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1-kptl,P:,',s4ts. (2ooolr-} EarLh Sdence23---32(Chikyu Kaguku) vel. 5･1, 23 32, 2C)OO 23
Petrofacies on sandy deposits of an ineised-valley fill: Upper Pleistocene in the Makinohara Upland, Shizuoka, Japan
', "and '** Yasuhiro Takashimizu Fujio Masuda Masaaki Tateishi
Abstract The Makinohara Upland, cenrral west Shizuoka Prefecture, central Japan, faces the Suruga Trough, which is formed by the subduction of' the Philippine Sea Plate beneath the Eurasia Plate. The Upper Pleistocene of the Makinohara Upltind consists of incised va[ley fi11s, which comprises a depositional sequence, Cempositional trends of the sands from the Makinohara Upland area (Makinohara sands) are p]otted in the Lt-rich field, w'ithin the lithic recycled-transitiona] field of Dickinson and Seel)' (1979) and Dickinson et al. The sands (1983). of the Makinohara Upland area ttnd Kanto area show mineralogically immature trend than those ot' the U,S,A, (continental area), The Makinohara sands are deposited in fluvial environments during lo-'stand and highstand periods, and regpectivel}, has,e dfl'erent plots on Qm-Fl-Lt and Ma (grain-size) versus Qml(Qm+Lt) diagrams, The sands ot' the LST mostly have high Qmf(Qm-+- Lt) ratios (",ell niatured), and those of the HST have Iow Qm,/' (Qm+Lt) ratio (poorly matured) , The sands of tsunami deposits, which sN'ere deposited in a barriersand body and a drowned valley environment of Makinohara Upper Pleistocene. are plotted in differentfields on the diagrams ofMa versus Qml(Qm +Lt) . Those deposited in the drowned vatley contain more monocrystalline quartz ; those deposited in the barrier sand body contain more lithic fragments, The drowned- valley tsunamiite is plotted in a similar fietd to the drowned valle}･ deposits. The tsunamiite in the barriet sand body is plotted En a similar field to the barr{cr sands and beach-shoreface sands. Relationships of grain-size characteristics and Qml' (Qm+Lt)plot do not show un>･ clear correlation.
KqJ words: detrital mode, incised-valley fill, Makinohara Upland, mineralogical maturity, petrofacies, tsunami depesits
souree area and tectonic setting of the Upper Pleistocene Introduction in Lhe Makinohara Upland, Shizuoka, Japan. Character-
Japan is located in an activ･e plate inargin. Man}' istics of the mineral composition and its relationship
studies of mineral and chernical compositions of sands with grain-size in the Upper Pleistocene sands of Ma- and sandstones hav･e been done to e]ucidate provenance kinohara IJpland, which are c()nsidered te have been
terranes (Kiminami et al. {eds) 1992), The relationships deposited in N,arious sedimentar}' environments, are de-
between depesitional environments and sand composi- scribed in this paper. This study aims at explaining the tions, has also been studied by many researchers (e.g,, sand characteristics on mineral compesition of incised- I)aviesand Ethridge 1975; Ito and DLilasuda 1987, 1989; va]Iey fi]Is that these do net clarify how petrofacies et al. 1991; Murakoshi Sakuraiet al. 1994; Critelliet al. changes, and the difference on petrofacies between lew- 1997). These studies has,e clarified how differentde- stand and highstund period. Moreov･er, the petrofacies of positional environments influence spatial ancl temporal two tsunamiites that were discovered from clrowned
variation in sand conipositioris. valley and barrier deposits were clarified, Sand compositions were studied to elucidate the
Received July 1,1, l999. Aecepted Deceinber 16, 1999. *Graduate School of' Seience and Technology, Niigutu Univcrsity, Niigata 950'2181, Japan, * ± Department of Earth Planetary and S¢ iences, Graduate Schoo[ of Scicnce, Kyoto Universily,Kyoto 606-8502, Jupun, "'Department of' Geology, Facult), of Seience, Niiguta University, Niigata 950-2･ l81. Japan.
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24 Yasuhiro Takashimizu, Fujio rv'[asudaand DvTasaaki Tateishi
Geological framework and stratigraphy DEIii$iiliiN]uvialMeistoeenesediments
N The Makinohara Upland, in central to western Sbizu-
oka Prefecture, central Japan has a length of 20 kilo- TerdarySystems N+G'1･-.tttt'b:.･･,./,.' meters frQm north to sQuth and a width of 10 kilometers ''･o･'.o'.1ny''.qrb'o･･-d,"O,b.'P,-,..q...1/..tt6....;.t.../,,. ShimantoBelt Nie.'tt6･?,'f'i" from east to w･est. It faces the west coast of Suruga Bay EE]E][Il]N :.tttt/t //.,;1.･1･ (Figs. 1, 2),a marinc trough formed by the active sub- ChichibuBelt
duction of the Philippine Sea Plate beneath the Eurasia Sanbagawa-MikabuBelt nt, k-o..e..,'s-dv/."tt-o,'･p･tt/d.D･･9,m/d,'P,g･･Q･o',.q''.･b'･P.1･6I,,,'e'P,gn''j'tt''.q･.q/.･･tt.o.'p,o.',･.o.'Q'P.'o'.ool-d"''/o'/lq'1.,.9'-b,.c,'1.e.1,bp',･,o･b.'p.･'･Pp'1ttg･geptut'ittttt/.tt/t''/1'/:"'/''tt''/t:ttt1tny.ttttltt.-t-･1,･,･1･:1･･tittttttve""pttt/ttttti"-''1･l,･!.o,//,rJ.'''"'."m':"'･tt.r':,･･･-tt11:1i:lii'/111'!/.,, Plate (e.g., Sugimura 196e),
s+.,e..nb,.6Pii,,･,o/,b.,'q'','9b･,.c'.P'''p,'..･'lq'''.o'･'a'･"F･lb･[･9'･･,b･l The stratigraphy and paleontology of the Upper I'leis-
tocene of the Makjnohara IJ'pland have been well 'se,e-"s･.eeS"'/O,'/ documented (e.g., Makiyama 196], 1963; Tsuchi 1958, ttttlottt.?･'glb'ottt l960; Osada 1980, 1998; Ikeya and Horie 1982; Sugiyama
et al. I988; Nirei and "Jatanabe 1990). The basements of ,N..s ,s.'q''･ this Upper Pleistocene eonsist of the Neogene Sagara tes.o'P ts-.si･--. Group and Kakegawa Group fonning fore-arc basin fi]1. nub"'/o'/ This is the place where the Philippine Sea plate goes 35dN..'E"ti.lobttttt.tio･ttloP...'6''''' down under the Eurasia plate, and keeps upheavjng at .,.g. tt'o.''.,,･619'?.･ts/o/tttt'o'ttt.t''SumgABa or Q･'･'.O.･b'9,p',o'.el･o･''',o' present, too. IIinterlancl of the )'Iakinohara Upland is
composecl mainly by Shimanto Super Group .p.･/tt'tttttttt ('`Shimanto z..--"-.l/ig<..,,,/1.,di. Belt" in Fig. O. tttt/tt//tttttttttttt/t/ttt,,/,.Qoiruver The facies consists of the Upper Pleis- succession /t't/ttt''li'/1'.,/.'ssMakinoh tocene deposits, which unconformabl.v overlie a Mio-
Pliocene forearc basin fill, consist of incised valley fill m"oO '' and shallow marine ancl fluvial deposits formed during a Upland n- single transgressive-and-regressive cycle (Sugiyama et
aL et al. are 1988,Takashimizu 1996).These deposits Fig. 1, Index map of the study area, Makinohara Upland,
classified into three formations, in ascending order] Shizuoka Prefecture, central Japan.
Furuya Mud (Tsuchi 1960; Ikeya and Horie 1982), Kyomatsubara Sand (Osada 1980; the equivalent of the Methods lower part of the Makinohara Gravel of Ikey･ a and I'Iorie 1982) and Makjnohara Gravel (Watanabe 1928; Takashimizu et al. (1999) clarified grain-size charac-
Sugiyama et al. 1988) . The Kyomatsubara Sand is absent teristics of sandy deposits from the same Upper Pleis-
in the northern part of the upland. The Ochii Gravel tocene of the Makinohara Upland. In the present study,
samples referred result of (Sugiyamaet al. 1988), a correlative of the Makinohara we used the same sand and its
Gravel, is restricted in the southern area (Sugiyama et grain-size analysis. A total of 160 samples were collected
al. 1988; Takashimizu et al. 1996), The Upper I'leis- from sandy beds on all of the studied outcrops except for
tocenedeposits in-fi]1 two paleo-valleys (Tsuchi 1960; the locality E, where sand beds poorly crop out. Sarnple Osada 1980; lkeya and Horie 1982). Takashirnizu et al. locations are shown in Fig. 2, and sample horizons are
(1996) studied the depositional facies (major lithology indicated on the left side of the measured sections in Fig.
and inferred dep6sitional environments are summarized 3. The samples are from the sandy beds of the following
in Table 1) ancl sequence stratigraphy of the Upper facies; lo"'er shoreface (25 samples), upper shoreface
Pleistocene and identified four depositional systems. (24 samples), beach (7 samples), fluvial (7 samples),
These are drewned valley, estuary, beach-shoreface and estuary mouth bars (10 samples), drowned valley (6
alluvial s},stems (Table 2). Moreover, two tsunami samples), bay floor (5 samples), barrier (re]ict barrier
deposits were discovered from the drownecl valley fill and tidal inlet): (16 samples), bay-head delta (18 sam-
and barrier sand body (Takashimizu et al. 1996; Taka- ples),alluvial facies (11 samples) and tsunarni facies (31 shimizu and Masuda 2000, in print) , samples) , (24)
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Petrofacies on sandy deposits of an incised-valley fill' Upper Pleistocene in the Makinohara Upland, Shizuoka,Japan 25
7 North 1 g"ean 'M :
/
l380 00' E 100km
il1'
L ･-1
Iiil Holoeene '
Kasana & Omaezaki
ewtttterrace deposits Malcinoharagravel
lli IIIOohii gravel
ew Kyoumatsubara sand
- Furuya mud i' Basements
Location ef iO/ Outcrop
Fig. 2. Geological map of the study area, Makinohara Shizuoka Prefecture, central Japan, A to J are lucations of outcrops described in Figure 3,Upland,
Samples were treated with epoxy resin and made into Results and discussions thin sections, and 20e-point counts w･ere made for each
section using the traditional method and Gazzi･Dickinson Qm-FI-Lt diagram method (Gazzi 1966; Dickinson 1970; Ingersoll et a!.
1984). The traditional method only describes the rela- Qm-Fl-Lt diagrams for each depositional facies of the
tionship between the grain-size and the mjneral composi- Upper Pleistocene sands in Makinohara Upland are
tion, but the Gazzi-Dickinson method has an advantage shown in Fig. 4 together with published data from the
to decrease the influence by grain-size. The minerals Pleistocene sand$ in the Kanto ancl 0saka areas. were divided into three categories, monocrystalline The Pleistocene and Holocene sands of river, shal]ow quartz grains (Qm), total feldspar (Fl) and total lithic marine, and barrier facies from the Kanto area (Masuda
fragments (Lt), The observed feldspars were identified and Ito 1988; Ito and b'Iasuda 1989) have a broad
using the staining method of Bailey and Stevens (1960), compositional fielcl in centrast to those of the rvIakino- {25}
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26 Yasuhiro Takashrmlzu, Fuiio Masuda and MasaakiTateishi
Table 1. L)escription and interpretation of the'Fakashimizu individual formatiens ef Upper Pleistocene deposits in the ]L･{akinohara Upland. Summarized from et al. 1996.
Area FormationThickness Descri tien Inte retation MakineharaGravel 3e-4emPoorly sorted gravel with trough eross- Giavel-dominatedbrajdedriver stratification,poorlysortedrnudandsi1ty gtsE sand with inverse graing stuctures
FuruyaMud <20mPoor]y sorted silVs"ty sand with roottet and delta, Bay fleor E ptant ftagments. poerly sorted siltisilty sandBay-head MakinoharaGravelISt40mPoorly sorted grave] with trough cross- GrEvel-deminatedbraidedriver stratifieation,poorlysortedmudandsilty sand with inverse graing stuctures
g KyomatsubaraSand qomBuTrowedibioturbatedfinelsi1tysand,wel1 Relietbarriersandbody.Tida1 tsMvp-E sorted fine to coarse sorted sand and granlllesinlet,Uppershoreface withmudrapes,heningbonestructuresand combincdfiowrjpples
Furuya Mud <25mPoor]ysortedsiltisiltysandintercalated Gravei-dominatedbraidedriver. pebbles, poorEy sorted pebbles End eobb]es Estuarymouth,Drownedvalley,
withtroughcross-stratification Bay floor Ochiigravel 5m Alternationsofwellsortedcoa[sesandsandBeach granu]eslpebb[es
g Kyoniatsubarasand IS-20mWe]] sorted fine sand with HCS, a]ternations Lowershoreface,Uppershoreface g8 ofsandsandgraveiswithplannertotrough cross-stratificationandwaveripptes
Furuyarnud <20mPoor]ysortedsilVsi1tysandinteTcalated Gravel-dominatedbraidedriver, pebb]es, poorly sorted pebbles and cobbles Estuarymouth,Drownedval]ey, withtroughcross-stratification Bay floor
hara area which have a narrow compositional field De ositionalsstemsDe ositional faciesS stems tracts DrownedvalleyGTavel-dominatedbraided LSTTSTTST dominated by total lithic fragments (Lt), The Pleis- Estuarymouth tocene river and shallow marine sands from the Osaka Drownedvalle tsluary Bay floorBanier(relictbaniersandTSTandHST area et al. 199,O have a compositional (Sakurai fielcl TST
intermediate between those of the Kanto and Makine- body and tida1 inlee Ba -hcad derta HST hara area. Beaeh-shorefaceLowershoreiace TSTandHST Cornpositional trends of the Pleistocene sands from UPpersherefaee HSTHST Beach Makinohara Upland plot are plotted in the Lt-rich field, A}1uvial Gravet-dominaredbraidedHST within the lithic recycled to transitional recycled of
Dickinson and Seely (1979) and Dickinson et al. (1983). Table 2. Depositional systems, facies and systems tracts of Upper Pleistocene in Makinohara from The lithic fragments of these sands in the Makinohara LJpland.Sumniarized Takashimizu et al, 1996. LST: Iowstand systems tract, TST; Upland are almost all-sedimentarv rocks, with a few trttnsgre$sive systems tract, IIST: highstand systems tract. metamorphic rocks and minor volcanic and plutonic rock fragments (Fig. :r)).
(QmtLt) ratios than those from of U.S.A., becau$e the on Maturing petrofacies `immature' former sands were deposited in an volcanic-
The mineralogical maturit}, of the sands from the arc region (Fig. 2), and the latter were deposited in a
`mature' Makinohara Upland area (referred in this paper as continental area (Ito 1992).
Makinohara sands) was compared with those of the Although both Makinohara sands and the sands of the
Kanto (Ito and Masuda 1989) and the U.S.A (Dav･ies and Kantu area were deposited in river to shallow-marine
Ethridge 1975) using Qml(Qm+Lt) versus Fl/(Qml- environments, the Makinohara sands are less mature and
Fl+Lt) plots (Fig, 6). The Kanto and U,S,A, sands were include more lithic fragments than the sands of Kanto
extracted from IIolocene rivers (Kokai river, Kanto area (Fig. 4). The Makinohara sands are alse plotted in area, Japan; Mississippi river, U.S,A,) and barrier sys- a narrower field than the Kanto sands (Fig. 6). These
tems (Paleo-Tokyo bay barrier system, Kanto area, differences are considered to reflect differences in the
Japan; Galveston barrier complex, U.S.A.). Makinohara geology of the basements and hinterlands, the size of the
sands and the sands of Kanto area show lower Qmf basins, and the distance from the source areas (catch- (26)
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Petrofacies on sand}, depesits of an incised-valley fill : Upper Pleistoccne in the Makinohara Upland, Shizuoka, Japan27
om･'ASB 97m BsB G H oooALLUVtAL t2omC SB 149m SB 86mt39135 ooooooooooooooooooooOooooDoODooQ ooOooDOO oo di ;1 tt-t-.i I oosgo.N,,. 3025't.20 t25 diicreElo!\EALLUVIA RSHeRE--FACELOOROWENOALLEVTUARYUTHVIAL BEACH .GqY.M.eco-e'VPPEHSHORE-- ooooOOQooDOOoooooolee-- F･:'tC!L'.ttt'ttt:t]'P2':'LowEnSHORE-.FACEMFS-FACE ooQooQ l eAnRIEnpmPALINLET) IG :,,:.':scv(:MFSSB l. OROWNEOVALLEY tne , -x2977-1osco . =･m'' 8mDooooooJooogeoooEoooeooEooofooo9oooyooo{oooODODSB ISIm FSB 75. oooooOC)Dsgg 37 I.･x･io DDOOOQ'BAYFLOOR di ALLVVIAL ;:: q th l sg 7e t46.145.t4065m UPPERsHonE･ o MFsBDROVVNEOVALLEYESTUARYMOUTH. o8eBAY.HEAb35. FLoon dit ALLVVIAL . sEs2L "eAy l;katk"-FAcE sssu g"J Cttdy,1LowEtssHORE- DROWNEDVALLEY ''# FMberMFS-FAcE dit isl･2 sBDRgAwYN?DevOARLL 65 .45 ttt DELTA31 D･tt.t'･,･･FLVMAL '' ESTUARYMOUTHFLUVfAL ' f aoE<'DorifsBAY eo SB 393e.N BAY-HEADDELTA E- FLOORrSVNAMI Eo" E- 4e' onowNEoVALLEY Fig. 3, Facies successions of the Upper Pleistocene jn the Mal{inohara Upland. A to H are localities shewn in Fig. 2. Numbers un the top'Ieft ef cotumn show elevation. Number and symbol, e on the left side of the colurnn shows sample number and sampling horizon, SB: sequence boundary, MFS ; maximum flooding surface. For details of correlution between each columns, see Tukashimizu et al, 1996. Note, due to the poor quality of the outcrops, no sumples were extracted at locality E. ment areas). The Makinohara sands are considered to (Qm+LO (Fig. 7a) diagrams. The sands deposited dur･ have had narrow a source area (anarro;v catchment ing the lowstand period mostly have high Qm/(Qm+Lt) areas) consisting of sedimentary rocks of the Shimanto ratios (w･ell rnatured), and those deposited during the Super Group ancl the Neogene basements of the Sagara highstancl period have low Qmf(Qm+Lt) ratio (poorly and Kakegawa Groups, which consist of immature sand matured) . Tal{ashirnizu et al, (1996) has showed that the 4). In (Fig, contrttst, the Kanto sands are considered to rivers of lowstand period were incised into the Tertiary have had a broad source area (a broad catchment areas) , basement and that the rivers of highstand period forms a which consists of Paleozoic to Cenozoic sedimentary, part of a large prograded alluvial fan. The sand composi- volcanic, and metamorphic rocks, tions of Sagara and Kakegawa Group show sirnilar mineralogical composition, which is near for the LST Difference between LST and HST river sands of Upper Pleistocene (Fig. 4) . Therefore, the fluvial sands on petrofacies LST riv･er sands are interpreted to have been derived The Upper Pleistocene of the Makinohara Upiand frorn the Neogene sediments of the Sagara and Kake- contains sands, which were deposited during lowstand, gawa Group that, in general, contains few metamorphic through transgressive to highstand period. Sand samples, rock fragments. The HST river sands were derived from in particular, from lowstand systems tract (LST) and the feldspathic and lithic arenites, and volcanic rocks of highstand systems tract (HST) have different plots on the pre-Neogene Shimanto Super Group, and they con- Qm-FI-Lt (Fig. 4) and Ma (grain-size) versus Qmf tain metamorphic rock fragments. They were derived (27) NII-Electronic Library Service The AssociationfortheGeologicalCollaborationAssociation for the Geological Collaboration in JapanJapan{AGCJ) (AGCJ) ']"als'cashiinizu 28 Yasuhiro Fuiio),Iasudaand 1･Iasaaki Tateishi D lowershoreface - bay iloor A uppershoreface i barrier(tidal inlet) O beach X re]ict barrier sand body × fiuvial(IS't) # bay-headdelta Qm Qm Qm e fluvial(HsT) N tsunami deposits it] drowncd valley " estuurvmouth ' t tsunami deposis inbarriersandbody V drownedvalley > Kukegawa/SagaraG. F ･･ Area M !.ny# lt nai ccled x es NN vv /･/E # Fl Fl t-- Lt Lt Lt Lt lt Fig. 4. Qni Fl'LL plots for rhe (Jpper Plei.t'tocene snnds deposited in thu A'lal{inohara Upland. [['he ?L'lakinohara sand doinin;ttes iTi Lr cen]pared "'ith the Os.aka a"d the Kante sand. from longer distances compared with the river uf LST b}' clerived t'roin near bv environments and have not to have "Paleo-Ooi ". Rix,er (Sugiyama et al. 1988) The different beell experienced a long distance transport from differ- characteristics of the LST and IIST river sands reflect ent ellv･lromneTlts, their different origins and the characteristics of rivers Grain-size characteristics versus that deposited them. mode composition Petrofacies of tsunami deposits and its origin Relationships of Ma versus Qm,/(Qm+Lt) and SGM The Makinohara sands contuin tsunannites deposited versus Qm,' (Qm+Lt) are shown in Figs. 8a and b. This in a barrier sand bod},and a drowned valley (Takashi- plot does not show any clear correlation between grain- mizu et al. 1996; Takashimizu and Masuda 2000, in size characteristics and mineralogical niaturing of the print) , They were p]otted in different fields on the dia- sands, For example, mineralogical maturity (Qml(Qm+ grams of Ma versus Qm,/ (Qm+Lt) diagrams (Fig, 7b). Lt) value) does not show particular values on arbitrary Those deposited in the drowned valley contain more grain-size and, the data plots are scattered. 1'he correla- monocrystalline quartz; those deposited in the barrier tien coefficient values of Ma-Qml(QmtLt) and SGM- sand body contain more lithic fragments. The drowned- Qm/' v･ alley tsunamiite was plotted in a field similar to that of Tuble 3, The sediment of beach and bay floor shows the drom,ned valley deposits, The tsunamiite in the bar- comparatively high correlation coefficient values; how- rier sand body was p]otted in a field similar to that of the ever, most sediment shows low･ values. barrier sands and beach-shoreface sancls, These relation- The results support that grain-size characteristics and ships suggest that thc two types of the tsunamiites were mineral composition have no clear relationship in the divided from different source sediments. However, both Makinohara area. It is considered that the transporta- tsunamiites show･ similar plots compared with the sands tion distance of sediments is not far enough owing to the that were deposited from close environments, Therefore, sma]l sedimentarv basin and the variabilitv of source both types of tsunamiites are interpreted to have been geology. "'Ioreover, the other reason for the low correla- (28) NII-Electronic Library Service The Association for thetheGeological Geological Collaboration min JapanJapan{AGCJ) (AGCJ) Petrofacies on sandL of an incised foalle} depostts fillk pper Pleibtocene in thc NIakinehara UpldndShizuoka Japan29 Fig 5 Photomicrograph of the Upper P!eistotelle sands of the Makinohara Upland a and b Ihe tsand deposited in lo"er shorefaLe envronmLnt ocalit} A) (I c dnd d The sancl depobited in fluLidl enwionment (Lecilit} A) Cemposmonal trendg ±or the Makinehara Lpldnd sands are dommated in hthie fragments tion between grain size Lharacteristics ("vld and SGM) those of U S A (continental area) and mmeral maturit} (Qmf(Qm+Lt)), is mterpreted ag 3 Mdkmohara sand deposited in fluvial envron the rneasured sands have fe" a Iargesized pdrticleband ments durmg lo-stand and highqtand periods hds gho- ts rock fragment r]ch composition although we used different plotg on Qm Fl Lt and Ma (grain si7e) the traditional method for counting the mineralg without versus Qm/' (Qm+Lt) GazziDickmson rnethod 4 Sands depositecl in fluval env]ronmcnts during lo"gtand penod mostlN haie high Qm!(Qm+Lt) Conclusion ratios ("ell matured), and those of highgtand Sand composition and grain size of the Lpper Pleis period haxe low Qm/(Qm-Lt) ratio (poorly tocene in the Makmohard Upland drc described and matured) clarified ds follo"s i 5 Tsunamiites deposited in a bdrrier sand body and a 1 Compositional trends for the N{akinohard Upland dro"nedxalleyenvnoilmentpiotindiffeientfields sands sho" in the Lt nch field, withm the 1ithic on the d]agrams of Md veisus Qrnt(Qm+Lt) recycled to transitionalrecvcled of Qm Fl Lt dia diagrams Those deposited in the drowned iallev gram bN Dickinson and Seel) (1979) and Dickm Lontam more monocrygtallme quart7, those de bon et al <1983) posited in thL barrier gand body contam more 2 The Malqnohara sands dnd the sands of the Kdnto ]ithic fragments The dro" ned valle) tsunamiite is area sho" minerdlogically immature trend than plotted m a similar field to the droxkned valle) (29) NII-Electronic Library Service The Association for thetheGeological Geological Collaboration in JapanJapan{AGCJ) (AGCJ) 30 Yasuhiro Takashimizu, Fujio Masuda and Masaaki Tateishi ･-7 ------eoe---!--- deposits. The tsunamiite in the barrier sand body ''ttl'tfJ AMaltineharaarea oKantoarea is plotted in a similar field to the barrier sands and mUSA -1 beach-shoreface sands. ,3 'IItl1ttto eooooo2eg -t----e'-.--Vda, ooegee,eOoBeOoooe" 6, A relationship of arithmetic mean values of grain- oooo size and Qm/(Qm+Lt) plot cloes not show any tttt clear correlation between grain-size characteris- ee 88 Xsees,x' .29 tics and mineralogical maturing of the sands. tf..Xoooooe ---s- ibooeoco e,Ofuooooooooe8o 'Fhe results described here are an example for the goo"o&oe :1xi-x, petrofacies and grain-size characteristics of a small lt. `immature' 9- Zo2beo% basin fill, and represent sand cornposition m .1 o%eeA eLbdiASk.eoooooterloooo-t-e-t" x,3aom trends on an active margin. oo------o------o3N...a--- plate Acknowledgments e "ie thank Dr. R. W'. Gallois (British Geological Sur- O ,1 2 ,3 .4 .5 .6 .7 .8 .9 1, vey) and Mr. 1'ad J, Choi and Mr. Chris Y. Anani Qml(Qm+Lt) (Niigata [Jniversity) for editing the English version of Fig. 6. Maturity of the sand of rvTakinohara, Kanto and USA this manuscript, arcas. Kanto and USA data are adopted from Ito and )v'Iasuda (1989) and Davies and Ethridge (197t)), ),Iakinohara sand is References iminature compared w･ith Kanto and USA sand. Bailey EH and Stevens RE (1960) Selective staining of K-feldspar and plagioclase on rock slabs and thin sections. Ma (PHI) 1.oo 2.oe 3,oo 4.oo O.04'OO × fluvial(LST) O.3 Q fluvial (HST) ... 1' D beach-shoreface v drowned valley O'o1g.O,2 i barriersandbody tsunami deposits in as drewnedvalley oO.40 v tsunami deposits in t @ barrier sand body v O,30oA+eo, [tsrfNv O.20vlia mo Fig. 7. Plot dingram between grain- e mav size and minera]ogical maturity. a) Sand O.10 deposited in f]uvial environment during nyot igfMD lowstand and highstand periods. B) Sand of the tsunami deposits and its o.oo close environinents (beach-shoreface, o.oo 1.00 2.00Ma 4.00 estuary mouth, drowned valley and bar- (PHI)3,oo rler sand bod}i (30) NII-Electronic Library Service The AssociationforAssociation for the Geological Collaboration in JapanJapan{AGCJ) (AGCJ) Petrofacies en sandy deposits of an incised-valley fill :Upper IJIeistocene in the Makinohara Upland,Shizuoka, Japan31 O.5 @r=O,39 @r=-O,13 O,5 v y Axt[kwt "xAXomp hza × × 2.o.2s :igo,2swNsEi ". A mp g o x × @oo#eo# tsxU4u Mt]th.g".t5El#A x sllYtAio# g O o "bA･ k#t # ott Ol 2Ma 4 O,2 O,6SGM1 1.40 (PHI)3 O lower shereface " e$tuary mouth X relict barrier sand body A upper shoreface V drowned valley # bay-head delta O beach e bay floor li tsunami depesits in drowned valley × fluvial A barrier (tidal inlet) t tsunani depesits in barrier sand body Q fluvial Fig, 8. a) Plot cliagram between grain-size (Ma) and mineralogieal maturity. b) Plot diagrain between grain'size (SGM) and mineralogical maturity, Both diagrams do not show any clear correlation bet",een grain-size characteristics and minera]ogical maturing of the sands, r: correlation coefficient value. Table 3. Correlation cuefficient values of each depositional envlronment. ･31.Dickinson Ma vs SGMvs WR, Beard LS, Brakenridge GR, Erjavec JL, -lowershoreface Ferguson RC, Inman KF, Knepp RA, Lindberg FA and .O.25O.04-O,82O,71O,12O,59O.07-O.96-O.36O.7SO,31e.15-O.28-O.37O,66e.6o-O.09-O,68-O.22rO.16O.08-O.79O,22O.14 Ryberg PT (1983) Prevenance of North American Phaner- uppershoreface ozoic sandstones in relation to tectonic setting. Geol Soc beachfiuvial(LSD Amer Bull, 94i 222T235, Gazzi P Le arenarie del flysch sopracretaceo dell' fiuvial(HST) (1966) Appenn{no modenese Correlazioni coni flysch di Mongh- estuarymouth ; drownedvalley icloro. pt{iner Petrogr Acta, 12: 69 97,"" bayfioorbanier Ikeya N and Her{e Y (1982) Sedimentary environments of (tidal inlet) the Furuva Formation CLate Pleist.ecene), Shizuoka Pre- relict baTrier sand bedy fecture,Japan.Daiyonki-Kenkyu(QuatRes,Japan),21:75 bay-headdelta -93.,*Ingersoll tsunami de osits in banier $and bod RV, Bullard TF, Furd RL, Grimin J P, Piekle JD all sarn les 039 -O,13 and Sares S "' (1984) The effect of grain size on detrital modes: A test of the Gazzi Dickinson point-counting method. Jour Sed Petro], 54: 103-116, iXmer Mineralogist, 45: I020 1025. Ito M (1992) Temporal s,ariations in sand stone from circum -Paeif{corogenicbeltsandtheirrelationtoglobalenv{ron- Critelli S, Pera EL and Ingersoll RV (1997) The effects of source !ithology, transport, deposition and sampling scale mental changes. Mem Geol Soc Japan, 38: 345, 359. on the composition of southern California sand. Ito M and Masuda F (1987) Detrital mode and size-distribu- Sedimentology, 44: 653"671, tion of the Late Pleistocene I'aleo Tokyo Bay sands, Davies KD and Ethridge FG (1975) Sandstone composition Japan. Ann Rep, Inst Geosci, Univ Tsukuba, no. 13: 83-86. and depositional environment. Amer Assoc Petro] Geol. Ito M and Masuda F (1989) Petrefacies of Paleo-Tokyo bay Bull, 59: 239-264. sands, the Upper Pleistocene of central Henshu, Japan, In: Dickinson WR (1970) Interpreting detrital modes of gre- Taira A and Masuda F (eds) Sed{mentary facies in the .vwaeke and arkose. Jour Sed Petrol, 40/ 695-7e7. Active }'Iate rvlargin. Terrapub, [L'okyo, 179-l96. Diekinson "'R and Seely DR (1979) Structure and stratigra- Kiminami K, Kumon F, Musushino M, Okada H and Shiki T phy of forearc regions. Amcr Assoc 1'etrol Geo] Bull, 63: 2 (eds) (1992) Composition and {)rigin of clastic rocks from (31) NII-Electronic Library Service The AssooiationAssociation for the GeologioalGeological Collaboration in Japan (AGCJ)（AGCJ ｝ 32 Yasuhi1℃ Takashi1τlizu ， Fujio Masuda and Masaaki Tateishi mobile ： cxamples 〔｝m the belts fr Japaneseis！ands ，Mem ． and petrologicalfeaturesinJapanand itsenvir 〔〕ns ．Jour Geol Soc 3S； 401p， Sect 2 12： 133153 Japan， Fac Sci，UnivTokyo ， ， ． Masuda F and Ito M （1988）Evoluti〔エn of sandc 〔＞mpesitioll m Takashimizu Y ， Sakai T and Masuda F （1996）Depesitional Kanto District、 central Japalユ． Anrl Rep 工nst Ge （〕sci ， UDiv facies and sequence of the Upper Pleistocene in Makino − Tsし1kuba ，14； 39 41 hara Upland， Shizuoka， Japan． Jour Geol Soc Japan，工02： t ± Makiyama J （1961）Geological map of thc Kakegawa dis． 879 893． trict at 1；50，000， Geol Surv Japan． Takashinlizu Y ， Masuda F and Tateishi M （1999）Grain−size ． Makiyalna J （1963）Exp ［allatory text of the geological Inap characteristics of sandy deposits of an incised valley fil1： ＊ ＊ of Kakegawa district． Gcol Surv 30p、 Pleistocene the Upland Japan， Upper in Makinohara ，Shizuoka， Murakoshi N ，Ito M and Masuda F （1991）Grain ana ［ysis of Japan． Jour Geo1 Soc Japan，105； 112 ． the sand deposited inPaleo TQkyo Ba ｝ area ． JourSed Soc Takashimizu Y and Masuda F （20｛｝O） Deposit｛onal facies − − ・ Japall， r］o ．34： 143 147， and sedimentary successions of Earthquake induced Tsu Nirei T alld Watanabe M （199 Fossil p〔〕llen assemblages nalni Deposits in Upper Pleistocene Incised Valley Fills， of the Furuya mud bed in Shizuoka， Prefecture， CentraI central Japan． Spec 王ssue Sed Geol， Elsevier．（in print） − s ’ ・ Japan， Jour Iliraoka Ellvir Sci Rep，3：65 74． Tsuchi R （1958）Pa ！eo ecolog ｝ of mollusca in the Pleis− ． ． Osada T （1980）Evolution〔〕fthe ：vIakinohara upland Shizuo tocene Furu｝a Mud ， Shizuoka Prefecture， Rep Lib Arts＆ 一 ka prefecture ， Japan， Daiyonki Kenkyu （Quat Res， Sci Fac ， Shizuoka Univ， Nat Sci，2：121 工28． ＊ ＊ Japan），19：1 14． Tsuchi R （1960）Geologic history ofthe Quaternary Forma・ Osada T （／998）Geological and geomorphoiogical s 加 dies〔｝f tions ill the Iower drainage of thc Oi river ， central Japan． ・ − ＊＊ the Middle to the Upper Quaternary neal Makirlohara Jour Geol SQc Japan，66： 639 653． ⊃ − Upland ， Westcrn Shizuoka Irefecture ， Cclltral Jap乏m ln Watanabc H （1928） Diluvium upland of Soudl Akaishi relation to the − Tcrrace Formationand Sedimentation n ユountainlands （summary ）．Jour Geol Soc Japan，35： 368 ＊ ＊ ＊ Monograph Assoc Geol CQII Japan，40；78P， 369． Sakurai M ， Masuda F， Okumura K and Yokokawa M （1994） − ’ Sand colnp 〔〕sitioll of the Pli〔｝ Pleistc）cene Osaka Gr 〔｝up ：A in Japanese 本 ＊ ＊ preliminary note ． Jour Sed S 〔，c Japan， no ．40： 16 ． h／ Japanese with English abstract 楙 Sugiyama Y ， Sangawa A ， Shimokawa K and Mizuno K in French with English abstract ・ 一． （1988）Gcol〔｝gy of the Olnaezaki distlict．、Vith geo】ogical t sheet map a し 1：50ρ00， Geol Surv Japan，153p．＊ Suginlura A （1960）Zonal arrangement of some geophysical 。。、。 h、。 。 T 。 k。 、 h、。 、。 u ，uj 、。 。，。 。 。。 「 ｝ M d d ・ incisedva 艮ley fill： Upper P 量eistocene in （Chikyu Kagaku ），54，23・32． 静岡県牧 ノ 原地域 の 上 部統 の 砂層 の 鉱物組成 牧 ノ 原 台地 の 上部更新統 の 砂 は 岩 片 に 富 み fieldに あた る ．牧 ノ 原 や 関東 の 第四 系 の 砂 は ア 期 と高海水準期の 河川 の 砂 は 異な る鉱物特性 を ー （Qm ＋ Lt）値 を 示 した ．バ リア 砂体 に 堆積 − （Qm 」 Lt）ダ イ ア グ ラ ム に お い て 異 な る 分布 を 中の もの は 岩片 に 富 む ．こ れ らは津波堆積物 の つ い て の 相関を検討 し た が ，両者 に 相関は ほ と L 供給源 （集水域） の 広 さ と地質の 多様吽、に よ る （32 ） 一 NII-ElectronicN 工 工 Eleotronio Library Service