Luận án Địa mạo trầm tích ứng dụng rừng Sác Gia Định

~~~-~-/~---~/~ ~~-~-. -~:==:: --::::---~~~~~~ ::: /~ :~S~~~~ ::---:::::=~ - ':::' :-~ -;;) ~ ~ HinhIV -.1.:M(Jtstfcdutruetramttchc6trongcaeddnvi dia r1'lQO tramtichcuaRilngSacGiaDinh. 1.-xiencheotrung 2.-xiencheophdng 3.-ntpnhanlea{a-caedinhnghfa;b-giatangg6clea;} {c-g6cleathongd6i;d-gidmg6clea} 26 '- ~: DI/ongld ladithllcviltthl/()ngdllf/ctrdng tJ cacgidngcdttilp gidpvdibiln dl cdn bdtsltcxdmth1lccUagio ( gidngmdi). ~ : DdyclingldnAnm6ngtdtcooxdydl/ftg,tuy nhihz,ch1/aphdi ld ddttdtchon,jngnghilp : ngllbitachi trdngnhl1nglOQicdyit cdnnlldc haycdycorl ngdn(chudi,Ida,tre...). 10(;lieua vung - catgi6ngd C~nGia e6 kich tln1'deminh(;lthdnva thuange6mauyangdd do e6ehuamQtluQngsetbun. Thanhph~nh(;lt dQehotha'ye6cd h(;ltcatminla ehuye'u: d (mm) 0,25- 0,125 0,125-0,005 < 0,005 % 24,70 47,35 26,95 C6 th~tha'yduQeea'utruexien eheo tnlng , da phltdngnha't1a ndi e6sl!hi~ndi~neuanhung1amongg6mmanhvd thl!ev~tdanhdau giai do(;lnnude yen tTnh(Hinh IV.2). Da'uve'tdQngv~thie'mnhl(ng khonglieu bi~uehomoi truang. MQt so'gi6ngco ehi~uday d(;ltt6i da khoang10m.Gi6ng thuangehuanudemua, t(;lOthanhmQtthuyea'ptreo g6mnudengQt. D6 ia thuyea'pnudeng9tduy nhateua Rung Sac Gia Dinh,du tnrluQngth~tit oi (chIdungehosinhho(;ltclingkh6ngdu). Tinh Dende kern vavdi tri~ukh6ng6n dinh,gi6ngthl(angbi tuQt1ddudisues6ngvadongiii. HlnhIV--1-:AnhmaybaytiI? 1/12.500chl;lPnam1992a D6ngHoacho thaysongbiin vadongIa diiphahaymanhIi?t caeIo~tgi6ng , cdn(Jiday. 27 --- ._."~ II ~ : (j nhT1ngnaimagidngcdtpMi chiucUng ldcnhi~utdcnhdnxdmthl/C(song,tri~u, dangyenbOon),dIJongkh~g dtlstlckhdng cl/ : giOngcdtbi tanpM, Xt1mth1/C, - -.J-. T" ", C . ~ . >--,,~,~":;x. ~r ,~ .r"" -- k:I' , ";~'" , . ,-~"" c; ,... " "" ,.",..~, .-- d ~" ', r ',iii"'" " " -. '" .I ~;d'~~,. ~ ' . .~,~ ~,~,~" . ,~ ' <~;;~.S~fr!~"',0.,. 'r! , .,.. ,,( !;J,.- , ". ~"" ~" / '." -»}":'~;"':"~;;:tD',/:;'*"'~ - , ,'~ :~,:' :o/}J:?-:,.;,:t[~.-;f-~';, " ,'- ~~ "':1-' ,;d:;'ri;.~;~ u~"\. ~"" If.,"/","" ,.' 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I ' I,y(, .";"'\"'.;, ,",.~... -""",:,-""",.""'\ .'~", ' ~r.J. , /~;' ' ;L.' \ , 'i"'~)~~' ", '~\ I"'~';'~~ ',' " if' 0,),1' L . 1 , '~,' f''...;r"';"";';1,~f~. ,"I'" ~;.~;:~~' -',.. ~1'II"~plr...,.:L - - -, ~ : DdylddduvttconsotlQicoonhi~uIOQt gi6ngcdbi tanpM diJdQiMi sOngvatri~u naimiliD6ngHOa. t-J 00 ,~:?"~..::;;'-:,'."~:::::~~;,:':;,.:~:~'!\)?S~.:~:~;/?'~r.':?~~<',1.':'f~',';;;:~::~i~~}~'.:7:""X;~:){;~ ,"~'o""""'\{"'("'" ""-"""""",~~,;~~""",,,:,"'1"'.'.V' Y""""'~':;~;';"'~"""""~;','""'~ ~:::, , ':; . ~: ' , '{ ~~;;;~:~{}i/ '{:.:tI~;{~i ~ri ~:~.~~~~~ , ~r , ~~~~~~1 ~i , :i~: , "(t .;.,~,:~t\ '" -4" 0, ,">"," ',"'" .,,;r;-. ';l0C!w:,.,~.,t"["~'\'jJ.~( "'".,1,- ~~~j~!tl~~k;;,rl~~f:; i [W~k3.~i "' , " '~ , " , . , '~,\ , ' , :\""""'~"""')"~',-\ , ~' , ";'.\"~'\""'2;""?/"-;""' . "'~ , ~'( , 'J. ~ o" ~",~," "" , .." J.t' ~'~:'}~;:~~:;>'1iji;:lkK"!~~J~~~' :"~'f::~:,~:~'~~'~;::,f,~~:jt~~~~;~y?.,e,lK:;;(';:'jr?~)";.;".,;..:,,. :;;:"',;';"" .i"'-~'YJ.:.~~ ,~..~,:o.'t"'il7i'."""""~,-,,,,":.I.:(."~;,:~':>,.:,,d~:1-:,:;:;',":",1:"'t ;i1k ;;;;;J::'i'~..d~'l.~~~:/"'j.i}:»~~C(,:i\, '~{i.:.(;;~:~~i':,~;;,',;:. ri;"1".1!J.-;:Bi-f' ~"'-Wt.~'" Vp',.""! " '. 5"" ~,.':"',}\1 !~\(~:f;'!j,~!,"CJ11~~~;fk)Jtzi~~**\1;';.'&1 (\~~! '~';i"'>""""f'i".~.j)~,.~~.\;J;~'j.:'.~~..,<ilJ1J.,~<.:,'""",,.',':"~k~h" !~':"";""'c'f" ;$~}~~J~!~~'~~j~~~~~f~~;~~~1i~}~t~~~~~~ ", (;,v,...".,.,.,!\.."".',~e""i'i!l:{;""""\'-""""""""I""""""""'LJ'-'f~"" ~ "i"--""'" ,..,,";r ~~1\:;~';j:~;~1¥~ :1% ~~~I~ t\~~~~'t~:jH;J;:;n('/i~~'~~@~#,~y~\;;~~~ ~?~; "', '." ",l:li~\""'k"jiJ"('{"-~:",.;,\.~." ."'-I'~:-",""'--::'".'.,.,," "."";.,,..,..\..t";""'i;'" ..~,~..:(.", ;~~~s§fl~Jl1~II§l~I~~~~~;'h~:~~;~ ~",)"!"",,,-,,',..:~1,r,--,.h'..r"",>~"',,I~-'."':_::X""~"-~',-""..,.i-'.~'K"~'h! "':j )~i~~)r~f~\il,\!W~~ir%~~0 J~~}t~~j~i; ~ltt~~ E>6NGTmJyT~U .E>'()ngthdy' .1ri~u. GG /"\ / \ M \ . ::J '~ ~ E-c 0 Z '0 ~ Hlnh IJl.4A_:Dia mQOdQcsdccuagi6ngre quQt,dodnhhuangkiln tQOgdy ra m~tcdchgidn tilp xuyenqua sT!ddi dong cua s6ng cd Chien cd, tQi Tra Vinh. Ddy La "khodnh chza kh6a" stf 7 cua Dornbusch (1969)v~gi6ngcdnc1msdutrongd& li~n. 20 A A' IV \0 ~ p~ 10 ~ ~. G> 0 0 CI) 0 cJ '0,. Q -10 ImU PEAT !Z2I CH ~OH CZlsP h='::=1SM PEAT.. thanbun GrGA GIONG . f>AMM~ SET, BUN. CAT TGC -20 0 1000 2000 3000 KHoANG cAcH, TfNH BANG MET 4000 Fnnh/Jl.4B.."Mrlt cdtngangquamQtkhugi6ngrequ~tchoth6yala tdngcrlacdcphTich~trdmrich.Dum cung LatrdmItchmr)ntamgidc chdu,ke'din ddmm4nchTiathanbLlnmongoBentrenLagi6ng va giT1a gi6ng. DB ..ad!tr6p SM .. cdtvEla CH .. bungiauhiluco SP .. cdtc6phdncdphCiltkern w 0 ~. BAIT~UCAT BAMM~ mnhIII5A-: Bciicdtvagi6ngmai0 HamLu6ng,nhintll m1iybayxu6ng,trong"khodnhchlakh6a"s6'6 cua Dornbusch(1969). wE-4 ~10 ~~ ~ ~. a ~ 0 ~ ~ U -10 <0' Q 20 A AI, .'cdtsdpcoh(ltxd'u .'setgiau hTluC{J 500 1000 1500 KHOANG cACH, TtNH BANG MET mnh IJL5B_.'Milt cdt!d!mIra ngangquac6nbi!n vagi6ng.Ta bi!n di vaG,c6nc6 tu6icaDddn.M~ttc?-phqp c6nnhllvc?-ytq.on~nphrlch~gi6ng,m~td(Jnvi tramrichtanchilytu cila tamgidcchdu. ~OH 1:8::::3s p OIONOMdI SP DB BArTJ-IUyTRl~Ucd 'TRAMTICH TAM OIAc CHAD c6 HdN obM CAT,BUN,SET -20 0 2000 Tuy v~y,dayclingla ddn vi co n~nmongcongtdnh vfi'ngch~cnha'trongta'tcacaeddnvi trfimrichhi~ndi~ntrongkhuVt.tc nay. Bay clingla da'tthichh<;jpchocaevu'oncay antrai nht(nhan, mangcfiu,xoai,tao,.du'a...ho~c ae10C;lirailmallcuavungcfin Gio va Ly Nhdn. Ddn vi nay n6i r6 trenanh may bay hay pictomap(tr~(c anh d6) . Dornbuschva nhomnghienct1uda trlnhbay trong"khoanh chla khoa" s6 6 va 7 nhfi'nggi6ngre quC;ltra'td~ctru'ngd d6ng b~ng songCau Long(Hinh IVA va IV.5). Gi6ng tha'ytll'anh may bay vung bandaoCfin Gio clingclIngd~ctinhdo. Va quado, ta tha'yco it nha'tla 3 hay 4 10C;ltgi6nghi~ndi~nd Ly Nhdn, va r6 hdn he'tla 10C;ltgi6ngd ban dao Cfin Gio. LoC;ltgi6ng nay thu'ongchC;lysongsongvdi bo bi~n hi~nt<;ti,chotha'yd blob di~nc~cbi?,bandao Cfin Gio chill anhhttdng nhi~ubdi hoC;ltdi?ngcuasong(Hinh IV.6). 10 16khoanki~mITatuye'nCfin ThC;lnh-B6ngHoa chungto di~unay.(Hinh IV.7) ? ffinhlV. 6_:Anhmaybaytll~1/12.500(rutnho)chothayco it nhat4 lo(lt gi8nghi~ndi~n(j bandaDcan Gi(j (LongBoa -Long Th(mh). 32 , ',' .~"'-~~~:k ~.~ ~- ~~" -:~.~;",",~~' ~ : HddaoiJ~t gidngcdtcd"amtilingdbac4nGio-Ddng Hoo-TP Hd chiMinh.GidngndyddykhodngO,3m,ndmten trht lap dtftddmI'fI4ncdhanno (nulikhoanddi 1,2m). ~: VI/OncdytIntrdinoigidngcdndy: ddttdtchon~g nghi'p. Noi ndogidngco chilu daykem( <2m), ngl/Qito thl/Ong pMi daogitngIII ch1lanl/dct1.lQicdy. BAC NAM " . , . Giuagidng Gidng £)§mm~n Ba:ithllytrieu(dthaybUn) TTA 10 RLl RL7 9 ..--- '"...r.' "',, "/,- -", /' -'' ---~- --, ~cf:.- :::::.::=> 5 RL7 :s6hi~uIe,khoan ';-" -"',--.- ..- ..-.- ~ ~ t>6NGBAC LTB Orr. 14 L~ 15 LT6 LTs TAYNAM LTI A~'.'" :;:-} ;:;~/?g~:~(::i;' s HlnhN - Z: Mijt cdttuylnBdcNamvaD6ngBdc-TdyNamcuavungbandaoCanGiG. I1l~ngang1/12.500, I1l~dtlng 1/200 IV.II.I.b.- Triing giuagi6ng: GiG'ahaigi6ngeh~ysongsongho~eg~pnhau,xuathi~nmQt tnlngthap,ndimahaichaogi6nggiapnhau(HinhIV.8A-B). (j day,V?t li~umilltuhaidinhgi6ngtUQtxu6ngsailm6iednmilaho~ekhi cobaa. NhocoluQngnuoetftmtutronggi6ngrI fa, ndidaythqeV?tkhaphong ? phil, donggapehoti I~mUllcaDtrongddnvi nay.0 dayco nhungI~eh nuoenho,gilip thongthudngvoi miceasongnhanheuacaesonglOn, t~onenmQtmoitruongnuoeIQ- voi thqeV?tehinhIa dltOC- va tn1ng, lingnuoethuongxuyen.V?t li~utr~mtichthuongla bunva set,cQng themsqhi~ndi~neuanhi~uchathuucdtrongmoitntongyemkhi lam sinhraluQngphenti~mtang- thuonga d~ngpyrit- lamehuadat. Hang daDeuacaesinhV?ts6ngtrongddnvi nay(nhucua,eong), ho~cr~cay bi buyho~i,t~odi~uki~nchodatthongkhi khientathuongg~ptrong phftudi~nnhung6ngphenjarositemallyangrdm, du khongnhi~u. LuQngphennaykhongdangk~sovoi luQngphenn~mtrongcaeddnvi khae,nhungdingdugayt6nkemIontrongvi~ccait~ohoahQedat. Thanhph~nh~tdQehothayV?tli~uehuyell labunvaset: 0,125- 0,063mm 0,063- 0,005mm <0,005mm 29,00% 50,20% 8,05% Ket quaphantichthanhph~nhoahQcdatcuaddnvi naycha thay: Mftuso' HD I-I 3,16 DG I-I X r/ La khoan-so (1-1) pH (H2O) 4 3,58 DQdftndi~n (mS/em) 10,42 9,5 10,5 DQchuatraGd6i (meq/l00g) 0,37 1,60 6,30 DQchuati~mtang (meq/l00g) 14,60 7,68 24,40 34 ~!~~ ',~,--:.-c~, ,', ,",' - ... , """",",- .": ." .-.~~ 'f:~~ " ~: Tabilndivao,cdcIOQtgidngndmsongsongnhau,cang sdutrongddtlib, th~cangcdhOT/,.Cdcgidngndycdchnhau biJinhilngtrunggiilagidng,nmmanlJdcm4ndd hi hdalQt ddndolllflngnlldcmliatdmtrongcdcgidngnayri ra.Do do cost!kiln diln cUadaan"dc. ~: AnhchliPcdcIOQtgidngndmchennhau,thdyd"qcqua3 tdng cdy: gdnnhdtzadlldc,tdngklza vllancdydntrdi (nhdn),cao nhdtzadaa,tre(dIOQtgi6ngxanhdtthtlyd"qc). 35 ~ f-..) "- 1::$. \:)-., f-..) <C). ~ ~- c.o ~ .00 ~"-c.o c.o ~ I~ ;...- ~ ;:.. c.o ~ '«:) "00 ~ ;:.. .-...... 0\ \() 0\ .......-- ~ <.':) ~ ~ E \:) ~ 1::$ ..~ f-..) ~ ~ '«::> <.':)- ~ ~ 1::$.-.... ~ f-..) ~ ~ ~ \:) ~ . . ~ 00 ~ ~ ~ ES '.-J C\ ~ ~10 ~ ~. ~ 0 0 ~ 0 ~ <0, Q -10 20 A ~ PEAT E53SM rzJ OH C2J SP IZ2I CH 'GIONGC6. . TRUNG GIDA GI6NG D1lill m~nthdytri'8u S:bT,BUN, CAT TGC -20 0 A' PEAT: thanbun 40001000 2000 3000 KHoANG eACH, TfNH BANG MbT ffinh IV - 8B~Meltcdtki!mIrachoIh(iydjatdngratrocJphlich~giilagi6ngcdnay..bendu6'iLaddmm{jn,sau d6dtnblmgm{jnhocJcd6ngthaylri~u,cu61cungdtndatd6ngL~/. OH : sethiluco,trtip CH : bunphasethiluco SM ..cd!vua SP ..cd!c6dci.sdpcoht xtiu ~--" - "- ~ I IIIIIJ' :.~'" I ~ , ~ I . : ~." .. "~" .- ,",. : -:.:.:. ~,. ~'( '.~. -:, ~ ~: Giila vUngddmm(jn,thinkthodngco nhilngkhodnhddtcdtmin-bUncUagiila gi&ng(haygidng)cd,dQbi mdimOn,chi cond~1 tdcday,nh~caDhdnddmmijn chungquanh,n~nthllbngdOngvdnmuc1i vQomUakh~. ~: Ph4nria cuadUmnaylQi rdtmOngo Dm chefl~cdldpddtddmm(jnndmMn dlldi.TuynhMn,My kh~g la mijt!xing tdtchothdysdnhayn~g nghitp: phen tihn tangiJ ldpddmmijnbhl dlJdisetriJ thankphenhOQtdQng. IV.II.I.c. Bai thuytri~u: Benngoaicuagi6nglabilicatc6kichthttoch~ttrungvamill, chilatit 10-25%manhvoso6coatvt..In.Bili catnayn~mthoaithoaira khoi: d6labili thuytri~u(HinhIV.9). Di~nrichcuabili tilythuQcvaophilophoirakhi mtocrang. , ? C6 noi, nhu d Can Th~nh,bili rQnghang 2-4km. Anh may bay Chl.1P loan bQ bili phoi ra khi trai cho thiy nhungchi tie'tdia m~od~cs~c (Hinh IV.IO): - Nhungne'pnhanlo~ilOn,do dongbi~nva s6ngbi~n dl1ngnell,gi6ngnhus6ngcatsam~c,gQilamega-ripplemark, - Nhunglongl~chsan,dodongbi~nc~tvaophftncatd chaobili. C6 it nhit 5 - 7 longl~chnhuv~yxayra sanmoi liln mtoc rbng,t~oHenmQtlacnhanunghQhi~nttt<;1ngIdba. Manh vo voi t~ora mQtchit ke'tdinh thuyl~tctl.tnhien. Do v~y,bell duoi lOpcat,xuit hi~ntitnglOpda catvoi d dQsantu 0,7- 1,5m.Tranglongl~ch,lo~idacatvoinay lQ len, bi s6ngdanhvo vaduavaot~nbabi~n. Noiday,chungtaitrilmrichvatie'pt~ICninhke't voi nhau.Cangxu6ngsan,lOpdacatvoi naycangrQng va cangday, ? lam thanhmQtthil dalle lien tt..Ic,c6 phanlop ro. (j Miii NltoCV~n, Thi~ngLi~ng,LongSon,d dQsan10m,da'catvoi lo~inayn~mblob hang(ngang),c6 dia tftngkharo, lieu bi~ucho tdm richtu thaidilu Holocene. Thanhphiloh~tdQchothiy : cat bun set 64,67% 12,05% 4% Bili thuytri€u n~mnoidilucacc6ncuasongIa noithlehh~jp chocacdQngv~ts6nghamdaynhungheu,so,di~p... IV.II.I.d.Doi biin : Do' la ht<;1ncatdQC,do dong nuocsongd~ptu bili thuy tri€u rakhoi.Bon vi nayn~mtrongkhuvrfcm~n,k~titbili bi~ntra ra va b~nvaobili thuytri€u nay. Doi quan trQnghon he'tn~md phia Nam Ly Nhon do lu<;1ngcatphongphucuasongSoaiR~p(cua B6ng Nai) dltara V3.0I11Lla 37 ID m ' .,..., . t ill\ - ~.,...,~-, ".~ -101 ~-= --. . ---- ~'...,.~:o. .<~"";.--' ,'"'\. ',. '.". ,.:;".'. .~.. '*: ... "I.:: I'i~:':<'::;':$,.;: .~'H~" ~. '.. ~~",,{..,,~, '~~"~",-:~t~~. ~t"/! ~; ; ~ ":i . " ~ : BliithUytriAucdnGih,pMntitpgidpvdiloq,t gidngcdtrlidcdo(cao/chodng2-3m),nht cod" ddctl/llngddildn. ~ II III , J . II 'I ~: Trang/chido,pMnndmvAphfabilnthicod" ddc/ch~gddngkl. Ngl/lJi ta cOnthdynhilnggflTt nlidcdllq,i trhtnln cdtCM bdi. w 00 ; ) r l E».M M4N r,j GlbNG MdI eM ,, B(1cAT \ BAITRIJrocAT \@ HlnhIJl.9.:A...Anh eh~pbiii thuytri~u(edt)tiImdybay,tll~ 1/50.000,ehoth6yedutruetrdmtieh b~rrujteua n6g6mnhi~unIp nhdn,longlc;zehva lriqrtedt. ~o A A" Dsp ~OH \J.) \D ~ 10 p~ ~ ~. 0 -6> 0 CI) 0-<-10 U <0' Q BAI T~U CAT SP : cdtc6phdncliph~tkern. OB : ddthr1uCG,trdp(setphabun) CAT/BUN,SET~ -20 0 1000 2000 3000 4000 KHoANG eACH. TfNH BANG MET InnhIJl.9J1..Mq.tcdt/dImIrangangquabtiithaytri~ucat(BTC)a banddocdnGio. --- -- -- - ~ - .-- II ., r;;. I I I :::~ o£:~ l ~. i~ ~-o ;:.. "J "<:) ~ ;:.. 1:~ ~-5 '5 or:O-e ~-'8I:.'S "~~-..r: ~~"t::St: ~ O- g-~-~ i ~ ~~ ~ ;:.. ~r:~~ ~ ~aor: .§~ iE; -t:) I;) ~. ~ ~ ~ II;) .... '€ ..s::..... I;) ..s::v-- ~0.. . "-f~'- -t:) C) ~ C) ~ Ir) ;::. . V ~ 1;). "-f~ '..s:: "-f V ~ ~....... ~ ();:) ~ ~.... 'C:) ~...... ~~~~ .... U~ I;) '.:::s ~~ -§ ~-t:) 1~ c.o v ,§ -€;::. ...... ~.~.?S..s:: ~ i~ ..s:: ~ ~']'.1~ "-f ~ ~ ~ EE 40 ~"YA "A') ". -~'":I;: "", lRnhIV :-11: AnhmdybaytI l~1/12.500(1992)vungbanddoLy Nh(/flehotMy e6utrueeuadoibiEnvadoibiEnngdm.Sau khi e6dQpTryAn vaDdu Titng,doi biEna ddydii bi .wi manr6t drldQi. 41 IiI (HinhIV.II). Mt}tdonviquaDtr<;mgm1an~maphiaNamCftnGia,do catcuaphuch~cii'asongcuavinhGanhRai. V~tli~ucuadoichuye'ula ca.tmill va bunthochenlfin voi nhungthiu kinhcat thova s~n.Baocaocuasa H~ngHa tu Dam 1965de'n1970chothiyr~ngsancacmuaIiI, songSoaiR~pd§yra tung hloicatthovas~n,n6chenvaonhungdoibi€'nngoaikhoi,t(;lODenmt}t thuc6nngftmphuct(;lpv~kichthuoch(;ltI§nciu tructrftmticho Nhi~udoi bi€'n c6 clIngduqcphathi~nqua v~tli~uciu t(;lOvavi trLDoibi€'nc6abilccuaLy Nhon con tuongdoi tn-;0Doi bi€'n n~mbell duoi Blnh Khanhla c6honhe'taRung Sac Gia dinh,daubdiu thai ky bi€'n bilt dfturut ra vao Holocenegiua. Trftm tich moi hon da phil len tungphftncac doi nay,Denkhongth€' nh~nra a anhmaybay duqc. Doi bi€'nngftmla ddnvi ti~nthancuacacdoibi€'n.N6 duqchlnhthanha nhungndinaoc6dongchaycuacii'asong,noicacday khongbaagiaIt}rad ml}ctri~uthipnhit 0 Quaquatdnhb6i tichsaucac tr~nIiI, chi~udaycuadoitangdftnlen,d€' doi ngftmthanhmt}tdoiblob thuang. Sand6,ne'ubi€'n tie'pt~clin rakhdi,doi bi€'nd6 se trathanh doi bi€'nc6 . Truonghqpnguqel~i,ne'ubi€'n tranvaodit li~ndo m~tc g6ebi h~thip vlly dokie'nt(;lO,ho~enuocsongbi ch~nl(;litrenngu6n, khie'nnuoebi€'ntranVaosong,t~oramt}tcut}cbi€'n tie'nnhant(;lo,v~t li~utrftmticheuaba:ithuytri~uho~cdftmm~nsephil leu d6 d€' x6a s(;lchdiu ve'tcuadoibi€'nnaynhuhi~ntha'ya Ly Nhdn.Va'nd~nayse duqcbanlu~nkyhdna chudngsan0 IV.II.I.e. BUngsaDgic3ng: Ne'ucacgi6ngcachnhauvaikm, sail gi6ngthLtongxua't hi~naonuocm~n,viIngnuocm~nvacacl(;lchnuocm~nmav~tli~umin nhubunvasetclingchithuucdde'nla'pdfty0 £)6la cacbungn~mtrang khu VL.tCmtocm~n,barntheocacgi6ngDengQi la bLtngsaugi6ng,theo mo hlnhcuaReineck,1965(mnh IV.12). Trong giai do(;lndftu,bungc6 kha Danggiao lLtuvoi bell ngoai,qua cac triIngnha gQi la "pha".V~ sail, sl}giao lLtuchim d(tt, bungbi co l~pdftnva che't. Xac ba thl}Cv~tt(;longu6nSulphurcho s~( t6nghqppyritFeS2rit phongphu 0 Day la moi tntangtichlily phen ti~mtangIonhdnhe't,VI hoancanhkY.khi traDenly tLtangtrangm6i truongkemDangluqngthuydt}ngnhuv~y. Cac tui phenkhungkhi6p 42 '-/" \J \../ 'c;} ,~ '-' ,-j'-' '-' /j ./>/~ Y /~/ ;::;'>?.~ /;::;-/ (-> II I I I / / / ; / / ; ;.o' / I / I I I I / I / / ; /--7 / / / BIfu - --"-- ------------------ .. .. 0 - "" .. 0) 0 .. .. . c)0 .. "0 0 .. 0 ....0_" 0 0). - ---- --- --- - --- ---- -- "111111111 11111111111 1111'111"1. 6. ...6.... . ... . ..6 -- --- -- ----- -- ---- - --- TRAM TfcH D~\1MAN -+chuytinsangTRAM TfcH DONGU)T (set,bun,hii'ucd) TRAM TfcH BAI AO BIEN -+chuytinsangTRAM TfCH DAM MA1~ (cat,bun) TRAM TICH DAy AO BIEN -+PHEN TIEM TANG -+DAM MN'>f (set) TRAM TfCH BAI BIEN CO CON(GIaNG) (dt) TRAM TfCH BAI BIEN KHONG CO CON -+chuytinsangBAI AO BIEN (cat) TRAM TfCH MAN DAY BIEN -+chuytinsangCONvA AO BIEN (cat,bun,set) THAN BUN PHEN TIEM TANG InnhN -12: mnh dnhcdablingsaugi6ngdo tamQtGObiln bi cQn ddnrrWthdnh. 43 \J \.J \J \J \../ '-' v '-' '-' '-' '-' '-' \../ '-' '-' \J V '-' '-' \J \J \J \J \J M4.T CAT LO KHOAN LK -8 DOSAU MATCXT Om O.2m O.8m lAm 3,2m TQA DO 7083508 MOTA bUnsetd6msilt setbUnnail den, r~cay setxamxanh /II; , DONVI TRAM TICR Bu'ngsailgi6ng d§m!§ym~n setxamxanhxenbunmicaIdoisong FnnhW - 13..Mii-tcdtl6 khoanLK - 8. 44 A,. :: .. ':,6.- :.t* - .. '. -:-:-- - l - - -- - -- -- - -- --- -- -- - -- --- -- --l - -- -...M_.-. ..- - -.:--::1"\'- --- -l - trongdfimm~nd€u xufttphattaday.S11hi(~ndi~ncuasetsmectite,do anhhuangcuadavoi vadamHhi'aphongh6atrenngu6n(Moormann, Pons,1974),hlnhnhuc6vai tro~o l~psetbala naytrongmoitniong giausilkvaki€m cuariam~n. Nhungchinhs11h6achuacuaphenti6m tang,dog~pdi€u ki~noxyth6acao, tC;lora khoangjarosite~l1aUvang romtrongdftt,da tangbudclamthoMh6asettruongndnay;chid~l<~i cackhoangb6nvungnhuillitevakaolinite. Ke'tquaphantichthanhphfinh6ahQc16 khoanLKS thuQe donvi bungsaugi6ng(n~mbelldudidfimm~nhi~ntC;li)ehothfty: Truong hQpnay ldp bungsaugi6ng con n~msau dltdi nWe thuycftpmila kho Denphen ti6mtangchuac6 dip trd thanhphen ho';lt dQng.Khi e6di€u ki~noxid h6a,pH cuadfttIOC;linfiy e6 th~dC;lt2,5 vdi luQng(SO4)2-la tren2% nhutruongh<;1pd trungphenRC;lChMltong. ClIng vdi s11lieu huycuasettru'ongnd , conc6 hi~ntltQngboa tanchfttvoi (d dC;lngvo so 6c) trongmoi t:ruongnay (Plaziat, 1974).S~( hi~ndi~ncua cae kim thC;lchcao thftyd vung dfttphen trangkhu v~te Blnh Chanh Phu Lam, va trongkhu Long Son-Ganh Rai dil ch(tngto di€u nay. Noi naGc6 sl! hi~ndi~ncua kim thC;lchcao, dltQCxem nhlt nhungd6mkhongphenn~mtrangd6ngchuaphennay. Dornbuschva nh6m(1969),cho thftyr6 cftutrucbl(ngsau gi6ngquakh6aanhmaybaytll~ 1/50.000cuavungnay(mnhIV.14). IV.II.l.f.PhQc h6i cddIu trfim tfch cd ban: Tren the'gidi,nghienCUllraubgididfttli6n/bi~nDelitam giacchaudaduade'nvi~cmohlnhh6acoche'b6i tichngangciiacae cii'asong. Colemanva Gagliano,1965duara mohlnhsauday (hlnh IV.15). Theo mo hlnhnay,quacacdon vi trfimtichbili bi~ne6 (ph((e h~bili bi~n)tlm thftyd Vinh ThC;lnh,Blnh Khanh,Gi6ng Chua, Th! Vai, Ly Nhon va bc1ccfin ThC;lnh,chungtoi phl;)ch6i dltQChltdng b6i tich ngangcuacaedongsong(tC;loDenphueh~longmang)cua RttngSac. 45 pH(nudc) Ec BCTB BCTT A13+ Fe (SO4)2- CI- mS/cm meqllOOg eq/lOO meq/l00g mg/l00g % % 2,98 10,41 2,60 25,63 8,38 175,2 1,34% 1,823% .+;:.. 0\ ,,\ ~ DA,.1 MAN \ A/ . PHUSACO . PHUSACOI . 'D~ Iv1~N mnh N - 14A: Dia mQOd(icsdc cuagi6ngre qU(lt cdmlmsautrongdeftli~n,phfa sau Labllngsaugi6ngcd. Teftcddctnvi trdmtlchmaihctnnayti€p gidpvai khdiphusacdNhctnTr(lch. ~-J 0 . . -10 I. . -20 0 ~'ET .-.~ - DAM M~N - I Z -",' e,AICATTHUY TRIEU PHU SA ~IAN 1- THAN ~ij~, I 2- 5ETHUUcd. , , :3-CATVLlA. , A..;BUN HUUcd . , S_<:ATT~P A' !I , I SET DO "'"",',--'-'" , ." ~:~'-""-""'-'" -"" -'/";" ~ NE~ £>.A'/'-".j:.-.,-"',;~~,_\- '.:,,-'t-':J,,-,- ,"""U .' , 1000 1500 , 2000500 HlnhN - 14B: Mijt cdtngangqualo<11gi6ngrequ~tcuaRilngSacGiaDinhc6,chothdyli~nh~girlan~nda, phusacdvamQtrongnhTlngtfchch&dduti~ncualo~tphusamai. A ".- ' I 1 5 c:J 2 E:ZJ 6 .'.'..I ,; 1 fZ2 I0I- . ..1 G:d Hlnh IV.is : Mo hinhthankl~ptamgiacchaudodnhhuangcuasong. Cll theomo hinhb6i richngangnhttv~y,thi phllc h~bili bi~n ohmbell dttoilop phil samoivaphil leDtIen lopphil sacd.Ph((ch~bi~n tie'n(tit cach nay 11.200Damde'n6.000Dam)(tdng h<Jps6 li~u ctla Biwas 1973,Fontaine,Delibrias1974,Kawamura,Laming 1974)tnii leD mQtlo~ttrftmrichbi~nDonggiau bun xamxanhc6 Htnvoi va cat min. Bi~u nayphil h<Jpvoi cac mlii khoanDongcua Dornbusch(1969)cling nhttcac mlii khoan saurim nttocngQt d Duyen Hili cua Sd Thuy L<Ji (Nguy~nH6ngBlnh, Le vanT6t, 1981). Tinh philm~nvagiauphencuatrftmrichbobi~nc6 y nghi'a quailtrQngtrongsilnxua't,nhttphifmcha'tm(ocngftmva tinhchuati~m tangcuada't. Iv.n.2.NHOMDAM ~N : Nh6mnayg6mc63donvi ladftmbunm~n,dftmlily m~nva d6ngthuytri~u.Bay la nh6mchie'mdi~nrichIon nha'trongRitngSac GiaBinh. IV.II.2.a.D~mbunm~n: Donvi naybQctheochaogi6ngcatnhttdphiahacC§n Th~nh,LyNhon,Gi6ngChua. Thanhphftnv~tli~ug6mit catmill, bunphasetva mUll xamxanh,hoanlOanilliJin( n6ngdQCl- khoiing1 - 1,5%).Nhj~unejjbj ~ 48 A B Ddnglilt TamgiBeeMu L6 khoan9 ;- B<'1bi~nmentai I .. \)j Biin +::-. 00 0" ,. ,. . ". Tieh chit dang l1,1t.. . . . BINH D6 B Hlnh N - 16..MijtcdtlytuiJngcho thdy81/thanh19pcuatamgiacchduRCCngSacGia Dinhquacae chu kY trdm Itch. (phongtheome?hlnh cua mQttamgiac chdu dangpIlat triln cua ColemanvaGagliano1964-1965) co l~pVaGmila nAng,khie'n n6ngdQClor vu'<;ftlen hon 2%. Trong mQt s6phil sac6 hond Blnh Chanh,PhuUim, Nha Be, manhvo hall ho~cso 6c bi v~nVyOva hoa lon, g<;fiymQtdQm~ncaohon nudcbi~ndo tri~u duaVaGt~ido. Dqc theovensong,dQm~nco khananggiamxu6ngdl(di 1%, nha'tla VaGmilamila. C5 Blnh Khanh,VaGthang9 - 10,da'tchi con 0,3 % dQm~nCl- . Dqc theochaoc6n,khongbaagia dQm~nVl(Qtqua 1% ; da s6 truangh<;fpla nha nudcngftmtha'mtiTcat gi6ng ra vaGthai di€m dftumilakho. C5 Gi6ngAo,dftmbunm~nco0,4%Cl-. Til~ cuasulfathayd6itiT0,4-0,8%d pH tu6 tdi4. IV.II.2.b.Dfimlfiym~n: Day la donvi trung, nudcng~pquanhnam,b! kh6ng che'bditri~ucaovathuyca'pcuada'tli~n.Ta co th€ tha'y1'6d!ahinhfifty qua"khoanhchiakhoa"s618cuaDornbusch(BlnhIV.17vaIV.18). Du co clingd!ahlnhnhutren,dftmIftym~nco 3 ai€m khac bi~tcoban: " / ,J / . - glausetvavangcatm!n, - hoaIftynhaolientl;lc, - giaumUllvapyrit. Thanhphftnkhoanghqccuadonvi naycho tha'ychuye'u 13.setba la smectite,it setillite honva ve'tcuakaolinite. Nhungnghien CUll bandftuv~ph6 ria X (Hoangthi Than 1973)va ph6 h6ng ngo~i (Chu Ph~mNg9c Son 1977,trongTrftn kim Th~chva nnc, 1978)cho tha'ytl l~ khoangmontmorillonited~ttu 40 - 60%. Co noi nhl( d Do Hoa cO,co ae'n80%montmorillonitetrongthanhphftnV?t li~uset. Sl.f hi~ndi~ncua setkeGhoava cha'tmUllaftt~onen tinhIftynhftod~cbi~t cuada'tdftmIftym~n,vdidQtrudngthanhtrungblob13.3 - 3,5. Quatdnhtn(dngthanhcuada'triTngIftym~nco lh~rhea d6idu<;fcbAngmAt,dosl!thayd6imallcuada'tiTxamxanhdenxam1\lc hayxamnailcochuanhungd6mrI vang. DQm~ncuada'tlo~inaythuangd trongkhoang 1- 2% Cr-. Con luQngsulfattiT0,6- 1,5%vdipH tiT6 - 3,5 . Day la lo<;tida't chuaphenti~mtangdungthuhai sailda'tbungsailgi6ng. Qua ldnh trudngthanhhoahqccuada'tlo~inayg6m2 giaido~nla oxi-hoava khoanghoacuacha'thuuco. Noicha'thuucocuada'triTngm~ncoIWjng cao,sl!oxi-hoano t<;tora sl!lull dayva phattri€n khe nt((. S\( In(dng 49 ~ ...... ~ ~.!\( ~ !::S '<:)~ ~ ;;:.- ao~ -§ ~"'Ii ~. -s-s ... ~.s-~~ ;:: .... )~~a.o .§ ~ ~f ~f j . ~i ~~ ao~ ao":i ~~..s::'"- a.o;:: '" )~'§;:...~ ~~ ~~ ~u VI 0 8M fflnh N - 17A: Mfit phdncuaRangSac Gia Dinh, nhln tr~ndnhmaybay1/50.000chothOyphtlch~ddmmQn namb~ndliOithdmthl!cvtjtcuarangngtjpmQn."Khodnhchlakh6a"s618cuaDornbusch. 20 VI ....... ~ 10 :i ''is ~ ~ :;E' 0 -6> 0 CI) 0 <-10u '0' Q -20 0 A A' ~ PEAT Ez:;] 0 H ~SP BAI T~U CAT .. BTC 8M DAM~N PEAT.. thanbun OH SP ..sethiluco,trrip ..edte6sdpcoh(ltkern SET/BUNpAT BmN 1000 3000 4000 i 2000 KHOA.NGCACH, TfNH BANG MET ffinhN - 17B.. Ddtddmnujnhi~nra khi luonedtvenbitn t(lOra biii thaytri~uedt(BYC),n6giupehocay dudemQeten.B~rt n(lngeuadudelamgidmwjn tdenude,bdyphusa nujnl(li, 1(10thankm~tphr1e h~bun/setgiaupyrit vasiderit,gQila ddmnujn,Day la 6phenti~mtang. VI N ,.' d' S6NGCiJALON ~,, BATTHfry 1RI~UBUN / ffinhIV -18 A: Nth mdybaytll~ 1/50.000ehothdyrilnglaym4nekeldyd& dammQn(rru1u:aimdcJm).B~n ngoai,vaoluenz,tcJerang,biiibunl~ra. \, ~ E>AM~ V1 UJ ~ ~10 ~~ ~ U ~. 6 0> 0 CI) 0 ~ (0.-10 Q 20 A A' PEAT.. thanbun ..sethtluco ..bunhtluco HlnhIV - 18B ..Mfjtcdtngangquabili thuytri~ugidubun.Tr~ntrdmtichmfjncuavjnhbiln kfn,ld bili bun thuytri~u,sauLlbtgLaddmmfjn.(j ddykhongc6hoancdnhtQoc6nbiln caD. ~ PEAT ~OH IZ21 CH " BAMMAN BIT BUN OR CR SET BUN CAT Bl~N -20 0 500 1000 1500 KHaMa eACH,TfNHBANa MET 2000 thanhh6ahQccuadit rungm~nc6lien h~trl!ctie'pde'ns~toxid h6acua sulfursAt,nhit la pyrit FeS2 - chit luon luon c6 m~ttrangbun khtt oxy cuarungm~n. Trang dit rung m~n , voi sl! th~ng du ki~m carbonate(chuye'ula CaCO3), clingcac hQpchit sulfur d~bi oxid h6a, H2SO4ph6ngthichra l<;tibi vo hi~uh6agftnmucpH trungboa,va th<;tch caoxuit hi~n(CaSO4 ,2H20).Trang di~uki~nnhuv~y,dit m~nkhong chuaphattdc3n(khu vt!cquanhThi~ngLi~ng).Khi c6 hQpchit sulfur th~ngdu',tinh chuaxuit hi~ns~ukhi tit ca carbonateki~mtrongm6i tru'ongbi lieu buy.Bit khi d6 se giampH, tucgia tangH+, Al 3+n.fdo duQcph6ngthich ra moi truong do st!boa tan khoang v~tset va Sl.t ngheonailcuabaztraod6i . Ke'tquacuaiclingla dit c6 pH thip, thltong la giua 3 va 4, ngheobaz traod6i, giau A13+tl! do d~traod6i (tntong hQpfiftyrit ph6bie'n0 vlingRungSac Gia Binh , nhu'vling nongtHrong B6 Hoa, nong tHrongQu~nGo vip, Nga Ba Ch6 Tru ). Cac lo<;ticHit sulfatchuaphen d6 duQcd~ctrungboi sl{hi~ndi~ncuajarosite mall yangrom thanhdambell ngoaim~tdit BQ chuacua dit tuy thuQcvao luQngpyritehi~ndi~nvadQthongkhi cuadit. v~ m~tsanxuit, dftmlftym~nc6 di~nrich rit rQng,l<,li giaupyrite,nense lamxiu dit cai t<;tonhi~ubonva rQnghonbit clf don vi trftmrich nao khac. Day khongphai la dit nong nghi~pnhlt nhi~u nguoilftmtu'ong,vi cai t<,lOn6 dc3duavao tr<5ngtrQtcanhlac thi kh6ng c6hi~uquakinh te'(Moormann,Pons,1974).B~ngchungla cackhu VL.fC dan rung0 dit dftmlftym~n,di doi voi khai muong,lam d~p,t<,longay jarosite,se lamchuadit ngaytrangmilan1ltadftu.MQt so'ao0 oay,l1ltoc chuatoi pH =3 vaomuanAng.Kinhnghi~mlen lie'p0 nongtHrongD6 Hoa vao cac flam 1970-1980cho thiy pH thip khie'nmia khong phat tric3nduQC,va ca dua cling bi thit b<;ti,vi dua khong chju chua OLt(;jC (Moorman1974). MQt vin d~dang quail tam khac nua la dit rttngm~n kh6ng bi chua nhu'ngbi ng~pnuoc bic3nfro l<;ti(do nhan t<;tohay do tri~u).Trang tru'onghQpnay, set giau voi thanhl~pkhi co Sl.ftntdng thanhbandftudo s~toxyd hoa cua pyrite,se fro thanhbaa boa Mg va Na, da"nde'nsl!phabuytrftmtrQngciu trucdit. Vi v~ycftntranh, kh6ng chohi~ntLtQngfiftyxayra 0 khuvl!c Thi~ngLi~ng,An Thoi D6ng.... MQt hi~ntu'Qngkhac c6 thc3xay ra 0 nhungvung oat rungm~ndu'Qckhai mu'ongva thamth~tcv~tbj dan s<;tch,dltoi khi h~u 54 e6mQtmuakhokeodaiho~ee6d l~b6ehdimtdeeaohonl6nght<;fng mua thim xuyen xu6ng dit .Mu6i trongdit rungm~ndatntdnglhanh setangtri gia, e6 thi gip miy lftnhon nudebiin . Sl,tbie'nd6i dQm~n theotUngdia phuongbi kh6ngehe'bdi nhi~uye'uto': dia m~o,dQthim euadit, khoangeachtUngu6nnuoelii .Bit bun set e6 phen ti~m tang, trong truong h<;fpnay, se t~ora mQth<;fpchit NaCI, AI, Fe va phue cha't sulfat boa tan, lam thaiIh nhung bai bAng acid va khong acid ma khong mQtcay hay eon gl e6 thi s6ng dU<;fctren d6, nhudang xay ra d cae khu vt.,tcDongtruong tom bo hoangd khu vt.,tcr~chHao Yo. Bftm lfty m~nchua nhi<3uvia than bun mong trong khu vt.,tcphia bifc Cftn Th~nh nhu An Nghla, Thu~n An, c6 b~day tu vai cm de'nvai tic, c6 noi tdi 1 m day. Nhung dung v<3m~tkinh te'ma xet, Slr khai iliac c6 nhi<3um~tbit l<;fico ban: tru IU<;fngit, chit IU<;fngkhong cao (d l~ huu co khong hon 30 - 35%), m~ttrai rQng nhi<3u,nude tftmqua cao, t~ophen noi khai iliac. Tuy nhien, trong mQt so'ranh c6, c6 nhi<3u cay bi chon vui, c6 kha Danglam chit d6t cho sinh ho~t. IV.II.2.c.D6ngthuytri~u: Bftmm~nphattriin mai,nangcaob<3m~tdftn,trd lhanh d6ngthuytri<3u(Hlnh IV.19). St.,thay d6i quail trQngla trftmrichchixay ravaohictri~ulen.Do d6,v~tli~ugiamIU<;fnglifngt~ra'tnhi<3u(30- 50%)va kich thuoch~tdIng rit min. Ba s6d6ng thuytri<3uc6 setm~n lftnmUll,vdi mQtd l~tren40%lu'<;fngtrftmtichtho.MQtkhacbi~tn[(a1a khongc6 thanh l~p pyrite nhud donvi trude,do v~y,dayla dil m~n ho~cdit l<;fchukhongphaidit chua. Tuy nhien,domaodftntranggiai do~nb6choiva thoathoimuakh6,dIngnhu'do vi~cdaokenhnll(ong sau,ch~mvaocaelOpdftmm~nchuaphen ti~mtangbelldltdi,Denda't d6ngthuytri<3ucling h6achua( mQtso'noi d Blnh Khanh).Bay la linh chuathusinhcuadit d6ngthuytri<3u. Bit d6ngthiiy tri<3uphattriin nhi~ud phia bifcCftnGio vaphialayflamLongThanh,keodaide'nBa Ria. Bay la vungda'tcao thu ba cua RungSacGia Binh,saudit gi6ngva dit nui.Nho bancha't dit kha thu~nl<;ficho Dongnghi~p,va khi c6 ngu6nnudengQtvao mua muadua de'n,DongdaDtr6ngdu'<;fCmQtv~ lUa, nhung vdi Dangsua't khongcao(Ph~mHoangHQ,1977). 55 """'1 I ,,/I:.);I I I i.;'~~,\F"- . --'~ . ". ",,'!" ' . ;! n . "'~" ~ .,';,; . r~i~! ~, 'I.~'I\~. ~~. ti'" '~J?i.. . i!'- . " , - . :~/ ' )' I <i " ', " \' i" 'J ~. . '>i, "" iii! . 1 ,it' , , 'h l.. ,~ .rr 11111 ~ ~ :s t'Q~.~ ~~> ~~. - ~~ ~ .... ~'5 ~~ ~ -.::: ~~ :s ~ ~ ~ .~ .oOi~ Co~ ~ § 00 ~ ~~.§ '. E;;;:; '" ] ~ 1: ~ 'S Co. ~! ~ .~ ~ ~:e ~~ *~ 'S.§..s::'" a~ ..s::~ ~'S '. ] @56 ~ f;) ~ ~ ~-- ~ ~ ~ ~ ~ ~ ~ -~- ~ ..~ ~ 00 ~ . ~~ ~ ~ ,~ ~- ~ 00 ~ ~ ~ <C) .~ f;) ~ -6 ~ ~ 00 ~ § ~ "'- 00- ~ ~ \:) ~~f;) ~ "5-~ - ~ ~ ~ \:)- ~~ 00 ~ ~o:;- ~IQ .~ ~- '- ~~ ~ ~ ~ ~ ~~ .g § 06Q ~ ~ ..~ ~ I ~ 0\"-1 "-I I ~ ~ ~ ~ DB CB : sethTluCd : bunFha set hTluCd -20 0 500 1000 1500 KHOA.NGeACH, TfNH BANG MET 2000 mnh IV - 19B: M(jtcdtkilm Ira (jm~td6ngthuytri~u: d610.n(Jimad6ng11!tho(jctamgidcchdubi nende lamchothdpdi. Tri~utas6ngIran tenb6iddpr6i rutdi ngay.Via tdngrat rD. IV.II.2.d.Y nghiatrong mohlnh tr§m tfch : Trang mo hlnh trftmtich cua Colemanva Gagliano (1965),dftmm~ntdin khaidhaibelllongmangchinh,dl1'av~tli~l1trftm tichtirngu<5nv~.Tinhb<5ingangkhongdangki machIc6tinhdip cao- tirdudilen- ladangn6i.Chonenciu tructrftmtichd daykhongthuQc lo~ixiencheo,mathuQclo~is~plablobhang(ngang)(BlnhIV.20). Trangmohlnhtdm tichcua Reineckva Singh(1980), dftmm~nph<ittri<snsaulungnh6mbC5bi<Sn,tie'pn6ivditn1ng iuagi<5ng vabungsaugi<5ng.Co che'tdm tichd dayviinla sl{dip caohonla b<5i ngang,vdiciu tructrftmtichtheelo~is~plablobhang(BlnhIV.2l). ph8!ItWi1IiIaIV .. .. bc5 ffinh IV.2Q: Sad8kh6icuatamgidcchauanhhuangbai song,dqmgthuy, cho th(l'ynhangmoi truiJngtrtlmrichva nhangtuangtramrich chinh. 58 Bie'tduQcqui lu~tphcitriin do,cacnhagiai doananhviin thamdii t~ndqngtrftmtichb€ m~tdi hiiu trftmtichb€ sau,t(tcla bie't duQcslJ'phcitriin cqthi cuadftmm~nmdi,di tirdosoyradftmm~ncd. Da sodi~ntichphilbdidftmm~ncd d€u n~mtr~tctie'ptren trftmtich bo biin cua giai do':lnbiin tran va biin nIt trongthoi Holocene.ChoDen,nhungmliikhoantir10-20metchotha'yslJ'l~pdi l~pl':licuathutlJ'saudaytirtrenxuongdudi: dftmm~nmdi- biii thuy tri€u - dftmm~ncd- biii thuytri€u cd- philsacd (ho~csltonrichco) . TruonghQpRirngSacGiaDinhla mQtb6ntrftmrich khongb6inhanh rabiin, Denphilsacd,biiithuytri€u cd,vadftmm~ncdd€u bichekin dudicac donvi b6itichhi~nt':li.Doi vdinhungkhuvlJ'Cco Sl{b6i rich nhanhrabiin, nhudd6ngb~ngsongcau Long(Moormann,Pons,1974) , cacbiii thuytri€u vadftmm~ntraixienrahenngoai,Denco thi phan bi~tngaytrongdonvi dftmm~nbiin rut,thanhdftmm~ncd 1,dftmm~n cd2 0 m6indidftmm~nc6lo ranhuv~ythlcomQth~thonggi6ng tu'ongung,nhutrongtru'onghQpcua dohCau Long ho~chuy~nGo Congo Con trongnhungvungcorirngm~nco dinhcuakhuVl{Cb6i tichch~m,da'tchillmQtgiaido':lnsinhdfttdaivara'tdai,trongdi€u -ki~n ye'mkhi,ke'tquala co chillhuuco richtqra'tnhi€u, de'nn6i co nhung ndida'tbie'nthanhda'thuucd(chuathanbun).Clingluc,lu'Qngpyritetrd Dencaohdn, du'ade'ntinhchuati€m tang.Nhu'v~y,da'tru'dngthanhtl.t nhienho~ckhaihoangd dayd€u g6mchuye'ula dfttphen(da'tsulfat chua),khonghQpho~ckhongthu~nIQichovi~ccanhlac. 59 '::.!. BI~ I I I / I / / """ /" / / I f I I I I / / " ~/- . ! ,,/ II 'C;! 'cJ. !la'!> I CII! l:';~ l)}m~y CII1 ~ 861b1\n k~-;:;/1Ng>lB8alt dqc Hinh Iv.21-: M6 hlnh thanh19pCaCtu6ngtramtich trangmQllam gi6c ch6u(Reineck,Singh,1980). IV.II.3. NHOM LONG SONG: Day la donvi b6i richchuyC"ucuaRungSacGia Dinh.Cae longmangcochi~urQngdi tu1dC"n1800metvaco chi~usaudi tu0,5 dC"n20met.Ggnnhu'60%chi~usauchungcualongmangd~udl(qCHip b~ngv~tli~utrgmrichsu6tthaiky khongco Iii. Hongcualongmang thu'ongcotri~ncao,nhungnoinaocochuatu 10%setsmectitetrdlen, hongtrdthanhthoaithoaivadayhoanongrit nhanh.Dayla lllQtviind~ lienh~rit nhi~udC"nsanxuit (giaothong,n~nmong)VISl!Idbo la lllQt taihQachoRungSacGiaDinhtrongtuonglai. 60 Cae long mangehinha day g6m co : song 86ng Nai (SoaiR(;lp), songLong Tau, song86ng Tranh, songThi Vai, r(;lehTa Chen (Co May). SongVam Co, dil khongDAmtrangdia ph~neuaRung SacGia 8inh, nhungefingdonggopmQtluQngnudeva v~tli~utdm itch quaDtrQngehokhuvlfenay. Cae longsongd~ubi anhhuang loan bQeuabannh~t tri~u,do v~ytrftmrich a long mangva hai bell bo xay ra tungeh~p trangngay. Khi tri~uxu6ng,phil sarabi~ng6mco 2 phftn: - phftn10bingduQetaitrangmtde - phftndaytruQtdaibell dudi . Kip khi tri~ulen, v~nt6era bi tri~tlieu, loanbQv~tli~u 10bingroi t(;lieh6, con v~tli~uday ngilngdi ehuy~nxuoi dong. Sail do, tri~uxu6ngvaquatrinhthtinhit l(;litie'pdi~n. Cho Dentdm tichva xoi mOllchenke nhau, lamn6ib~tlen mallthuffn co baneuakhu vl.ic eli'asong.(j day,khongth~apd~ngqui lu~tbo 1d bo b6i euatHInghiu hay thuQngluu song. MQtbo co th~vila la ma cling vila b6i, tuy con nude.Ke'tquahi~nra la doeuQediu tranhgiii'adongra vadongVaG. De'nmilalfi, dongra Ia apdaovi v~nt6e khai dQngqua IOn. V~tli~uthonhucat vaeuQitra thanh10hl'ng, Dentroi tuQtra bo bi~n,d~khi g~ptri~ulen, chungroi xu6ngday nudenhusetva buncLla milamtdcki~t. 8i~u fiftyco th~ki~mITatrongcaeehuye'nHiymallhi~n nay,efingnhutrangbaaeaohAngDameuasa HAngHa, thuQcBe)Cong Chanhtrudekia (Hinh IV.22). M~tkhae,dQdaodQngmlfemtdetri~u H trang2 khu vlfeeli'asongSoai R(;lp- NhaBe vaLongTau - Thi Viti hoi khaenhau mQtit. H a phiadongDamd(;lt3,3- 3,4met, trangkhi H d phia Uly hacchId(;lt2,6 - 2,8met. TO~lllbQkhuvlfegftnsongLong Tau - ThtVai co dinh tri~ueao so vdi dQcrheaeli'asongSoai R(;lp- Nha Be (hcin 30cm),trongkhi ChaDtri~uthip aSoai R(;lp- Nha Be l(;licaoheinvung LongTau- Thi Viti tll'20- 25cm.Nhuv~y,vilngLongTau - Tht Vai chill anhhttangeuatri~ubi~nnhi~uhon vilngSoai R(;lp- Nha Be . Lue tri~udang vilng h(;lluu dong Damva dong bi xam nh~p m~ntnioe , trong khi tri~urUt,dongehaymangrheanudetITthttQngngu6nv~ it m~nhon l(;li co huangdongDam(ttiela huangsongSoai R(;lp).Do do, s~tngQthoaakhu v~tcdongva dongDaml(;lidi~nra eh~mhejnva ye'u dftn.Ke'tqua la khu v~icdong va dong Damchill lac dl!ng eLla lllidc 61 bi~nlau hon so vdi cac vung tay va tay b~c (B<lingcong Minh va Nguy~nhfi'uNhan, 1993-1994)(Hinh IV,23), Ke'tquanily duQCphiloanhr6 trencacdon vi triimtichcua haikhuvlfc : vung SoaiR<;1p- Nha Be g6mcac de thuytrieuclingvdi slf t<;1ol~pcacgi6ngcatdQcyenbd tay Ly Nhon; trongkhi vlingLong Tau- Thi Vai g6mtoanv~tli~utriimtichbunsetcuadilmm~n, ! .~"""'L1 t ~« ","00"\r" '"' . \ H . ~>J<1 ",..Y. .' ~ A. ... .' ..~ -, "'K.. 0;:'~ ~ s...,~ "" ~.".. "'::"'\: ~ " , , /~'.. ..".. ,.\\, "', ". =--~ /' .. ,,' " ~ . ..:..:..:-z.>..".";" -, ,:: :: ..'.." ~.:--.: (.-.\.. ~.:::,:." ", ~::.:",.." :: ::,'..'" .:. 0-'.;-"":""" ,~"":,,,;,""""':"":' ,,,"' , ' ':,"",": -::', "".." """""" ~" . '\.~' P.. .. ,. " .. .. .. " :' --, 'o,'", ".~. --"l;:",".. . .." --' :: --f . :' ":''(""' X"' ~' ,~ " " " """" " " " ".,: " ,...,..uu" ~b"" ",, ' ," h ..".M~~',;,;,. '.~~, h"~"':"-<:~""':.""" ," .-. , ".., ,""~",,".~' "~,.." ,,-~~c:f:o""" .:"",..:.~:.. ,," M -,"'i,":.,'...h.W"""""" ".~ ..M .."..""I.";"u' ",:' ,;.-",>, ",'"" .. ' :', ,-,. :,' .', '::'... .." "..~.. ,. ..'" c' ..".. .. -.. . ".. "-~: :::....~::'~,: ..:.:O:,..~~:':: :~...~:,'.,..':",',.-,,:. I. ,," ~ " ',' .. "" ~' . I I~" "."",..:"":,-",, ,, ".- ".-"'" "," ~f~~~W:~!1 r .'.. , $~~ ~.',," . " " " . " . .. ' .. ' .' BUN " ,"""":""":'::'" ,,°.,,' ."MH'" '" -"- "" ,-~" .. ..". "," ',w c;;'.. . .. cg",,- C~T 1,<.',) ,< . .',.,'",:;.",":, CAT S AN. ' :' " " ~ , ' , ,-~ ,, - - ", ' , " , ~.\ " " -' ' , ' ! ",-" l /'. vo6~I, ":--':~' - :-:;-':~~~~~ " .. -, :-:;,_~ 5V-.' .. " .. i ffinhIV22 ..Band8Cila Tdu - Cila D(ii - Soai R(ip vjnh GctnhR6i Ill!) 1/40.000(1965-1970)cho thay tinh chat cua w7tli!)u lrdm rich dciy.(Nha ThuyVi;ln,1970) ffinh IV.2-i .. Ban d8 phan bo khonggian mifcnudc triJu rut lit D1NH CAD xuong CHAN THA'P t(ii H(i luu song D8ng Nai (lheo D(lng cong Minh va Nguy~nhilu Nhan, 1993-1994) Nhd slfphanbo trungthlfccuacha'trilmtichrheaanh huangkepcuadongnudcvatrieu,donvi b6itichlongsongtrdnend~ phanbi~t.£>6la de t\1'nhien,de thuytrieu,bi'iib6i, doi song,c()n song,vdinhungdonV!mdivacd', 62 '5 km )0 km =- I .~~~Ol I' Long Thanh /~ ,,;1/. ...j~ ~,. i i~al I i I I r , '5f.m ~ ::0 II :1 :uj \ Ci :=;1 ddianhhuangsongehuy€u > ddigiapnude ddianhhuangtri€u I ehuy€u ~ 0 COO THiCH HlnhW . 23: Phdnb5khc5ngianmI!ent/oetri~urut taDjNH CADxu5ng CHANTHAP t~iH~lliusc5ngD6ngNai ( theoNguy~nhrluNhdnva DcjngCc5ngMinh,1994). 63 IV.II.3.a. De 111nhien : Ca'utruevi monftyxua'thi~nkem0 Rung SacGia Djnh . Day la noi danhda'uRung SacGia Dinh khongcon mYa v~phia ngu6n. De tlf nhien duqelt1songthanhl?p vdi V?t li~utrungblob va min nhl1' bunthophacatmill, e6 l~nset.VaGmualt1(nuderang),V?t li~u10Il?1'ng tho e6khuynhhl1'dngtranquaba songva roi xuangd6 tn1'de.V?t li~u min bon,tranra xa bon, t(;lonen trftmrich min euad6ng ll;}tnAm0 Cat Lai, BungSailXa va phiadongLong Thanh. Hlnh IV.24la khoiinhchlakh6asaIl euaDornbuschv~ detunhien. De tlf nhien xua'thi~nr6 nha't0 khu vlfc Vlnh Th<;lnh, nhungl(;linAmbell dudi d6ngthuytri~u0 Blnh Khanh - t<;liday mdi bat dftuRung SacGia Dinh mQteachdungnghla.Chungtoi da khoanki~m ITat<;lid6 va b~tg~pV?tli~uduoi cuade tlf nhien0 dQSail0,5 -0,8 met vdi bunthophasetc6 ehuatha'ukinhcatmangtu 1de'n5 mm. d dlnh de va phiahongdayra dongnudc,cha'ttdm rich bi thlfeV?tb~yl(;li,t<;lora ra'tnhi~uvungxoay lQn,d~l(;lica'utruc trftm rich phue t(;lpnhu xien eheo, phan hi ohio (ripple cross-lamination). Ngoai ra,kich thudeh(;ltcuaeha'tdm richnoi de tlfnhiend~umin h(jnd dl1'anglong mangnen t(;lOea'utrucxien cheohi th?tmill, kich thl1'ocnho, duangeao(scourtruncation),la songhangva da'uve'tth~1'CV?t(n~t<;lich6 va miinh va) la ph6 bie'n . Theo Coleman va nh6m (1964) (trang Reineck,Singh,1980),ea'utruela dqn s6ngva ne'pnhan lea (climbing ripple)13.d~etnl'ngchomoi tn1'angcuade tlf nhien. Hang sinhV?tcling dftykh~pva 51fke'tthaieunghi~ndi~n(s~tva voi) : ke'tthai sat thayd Tam Thon Hi~p,ke'tthoi voi xua'thi~n0 Thi~ngLi~ng,thllQcsongThj viii (Tdn Kim Th<;lehva nh6m,1978). IV.II.3.b.De thuytri~u: D6 la lo(;ltde dl1'qethanhl?p tu Nha Be de'nCftn Gi0. Tuy dog thanhphftnca'utrucva d<;lngd~ugiang nhl1'de t~1'nhien, de thuytri~uchI IQra VaGluetri~uxuang.Nhu V?y,m~tde bAngho~cthap hondlnhtri~ucao,vakhongbaagiOchimxuangbell dudi tri~utha'p. De thuy tri~ue6 b~nganghyp, VaGkhoang vai Chl.lC met,d6ngnha'tva khongtllanrheaqui lu?t b6i 10cua dong /1l1'ochay mQtchi~unhu0 noidlnhtamgiacchao.Do d6, kh6xaedinh vj tri ha?c slfhi~ndi~neuade mQteach1'6r~t.Vi v?y, phiii thu0ngxuyentheod6i 64 0\ VI '/ BUNG SADDb BSE> ~ ft ;; L" 9. £>TN 'Ii i>-. £>TN<' ,,/""'~"X~, A . .Db TU NHIbN ~ ~ ~ CI) (II BSE> Hlnh N - 24A: Anhch~pdettfnhien(jLongAn,tilmdybay1/50.000,vapMngididodncilanh6mDornbusch (1969).DdyLa"khodnhchzakh6a"s611cilanh6mtdcgidd6. 20 0\ 0\ ~ :i 10 "1::] ~ ~. -60> 0 c;n 0 ~ <0- Q-IO A .. A r:zaCL rzJ CH E:J SM CL CH ..set ..setphahilu C(J D~TV NHIbN SM ..cdthQttrungblnh DTN ..d~t1/nhi~n BSD ..bTblgsaud~ 0 1000 2000 3000 KHoANG CACH, TmH BANG MET 400C Hlnh N - 24B.. MijtcdtkilmIrangangquam~tphtlch~d~11/nhi~n. st!bie'ndQngeuacaede thuytri~u- ho~ebhnganhv~tinhehl]ptheo ehuky voigiaiGOaDtt!dQng,ho~edovelientt]eduoidit - d~tranhmqi st!eh~mtr~coh<;tide'nsanxuit . De thuytri~ula ndi tr6nglua nuoevaomuamlJ'a,voi Dangsuitkhongeao.Nhungne'udftutuvaodayeongtdnhthuylQinQi d6ngthieftnphaiehuyde'ncaeddnvidftmm~ne6vabungsaugi6ng e6ohmbellduoidethuytri~ufifty,d~khonglamdit ehua. IV.II.3.e.Bi'iib6i: Dayla ddnvi trftmtichpht]euade thuytri~u.0 nhii'ng ndico longsongrQng,ho~elongsongdilbi st]PId truoed6,phusamoi- nhav~nt6enuoethichhQp- de'nb6i tt].V~m~tfifty,thamth~J'ev~tveil ba nhu la dua nuoe,mim, gia, Vyt,duoe... d~ugill vai tro quail trqng trongvi~eb~ychit trftmtichl<;ti,ho~etrt!etie'pbhngthanth~euachung, ho~egiantie'pbhngeachtri~tlieu v~nt6eeuadongehay. Bunphasetla v~tli~uehinh.Trungbinhbunehie'm60- 70%,settu 30 - 40% . Chit hii'ucdkhongduoi03%. Bili b6i tie'nd~nra long songbhngnhii'ngv~tsongsong,rit d~nh~nthiy trenanhmaybay. Hili b6i b~tdftubhnggiai do<;tnohmhen dlJ'oim~tntJ'oc rong,Dengqi la bili b6i ngftm.Theo qua trinheh6ngchit, no trd thanh ml'alQ mla ngftmDengqi chungHi bili b6i , ngangvoi de t~(nhien d dlnh tamgiaeehau RungSac.Khi bi~nrut dftnra khdi hdnnii'a,thi bili b6ingftmselQhin len,t<;tohanhdetri~uvadett!nhien. Nh[(ngbili b6i ngftmbi dftyvaotrongdit li~n,nhungehuan6ihin leudl(Qe, vi qua tdnhDende lamchom~tdit conthip, thiv~ncon xamxflpnt(ocm~n, bie'nthanhbili b6ie6,mQtddnvi da euad~mm~n. De thuy tri~uva bili b6i ngftmd~uco dQ trt(dngthanh eip 4 - 5. Sangde'nbili b6i e6, dQtrudngthanhd<;ttcip 3, doi khi la eip 2. Phandinhraubgioi caeddnvi trftmrichnftyse phl;lCVl]choqui ho<;tehtr6ngrungm~nt6tbon. IV.II.3.d. Doi song: Day la ddnvi pht]cuade thuytri~u,d6ngthaicGngla ddnvi trftmrichd~ebi~t.Vi de thuytri~ung~pnt(oclen,doi songd huy~nDuyenhai clingehiuanhhuangtri~unhuv~y.86 la doi s()ng ngam. 67 ---- ~ / ~- '- 1/ I ( \ \"'~- ------ / ~ I /~-, " I I '<: \ \ - \ \ /'--- \.'-/---/- '--~/ - --' - - / A 8 c ~, i ,- -~=) I) /~ ffinh IY- 25A : Ba cdchtq.odoq.nsongbo: A- chutecut-off B.- neckcut-off c.- avulsion ffinh /[1-25B: TrinhIT!tich tl!-mjnddnIf tuiJngcuamQtdoi song.PhdntrencungduqcphilbJi mQtlapbun. E ~- -!:? ~ ffinh /J/- 25C : NhilngcdutruetramItchhi~ndi~nIrongde IT! nhiencuasongBrahmaputra(Coleman,1969). 68 Doi songc6 diu trucxien cheoth~ng,khac vdi cilu truc giii'along mang,thuQclo~ixiencheotriing.(HinhIV.25) Doi song xay ra d mQtdi~mcua de, noi d6, b6i rich ngangtrd Denap dao. Nhii'ngluon cat song troi v~,d~udung l~i d6, cling luc thamth~(cv~tndi nhanhra long song,cling b§:ygiCi'chill trftm richl~i.Khi c6 Iii duathemv~tli~uphongphu v~,doi songla noi giam v~nt6c cua dong chay, DenhungthemmQts6 v~tli~u trftmrich mQt cachlien t\Icd lOp10bIng . Do d6, doi songnhora giii'along songva c6 kha Dangt~okhuc u6n ho~cbit nghenlong song,va ta c6 don v~lc)ng songc6. (Hinh IV.26 va IV.27). Noi mQtlongsongc6 - dangche'tho~cbi b6 (do(;lnb6 hayabandonedcourse),chilltrftmrichtrdDenmill h~tbon.Nhi~unoi vftnconcat,th~mchi cattho, riftph6bie'nd tamgiacchaoCll'uLong.a RungSacGiaBinh,mQts6do~nbonh1.1'the'clingduQcphathi~nd gilfa Ly NhdnvaBinhKhanh. Nguoitaph\Ich6ido~nbob~ngcaccilutruc ne'pnhan(ripple-mark)xiencheotriingvacaclopc6thanthlrCv~tcon nguyenv~n(traml\It). Saugiaido~ncatIa giaido~nset.Bay la cilu tructrftm richmillh~tcuaao: cilutrucphanla (lamination).Ne'udo~nb6xayra dQtngQt,trftmrichcatbandftuseduQcthaytOaDbQb~ngsetminh(;lt. Bay Ia trt(onghQpcuasetxamxanhtimthilynoimiii khoanTamThon Hi~p(SdThuyLQi,1980). Tren nguyent~c, doi c6 d~ngparabold~u. Slr khacbi~t cua dongchay,cua kich thudch~t va anh hudngbilt ky clla thamthlrC v~tkhie'nchod~ngcua n6 l~chdi . Vi d\I truonghQpcua cac doi d dqc IDeosongB6ng Tranh,songThi Viii, d T~cOng Trun. asongOng,doi phattri~nm~nhde'ndQlamlongsongu6nkhucriftnh~t,tnidekhi d6 ra cii'aB6ng Tranh. Tham tht1cv~tn~mtrendoi bi tanpha,thl trftmrichd d6 miltcanb~ng, Dennhi~udoi dfibi ld. Doi bie'nthanhbfii b6i, r6i bfii b6i ngftmva cu6iclingbie'nmilth~n.Vai trocualam nghi~pd day qua th~t quaDtrQngtranggiacdQkinh te'. 69 I 0 E>TN fflnh IJl2M ..Anh ch~pm~tdOf;ms6ngchit, cOngQiLado~ms6ngbo (DSB)hoQcLOngs6ngcd (LSC). "Khodnhchlakh6a"s6 14cuaDornbusch(1969)chothdykhucudncuast1ngD&ngNai thanhmQt aollliJi li~mr6i tad6trOthanhdoQns6ngchit. -..) ...... 20 A A' : bunmin : cdtvU'a : set hT1uC(J GW : sQnsoivi~nchuy : cdtttint~n Hinh IV26.B: Mq.tcdt/dImIra chothdym~tphach~vcfibiin d6i wjt ch& khdd~tng~t,n6 gidi thiGhtQisao tr~nm~tdi~ntfchbe,c6nhi~ulo(li d&, loQim6ngkhdCnhau. ~ ~~ ~ ~. 6 0> 0 CI:) 0 ' ,Vt.< . " ~ :.v- ' u ' " '/! :...:./ ' ~~~!'"() . , 0, <0,-10 .' . ,'.", ,,"" '- ~ .0 'pm) SA cC , ' , " ' '. ,0 0 . . ~',,:i,:"~:,:,<,,:o.',~ :-~;,:,~~:,~,'o,;.,.~::',',.,'.::o-.. -'::'.'1:\" ,., ~..',;,:- ,:;.:'--- ' ;,.':, "I"... 0' ' " ',",0:';":':'" --.;;....v- ~ ~' ,:""':--': ' " .' , I: ...~- '-:.:~ .Y' ML SM CH SP -20 0 1000 2000 3000 4000, KHoANG CACH. TfNH BANG MbT -J N BUNG SAD Dll BSD CS lRnh IJJ27.A.: ThanhtQodoi s6ngLam~tphtlch~trdmtick thz(cmgtjpiJ Rilng SdcGia Dinh. "KhodnhcMa kh6a"s62 cua Dornbuschdll(1cthilt ltjp tr~ns~ngHtju.Phdn gidi dodncua tdcgid kh~ngchtiy dIn edutrueICingtrllOngeuadoi. GW ,'s(ln tho 20 A A' c::.:J S M CZJ S P rz:aCL I"".~:olGW ~CH -.J V) ~ ..~ 10 ~ ~.-6> 0 r:I'J 0 cJ , '0' °t " '()" ',' 'I/- v ,~ -I ," " I ',' " . ",,' "'"' " , '--' "- -- ~ -- ' 0 --:- ' -- '. . ,' /,,',Q'.',""""""'~. ,'-, .,' , ,', '. ',,",' () " '" o .~-.,o",',<J, "0 ,pI-J.USAc6 "0 ',.'0,', ','0"'" O"'0'~",O"'o',,\),'o':o,,',,'o,:o' ',°,' ,° "o':?'(,'o"",o '~o' "0.',°1,0"':0,.°-20" '. . 0 , ,0" " 0 1000 2000 3000 4000; KHOANG CACH, TfNH BANG MET CH .. LONG S6NG cd D~TV~N SM CL SP " catvaa " set " cat lin l~n "sethilu co fflnh IJl.27.B"Mt)tcdt!dImIra cuam~tdoi chothdyvi trl dq,cbi~tcuab6i tichngang IV. II. 3.e.C6nsong: D6 la ndiv~tli~ututho(catphas~n)de'nmin(bun lin set) rich t~ va d~nd~nbit nghen long song (Hinh IV.28 , IV.29). . Trangcdche'tdm rich,dayla v~tli~ucualOptrftmrichday, chungtn1Qtdaitheotri~nsongvachIdungI~ikhi g~pchuangng?itren duongdi.Ba sachuangng~ila nhfi'ngkhaicatphas?n,doh1nwnhdem v~bod mQtkhucsongnaGd6,t?OramQtnutch~nt~tnhien.Khi v~ntac dongbi giam,bun va set Hiplen phia trenc6n, r6i de'nthamthlJ'C v~t.Ne'uv~ntackhonggiam,catthonholenkhoim~tnttacnhl(tHrong hQpd phiaNamcuaCatLai vadQctheoxii BlnhKhanh,clingnhl(dQc rheasongThi Viii.Baylanhfi'ngmocatchonganhxayd~tng. Khi longsongbi Hipc?n,c6nsongbie'nthanhc6nsong c6,nhumQtsaconhi~ndi~nt?isongLongTau,songB6ngTranh.MQt di~mdangghinh~nlaBiii SanHo(BancdeCorail)lIensongLongTau, g~nB6 Hoa cli, la mQtlo?i c6nsongvai catva s?ntho,trongd6 s~n lateritelaph6bie'n. C6n songbie'nthanhnutch~nkhi c6 b~rQngb:tngb6 rQngcuasong.Khucsongt~tnghentrdthanhao to,hungtdm tichId bing(bunmill va set)clingxacba thvcv~t.Setchie'md l~lIen 60%. Bay la lo~isetbala (smectite)d6ngthaiclingla n~nm6ngye'uhdnhe't cuaRungSacGiaBinh.Xacbii thlfcv~tlingthait?Opyritenguyensinh PeS,r6i thusinhPeS2 , tuclaphenti~mtangtrongdit. Lo?i phenn~y clingngangt~mvaiphencuabltngsailgi6ng.Do v~y,khibi daDbailen, selamchodQchuaIanra trendatcuad6ngthuytri~uvanit phenphil belltrenchung( nhutHronghQpcac16khoanLKI , 16khoansa2...) IV.II.3.f. Y nghTatr~mtfchcualongsong: Cacnhanhlieunuacn:tmchangchittrangRungSacGia Binh chothiy mallthu§ngifi'adongchaycuasongva tri~ula gayg~t. Tri~uc6saibi~tv~mlfcla 3- 4 met,khie'nchov~ntacravaVaGd mQt diadi~mnaGd6quailtrQngnhunhau,dod6luQngnuacc6xuhl(angmd themnhanhmai.Xu huangd6phatra nhungkhongthanh,h~uquala lamchonhanhlieunuactrdlienngo:tnngoeo,nhit la ndiduaidayn€n la v~tli~ucat(Moore,1966);vi d~nhukhuv~tcanhhuangbdikhaiphil saNhdnTr?chvakhaimacmathoh?tdi tuLongThanhde'nVlingTau. Longsongla mQtbangtaiphilsa,d6ngthaiclingla m(H lacnhanxoi mankhungkhie'pcuaRungSacGia Binh. Can b:tngll(u 74 ~ ~ ~ <~ (/)CI) o~ $ ~ 75 ----.0- \() 0- ........'-- :: (,.) VJ :::: -C:> E C) Q ~ ~:::: (,.) ~ ~ C) ~ ~ C() ~ ;::.. b' -C:> f ~ ~ 10.--. /~-. ~.,... :: ~ ----. 0'-- C() ~"'0 VJ ~ (,.) ;>-.. ~ :: C() ~"'0 VJ C) ~""'" '.... () -..J 0\ i ..i 10 ~ ~' ~ 0 0 (I) 0 (j <0'-10~ 20 A A' : set : cdtvU'a 250 500 750 KHOANG CACH, TtNH BANG MET Hlnh [Ji.28.B..Mtj.tcdt/dIm Ira chothdywjt li~ucualllqn cdts~ngndmb~ndllai, b~ntr~ncd wjt li~uminhan cuac6ns~ngphuten, E::ZJCL (:.:J SM CL SM £)TN TRAM TfcH KH(jNG R6 -20 0 1000 -.J -.J E>8hfnhi&t DTN ..-- C6N S6NG cs 00 ~. (;) ~) c:. BSD CS~ Htnh IJl-29.A: Anh chl!pm~tluqncdtsc5ng(tll~ 1/ 50.000)tT~nsc5ngHcj.uvOiphdngidi dodncua Dornbusch (1969).Luqn cdtsc5ng(LCS) Lati~nrheincuaell Laosc5ngvaconduqcgQila c6nsc1ng(CS). J 00 20 A A' CH CL ..sethilu co ..setdeo 10 ...J I/) ~ I/) a: w ~ w ~ 0 0CH E2J CL f22J SP SP ..catcdphdncdph(ltkern PhdnCH cdthl thuQcdanvi btlng sau de hoijc set mijn cua citabiln cd. Innh IJl29.B..Mi)tcdtkilrnIraxuyenqualuqncdtsong(LCS)chothdylienh~va;longsongvadays6ng. S6NGHJU ..T LU<;1NcAT S6NG ~ z 0 ~> W ...J w -10 ':,:,::':',>,:Oo:',.:,o::O':~:",""'O" , :"," ~.:ovi~~;i~c~~:'<:: :',:',..' '}..' -'0. ,..,., ~f". .' ," , , , ' . , /.". " ?;r/?>~/7?~ ~ < BUNG SAUB~ HoAc SET BrE.N l , .- --0 --- . ,. . 1000 2000 3000 DISTANCE, METERS 4000 -20 0