Polarforschung 68, 93 - 100, 1998 (erschienen 2000)

Drift of Greenland and Correlation of Tertiary Teetonic Events in the West Spitsbergen and Eurekan Fold-Thrust Belts.

By Claude Lepvrier'

THEME 6: Eurekan Teetonics in Canada, North Greenland, 1989). In a more recent hypothesis (LYBERIS & MANBY 1993), Spitsbergen; Fold belts adjacent to Exensional Ocean it has been claimed that both the West Spitsbergen and the Basins Eurekan belts did not form in a transpressional setting but were the result of a Greenland-Svalbard convergence in Late Summary: In the Eurekau ancl Spitsbergen "orogens", the Tertiary tectonic to Early Paleocene time. clevelopment is similarly two-phase, inclucling an earlier phase oftranspression followecl by a major phase of compression. The first evcnt, which is Iikely Upper-Paleocene to Early Eocene in age, can be correlatecl with the northeasterly Many attempts have been made, separately for each belt, to displacement of Greenlancl which took place just after chron 25, It corresponels relate the tectonic evolution to the plate-tectonic framework. In to a regime of transpression with a significant coupling of thc transcurrent ancl the present paper, taking into account the timing of the tectonic convergent componcnts. The scconcl event, which culminatcd areund mid­ events in the two areas, the deformational stage history and the Eocene, is compatible with the chron 24 to chron 21 anel chron 13 northcrly to northwesterly near-orthogonal convergent motion of Grecnlanel relative to sequence of stresses directions, deduced from kinematic analysis Ellesmerc island. It agrces also with the oblique-slip motion which still prevailecl of Tertiary structures, are compared each other and correlated for the same periocl of time between the Greenlancl- Spitsbergcn paleotransfonn, with the successive stages of the drift of Greenland relative to but with a dominared component of convergence across thc plate-bounclary as the North-America and Eurasia plates. a result of strain partitioning.

GEOLOGIC SETTING KINEMATIC STAGES AND PALEOSTRESS HIS TORY IN THE EUREKAN AND SPITSBERGEN FOLD-AND­ The Eurekan "Orogen" (FoRTIER 1963, THORSTEINSSON & TOZER THRUST-BELTS 1970, DE PAOR et aL 1989, TRETTIN 1989, 1991, OKULITCH & & TRETTIN 1991) in the northeastern Canadian Arctic Archipelago In Spitsbergen the fold-thrust belt (HARLAND 1969, HARLAND (Ellesmere and Axel Heiberg islands) and the West-Spitsbergen HORSFIELD 1974, BIRKENMAJER 1981, DALLMANN et al. 1993), "Orogen" (HARLAND 1969, HARLAND & HORSFIELD 1974, about 300 km long, strikes NNW-SSE, paralleling the western BIRKENMAJER 1972, 1981, STEEL et al. 1985, DALLMANN et al. continental margin, except at the northern tip of the deformed 1993) in the Norwegian Svalbard Archipelago, are Arctic belts, zone, in Brogger peninsula, where the structures shift to WNW­ main1y formed, if not totally, during Tertiary () time. ESE. Equivalent but small-scale WNW-ESE structures, with an Both are genetically Iinked to the drift of Greenland with respect en echelon arrangement oblique to the general trend of the fold­ to North-America and Eurasia (Fig.l). The West Spitsbergen thrust belt, have been recognized elsewhere, in Nordenskiöld fold-thrust belt has been ascribed to dextral transpression Land (BRAATHEN & BERGH 1995). In the Eurekan orogen of the (HARLAND 1965, 1969, LowELL 1972) along the intracontinental Canadian Arctic, several structural domains are distinguished paleotransform (De Geer-Hornsund Fault Zone) which formed (OKULITCH & TRETTIN 1991); the structural directions are not during Paleocene-Eocene time and linked the coeval straight but arcuate turning from N-S in Axel Heiberg Island to Norwegian-Greenland and Gakkel-Nansen (Eurasian) oceanic NE-SW in north-central Ellesmere Island. In both cases ben ding basins (TALWANI & ELDHOLM 1977, MYRHE & ELDHOLM 1988, is probably not a consequence ofTertiary shearing (BIRKENMAJER ELDHOUvl et al. 1987, 1990). The Canadian Eurekan fold-thrust 1981, HUGON 1983) but is inherited and due to preexisting fabric belt and its extension in North-Greenland, is due to the general in the basement. Deformation is superimposed with the same anticlockwise rotation (KERR 1967) and northerly motion of trend onto structures related to the Caledonian orogeny including Greenland relative to the Canadian Arctic, as a consequence of the late Ellesmerian and Svalbardian events and the Labrador Sea and Baffin Bay opening, since the Late causes the contractional reactivation and inversion of Cretaceous until the Eocene-Oligocene boundary (SRIVASTAVA, extensional structures related to the Late Paleozoic rifting 1978 1985, SRIVASTAVA & TAPSCOTT 1986, ROEST & SRIVASTAVA episode (MAHER & WELBON 1992). The two fold-thrust belts are characterized by the involvement in deformation, at various degree, of the to Paleogene strata of the Sverdrup I Laboratoire de Tcctonique, ESA 7072 CNRS, Universire Pierre & Marie Curie, Boite basin (including the Eureka Sound Group) and the equivalent 129,4 Plaee JllSSIClI, F-7S2S2 Paris cedex OS,France; -cclaude.lcpvrierrsilgs.jussicu.fr» sedimentary pile of Spitsbergen (including the Tertiary Manuscript received 03 December 1998. acceptcd 29 June 1999 deposits).

93 ----=-+-----+---_---1--9

SCANDINAV,\ ""-_~~~.~ _._L,~_.-ll.L~.'LLL ~ _.__LI.Yln~__'____ .. .. _ __L.. .. __ ...J Fig. 1: Present-day loeation ofthe Eurekan and Spitsbergen orogenie systcm in the Arctic. NP = North Pole; M.A.R = Mid Aretie Riclge; SPZ Spitsbergen Fracture Zone; MFZ =Molloy Fracturc Zone; HFZ =Hornsund Fault Zone; GFZ =Greenlancl Fault Zone; lMFZ =Jan Mayen Fault Zone; Kn R =Knipovieh Riclge; M.R. = Mohns Ridge; Ko. R. = Kolbeinsy R.

Spitsbergen fold-and-thrust belt Kinematic analysis of fault populations conducted at different Iocations, in the post-Devonian strata and also in the Tertiary The prevailing structural features are those of an cast-verging deposits, shows that the deformational history is polyphase. compressional near-orthogonal fold-and-thrust belt and cannot be considered as type example of a strike-slip belt, as previously A sequence of dextral transpression followed by compression assumed (LOWELL 1972). From the western hinterland to the and final transtension has been defined in the Brogger and foreland the tectonic style varies from thick-skinned (basement­ Forlandsundet areas (LEPYRIER & GEYSSANT 1985, LEPYRIER involved) to thin-skinned (detachment-dominated) thrust 1990, 1992). The major and widespread phase of pure tectonics, as a result of decollement horizons (Upper Paleozoic contractional nature corresponds to an east-northeast-west­ evaporites, Mesozoic shales) within the post-Devonian sequence southwest (70-80 ON) direction of o l, orthogonal to the trace (N0TTYEDT et al. 1988). A model of decoupling of the dextral of the paleotransform. This event largely overprints the effects transpressional motion between Greenland and Svalbard has of a first episode characterized by a N-S to 10-20 direction of been invoked in which the transcurrent component is supposed o l and marked by dextral strike-slip movements along faults to be confined to the internal part of the fold belt, 01' even to an parallel to the paleotransform. In western Spitsbergen; the early off-shore zone, (MAHER & CRADDOCK 1988, N0TTYEDT et al. development as pull-apart basins of the Forlandsundet graben 1988). In the Forlandsundet area, some structures parallel to the (RYE-LARSEN 1982) and other comparable structures on the paleotransform show evidence of transcurrent movements. The continental margin (EIKEN & AUSTEGARD 1987), as weil as the en echelon arrangement of surface high magnetic-anornalies northerly thrusting movements recognized in the Brcgger (KRASIL'SCIKOY et al. 1995), along the NW-trending eastern peninsula, are coevally attributed to this first episode, as far as marginal fault of the Forlandsundet, is inferred to be the result these structures represent extensional and contractional relay of strike-slip faulting movement within an overall dextral regime zones of a dextral strike-slip system (LEPYRIER 1988). Along the of transpression (OHTA et al. 1995). Orogen-parallel motion have Carboniferous slice of SE Forlandsundet the strike-slip also been documented in the crystalline basernent, at the SE movements, compatible with an overall dextral setting, are not margin of the Forlandsundet, along a major fault zone involv­ attribu ted to this early stage bu t seem to postdate the ing Carboniferous strata (LEPYRIER 1990, 1992, MAHER et al. compressional episode (MAHER et al. 1997). 1997). Some structures in southern Spitsbergen also imply dextral strike-slip movements (DALLMANN 1992). A similar polyphase kinematic history is found in the Nor-

94 denskiöld Land (BRAATHEN & BERGI-I 1995); prior to the final TIMING OF TECTONIC EVENTS extension, deformation is the result of two kinematic stages: successively NNE-SSW dextral transpression and WSW-ENE Age ofthe major deformational episode shortening. In Spitsbergen as weIl in the Canadian Arctic, the major de­ From the analysis of striated fault-planes in the Tertiary stra­ formational episode (stage 2 structures) of contractional nature tigraphic units of the Central Basin, a comparable succession of is Tertiary in age, as proved in particular by the clear involve­ stress tensors has been established (KLEINSPEHN et al. 1989, ment of Tertiary strata in the deformation. The recent hypothesis TEYSSIER et al. 1995) with two regionally significant tensors, for a late Cretaceous-early Paleocene main tectonic development successively oriented North-South and Northeast-Southwest. (LYBERIS & MANBY 1993, 1994) has been extensively discussed Short-lived and local faulting events including sinistral strike­ and rejected (LEPVRIER 1994, MAHER et al. 1995). slip movements occured in between. In the Canadian Arctic, deformation terminated by the end of Except for local variations of the paleostress field close to the Eocene with the deposition of the Eureka Sound Group (MIALL plate boundary and the existence of local and short-lived events, 1986, RICKETTS 1988) and only the Neogene Beaufort Forma­ the kinematic evolution established from different locations is tion is post-deformational. Thrust movements along Stolz and therefore consistent at a regional scale and consistent with the Lake Hazen Faults are dated by the synorogenic mid-Eocene major structures. Apart from the final extension, this history conglomerates of the Buchanan Lake Formation, at the top of includes two main stages: a N-NNE-S-SSW transpression which the Eureka Sound Group (RICKETTS & McINTYRE 1986, MIALL allows dextral strike-slip movements on faults parallel to the 1988, RICKETTS 1988); upper(?) Paleocene sediments are paleotransform and an ENE-WSW compression similarly involved in the Parrish Glacier and other thrusts subperpendicular to the paleotransform. However, using a along Nares strait (MAYR & OE VRIES 1982). In North­ similar analytical method of small-scaled structures, MANBY & Greenland the south-dipping Kap Cannon thrust, at the LYBERIS (1995) consider the change in shortening direction northern coast of Peary Land also moved during the Eocene (Bregger peninsula, Nordenskiöld Land) as progressive and not (SOPER et al. 1982). representative of distinct kinematic phases; they define an opposite succession with an initial ENE-WSW compression and In Spitsbergen, in spite of stratigraphic uncertainties that still a later strike-slip regime, which appears to be invalid from field exist, a late Paleocene to Eocene age for the main episode of evidences. deformation is generally favored, on the basis of various observations (MAHER et al. 1995).

Eurekan fold-and-thrust belt (Ellesmere and Axel Heiberg In the Central Basin, the onset of transpression is documented islands) by the reversal of the source supply in the latest Paleocene as a response to upthrusting of the western zone; this episode marks The Eurekan deformation concerns a wide zone characterized its evolution as a foreland piggy-back basin with an eastward by eastwards to southeastwards thrusts (Stolz Thrust, Vesle migration of the depocenter (KELLOGG 1975, STEEL et al. 1981, Fjord Thrust, Lake Hazen thrust, Parrish Glacier thrust etc.) and N0TTVEOT et al. 1988, HELLANO-HANSEN 1990). Within the overturned folds. Decollement horizons give rise to flat-ramp overall regime of dextral transpression, MÜLLER & SPIELHAGEN geometries (OKULITCH 1982, OSAOETZ 1982). Tertiary sediments (1990) separate a dominantly compressive phase restricted to the of the Eureka Sound group are fragmented in several foredeep late Paleocene - early Eocene and a strike-slip-dominated dextral subbasins within the belt and along Nares Strait (MAYR & OE transpression in early to middle Eocene. The stress tensor VRIES 1982). Structural and kinematic analysis of faults have recorded in the Central basin and related to the phase of ortho­ been performed in Central Ellesmere and Axel Heiberg Islands gonal compression, is similarly attributed to the late Paleocene­ (OE PAaRet al. 1989, LEPVRIER et al. 1996). The major phase of Eocene period of time (KLEINSPEHN et al. 1989, TEYSSIER et al. deformation is characterized by a direction of 0"1 turning from 1995). WNW-ESE in eastern Axel Heiberg Island along the Stolz thrust to NNW-SSE in north-central Ellesmere Island (BIue Moun­ In the Forlandsundet basin, the age of the youngest strata is early tains, Lake Hazen thrusts), allowing there a moderate Oligocene (FEYLING-HANSEN & ULLEBERG 1984) or most component of dextral motion (HIGGINS & SOPER 1983). Older probably restricted to the Eocene (MANUM & THRONOSEN 1986). structures expressed by tensional gashes and by rare reverse The entire sequence suffered ENE-directed compression by the faults have been evidenced in the BIue Mountains area. The late Eocene-early Oligocene, before the tectonic regime changed reconstructed direction of 0"1 is NE-SW oriented, allowing, as into extension (LEPVRIER & GEYSSANT 1985, LEPVRIER 1990, it has been suggested (MIALL 1985), left-Iateral displacements GABRIELSEN et al. 1992, KLEINSPEHN & TEYSSIER 1992). LYBERIS before thrusting along the faults which run through Ellesmere & MANBY (1993) fail to recognize the existence of the ENE­ Island slighty oblique to the Nares Strait. Along the Nares Strait WSW to EW compression in the Tertiary rocks of Forlandsundet itself, strike-slip faulting has been reported in Judge Daly basin which would be only affected by the late dextral Promontory (MAYR & OE VRIES 1982). transtension and NW-SE extension.

95 \0 0\

North•• Pole

AXEL HEIBERG I. 50'

ELLESMERE I.

FIXED 40" PRE2)

30 ~~~CJ/\ BARENTS SHELF

SPITSBERGEN BAFFIN BAY '& '" BJ0RN0YA ""

10 0" &

Fig. 2: Restered paleopositions, at chron 21 and chron 13. of Greenland and Spitsbergen-Barcnts sea blocks with respect to Canadian Arctic Islands. Thc plate-tectonic model of SRrvAsTAvA & TAPSCOTT (1986) is used in this reconstruction. Ellesmere and Axel Heiberg are maintained fixed in their prcsent day position (Polar projection with present-day grid). The different landmasses are represented with their modern coastlines. The main structures (faults and thrusts) active during thc major phase of deformation (mid to late Eocene) are reported on the chron 21 situation, togcther with the corresponding directions of compression (arrows) and thc main arcas of Paleogcne deposits. Abbreviations are as fol1ows: ST =Stolz Thrust, VFT = Vesle Fjord Thrust. BMT = Blue Mountains =Thrust, PGT = Parrish Glacier Thrust, LHT = Lake Hazen Thrust, NLFZ = Nyeboc Land Fault Zone, HFFZ = Harder Fjord Fault Zone, KCT = Kap Canon Thrust, TLFZ = Trolle Land Fault Zone, HFZ = Hornsund Fault Zone, BFZ = Billefjorden Fault Zone, LFZ = Lomfjorden Fault Zone; PMA = Princess Margaret Arch, GU = Grantland Uplift; CB = Central Basin, FB = Forlandsundet Basin, ES = Eureka Sound. E = Eureka, A = Alert, NA = Ny Alesund. L = Longyearbyen. Age 0/ earlier movements This plate tectonic evolution, from the late Cretaceous or the early Paleocene to the Oligocene, implies aperiod of orthogo­ The onset of deformation for the earlier structures (stage 1) and nal convergence between Greenland and North America along for strike-slip movements is more difficult to constrain. In Nares Strait (Wegener fault), preceeded by a first and signifi­ Ellesmere Island, they are tentatively attributed to the early to cant episode of left-lateral motion. Although the amount of middle Eocene (MIALL 1985). Recent apatite fission track data sinistral displacement has been considerably reduced in a more (ARNE et al. 1998), from the Vesle Fjord Thrust, indicate an recent model (ROEST & SRIVASTA VA 1989), this question has been initiation of fault movement during the Paleocene. a matter of controversy (KERR 1980, DAWES & KERR 1982, HIGGINS & SOPER 1989). The model of SRIVASTAVA & TAPSCOTT In Spitsbergen, the WNW-ESE stage 1 structures related to the (1986) used in our reconstruction Fig.2 and the amount of N-NNE-S-SSW direction of shortening may have been formed sinistral displacement along Nares Strait are not discussed in this only in the Late Paleocene-earliest Eocene just prior to the main paper. Sinistral strike-slip faulting are known in Judge Daly compressional event, a short period separating the two events Basin at the northeastern part of the Strait (MAYR & OE VRIES (BRAATHEN et al. 1995). The early development of the 1982) but it has been suggested that the movement was Forlandsundet basin as a transtensional relay zone within a distributed throughout the foldbelt itself, forming a diffuse plate dextral transpressional setting is probably synchronous with boundary (MIALL 1983, HUGON 1983). these stage 1 structures (STEEL et al. 1985, LEPVRIER 1988, GABRIELSEN et al. 1992). However, an earlier formation of these The direction of 01 for the major compressional phase (stage 2 stage 1 structures cannot be excluded. An early Paleocene and structures) fits well with the north to northwestwards movement possibly a Late Cretaceous age is suggested (BRAATHEN & BERGH of convergence between Greenland and Ellesmere Island. The 1995). According to the paleostress record in the Central Basin, preceeding oblique-slip regime of deformation (sinistral the oldest north-south stress tensor was established as soon as transpression) can be related to the northeastwards displacement the Late Cretaceous-earliest Paleocene, followed until the Late of Greenland. A mechanism of coupling could have existed Paleocene by short-lived faulting events (KLEINSPEHN et aI. 1989, during this phase but some of the ENE to NE faults of northern TEYSSIER et al. 1995). Fission track analyses tend to indicate an Ellesmere could have been successively the site of strike-slip initial 70-50 Ma cooling period due to uplift (BLYTE & faulting and thrusting as suggested by MIALL (1985). The arcuate KLEINSPEHN 1997) but only minor structures can be attributed to distribution of 01 during the second event is better explained the Late Cretaceous to early Paleocene time interval (MAHER et by the influence of basement acting as an indenter (LEPVRIER et aI. 1997). However, in the Kronprins Christian Land of NE aI. 1996) than by the effect of pivotal tectonism (PIERCE 1982, Greenland, dextral transpression has been argued as Late Cre­ OE PAOR et aI. 1989). On the other hand, the WNW to NW taceous (HÄKANSSON & PEOERSEN 1982). direction of compression observed on Axel Heiberg Island could be slightly younger than the thrusts on Ellesmere Island and could coincide with the latest WNW drift of Greenland. CORRELATIONS OF TECTONIC EVENTS WITH THE DRIFT OF GREENLAND Along the intracontinental paleotransform between Greenland and Svalbard, the plate tectonic model implies dextral motion, From magnetic anomalies recorded in the Labrador Sea, Baffin with successively strike-slip, compression-dominated trans­ Bay (SRIVASTAVA 1978, SRIVASTAVA & TAPSC01T 1986, ROEST & pression (chrons 25-24), strike-slip-dominated transpression SRIVASTAVA 1989) and Norwegian-Greenland Sea (TALWANI & (chrons 24-21) and then strike-slip followed by transtension after ELDHOLM 1977, MYRHE & ELDHOLM 1988, ELDHOLM et aI. 1990, chron 13 (MÜLLER & SPIELHAGEN 1995). A short-lived period of V ÄGNES et al. 1988, FALEIDE et aI. 1993, SKILBREI & SRIVASTA VA sinistral motion could have existed (SKILBREI & SRIVASTAVA 1993), it has been demonstrated that Greenland was an 1994). independant plate with respect to the North America and Eurasia plates between chrons 25-24 and 13. Prior to the existence of The sedimentary development of the Tertiary Central Basin is this three-plates system, Greenland was linked to Eurasia; but consistent with the motion between the Greenland and Eurasia since chron 33 (80 Ma) it moved away from America in a east­ plates and particularly with the onset of transpression in late northeast direction. A major anticlockwise change to the north­ Paleocene (MÜLLER & SPIELHAGEN 1990). The kinematic history northeast occured during the chrons 25-24 interval (59-56 Ma), and paleostress evolution established from fault-slip analysis which marked the beginning of sea-floor spreading in the coeval (LEPVRIER & GEYSSANT 1985, KLEINSPEHN et aI. 1989, BRAATHEN Norwegian-Greenland and Eurasian Oceanic Basins. Then & BERGH 1995, GABRIELSEN et aI. 1992, LEPVRIER 1992, TEYSSIER Greenland moved northeastwards and finally from chron 21 (49 et aI. 1995) are also in accordance with dextral transpression, Ma) until chron 13 (36 Ma) moved north-northwestwards. Af­ However, there is an apparent discrepancy between the ter chron 13 it became attached to America but continued to compressional nature of the main tectonic episode, with a 70­ separate from Eurasia in a WNW direction. According to the 80 ON direction of shortening, subperpendicular to the trace of reinterpretation of previous data, sea-floor spreading in the the paleotransform and the plate setting. This situation, wh ich Labrador Sea is thought to have started only from chron 27 in is not surprising for a regime of transpression (HARLANO 1997), the Paleocene and not in the Late Cretaceous (CHALMERS & can be explained by decoupling of the two components of LAURSEN 1995). transcurrence and convergence (MAHER & CRAOOOCK 1988). A

97 coupled to decoupled succession has been proposed to account synchronous ENE-vergent stuctures which developed in for the stage 1 and stage 2 structures (LEPVRIER 1992, B RAATHEN Spitsbergen as a result of decoupled transpression. The stage 1 et al. 1995, TEYSSIER et al. 1995). Coupling was prevailing during structures are consistent with the northeastward displacement of the formation of the stage 1 structures when Greenland and Greenland which took place after chron 25; they correspond Spitsbergen starts to slide past each other. Conversevely, stage respectively in the two areas to oblique sinistral and dextral 2 structures are related to decoupling. The orogen parallel regime of transpression, with coupling of the components of motion observed in the hinterland of the fold-thrust-belt is transcurrence and convergence. The earlier period of sea-floor coeva1 with the orogen-perpendicular transport to the ENE in spreading in the Labrador Sea, from the late Cretaceous or the the foreland (MAHER et al. 1997). The chron 25 to chron 24 early Paleocene to the late Paleocene, is on1y responsible of interval, marked by the drastic counterclockwise rotation of uplift, without significant contractional deformation. Greenland could correspond to the change from coupling to decoupling. Short-lived intervals of decoupling could exist The sequence of tectonic events in Spitsbergen and in Canadian during this period. A correlation diagram of Tertiary regional Arctic shows a good accordance and fits rather weIl with the teetonic events and plate-tectonic stages is given in Table 1. plate teetonic setting. However, the correlation established in

plate tectonic frarnework age ofteetonie events ehronostratigraphie age chronometrie magnetic sea-floor spreading motion of Ellesmere IsIand age (Ma) anornalies Spitsbergen Labrador sea Norw-Greenl. Greenland AxeI lIeiberg Island ~ ......

OLIGOCENE WNW transtension-extension

36 13 ~ ...... ~ ...... Priabonian upper Bartonian rranspression WNW-ESE NW (with decoupling): (Axel Heibcrg Island) ~ ENE-WSWorthogonal NNW-SSE W mid compression (foreland) (Ellesmere Island) @ 21 N dextral strike-slip orthogonal compression 49 (hinterland)

lower Ypresian NE

56 24 sinistral N-S lo NNE-SSW ENE-WSW to NE-SW sinistral transpression 59 rotation dextral transpression upper Thanetian 25 (with coupIing) (coupling ?) ffi 8 60.5 26 W ~ transtension 0.. lower Danian ENE with dexlral strike-slip HALMERS 65 f--29- &LARSEN Maestrichtian 1995) LATE ROEST CRETAC. uplift uplift Campanian 80 33 & SRIVASTAVA (1989)

Tab. I: Correlation diagram ofregional tectonic events (Spitsbergen and Ellesmere-Axel Heiberg islands) and plate-tectonic stages. The time scale isfrom KENT GRADSTEtN (1986).

CONCLUSIONS this paper needs to be confirmed, because of the remaining uncertainties on the stratigraphie age of the Tertiary Formations A two-stage tectonic development characterizes the Eurekan involved in the deformation. Furthermore, this correlation needs fold-thrust belt ofthe Canadian Arctic and the Spitsbergen fold­ to be corroborated by additional data from North and Northeast thrust belt, with a climax of deformation around mid-Eocene. Greenland. The sequence of tectonic events is fully compatible with the motion of Greenland with respect to Eurasian and North Ame­ rican plates (Tab. 1). The northerly to northwesterly motion ACKNOWLEDGMENTS which took place from chron 24 to chron 13, through chron 21, (Fig. 2) coincides with the stage 2 structures observed on This study has been supported by the French Polar Institute Ellesmere and Axel Heiberg islands. It accounts also for the (IFRTP) and by the GDR n049 "Recherches Arctiques" of the

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