Jul 5, 1993 - plain, laida and peat bogs the mme xegion, where Pleistocene ice wedges were found. Mean value dl'O for active ice growth veins is: a : -18% ...
PERMAFROST Sixth International Conference
July 5-9, 1993 Beijing China
Organized by Lanzhou Institute of Glaciology and Geocryology Chinese Academy of Sciences & Chinese Society of
Glaciology and,Geocryology
South China University of Technology Prm
NORTHERN
ASIACRYOLITBOLOk4X EVOLUTION IN LATE QUATgRNARY Yurij X. Vasil'chuk
Theoretical Problems Department, The Ruusfan Academyof Scienceu, Vesnina12, 121002, Mcscow,RUSSIA There were studied about 50 base mxpencea. Oxygen isotope analyuis of ayngenetic ica.wedgem allovedto reconstruct winter temperaturea which were lower than m o d e r n onea & o u t 8-10°C (total winter temparnturaa) and stayed quite severe clopled and to modern ones during Eolocens. The eormlation analyrim of axtend maisiveof palynologic data permitted to ovaluate the uumer paleotemperaturem. They were lower about 1-5O C than modern onam in Lata Pleistocene cryochron just during warreat epoch of murmer teaperaturem could ba about 1-3OC warmer than modern ones.The summer temperatures were exceeded modern a m e x teaperatures about4-5OC in Holocene optimum The total tempraturea of nakedfrozen grounds were lower about S-9OC during Late Pleistocene cryochron and were clo0e to modern onesin Eolocene opqiaum
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INTRODUCTION
deposit. One of the most interest pahogeographic and paleoclhatic objects arathe Late PleirnThere are Eout enviro-ental events attracted tocene seguencea withthick syngenetic i c e Predgcs t h e mart attention of investigators of the last which were forming continuously.Uuuring lamt4 0 40-50 Kyr himtory. These are Ocean level changes, Kyr in North of Asia. This fact i a allowed to redynamics of cover glsciationa, cryolithozone chanconlrider the accepted galeoclimatic views,.according to latter the noticeable waming:occurred ges, climatic fluctuations.AL1of them are interacted more or leas. The new information about during the Middle of Wurm (Weichelian,'Wisconsin, each other gives knowledge abaut the all other. Dsvenaian) and Early and Middle Bolocehe. As it So we believed the new data of cryolithozone is found by our study that warn not correct for North of Ani&. The syncryolithogen proceaaes were dynamics whichwere received last yearmcan be useful for study of adjacent field.. took place quite actively during laet 40 Xyr including MiddleWurn and Early andUiddle Holocene The main attention we have spared for investao.The using ofcomplex isotope tigations ofbasis sequences of myncryogenip paleogeocryologic analysisi s allowed to receive thicknesuea by complex of conjugated methodm named the complex iaotope paleogeocryalogic the quantitative characterof ayncryolithogenemis analysis geotemperature conditionsin North o f Asia during It includea both well-known methods (such as pollen, diataa, microfauna, lart 4 0 Kyr. oxygen isotope diagrams received fxoa Late Pleistocene(Figure 1) and Holocene paleobatany,hydroch~irtryet al.) and the new (Figure 2) syngenetic icepredgei of lorthern Asia method i.e. the study of axygen and hydrogen comare the base of such paleoreconutructions. The position of ground i c e . All basis mequenceswere distribution trend has been determined for the dated aa ctmplete as possible by radiocarbon of Northern Aaia ice wedges different of age. any organic matter. It in allowed to make - The dl'O trend in U t e Pleiatacene ice chronologic correlation reliable enough, The wedges wasahilar to mdern one $.e. d ' " ~+came deuterium corponition data frol ground ice had more negative from West toward Ealrt by 8-10 h been received more than 40 years ago by R.Teis , f r m -19 i -25 b in Weatern Siberia ice wedges but regular studyor stable iuotopeain perto -30 + -35 % in Northern Yakutia then it i s bemafrost began more late. However we must marked cads as high aa -28 f -33% in North of C h c b t k a that,our invcutigationa are differed from other - . and Central areas of Magadan Region (by 2-3 % ones by the obligatory procedurei.e. radi&arboh' dating of ayncryogenic thicknesses containing ice ),and as highas -23 f -29 % in the Last of Chuckotka (by6 - 8 % ). These data are evidenced the Air wedges. (Vasil'chuk, 1982; 1988-1992) Thiu is m&as Transportation warn uimilar to madarn one in provided the dating bothof the frozen thicknesa the end of Late Pleistocene thtoitgh,Asia Suband syngenetic ice wedges. The technique of this arctic. weat direction of ~ i r - a s Tranapoktation procedure were described earlier in detail was duuinatadin the considerable part of Eurasia (Vaail'chuk, 1991, 1992). continent. Atlantic influence wIB essential from Jamal peninsula to Uorth-last YakutSa, but it Was possible weakerthan moderh tine due t 0 more freThe interpolation method was used for dating quent cold and dry Ardtic hir MSS advection-. The of mingle sample or series of samples or part of influence of pacific air masses were probably ilotopa diagramtoo. ft is provided discountof formation characterof concrete ground ice , ,
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correlationof Late Pleietocene ice wedgea of different regions cryalithozone:a-t ice wedges diagrams: a near Gyda uettlement (up) and near Seyaha settlement in depression near Kular settlement, c Bykovaky peninsulain ( d m ) in the,North of Western.Siberia; b in the Borth.of Yakutiar d - m e r omolon river, e Plakhin6ky Yar natural the mouth of IAiakiver; d-g Duvnnny Yar nptural expoaure: h -Central Yacutia, natural exposuxe, f - near Xeleny Uyn krttlemsnt:,I g elgoaure in valley of Vilu-y 'river.neaE mouth o f 'Qalychima river; + irk Chpckotka : i - . in the hion island, j natural expomure Ledovy Obryv in Hain river, k near Anadyr town I 1 - C-14 date of organic matter frw thickness which synchronous to ice wedges; a author'# data, b literature data;2 - oxygen isotope zone indexear Y temperate (close to present condition#);Y X temperate cold;X cold; OX very cold. Ordinate axis is radiocarbon age, received by interpolation of radiocarbon dates, horizontal coordinate i s M"o - dl'O difference between value dl'O frop ice wedges and from active ice growth veinsflood from plain, laida and peat bogs the mme xegion, where Pleistocene ice wedges were found. Mean value dl'O for active ice growth veins is: a : -18% ; b-g : -26%. ,h: - 2 4 , 5 r , I:-26% (the later displacementof isotope j I -22% : k : -16 %, . , , prov€ncei haa been taken consideration): in
Fig.1. Interregional oxygen i s o b o p . diagram
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leue than preaent in the eaat areas of Northern Mia. The continentalanticyclonicregime dom:nated here in winterm particularly. -$e qolocene ice wedges havepreservedthenivilrion mame zendendk'.in 6 l a 0 ,dietribution i,e. decrease been of bl'o valuea wai'bp.tq'6-8%' to the East from 1 4 + -20,a in WesternSiberia ice wedgesto -23 + -28 $. in Northern Yakutia onus. Ewever the values af j ? . ' O i? Chuckotka ice wei3ges incre,asedup ,,t6 ,
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15 i -21 8 The modern dintribution of oxygen18 inrecentice veinshootsand in mnoycover (average winter va1urs)si.s :aLomed to Bolocenc.
%o oxygen-iaatope aones which had offered .arlier fvasil'chuk, 1991) was ueed for correlation Qf oxygen isotope diagram. . .
The studyof dependence of oxygen sotope paremetera in recent ice wedges ( dl'O )from , .
Pig. 2. Interregional oxygen isokope diagram Correlation of Holocene ice wedges of different ' maions of Eurasia cryolitho- %one t a-o ice wedgea diagram#: a-d in the Uorth of Western Siberiat a near .dk&t;tlenent wraaaway (the first terrace) , b near aettlement Seyaha (Beat on the tliird terrace ) , c near settlement near trading stationmtjujsale~(peaton the second terrace ) t e q#ia;(Eat,on tbe first terrace ), d Bykovsky peninebla in the mouth o f Lena,river'(peat on the second terrace ), f-i in NorthYakutia:' f mouth of (Iholon river (flood plain), g - neak exposure PlakhinskyYar (fload plain),h near settlement near exposure Duvanny Yar (alau), 1-1 in Chuckotka : j - island AiOn (peat Xelehy My8 ( f l o d plain ),i near.Anadyr on the third terrace), k on the Hain river ( alas i.e. peat on the ice wedge complex), 1 in Central Yakutia": m flood plain of Viluy. river near mouthof town (peat on the first terracti ); m-n ( lacustria sedimentsin upper part 60 m terrace ), !J!yalycbiaa rkwer, n natural expoaure Momontova Gora o expomure of the first terrace Chara river, Northern Babajkalje r 1 C-14 date of organic matter from literature data] 2 oxygen isotope zone thickness which synchronouse to ice wedges, a author'a data, b indexea : Y X cold-temperate, YT - warm-temperate, the rest values of d l ' 0 belong to zone Y ,i.e. temperate, age of the i c e wedges , on the horizonfal.'c&&dinate cloue to modern condition, On .theordinate axis radiocarbon d l ',O" i. e. difference between value of dl'O from ice wedge and tram ice growth veins; mean value dl'O for ice, ~gFob+h.V?iqS are, for q ~ d: -J8 h ,,,fore-i : -26 %. , f o r j I -21% , for k I -22% , far 1 : -16%. , far n : -24,5% , for n : -26%,, for a -ii,5e
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NORTHERN ASIA CRYOLITHO%ONs EVOLUTIOl IN U T E QUATERNARY Yurij K. Vasil'chuk Theoretical Problems Department, The Rus6ian Academy of Sciences, Vesnina 12, 121002, MCUCOW,RVSSIA
There were studied about 50 b e e reguences. Oxygen isotope analyaia of syngenetic ice.wedges allwwed to reconstruct.wintsrtemperatures which were lower than.modern ones about 8-LO°C (total winter t m m p r a t u m a ) and stayed quite sevare and clowad to modern ones during Bolocene. The aorrslation snalyrin of extend massive o f palynologic data parmittad to evaluate the aumer paleoterperaturse. They were lower about 1-5O C than modern onem in Late Pleistocene cryochron just during warmeat epoch o f 8-r tempraturea could be about 1-3OC warmer than modern one6.The uum- , mer tampamatureswere exceeded modern a m e r temperatures a b u t I-SOC in Holocene optiaup The total tempmaturer of naked frozen grounds were lower about 5-9OC during Late Pleistocene cryochron and were cloae to modern ones in Holocene optimum
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INTRODUCTION
Onedeposit. of the most interest paleogeographic and paleoclimatic'objedts are the Late P h i s There are four environmental events attracted tocene aquences with thick syngeneticice' wQdge0 the most attention of investigator8 of the laat which were foming continuwsly.during lamt 4 0 ' 10-50 ltyr himtory. These are Ocean level changes, Kyr in North of Asia. This fact is allowed to redynaaicm of covtr glaciations, cryolithozone chanconsider the accepted paleocliaatic views,,accordgcu, climatic fluctuationa.Al1 of them arc inter- ing to latter the nokiceable varming'occurre6. acted more or lesa. The new informtion about during the Uiddle of mrm (Weichelian, Wiuconsin, each other gives knowledge about all the other. Wvensisn) and Early and Middle Bolocdne. As it So we believed the new data of cryolithozona is found by our study that waa not correct for dynamic8 which were received last years can be U o r t h of A d a . The syncryolithagen processes 'were useful for study of adjacent fields. took place quite actively during last 40 fyr inThe Pain attention we have upared for inveacluding Uiddle Wurn and Early and Hiddle Holocene too.The using of c m p l e x isotope tigations of basis sequences of syncryogenic paleogeocryabgic bnalysis is allowed to receive thicknessem by complex o f conjugated methods named the complex isotope paaleogeocryologic the quantitative character of syncryolithogenesis analysis It includes both wel.1-known methdds geotemperature conditions in North of Aaia during 40 Kyr. Oxygen imotope diagrams received (such as pollen, diators, microfauna, laat paleobotany,hydrochmi#try et al.) and the new from Late Plaistocene (Figure 1) and Holocene method i.e. the ntudy of ,oxygen and hydrogan c w (Figure 2) syngenetic ice wedges of Northern Asia position o f ground ice. ~ l bamia l aequences were are the base of rruch paleoreconatructiona. The dated aa collplete a8 po6aibls by radiocarbon of distribution trend has been determined for the any organic matter. It is allowed to make Northern Asia ice wedges of different age. chronologic correlation reliable enough. The The dl'o trend in LatePleimtocene ice deuterium copposition data from ground ice had wedges was bbilar to.modern one .e. 8' ' 0 .+emme been received more than 4 0 years ago by R.Teis more negative from Weat toward East by 8-10 t. but regular study of stable isotopes in p r from -19 L -25 b in Western Siberia ice wedges ' to -30 f -35 b in Northern Yakutia then it i s bemafrost began more late. Eavever we must marked that,our investigatione are differed from other came as high as -28 + -33%. in North of CItuchotka ones by the obligatory procedure i,e. radliocarbon' and Central areas of nagadan Region (by 2-3 % dating of atyncryogenic thicknemses containing ice ' , ),and au high as -23 + -29 0. in the Esmt o f Chuckwedges. (Vauil'chuk, 19828 1988-1992) !Phis i s otka (by 6-8 % ) Theme data are evidenced the Air nass Tranaportation was mimilax to modern one in provided the dating both of the frozen thickness and rynganetic ice wedges. The technique o f this the end of Late Pleistocene t h l w g h , A e i a Sub-, procedure were described earlier in detail arctic. West direction of A i r , m a s s TranbpQhation was dominated inconmidsrable the part of Eurasia (Vasil'chuk, 1991, 1992). continent. Atlantic influence waa essential ftam Jamal geninsula'to North-last Yakutia, .but it was possible weaker than moderh tine due t o hoEe frep e n t cold and dry hrdtic air mass advection-. The The interpolation method was used for dating of ningle aarple or series o f samplem or part o f influence'of pacific air masses were probably isotope diagram too. It is provided discount of formation character of concrete ground ice , ,
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945
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Fig.1, Interregional oxygen isotope.diagram correlation of Late Pleistocene ice wedges of different regions of Eurania cryolithozoner a-k ice wedges diagrams: a near Gyda settlement (up) and near Seyaha settlement (down) in thsl4olth of Weatexn.Siberia; b - in depresaion near Kular settlement, c Bykovaky peninsula in Lower Opolon river, e - PlakhinaRy Yar natural the mouth of M'na .*r-iver; d-g in the Worth .of Yakutia: d exposure, f near Zeleny. Uyn buttlament,. 4 Duvanny Yas netural qxpoaure; h -Centrql Yacutia, natural mouth o f Walychima river; i-k. Cwckotka : i- : in the Aion ialand, expoaure in valley o f Viluy river.neaE 1 natural exposure Ledovy Obryv in Hain rivex, k near hnadyr town r 1 - C-14 date o f organic matter from thickness which synchronoust o ice wedges ; a author's data, b literature data; 2 oxygen isotope zone temperate cold; X cold; OX very cold. Ordinate indexes: Y - temperate (closeto present conditions);YX axis is radiocarbon age, received by interpolation o f radiocarbon dates, horizontal coordinate is M " o - d1'0 difference between value dl'o from icewedges and from active ice growth veins from f l d plain, laida and peat bogn the name region, where Pleirtocene ice wedges were faund. Mean value d l ' 0 for active ice growth veins is: a a -18% ; b-g : -26%. ,h: -24,5r , i: -26% (the later displacament o f irotope provinceb haa been taken consideration): in j : -22% : k : -16 % . ., .
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Fig.2. Interregional oxygen.irotopa diagram correlation of Holocene ice wedges of different :&gions of Euraaia cryblitho- zone : a-o ice wedges diagraaar a-d in the North of Western Siberia : a near .Y&tittlement Ktgaaaway (thefiret terrace) , b - near settlement Seyaha(*at on thet'hird terrace ), c near settlement ~ ~ + ~ ( , ~ a C , o nfirst . t h eterrace ), d near trading station Uatjujsale'jpeat on the aecond terrace ) # e Bykovaky peninsula in the mouth of Lena ..$iytig' (peat on the eecond terrace ), f-i - in lrorth Yakutia:' f mouth of cgolon river (flood plain), g neax expoaura Plakhinrlky Yar ( f l o o d plain),h near eettlement Z e h h y Hya (flood plain ),i - near exposure Duvanny Yar (alas), j-1 in Chuckatka : j inland Aion (peat on the third terrace), k on the Hain river ( alas i.e. peat on the ice wedge complex ) , 1 neai.Anadyr town (peaton the first terrace ); m-n in central Yakutia': m flood plain of Viluy river near mouth of Tyalychira rimr, n natural exposure llamantova Gora ( lacuutrim 8lKfiments in upper part 6 0 m terrace ), 0 - e-sure of the first terrace Chara river, Northern Zabajkalje I I. c-14 date of organic matter from author'B data, b literature data; 2 oxygen isotope zone thickness which synchronouae to ice wedges , a indexes : YX cold-temperate, YT warm-temperate, the rest valueeof d l ' 0 belong t o zone Y ,i.e, temperate, close to modern condition. On,the ordinate a x i s radiocarbon age of the ice wedges, on t h e horizantdltciiordinate d."p i.e. difference between value of & l a gfrom ice wedge and frcm ice qr&h veins: mean value 8' ' 0 for
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Fig.3, Comparison of character variation@ oxygen -18 content from recent ice growth veino (which wexe formed during last 100 years) (a) and total winter tempersturem (b) averaging at lart 60 - 100 ysarm. Iaolines : 1 nursly drown, 2 - supposed d r w n , 3 - South boundary of present active growth of ice veins.
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winter temperatures of the air'iu demonstrated the close relationship of these characteristicm (figure.3). 80 it is allowed to derive a simple equations of regression. EoLocene
tal.
w i n t e r = dl'ovein
(
*
~ O C )
(1)
( 5
(2)
t9m.january
e
S towintmr
= 2 5 0 d l a 0 v e i n ( f 500°C)
1,s dl'ovain
~ O C )
(3)
Theue equations were used for interpretation
of oxygen iaotope data to winter paleotemperature values (Table.1). The mean winter temperaturea were lees by 8-10° C than modern ones during (40-10 lryr epoch of Late Pleistocenecryochron approximately: B.P.), while Holocene winter temperatures were cloaed to modern ones even during Holocene" OPT tinun*. The mean January temperature0 ware oscallated symbatially too, as they were by 11-16OC
lower than modern ones and the total winter temperatures were leau than modern ones by 2000: 30OO0C in Late Pleistocene cryochron whils temperatures were close to the modern oneu The numerounpalynologic data were provided the reconstruction of summer temperature charmteriaticr Subfossil pollen spectra were studied and comparedwith vegetation season tamperataras. It is performed the existence of steady 'relationship for total value ( & ) o f tree pollen (without value of far transported pallen o f Pinus sibirica and Pinus silveotris) in flood plain, watte,m&mh deposits from total pomitivs teuperatureu. ,Thin dependence may bs expressed by follow equation but , .
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9
t D~~mm.r
40 Pt
(
f 30OOC)
(4)
Table 1. The ground taEMratures ( f+z0c - tk snaw and vegetation cover taken away) in the North Eursaia CqQlitozone Late Quaternary total sumel (St.) and total winter ( & t . ~ air temperaturea (degreeomday) wedges (in to SHOW), mean air winter (t, ". , c ) and mean January (tj c 1 :zir and values a1 0 in temperatures
%.~
IJ on the fig.4AI location of the
tq r
s
Pt r
d l 0 0,
t.
mequsnces. 30 1. river Seyaha 13 2.IeJnnd Itotel'ny 3,Ys;:dri:iula Bykwsky 4 . SekiAm. fular S,VOrQntUOV8ky Yar 6. PlakhinnkyYar 7.Duvanny Yar2 8.L-r adon 9. Settlm. leleny My6 10.Ialand Aion 13 Il.min riw?3 12 .Viluj river
-15 8
-19
2
-2 1 -21
2 2 1
-22 -21 -20 -20
+so0
+500
-32
-8000
+so0 +SO0
-31,5
-7125 -8250
-33
+500 1 3
-31 -29 ,s
+so0 +500 +9QO +so0
-19 -11 -18
-6000
30
t1200 22
-32
-3 1 -28
- I4
-30.5 Kyr B.P.
+so0 +so0
-22
'I
6
+so0
-14 -25 -31
1
+SO0 +500 +500--
7
1
'
2
3 2 3
-21
-32
-31
t 500 -31,s f500 -1150 -31 f500 -29 +so0 -31
2
t500
-29,5
4
+500
-201-31 5
1.
+500
12
I -41
-20,s -29,s t800 -32 +SO0 -7900 -31,s 10
-7750
tpromant
-32 -32 -33 -31
-48 -47
-13 -4 9 -46 -44
-4 2
-31
-46
-LO
-3 3
-10 -10
-30
-5500 -5250 -31 -6250
-22 -32 -25 -7 7 50 -31 -8000 -32 -7750 -3 1 -7900 -41 -32 -31 -7250 -29 -1 150 -31
,
-32 -4 6
-16
-14 -13 -12 -12 -12
-43 -4 6
-12 -12
-48 -46
-12
-7400
-30
-4 4
-21-5100 -7100
-29
-43
-9
-7400
-30
-44
-10
-16
-2 3
-20
-29
-6 -10
-18
-27
-10
-19 -20 -21
-28
-29 -32
-10 -11 -14
-19
-4750
+PO0
-19 I 5 -2 1
-4900 -5250
-9900 -6250 -6750
+600
-27 ,5
+goo
htvanny -15
12
+PO0
'-26
-7
-16 Aol~skW 1 2 , A l j o s h k i n s k a y a -14
11
+9OQ
13
-2 8 -25
-27
-4 1 -31 -40
-13
-6500
-26
-39
-12
-27
-6750
-2 1
-40
-13
t1000
-25,5
-6400
-2 6
-38
-12
+1800'
-28,s -23 -22 -17
-4 3 -34
-12
-33 -26
-13
B*
ter-ce
-15 -11 -12
10 72 8
+I600 t600
-7
15 25
f1200 -20*1200
-9
.
-7600
flOOO
-25 -21
,
-30
-10 -14 -13 -15 -14
-4 6
-3900 -4900 -4400
8
-4 3 -4s
-7000
-15 ,5 -19,5 -17 I S
6
-36
-29
-32 -31 -20
-1350
t1000 +goo
11 13
-i4
- 5 lyr B.P.
4-800
13.Hamontova Gora 14.Chara river 15. Inland Aion 16.Tovn Anadyr 17,Min river
tj
-12 -12 -12 -12 -9
-1400 -8000 -48
15 9
~
-7500
+loo0
+loo0
li.,i&asnear
-7250
20
Y ar
*
.>,,
ground.
-24 -29 -30
1 13
of
tr:u,
- 25 Kyr B , p .
+a00 +500
-19
-12 13.Ssyaba river .Gyda 14 river -13 1S.foland xotel'ny . -16. , 16 .Setth. Kular 4 -2 1 t21 17.Rlakhin6ky Yar 18.Settlm. zeleny nys -21 19.hvanny Yar -2 0 2Q.Krasivoe sequence -19 2l.Lower Omolon -18 22.Aljoshkinmkaya -19 ter-ce 23 Island Aion -18 24.Town Anadyr -12 25.Main river -16 26 .Vilu j river -18 27.Seq. Penix uw, -11 ltolyma N on the fig.4B 1.Sattlm. Kharasaway -8 2. Settlm.Seyaha -10 3.Nqarkatetnedayakh -10 R. 4',.. Setthsnt Gyda -11 5 . S a t t h . Hatjujsale -12 6 . Island Icaly -13 Ljakhovski 7,Bykovmky peninmula -16 8 . Zagadochnye lakes -13 9.Alas of Plakhinski -16.
10.Alpa Yai . ,
s t"
8-
-1100
-29
-5750
-2 3
-5100
-22 -17 -20
-4250 -5000
-13 -12
-8
-a -n,-""-
-30 , ?
948
' .
-
'.
We have t 8 t h t x d annual ground tempiratures having taken totalsupper and winter tempgaturs8 inco ws haved " 9*. . winterizing influence of vegetation and an&.covex intentionally. Theme data ia nhowed in' Table 1 and Figure 1. The temperaturesare showed for conventionally naked ground. One can nee the pemuftaat grounds were Coldar'thanmodern one by 5-10° C during Late Pleistodsne cxyochron over all area of Northern Asia cryoLithaaone. The temperatures of naked permafrost ground0 were about -12 + -17OC in theNorth of Weatern Siberia ( Y a m 1 and Gydan peninmulan); -18 + , , -22OC in Northern Yakutia; -16 i -2OOC in Central Yakutia; -12 i. -17% in Chuckotka. The temperatures of naked permafrost grounds were close to modern ones in Bolocune'including optimum They ware about -8 -6 -12% in *aha1 and Gydan peninsulas; -11 + -16OC id Northekn . ' ' . Yakutia; -10 i -15OC in Central Yakutia; -8 + 12% in Trnnlrbaikal region; -6 i-10% in Chuckotka.
"orEt*on.
.
CONCLUSIOla This temperature model is explained the developnent feature. of eyncryoqgenie permfroat thicknees quit? enough. The permafrost thicknessur were forming more southern in Late Pleistocene cryochron than present. Their area ban decreased in Holocene.Now they are forming over all Cryolithozone in areas of recent accumulation such am flood-plains, wattes, marehes and bogm, The role of myncryogenic permafrost ae paleogeographical indicator is important f o r the paleoglaciologic reconstructions. This factor is disregarded frequently for paleogLaciologic reconatruction. of: the end of Late Pleiatocene. However the thicknon-deformed syngenetic ice wedges are spread over Seaaide Subarctic Plains everywhere. They were forming continuoubly 40-10 Kyr B.P., and could not cover by Ice sheets neither during forming of ice wedgee as thick ice cover prevanted from the front cracking the bottom ground, no eubsequently as ice sheet pressure should to deform ice wedges. But there is no any deformations even for shallow ice wedges whichis lied from depth about 1-2 netars. SO, there ie aumtary of new notion received as a result of 8tudy of Late Quaternary syncryogenic permafrost of Northern haia by the complex oxygen iaotope paleogeocryologic analysis. Execution of analogoun investigations in Northern araas of Finland, Sweden, Norsrcy (where Eolocene permafrost is spread) and Northern Canada and rlaskn (where Late Pleistocene rryncryogenic thicknesses are spread as much as in Northern Asia) may t o cmplete tha notion of paleocxyologic evolution of Northern Hemisphere, It huve to answer ta %-e difficult questions of Cover Glaciationdynamic, sea level changes and environmental changes an a whole.
Pig.4. Mean annual temperatures distribution character (the anow and vegetation cover taken away) on parmafroat ground surface t A - during fate Pleistocanu chryochron: a 30-25 Kyr (continuad lines), b 22-14 Kyr (dotted lines); B during Bolocane optimum 1 -temperatureisolines; 2 - p of evaluated temperatures: for A and B see Table 1; 3 preeent temperature9 on ground surface
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Pollen tree values were determinate from the name sequences as oxygen ieotope sampling had carried out in ice wedges. In isolated cass the neighboring sequences were used for such examinations. Theae data having been averaged in the most interert time intervals and procelreed as value8 of summer paleotemperaturea are presented in Table,l, too. So it i n showed Bummer temperatures were less stable than winter ones. However they were lower than modern temperatures (by 15OC for mean summer temperaturee and by 200-500'C for total vegetation season temperatures). But there were sope short pexiods of Bummer warming i n Late Pleistocenecryochron 40-10 Kyr 8 . P., when mean summer temperatures were higher by 13% and total summer temperatures were more by 200-30Ooc than modernones. The calculation of e m m e r temperatures determination is not such accurate as winter, but this fact doen not influence on general temperature course due t o difference between duration of summer and winter periods, Summer lasts 2-4 months while winter ~a a rule lasts 8-10 montbu. So absolute values of total winter temperaturea are 6LO times much than summer ones and even twice or three time increase of total u-er temperatures doea not influenced on annual temperature course. It is the dynamicof winter temperatures was determined and i s detarmining now changes of temperature field of Northern haia permafrost.
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Vasil'shuk Yu. X. (1982) Regularities o f development of engineering geology conditionn in the northof Western Siberia in the Holocene, S u r a n a r y of Ph.D. Thesis (in geology and mineralogy) H o s c ~State University. Moacow. 27 p. Nauka publ.( 305 p . io volume of Thesie ) (In Rueaian).
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t a s., i l O c t i u k "Y i . K. ( 1 9 8 8 ) P a l e o g e o c r y o l o g i c a l L h t e r p r c t a t i o n of oqgan iaotope composition Qf Late Pleiotocene and Holocene refumed ice-wedges of Yakutia. In Tranmactionr (Doklady) of t h e USSR ' x c a d w of Sciences. V o l . 298, No. 2 , p. 125-429. ( I n Runmian). Varil'chuk Yu., (1984) Pprmation conditio&".Q f the Ute Pleistocene. and pol-ene ice-wedges of Chukotkd (inotopa-cryolitological an c h r o n o l o g i caanl a l y m i m ) . In TKant3aCtiOnS (Doklady) of t h e USSR Academy o f Sciences. V o l . 309 No 1. 920-924.(1n Rumaian). Vanil'chuk Yu. K. (1990) Isotopegeochemicalehara c t e x i c t i c e of the Late Pleiatocana ice-wdge c q l a x o f Culex depreomion. ITn r a n s a c t i o n s ."( Dpltlady) of t h e USSR Acad-y of Sciencei. V o l e ,>io.:!no. 1. p. 154-157.' ( ~ RQbsian). n Va811°chuk Yu K. ( 1 9 9 1 ) Late w a t e r h a r y a y n c r y o g e n i c p e r a a f k om s te d i a a n t 8 of Northern Euramiar Structure, oxygen-iaotope composition and forming I
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conditionrr. S w r y o f Dr.lci. Theaie (in geology and mineralogy) P e r m a f r o a t f n a t i t u t e of S i b e r i a n k a n c h Academy of Science af WSSR.,,~Mamcw. 4 8 p. (622 p. i u vohas I &,nd 244 p.- vol& 2 of Thesie (In Russian). Va8i1°chuk Yu.K. ( 1 9 9 2 ) Oxygen isotope c o m p a i t i o n o f ground ice ( a m l i e a t i o n to paleogeocryological r e c o n s t r u c t i o n s ) . uomcoy. - V a l , 1.-421 p. vo1.2.264 p.(In Ruooian). Vasil'chuk Yu,lI. ( 1 9 9 2 ) ContraUictorlnees.of modern p a l a e a c l i a a t i c a n dp a l a e o g l a c i o l o g i cm d s l a of Late P l e i n t o c e n s in the l i g h t o f permafrost data. In Buried glacier ice and parmafroat in glaciated areas. Termination of P l s i n t m e n e i n permafroat areas. Naatracta w o r k i w group meeting IGCP P r o j e c t 253. Tallinn.June 8 4 3 , 1 9 9 2 . p.15-16. Vaoil'chuk Yu.K. ( 1 9 9 2 ) C o r r e l a t i o n o€ paleoclimate avant8 i n E u r a s i a lamt 40 Kyr E. P. In 2 9 t h I n t e r n a t i o n a l ~ o l o g i c aCongreas. l Kioto.Yapan.24 Aug.-2 Sep*1992. Vo1.2. p.3EE.
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