Cd thfla n h a n sfl khac biet ve khf hau gifla thdi ky Pleistocene va thdi ky Holocene d Ddng Nam A, chflng ta mdi cd the giai thfch dflde mdt so bien chuyen trong qudn ddng vat gi[r]
(1)MOI TRUONG TU NHIEN DONG NAM A •
THdl PLEISTOCENE
VU C O N G QUY*
Hien nay, cac n h a khoa hgc dfldng nhfl nha't trf coi Dong Nam A la mgt thiic the dia ly m a n g sac thai n e n g
Ve ca'u trflc dia chat, loan bg Ddng N a m A n a m tren nen luc dia cd cd tudi Paleozoi, vdi van ddng tao nui cud! cflng tudi Greta, thudc kieu Thai Binh Dfldng, kem theo sfl p h u m trao Riolit va xam n h a p G r a n i t tudi T r i a l , J u r a hay Greta Lich sit p h a t trien rat phflc tap cua dia cha't la cdi ngudn sau xa dem lai cho Ddng N a m A mdt bfle t r a n h dia h i n h da d a n g nhfl
Ngfldi ta thfldng chia Ddng N a m A t h a n h hai vflng dia h i n h k h a c n h a u : Ddng Nam A luc dia va Ddng N a m A hai dao Tren khoi Ddng N a m A luc dia, tfl Tay M y a n m a trd di, cac day nui xua't p h a t tfl cao nguyen Tay T a n g va Van Quy toa xud'ng theo hiidng k m h tuyen, thtiu ggn nhflng cao nguyen ngi dia rdng ldn nhfl cao nguj'en S h a n , Korat, K h a m Mudn, Boloven, Tay Nguyen, rdi d a m t h d n g bien tao dieu kien cho nhflng sdng ldn chay theo cflng hfldng, bdi ddp nen nhflng
* Vfl Cong Quy Vien Nghien cifu Dong Nam A
chau tho q u a n trgng Nhin chung, cau trflc dia chat khoi Ddng Nam A luc dia ddn gian hdn khdi Ddng Nam A hai dao d khoi Dong N a m A hiii dao, ngfldi ta tha'y cd sfl ket hdp cua cac ca'u trflc tre (Gdm nhflng n h a n h thudc ddi udn nep Tan smh tfl Tay M y a n m a xudng den S u m a t r a , J a v a , T i m o r va n h a n h tfl Philippin xud'ng) vdi cac m a n g luc dia cfl hi sut Ifln cdn sdt lai Sfl bieu hien m a n h me cua cac van dgng kien tao mdi, cua nhflng boat ddng nfli Ifla va ddng da't dfl ddi, cflng lam cho dia hinh cua khdi chia vun t h a n h muon nghin hdn dao ldn nhd
(2)14 Nghien edu Ddng Nam A 6/2009
t r u n g binh h a n g n a m t r e n 20"C, phdn ldn tren 25"C Nhieu nhii khoa hgc chia hiiu Dong Xam A lam hai loai: Khf hiiu xich dao va khf hiiu gid mfla xfch dao Loiii khf hiiu thfl n h a t phd bien d k h u \'flc Ddng Xam A hai dao Dac diem cua vflng h a u la sfl bien ddi h a n g n a m cua dci ndng ra't dieu hoa Sfl chenh lech nhiet theo cac mfla rat nhd Loai hiiu thfl hai kha phd bien d vflng Dong X a m A luc dia O day co gio ndng thdi mfla va den mfla ddng thi ditgc tha\' the b a n g cac ddt gid kho l a n h Ciic k h u viic rieng biet khac n h a u chu veu d chd mua khd n a m dai hay n g a n
\ h i n chung, Ddng Xam A cd lUdng lim lucing ddi ldn Sfl khiic nhiiu ve ludng am gifla cac khu \'ilc ]jhu thucic vao sfl p h a n bd iij) luc khdng khi, hoiin lifii gid mfla va dia h i n h tfl'ng k h u viic
Trong nhieu miit, dieu kien lfl nhien Ddng Xam A thdi Pleistocene khdng khac bict ngiiy na\' ldn lam Trong sudt the Pleistocene Ddng Xam A van la mdt khu \'flc nhiet ddi am chiu a n h hifdng cfla giiio mfla Theo R.F F l i n t , t r o n g t h e Pleistocene, da ton tai nhflng v a n h dai khd Clin chi tuyen Dieu dd cd nghia la bay gid da xuat hien nhiing vflng ap cao can chf luyen, hoim luu khf quyen va gid mfla n h u
Trong n h i e u vflng t r e n trai dat thdi Pleistocene chiu iinh h u d n g cua b a n g lhi Ddng Xam A khdng cd b a n g Thay cho cac thdi ky b a n g va gian bang, d Ddng Xam A xay cac thdi ky miia va
gian mfla tfldng flng Tuy vay, gifla thdi ky miia va gian mfla h a y thdi ky khd, nhiet va a m k h d n g c h e n h lech qua ldn Khi thdi ky b a n g h a xay r a d vflng Bac h a y vflng nui cao nhfl Hymalaj'a, thi d Xhiet ddi, sfl bdc hdi dai ditdng gay nen thdi ky mfla N h i i n g t r o n g thdi ky gian bang, d vflng nay, gid mfla m a n h hdn, nen van cd the gay miia a m
Tfnh chat nhiet ddi dm cua hau Ddng X a m A thdi Pleistocene cdn difdc bieu hien qua q u a n thflc vat va ddng vat
(3)Vil Cdng Quy - Mc>i tridnig tu nhien Ddng Nam A tlufi ky Pleistocene 15
vao trong, khf h a u khd hdn, la xavan va rflng cay r u n g hi m u a khd
C h u n g ta cd t h e cho r a n g the Pleistocene, d Ddng N a m A, cung gid'ng nhfl nay, da ton tai hai loai rflng: Rflng mfla thfldng x a n h va rflng gid mfla Rflng gid mfla la rflng cd cay r u n g la mfla khd hay la rflng hdii ndp cay thfldng x a n h va cay r u n g la Nhflng n g h i e n cflu mdi ve bao tif p h a n h o a t r o n g t r a m tfch Pleistocene d mien Bac Viet N a m cung dan de'n ket l u a n dd Tai day, t r a m tfch Pleistocene h a n g dgng h a y ddng bang, cac n h a n g h i e n cflu thfldng gap pha'n hoa ciia nhflng loai cay cua rflng la rdng thfldng x a n h t h u d c hg D a u (Leguminosae), hg Ca phe (Rubiaceae), hg Thdu ddu (Euphorbiaceae) va nhflng cay hg Dfla (Palmae) dac t r u n g cho nhiet ddi Nhflng ben canh dd da cd nhflng loai cay r u n g la mfla ddng nhif xoan(Melia), sau s a u ( L i q u i d a m b a r ) Nhfl vay la da cd nhflng rflng hdn hdp thUdng xanh va r u n g la Nhip dieu n a m vc'ii sU p h a n hoa hai mfla ndng lanh ro r a n g difdc quyet dinh bdi che gid mfla C h i n h gid mfla Ddng bdc da tao sdc t h a i A nhiet ddi cho thien nhien Sdc t h a i dd cang dam vdi sfl hien dien cua nhflng ciiy hg Sdi de (Fagaceae) va nhflng cay la kmi T h a m chf, t r d m tfch Pleistocene ciia ddng b a n g Bdc bd, ngitdi ta cdn gap ca nhflng gid'ng cay fla l a n h hg Gang Id (Betulaceae) nhfl Gang Id (betula), Tdng q u a n siii (Aluus) ma chi tha'y tren nui cao Theo mgt s d n h a nghien cflu, mdt sd giai doan khd lanh hdn ciia
the Pleistocene d Ddng N a m A, rfl'ng mfla thfldng xanh da thu hep dien p h a n bo' va rflng gid mfla hon hdp md rong
Sfl on dinh tfldng ddi ciia khf h a u Pleistocene Ddng N a m A cung bieu hien d tinh chat qudn dgng vat
Hien nay, nhieu ngiidi coi q u a n dgng vat d cac ldp Thfldng I r r a w a d y M y a n m a cung nhfl cac q u a n dgng vat Kali-Glagah va Tjidulang d J a v a mdi thiic sU la quan ddng vat Pleistocene sdm(vdi y nghia Villafranca) tUdng dfldng vdi quan dgng vat d cac ddi T a t r o t - Pinjor lorit Siwalik d An Do Trong cac ldp chfla nhflng qudn dgng vat dd chfla tim thay da'u vet boa thach ngfldi
(4)Gunz-16 Nghien cdu Dong Nam A 6/2009
Mindel, cdn q u a n dgng vat Trinil vao thdi ky b a n g h a Midel H.D K a h l k e keo nien dai hai q u a n dgng viit xud'ng m u d n hdn Theo ong, q u a n dgng viil Djetis tdn tai tfl thdi ky gian b a n g Gunz-Mindel den Mindel I, cdn qudn dgng vat Trinil tdn tai vao Mindel II Hien da cd nhflng nien diii tuyet ddi xac dinh b a n g p h u d n g p h a p K"*/A'" cho hai q u a n dong vat Ldp chfla q u a n dgng vat Trinil co m e n dai tfl' 50 van n a m den 70 viin n a m each va ldp chfla q u a n dgng vat Djetis d Modjokerto cd m e n dai la trieu 90 van n a m ciich
Trfldc cliiy, Von Koenigswald da ggi cjuan ddng vat Trinil la qiuin dc)ng vat T r u n g Qud'c-Ma Lai (Sino-Malayan) vi nd chfla nhieu yeu td' gan gui vdi q u a n ddng vat da p h a t hien cac h a n g ddng d Nam T r u n g Qudc Hien ciic n h a khoa hoc thay r a n g chinh Irong qiuin dcing vat Djetis cflng da cd nhieu yeu to diic trflng cho quiin dgng viit Xiim T r u n g Qud'c, tflc q u a n dgng vtil thugc phfl'c he Stegodon-Ailuropoda (Voi r a n g kiem-Ga'u tre) Den chiing la biet r a n g q u a n dgng vat Slegodon-Ailuropoda k h o n g phdi chi p h a n bd d vflng Nam T r u n g Qudc ma cdn la q u a n ddng v a t dac trflng cho t h e Pleistocene d Ddng N a m A, da p h a t hien d Viet N a m , Lao, C a m p u c h i a , M y a n m a , Malaixia Do chd cd dia diem khdng tim Ihii'y ga'u Ire (Ailuropoda) nen cd ngfldi ggi q u a n ddng viit niiy la Stegodon-Pongo (Voi r a n g kiem- Difdi udi) Trong tinh hinh hieu biet hien nay, c h u n g la biet r a n g ciuan dcing viit Stegodon - \iluropocla hay
Stegodon-Pongo da tdn tai d Ddng N a m A sud't thdi ky Pleistocene, tfl sd ky den h a u ky Sfl bien c h u y e n ciia nd khdng rd r a n g va r a t c h a m chap C h a n g ban: Neu chflng ta so s a n h q u a n ddng v a t t r a m tfch h a n g m a u dd d Viet N a m ma H.D K a h l k e d i n h m e n dai vao Pleistocene t r u n g ky, tfldng dfldng vdi thdi ky gian b a n g Holstein(tflc Mindel-Riss) vdi qudn ddng vat t r o n g ldp t r a m tich h a n g m a u v a n g ma H D K a h l k e dinh nien dai vao Pleistocene h a u ky, tfldng dfldng gian b a n g Eem (Fem) tflc Riss-Wurm) thi tha'y c h u n g gan gfli nhfl ddng nha't vdi n h a u Ta't ca cac gid'ng loai deu cd chung d cii hai t r a m tich Gifla h a i thdi ky gian b a n g ndi t r e n cd de'n h a n g chuc van nam trdi qua, the m a k h d n g tha'y cd sfl thay doi niio Irong qudn ddng vat Dieu dd ndi len sfl dn dinh cua h a u va cac dieu kien s m h thai k h a c t h e Pleistocene k h u vUc
Nhfl vay la q u a t i n h dn dinh ciia qudn thiic vat va q u a n dgng v a t c h u n g ta cd the tha'y r a n g sud't t h e Pleistocene, h a u Ddng N a m A k h d n g cd bien ddng ldn, hay ndi dflng hdn, dao ddng vdi bien nhd Tfl sfl dn dinh cua q u a n thflc vat va qudn ddng vat, cd t h e nghi r d n g ddi tUcJng san b a n va h a i lu<3m cita ngUdi nguyen t h u y thdi dd cflng dn dinh Dieu dd cd mgt y nghTa ra't ldn ddi vdi h i n h t h a i va nhip p h a t trien ciia v a n hoa-ky t h u a t thdi dai dd da d Ddng N a m A
(5)V'/7 Cdng Quy - Mdi truang tu nhien Dong Nam A tlufi ky PIcis tocciic 17
ldn, khdng cd nghia la sud't thdi ky nay, hiiu k h d n g h o a n toan khdng cd dao dgng va cang k h d n g cd nghTa la khf hau the Pleistocene d day h o a n toan gid'ng vdi hiiu Holocene hay hien tai Nhfl chung ta da biet, Dong N a m A khdng co b a n g the Pleistocene (Trfl hien tfldng ddng b a n g d mdt so' nui cao n h u Kinabalu d K a l i m a n t a n ) va dd, khong chui dnh hUdng t n i c tiep cfla b a n g Nhflng nhflng thdi ky b a n g va gian bang ndi tiep n h a u t r e n t r a i da't the Pleistocene da gay n e n sfl d a n g cao hay tha'p cua mflc nflde dai dfldng, lam t h a y doi ra't ldn dia hinh d Ddng N a m A
Trfldc day, G.A.F Molengraaff cho rdng thdi ky b a n g thfl lfl (tflc bang Wurn) miic nUdc bien d Ddng Nam A tha'p xud'ng 75 met so vdi mUc nUdc bien hien tai De T e r r a cung ddng y vdi y kien dd va cho r a n g mifc nifdc bien thdi ky b a n g thfl hai (lflc biing Mindel), cd the xud'ng den 115 met dfldi mtic nflde bien hicn Theo W.L Donn, W E F a r r a n d va M.Ewing thi miic nitdc bicn thdi ky b a n g h a thfl ba (lflc bang Riss) cdn xudng den khoang gifl'a 137m vil 159 m Mot sd cdng trinh nghien cflu gan day da trinh bay mdt each chi tiet hdn sfl dao ddng cua mflc nu'dc bien Ddng Nam A vao giai doan fiidl cua b a n g cucii cflng T r o n g k h o a n g 35.000 nam-25.000 n a m each nay, mflc nflde bien xudiig k h o a n g 100-120 in diidi miic nflde bien h i e n Miic nflde bien khoang 120 m dflde gifl tfl 22.000 n a m de'n 18,000 n a m each Tfl 18.000
n a m den 15.000 n a m , bien lai dang len n h a n h chdng va mflc nude dao dgng khoang 60de'n 40 m dudi mflc hien Vao k h o a n g 10.000 n a m each nay, miic nudc bieii len de'n 10-15 m dudi miic hien
(6)18 Nghien cdu Dong Nam A 6/2009
n a m he t h o n g sdng dd vao vflng bien Ddng S u m a t r a va vflng bien phfa N a m eo bien M a l l a c a s s a r Eo bien n a y ludn luon n g a n each luc dia S u n d a vdi ddo Sulawesi Dao J a v a va dao Bali cflng n a m vflng da't S u n d a vii khdng bao gid noi lien vdi cac dao nhd k h a c cua q u a n dao Indonexia eo bien gifla diio B a h va dao Lonibok k h a sau Q u a n diio Philipjiin trfl P a l a w a n , cung biel liip vdi S u n d a the Pleistocene Nhd nhflng van dgng kien liio the Pleistocene, dien lich cfla q u a n da^ Philippin du'dc md rdng vdi sfl cd m a t cua h a n g loat dao nhd mdi ndi len, lien ket vdi nhflng ddo ldn Theo mdt sd nha nghien cflu, qiuin dao Philippin cflng ddi dinh vdi dao Dai Loan va du'dc ndi lien vdi luc dia chau A
Trong the PleistoccMie, diio Tiin Ghine thitdng ndi hen vdi diio uc b a n g nen luc dia du'dc ggi lii S a h u l Xlufng gifla Sahul vil S u n d a , thdi Pleistocene chitii bao gid cd cau ndi hen vdi Xgan c:ach gifla hai vflng niiy hi khu vfle cac dao Ddng N a m A, du'dc ggi lii k h u viic W a l l a c e a , n a m gifl'a d u d n g W a l l a c e (Riislcy vach ra) vii dudng phiin gidi cua q u a n dgng viit Uc '
Triidc day n h i e u n h a khoa hgc mud'n lien he cac thdi ky miia va khd t r o n g t h e Pleistocene d Ddng N a m A vdi cac thdi ky b a n g va gian b a n g d H i m a l a y a Nhu'ng nhflng cdng t r i n h gan diiy, dfla vao sfl phiin tfch liii ciic cfl lieu Pleistocene, da cho r a n g viec lien he iiliu vay la khong chac c h a n Tuy iihiiui, rd rimg lii nhflng bien dgng ve dia hinh d Ddng X a m A nhfl
da ndi t r e n la sfl dao dgng mflc nflde bien gay nen, m a sfl dao ddng n a y sinh chu yeu la tac ddng cua cac thdi ky b a n g h a va gian b a n g t r e n h a n h tinh Xhflng bien ddng ve m a t dia h i n h dd den lugt lai a n h h u d n g den dieu kien smh t h a i d n h i e u vflng ciia Ddng N a m A the Pleistocene va h i e n n h i e n la cd tac ddng ldn den cudc sd'ng cua ngu'di thdi tien sif
Trudc day ngu'di ta Ihitdng nha'n manh nhflng diem gan gfli ve k h i h a u gifla thdi ky Pleistocene va thdi ky Holocene d Dong N a m A N h i i n g gan day, da cd nhieu n h a nghien cflu lflu y c h u n g ta nhflng sfl khac bict cua khf h a u Ddng N a m A gifla hat thdi ky Sfl lflu y dd ro r a n g la can thiol Thflc ra, tfl lau, cflng da cd nhflng hgc gia cho r a n g the Pleistocene , Ddng X a m A da t r a i qua nhflng thdi ky liinh vil khd hdn Ngay tfl nam 1911, nghien cflu ciic hoa t h a c h thflc viit d Trinil, ldp chfla di cdt ngfldi vfldn J a v a , n h a cd thflc v a t hoc J u l i u s S c h u s t e r n h a n r a r a n g t r o n g so'54 loai cay lim ditdc d day, cd 24 loai hien n a y vdn sd'ng d J a v a nhiing d cao 600-1200 m t r e n m a t bien Tfl dd, S c h u s t e r cho rdng vao T r u n g ky Pleistocene, khf h a u Java l a n h hdn nay, n h i e t tha'p hdn chflng 6-8
(7)VuCongQuy - Mdi trudng tu nhien Dong Nam A thai ky Pleistoc enc 19
C a n g cang cd t h e m nhflng chflng cfl mdi de cd the nghi nhfl Schuster la thdi ky Pleistocene da cd nhflng giai doan l a n h hdn n g a y H.Th Verstappen cho biet r d n g vflng Ma lai, cac thdi ky b a n g ha, cd mgt khf h a u khd hdn nay, Ifldng mUa tha'p hdn va cd mdt mfla khd dai hdn R.M Petersen cflng chflng m i n h r a n g d vflng H a n g N i a h ( S a r a w a k ) vao cudi h a u ky Pleistocene tfldng dfldng giai doan cudi ciia b a n g h a W u r n , khf h a u liinh hdn va theo mfla, khd hdn Cac p h a n tfch chat da't d H a n g Niah Bruno Sabels tien h a n h cflng ra't thfl vi Theo Sabels, cac ldp da't cd nien dai W u r n mudn d Hang Niah chfla mgt h a m Ifldng m a n g a n tha'p, mdt h a m Ifldng Phdt t h a p va PH cao Tfl dd Sabels cho rdng khf hau d Hang Niah thdi dd lanh hdn nhieu
Cd thfla n h a n sfl khac biet ve khf hau gifla thdi ky Pleistocene va thdi ky Holocene d Ddng Nam A, chflng ta mdi cd the giai thfch dflde mdt so bien chuyen qudn ddng vat gifla hai thdi ky S a n g thdi ky Holocene, qudn ddng vat hien dai thay the cho qudn ddng vat Stegodon-Ailuropoda Voi r a n g kiem (Stegodon) va mgt sd' gid'ng khac bi tieu diet, Ga'u Ire (Ailuropoda) thu hep vflng phiin bd mdt linh N a m T r u n g Qud'c, Dfldi fldi(Pongo) thi chi cdn lai d mdt sd'hdn dao Indonesia Sfl thu hep vflng p h a n bd cua Dfldi fldi ve phia n a m khien ta nghi rdng da cd mot giai doan lanh ma khf hau d vung bdc Ddng Nain A hay ban dao Ddng Dfldng khdng cdn t h u a n Idi cho sti tdn tai
cua Dfldi fldi nfla Giai doan dd b a n la flng vdi kboiing cuoi thdi ky b a n g h a W u r n
Nhfl vay, t r o n g sud't thdi ky Pleistocene, Dong N a m A la k h u vfle nhiet ddi gid mfla Do a n h hfldng cua cac thdi ky b a n g va gian b a n g t r e n h a n h tinh, dia hinh Ddng Nam A cd nhflng bien ddng ldn, h a u cflng cd nhflng thdi ky ndng lanh khac n h a u N h u n g nhflng dao dgng h a u dd khdng du ldn de lam thay ddi quan dgng vat va q u a n thUc vat Tuy nhien, gifla khf h a u Pleistocene va Holocene cflng cd nhflng sfl khac biet dang ke Sfl khac biet dd rd hdn d k h u vfle luc dia phfa Bac va ft hdn d vflng hai dao phia Nam
Do dieu kien tfl nhien Ddng Nam A thdi Pleistocene khong thay doi nhieu so vdi Mdi trfldng tfl nhien dd r a t t h u a n lgi cho sfl p h a t sinh va p h a t trien cua ngfldi cd d Dong Nam A va hinh t h a n h nen dien mao cua van boa Ddng Nam A thdi tien sfl./
C H U T H I C H
1 Ha Van Tan Moi trUdng tU nhien Dong
Nam A thdi Pleistocene Trong: Khao cd
hgc tien sfl va sd sfl Dong Nam A Tu lieu Vien nghien cflu Dong Nam A
Tran Quo'c Tri Moi triidng dia ly Dong Nam
A cudi Pleistocene - ddu Holocene Trong:
Nhflng va'n de cd ban cua Dong Nam A hoc Tu lieu Vien nghien cflu Dong Nam A 2 Ha Van Ta'n Khao cd hgc Dong Nam A
-Nhdng phdt hien ddng quan tdm Trong: