Geogr. Pis. Dinam. Quat. 24 (2001), 85-98, 12 jigg. GENNADI F. UFIMTSEV (~'~) TECTONIC RELIEF OF EURASIA ABSTRACT: U FIMTSEV G.F., Tectonic relief of Eurasia. (IT ISSN B MO.'10JII>I X 1I0JlIIl1iKilLIX 1I01lCilX IIpCOO.'''LlilIlOT Ch:.'la Jl'laTI>IC mpLI, 0391-9838,2001). 1I0h:POBlII>IC (lIa JlIllll ly rLlfI cno a ) oporcuu H .'lIl1ICfllILIC xpyunuo CII(),l LI. The tectonic relief of Eurasi a has a concentric-radial structure and is r'H\fa.rIaH JIIl.rIHlIOTClI ,\ IOP I/lO.'IOIW ICCh:IU I auanoro» 110 OTIIOIIICIIIIIIO h: BCmlh:"" ~ characterized by the interchange (from north to south ) of belts of plat­ II(MlllITl1l1\1 m :TpoBlILIX ayr , ycrynu 110 Oh:pa(lII<DI IU JlIlillllM1X form plains, rejuvenated mountains and young mount ains. The Gond­ h:OIlTlll ICI1"1"011. wanaland subcontinents of Arabia and Hindustan join from the south. Ypa.t-Oaau-Ma.taraocapcxa» OCI> rparururr C ycryuoxt :lm IlIOr:! A belt of platform plains is linked by the Urals meridional sutural 1I0ll CPX1I0Gll, h:OTOpall orofipa.cacr mllleil\lCIIT ,IeTa 'I\Je IlTa h:opa­ r :l( ~ p h: a.% lI h l\ l orogen. Ancient platforms are characterized by the prevalence of ho­ \laIlTl-III. Oua jle . ll1T Ellpa:llllio ua JlBC 'la enl C pacno.ro­ mogenous uplifts, whereas young platforms typically have subsidences iKClll1CM ocuonuux MOpIIIOTCh:TOIII1'ICI:h:IIX .l.lIe \l CIITOII. Bo:lPOiK,ICIIIII>IC Ah:T1I1lIl),J( ~ and differentiated uplifts. ropu npocrupanorcn II Ellpa:llll1 h: 1I0ry 0'1' J TOn OCI1. a.%IIII1~I­ In the rejuvenated mountain belts there are large domes , tectonic J JICMCIITLI MOJI011OI1 TCh:TOIllIh:11 (lial1h:aJlbCh:illl puqrronan ao na, Oh:PYiK CIllf( ~\I ) clustering in belts of intercontinental collision of lithospheric plates, in­ Ch:I1H II01lC II TI10CT-r'I1\1a.fJaIl C (IX x a p a xrcp re y norrn 11II0fl tercontinental and marginal-continental rifts. 1I0llCP C :3Cp h:a Jl bIlOI1 CIU1\1CTP IICfI. In the young mobile belts folded mount ains, cover (overthrust KJlIIOll El3hlf. 0 1013,\ : TCh:TOIIJ1IICCh:HfI p c .ru.elll, \I()pll)on~h:TOllllh:a, sheet) orogens and linear large domes prevail. The Himalayas are mor­ MO.'IOJIall TCKTOIlI1h:a, Enpa:1I111 , Ypan- Onan-Ma.unurxupcxan ou., phologically analogous as regards the uplifts of island arcs. Great scarps IIJIaTI/lop\,ICllllall pauuuua , nmpOiKjlClIlILIC ropu, \lO.'IOjIOl1 II0jllll1iKllbifi extend throughout the margins of the Gondwanaland contin ents. II01lC. The Ural-Om an-Madagascar axis borders on a scarp of the earth surface, which reflects a lineament of the core-mantle detachment. This divides Eurasia into two parts with mirror-sh aped disposition of the main morphotectonic element s. Rejuvenated mount ains extend in Eu­ rasia to the south of this axis. Active elements of young tectonics (Baikal INTRODUCTION rift zone, the Alpine belt and the TibetHimalayas with its surrounding areas are charact erized by transverse mirror symmetry. Eurasia is the largest and the most complex continent KEY W ORDS: Morphotectonics, Young tectonics, Eurasia, The from geological and geomorphologic points of view. This Ural-Oman-Madagascar axis, Platform plain, Rejuvenated mount ains, is well reflected in the structure of the upper parts of the Young mobile belt. lithosphere, which has a relief without erosional forms (Philisofov, 1975). Models of tectonic relief reflect a com­ l)r":U10\1E: UFIMTSEV G.F., T Ch:TOIlI1'ICCh:1111 P C,iII>Cql Enpa31111 . (IT bination of various tectonic forms. This kind of structural ISSN 0391-9838, 2001). analysis of young tectonic povides a foundation for the T Ch:TOII11'ICCh:11 11 p C.lII,c<11 Ellpa:lI1l1 OOJJa JUleT h:OIll\( ~IITPI1'I C Ch:II- following theory (Ufimtsev, 1984). P iLUla.iIJ,lIf1 c rpyxryp o n 11 x a p a crcp uaycn:n C\ICIIOI1 (c «cnc p a na 1101') 1I01lCOII II.1JaT<IIOP,\ICIIIILIX pa11111111 , lIo:lPOiKJIClIlIl>IX 11 MOJlOllLIX rap. Results of morphometric analysis, long-term research 1'01l ,lBaIlCh:I1C CyO h:OIlTllllCIlTLI Apamu: 11 Hiuocrana IIPI1COCI1I1H110TClI on the recent tectonics of Eastern and Inner Asia (Ufimt­ C 1I0ra. sev, 1984; 1991; 1992), field observations in some regions 1I01l<: IIJJaT<!IOpMCIIIILIX pauuun OTLR~ JllICTClI ypaJII>Ch:I1M MCp1111110­ of Western and Southern Europe with detailed morpho­ Ila JII>IILI\1 IIIOBlILI\l oporonoxr, Jl p CBllIlC IIJJaTC/lOP\ILI x a pancpl1:lyllOT ClI metric analysis of typical tectonic forms of relief carried IIPCOO .lla JIalll1 CM ro\10rCIICTI1'ICCh:I1 X 1I0JIIIlITI111, roraa h:ah: Jl.IIlI MO.rIO,lLIX 1I:1a TqIOp\1 '1'11 II11'1 IILI 1I0rpyiK cIII111 11 OOOCOOJICIIIILIC II(MlIlIHll1. out by the author and original data by other researchers B 1I0JH:a X lIo:lpOiK,lellllLIX rop CCT I> h:PYIIIILIC CIIOJILI, Ch:yl1l1alll1c II are at the loasis of this note. 1I01lGIX \I CiKh:0IlTI1I1CIITa .!II>1I0fl h:O.'lJlI1:31111 Jll1TOu jlc P lIl> lX umrr, MCiKh:OIl­ TI1CIITa.%IILIC 11 Oh:paI1I1110-h:OIlTI1I1CTa JII>IILIC pl1qrrLI. TECTONIC ZONING ("') Institute of the Earth Crust, Lermontov str. 128, 664033 Irkutsk, The plain-platform regions, like platforms or plains Russia. Research supported by a grant from the Russian Science Foundation and orogenic forms of Eurasia, are grouped in belts with (96-05-64773). a regular change of strike from north to south (fig.1.). 85 FIG. 1 - Scheme of Eurasia and its surrounding morphotecton­ ics. Plain-platformal regions: 1 ­ common uplifts; 2 - intensive subsidences up to an avanshelf level and linear troughs; 3 - com­ mom subsidences; 4-5 - shield­ form domal uplifts including the same on margins of platforms (5); 6 . incline uplifted blocks on margins of continents; 7 - in­ clined piedmonts; 8 . zones of piedmont folds; 9 - foredeep and piedmont troughs. Rejuve­ nated orogens: 10 - large domal uplifts; 11 - block uplifts; 12 ­ arched-clumpy zones of linear warping and tectonic clustering; 13-14 - midland (13) and margi­ nal continental (14) rift zones; 15 - block fields; 16 - lowed in­ terrnountains and basins. Young mobile belts; 17 - folded and [G-~-d cover-folded mountains; 18 - do ­ f mal uplifts; 19 - intermontane 0 • o 0 0 and large intermontane basins; [8)• • 0 20 - arched-clumpy zones of lin­ • • 0 2 ear warping; 21 - mountains on ····· uplifted highly socle (tiberian D...... 3 type); 22 - step-like clumpy up­ lifts (himalayas type). Mediterra­ + + + + + + + nean regions and regions of ++++'/ transition from continent to ocean; 23 - island-arched uplifts; 24 - continental borderlands; 25 - deep -seated depressions of mediterranean and marginal mDJI2 seas; 26 - deep-seated trenches; 27 - intercontinental rifts; 28 ­ ~/8 oceanic regions; 29 - continental slope; 30 - lineaments including thrusts (a); 31-32 - great escarps (31) and their analogues (32). The northern part of this continental mass is made up of are small isolated groups of rejuvenated forms also in the a wide belt of great platform plains. This belt consists of north of Scotland. hilly surfaces, plateau and uplands of the Siberia and The belt of young (alpine) mountains forming the Al­ East Europe and plains of the West-Siberia. Plain­ pine-Himalayas megabelt is situated more southward. platform Eurasia is subdivided into two sub-belts: 1) low This megabelt spreads from the Iberian peninsula up to accumulative plains of the Arctic shelf and coastal low­ Indo-China and consists of some young mobile belts dif­ lands (Zamarayev, 1967); 2) uplifted parts of ancient and fering in structure and type of common deformations of young platforms dipping southward. This plain belt is the base surface (from west to east): the Alpine belt of dissected by the extensive narrow sutural uplifted block Europe, Asia Minor-Iranian and Tibet-Himalayas belts, of the Urals. the group of young orogens of the Indo-China peninsula. The other belt consists of rejuvenated mountains. It The first and last elements of this row are young forms has a width of more than 1000 km in the east of Eurasia. conjugated with intercontinental morphotectonic systems This belt spreads from the south piedmonts of Tien Shan of the Mediterranean region and Zondian region. In the and the Gobian Altai ridges up to the Siberian platform east of Eurasia the young (alpine) orogens do not form a and from the Amudaria River head up to the Dezhnev connected group and are situated where is the complex cape. This belt is interrupted in the west because rejuve­ transition from continent to ocean system (fig. 1). nated mountains occur in Central and Western Europe Original discrepancy is observed in the placement of either accompanying the Alpine belt or as fragments in its rejuvenated and young orogens: rejuvenated mountains structure (Iberian peninsula, Rodopy mountains). There are more widespread in the east of Eurasia, where the al- 86 pine constructions are sparser. The southern fragments close to the avanshelf level. Some of them are an aulaco­ of this continental mass consist of the platform plains of gene-lilie type and are open in abyssal basin of marginal the Arabian and Hindustan subcontinents attached to seas (depressions of the Tatar and Taiwan straits). Eurasia itself. The steps of common uplifts on the platform plains Some regularity is not difficult to note in the belt differ in amplitudes and intensity of young displacements structure of Eurasia. This indicates the increase and con­ and as a result they are hilly uplands, plateaus or high­ solidation of this mass. On the other hand, we can clearly lands. Gentle arched uplifts (neotectonic anteclines) de­ observe regions where the complex and different process veloping by inheritance (Anabar uplift) or inversely (Pu­ of this continent formation has continued: these are the torana plateau uplift) are associated with them (fig. 2).