shape and sca}e. The core portion of tlae dome composed mainly of cordierite migmatite and is surrounded by the banded biotite gneiss. The dome with 3 km wide at the main "portion, extends to north-west forming the trail of the "Falling star" which reduces the width out within 1O kila witlit monoclinic inclination to etist. ' The structural stt}dy of tlae Oshirabetsu dome with special references to petrofabric analysis has been carried out by the present author (KizAKi, l956). Tlae rearrangement of the data with new informations having obtained since tl'ien, is performed for the present study on tliLe problem of the migmatite tectomcs. MIGMATITE DOME IN THE HIDAKA METAMORPHIC BELT 165 . .r i'f" i li - -- g gl,decgtsaG,.,. g, t- t '- -' i ' - - i li-' rw S,C.hlS5?.S" [IEEg Granite 4 . ss ------4 -- -E i [!IE] genefidisetd [ll:] Gabbro H s sc -- be8-- - - M CMOi6d.iSIit,e. .Rl6 Fotietionr . . ., xtw"twro va GMri8pk'ltlf,. .ut4s Llneatio ' ' pt pt sp))･,t --- Fautt ' ' ' epm " ew- "si'l･,:i,r',5,O,,i"tuar/1,f/i/,iik' l e """ :: ,,"･S¥･,/¥iscs -- -- -tt ･ ･ .igNr ･ ･' xfuss tw N N tuitb i - if- l IN s-N s tu. t tata ' pt, oo N-s" t'S re Nt !..di / N N"""l-t ewt45ljteess"#'gemstsi'g N /N " .kto ag#ogiE = 'km / kK. "e. - " ei- -eM N .. uatv..Sk ･ tw tl Fig. 8 Tectonic map of Oshirabetsu dome. Mt.o?.v.!.B.e,tiETsu ttttttttt ttt.tt. m N .,s"'l,, ''"l..'ii"･.,., "/;' looo l SW)1 1, $ssiilixigili ,,iS:sllli'/llsis?, zi2;tStlllli[(i'.N..N-moNi` e " le t.. oL i) ge" NE o >/-K : /N ij pm hla4 IX "P ':s httlittt:t;t Fig. 9 Cross section of Oshirabetsu dome. A gabbro body on the north-eastern side of the dome, separates the biotite hornfels zone distributed outsicle. Tlae linear arrangement of small granitic inigmatite sl/ieet occurs along the sl'ieared zone in the hornfels aureole. On the eastern side of the dome, the gabbro and g;anite bodies are separated by schistose b' iotite hornfelS accompanied with sheared zone and thrust fat}lt. The schistose biotite hornfels, banded biotite gneiss aRd cordierite migmatite which l66 I<. KIzAKL are separated by sheared zone are among the other tectonic units of the core of the belt on the south-western side. StructLl1'e Foliation: The foliation is defined in the above chapter. Then diagram in FigL}re IO shows one siilgle i'naximum Sl and great circle girdle including submaximum Sd. These signify that two sorts of structL}re are involved: Sl indicates the general trend of the metamorphic belt while the great circle girdle represents the foliation of the main portion of the dome on the south-eastern part. It is further clear in the B diagrain that a later cleformation is superimposed on the "Falling star" structure because two great circle girdles are crossed each other in Figure l 1. The great circle girdle whicla includes tlie maxiinuirk 61 corresponds to Sl while the girdle with 6d to Sd in whicliL the latter concerns the movement of the main dome formation in the later stage than the former which is the movement associated with the formation of the general trend of the belt. The superimposed deformation of the Oshirabetsu dorne can be separated from the earlier deformations of which the original monoclinic strt}cture and southward flow parallel to the general trend of the belt: the synkinematic stage I and II, is succeeded by the up-doming toward east-south east at the main portion: the latekinematic stage. The discrimination of the latekinenaatic stage from the synkinematic one is more certain in the ,OshirabetsuL dome area than in the Pipairo synclinal structure because of the shallower level of the tectonics. Lineation: The distribution of the lineation reveals the coincidence to the 6d girdle though there is an indication to the 61 girdle. It suggests that tlae inajority of the lineation could be orieRted clue to the doming that is at tl'ie latekinematic stage (Fig. I2). Deformation of paieosomes: Many paleosomes in the cordierite migmatite which shows the agmatic and schollen structures are scattered having the banded biotite gneiss and schistose biotite hornfels in composition. MaRy of them show various grade of rotational patterns iR shape (KizAKi, 1956), which suggest that the migmatite flows t}nder the elasto-plastic conditions of the almandine amphibolite facies so that the paleosomes rotate as the result of the differential flow of the migmatite. The rotational pattern of each paleosome, therefore, should represents the direction of the partial movement on the point where, the paleosome rotates and then the sum total of the partial movement, would configure the movement picture of t}ie dome. Actually, most of the paleosomes rotate on the plane normal to the lineation i.e. (ac) plane, while some do on the plane (bc) parallel to the MIGMATITE DOME IN THE HIDAKA METAMORPHIC BELT l67 IJfi N od ,C 1 ' -Arfx -Y .f,l,Ei '' - -- .,, Si s Fig, 10 7 diagram of Oshirabetsu dome. Si indicates the foliation pole of the general trend of the belt and Sd show's the foliation of tlie dome. N x wa rptxp, es- . .i£2･ al.. Pd '.ee :'l- -" '' ee e'":IB ': Lx.s... . ."-･-7rH-'- ..N ""ggtr y f s Fig. 11 6 diagram of Oshirabetsu dome. 6 pole signifies the general trend while l3d does the dome. l68 K. KIzAKI i･ N C; l. :. -. :. : l'.･--. .----: - .:: ,,. , ,ii i･i ,.g. ii'i. b .. ,, - ttt t. .tt :t. s Fig. 12 Lineation diagram of Oshirabetsu dome. ba pa,(11jsii'lf'f' nytzlz?iti c eckq,es `;t' 2ws )l･4, l･//, ,i.is {l??l,, i % i' i"1 I･I l. IN{' + i" l 1 :i,/1 : 1'1 l 1 " <･l f{ , Fig. 13 Triclinic deformation of paleosome. lineation. It is sometimes observecl that the rotations both on the (ac) and (bc) planes occLir on one specimen (Fig. 13). This is clearly superimposed structure which is also revealed by the petrofabric analysis (op. cit.). The distribution of quartz axes shows mainly (ac) girdle with symmetry to the b-axis but some tendency toward (bc) girdle which is believecl to be a relict fabric because the movement symmetry to the b-axis should be tlie result of the later and main doming upward. Therefore, the sequence of deformation can be clarified as to the earlier inoRocliRic structure from the later doine structure. Now, when every rotational direction of each paleosome is compilecl on the map of' its location, it is tliien foLmd that the direction of the rotation on each MIGMATITE DOME IN THE HIDAKA METAMORPHIC BELT 169 side is reverse (Fig. I4). It is therefore, evident that the center of the dome moves differentially up faster than tliLe ovter portion of it resuitii'ig in the rotation of the paleosomes. The direction of the tectonic transport of the clome is then to be Borma} to the b-axis, being about 40 degrees L}pward to east-south east. D ff DZ Sff4 %o, Dlf3N ,s'is' 1 slrsf sss sff S ss sSir s Fig. 14 Differential upward movement of Oshirabetsu dome due to the rotation of paleosomes. Configt{ration of Diapir It is now evident that the synclinal structure of the Pipairo complex aBd OshirabetsL} dome attribute to the same tectoiiic facies and style of which the reasons are as follows; 1) Shape is similar like "Falling star" 2) Scale is just identical each other: 3 km wide at the main portion and 10 km long, 3) Composition ls n'iigmatites of agmatic, schollen and nebulitic nature. 4) Direction of tectonic transport is toward south upward at the synkinematic . stage II and afterward turns toward east at the latekinematic stage. 5) Granitic migmatites occur on the eastern outside of the dome more or less. 6) Both are reiated to gabbro aRcl granite. 7) Southern end of the dome is bounded by overthrusting fault. Therefore, the structure can be comprized as a diapir of which the synciinal structure of the Pipairo complex should be the lower.level and tl'ie Oshirabetsu dome the upper level. The geological an{il structL}ral environments indicate the good accordance with it when the configuration is carried ,out as showR in the vertical section (Fig. I5). The structure is not the diapir sensu stricto but the embrionic stage of it, advanced pillow structure by TRusHEiM (TRusHmM, l960), evidenced by the latekinematic up-doming of the Oshirabetsu dome. As analysed in the above chapter, the so"th-east south movement of the synkinematic stage have turned upward in the direction oi' east-south east at 玉70 K．KiZAKi 、」｛ ）へ ∫ ∫鴫 ，一＿ ，’ 、 プ ∫ ’ 、 ’ ！ ノ ！ ＿ ∫ ら サ ！ ’ 、 ．ρ噛，．． ，・・，・・’・ r，幽，F，，．轟・畠… 幽・ ’’”ン 、 、 ” t ∫ ， ” 1 ノ ” ロ ∫ l 1鰯9．1 ， ‘ ’ ， t ， ’ 1 ’ 璽 ～ 1 し ノ へ 、 ’轡㊤夢 ～ 、』、、 夢 醗1穿．，、彦。．翻，。、∵．．，． ミ も ＿ PIPAI陵。し． ＿》＿＿．、 ’ 2 ・、・・一… пc”…層 ～、 ＼’Gr． 6、、婿夢幽 夢戯 6几く、 ＼ 、 、 搬穿多1夢 、＼＼、 ＼ 、、、、 、 、 Oo⑫ 。。 B 、、、 、 、 曳馬 Fig．15 Configuration of the dome in the vertical sectio王〕， 1玉8， 総． 、＝ボ・∴ f奮 訟llr・・ ●：｝ご．～智〆恥． “灘 ’・・ミ離 § く ’＼．’＆㌧◎ 覧、ノ 鵡■●魅 Fig．16 Three dimentiollal form of the dome． MIGMATITE DOME IN THE HIDAI Appendix The configL}ration procluces the three dimensional picture of the structure of "Falling star" that has 10 km long and 3 km wide at the main protion with 4km deep. Therefore, the volume ofthe "Fallingstar" istobe calculated approximately as 43.4 km3 . The upward velocity of the "Falling star" or cloine should be calculated by using the SToKEs'LAw without considering any other functions. 2 g･r(d'- d) V= g' n d' = 2.80: the average density of the sediments of the Hidaka supergroup, d = 2.73: the average density of the cordierite migmatite, r is the radius of the dome. n is the viscosity of cordierite migmatite that is the problem to be remained. If the n = 102 i 'is taken, the upward velocity of the dome shoL}ld be V = O.23 mm yr-i . The figure corresponds to the velocity of the epeirogenetic movement as well as the velocity of the diapir movement of salt mass by TRusHEIM (op. cit.). Therefore, it might be reasonable so far as it is coilcerRed. The upwarci velocity of the migmatite clome, however, shoulci be more than that figure because the value of it should be smaller than I02i due to the higher temperature of the core of the metamorphic belt and also the tectonic force should be another function to be considered. Acknowlecigement The author is grateful to Professor T. IsHiKAwA for his encouragement and helping throLighout the various stages of this study. [l]haRks are due particulary to his colieagues of Messrs H. TANAKA, K. NilDA aiid T. UDA for helping the preparation of the manuscript. References Cited HARLAND, W.B. (l956): Tectonic Facies, Orientation Sequence, Style and Date, Geol. Mag. 93,111 - 120. HiRoTA, S. (1963): Granitization in the Horoman District, Southern Part of the Hidaka Metamorp}iic Zone (1), Jour, Geol. Soc. Japan, 69, 82 - 98. HuNAHAsHI, M., HAsHIMoTo, S., AsAI, H., IGI, S., SoTozAKI, Y., KIzAKI, K., HiRoTA, S. and KAsuGAI,A., (i956): Gneisses and Migmatites in the Southern Extreme Region of the Hidaka Metamorphic Zone, Hokkaido, Jour. Geol. Soc. Japan, 62, I, 401 - 408,II,464 - 471, III, 54l - 549. HuNAHAsHi, M., (l957): Alpine Orogenic Movement in Hokkaido, Japan, Jour. Fac. Sci. Hokkaido Univ.6,415 - 464. KAwANo, Y. and UEDA, Y. (1967): K - Ar datiRg on the Igneous Rocks in Japan (VI) - Granitic Rocks, Summary --, Jour. Petrogr. Miner. Econom. GeoL, S7, 177 - 187. KizAKi, K. (1956): Petrofabrics of the Oshirabetsu Dome in the Southern Hidaka Metamorpkic Zone, Hokkaido, Japan, Jour. Fac. Sci. Hokkaido Univ. 9, 289 - 3l7. KizAm, K. (1964a): Hidaka Orogeny - A Type of Alpine Orogeny - Proc. Int. Geol. Congress, India, Section 11, 1 - l6. KizAKi, K. (1964b): On Migmatites of the Hidaka Metamorphic Belt, Jour. Fac. Sci. Hokkaido Univ. 12, 111 - l69. ToNozAKI, Y. (1965): Studies on the Hidaka Metamorphic Belt of the Southern Hidaka Mountains, Hokkaido, Bull. Hokkaido Univ. Education, 13 , 1-98. TRusHEiM, F. (1968): Mechanism of Salt Migration in Northern Germany, Bull. Am. Assoc. Petrol. Geol., 44,1915 - 1940. (Manuscript received August 31 , l971)