Abstract This volume describes and interprets the geology of the northern margin of the North American continent in the Canadian Arctic Archipelago and North Greenland 1 . The northwestern part of this region is underlain by the Innuitian Tectonic Province, which comprises strata of the Late Proterozoic to Late Devonian Franklinian mobile belt, the Carboniferous to Paleogene Sverdrup Basin, and the Cretaceous-Cenozoic Arctic Continental Terrace Wedge (Fig. 4.1). The Franklinian mobile belt, deformed in Late Silurian to Early Carboniferous time, and the Sverdrup Basin, deformed in Paleogene time, together constitute the Innuitian Orogen. The junction of the Franklinian mobile belt with the Caledonides is concealed by the Wandel Sea off northeastern Greenland, and also by the upper Paleozoic and younger strata of the Wandel Sea Basin, the junction with the Cordillera and the Arctic Alaska Plate is covered by the Beaufort Sea. The southeastern part of the region discussed in this volume is underlain by the Arctic Platform, characterized by Cambrian to Paleogene strata that are contiguous with those in the Innuitian Orogen but relatively undisturbed. The Arctic Platform is a part of the sedimentary cover of the North American craton that is separated from other parts, such as the Interior and Hudson platforms, by Recent seaways or erosional gaps. Until World War II, explorers moved freely between the archipelago and Greenland, but in the post-war period the international boundary has become increasingly effective, and geological investigations have been carried out separately in the two areas. As a result, somewhat different stratigraphic and

Abstract The region discussed in this chapter encompasses the Canadian Arctic and northern Greenland. A dividing seaway — Davis Strait, Baffin Bay, Nares Strait — forms a prominent route by which generations of explorers, from the Norsemen to the classical late 19th century voyages of geographic discovery, pushed north to explore the mysteries of “Ultima Thule”. Ardent pursuit of two geographic objectives, the Northwest Passage and the North Pole, resulted in the discovery and outline mapping of much of the region. Ship and sledge expeditions directed at specific scientific programs followed in the 20th century; these activities were superseded by aircraftsupported operations in the years following World War II. Geographic and geological research continues, now supported by Canadian and Danish government agencies and private operators. Paradoxically, it was as recently as 1978 that the region’s (and the Earth’s) most northerly land was discovered: a Danish helicopter party that year landed on Oodaaq Ø, a small island at about 83°40N off the north Greenland coast. This account of exploration in the Innuitian Region is divided into five roughly chronological sections: I. Paleoeskimo habitation and Norsemen, 2000 B.C. – A.D. 1500; II. Early mariners and the Franklin Search, 1576-1859; III. Exploration along the Polar Route, 1852-1909;IV. Geological exploration by ship and dog sledge, 1903-1947; V. The aircraft age of geological study, 19 47 to the present. Brief notes on the development of geological understandingof the region follow sections II to IV 1 . Archeological finds indicatethat the Innuitian Region was inhabitated by paleo-eskimos as far

Abstract The geomorphic regions of the Canadian Arctic Archipelago 1 , one of the great archipelagos of the world, and of northern Greenland are described and illustrated in this chapter. Also included in the description are two large peninsulas, Melville and Boothia, that extend from mainland North America northward into the Arctic Islands. The land forms of this region are controlled, to some extent, by the lithology and structure of the bedrock, and therefore the geomorphic subdivisions distinguished here (Fig. 3.1) correspond fairly closely to the stratigraphic-structural provinces delineated in Chapter 4 (Fig. 4.3). The influence of Tertiary to recent events (uplift, erosion, glaciation, and sea level changes) on the genesis of these land forms is discussed in Chapters 18 and 19. The region measures about 3000 km from east to west and 2000 km from the southern islands to the northern tip of Ellesmere Island. Several large ice caps occur on the eastern Canadian Arctic Islands, and the region is bordered to the east by the great Greenland ice sheet — The Inland Ice. The land area described here exceeds 1450 000 km 2 . A network of channels divides the Canadian islands; many of the channels are broad seaways whereas others are narrow and resemble drowned river systems. Baffin Bay and Nares Strait separate the islands of Canada from Greenland. Baffin Bay and Nares Strait separate the islands of Canada from Greenland. Northern Greenland and the Arctic Islands are characterized by glacier-covered mountains, towering sea cliffs, dark canyons, rolling lowlands, and immense, icefilled

Abstract This chapter summarizes the major geological components and inferred tectonic events of the Arctic Islands and North Greenland and explains the currently used terms. References are mostly restricted to historical remarks and original definitions; additional references and details are given in later chapters. Basic elements of the present framework were introduced by Schuchert (1923), who made the first synthesis of North American geology that included the Arctic (Fig. 4.1). The results of the vigorous exploration in the Canadian Arctic Islands in the 1950s and early 1960s were compiled by Fortieretal. (1954), Fortier(1957), Douglasetal. (1963), and by Thorsteinsson and Tozer (1960, 1970), whose “geological provinces” (Fig. 4.2) have served as the basis for all subsequent syntheses. Comprehensive later accounts of this region include Trettin et al. (1972), Drummond (1973, 1974), Stuart Smith and Wennekers (1977), Trettin and Balkwill (1979), and Kerr (1981). Syntheses of the geology of North Greenland were made by Koch (1925, 1935, 1961), Dawes (1971, 1976), Dawes and Soper (1973), and Dawes and Peel (1981). The first-order elements of the present tectonic framework, all introduced previously, are Canadian Shield, Arctic Platform, and Innuitian Tectonic Province. The Canadian Shield borders the Arctic Platform on the southeast and extends into it as salients and inliers, such as the core of the Boothia Uplift1, Minto Arch, Melville Horst, and the Wellington and Duke of York highs, exhumed hills on the Late Proterozoic – Cambrian erosion surface (Chapter 3). It consists of a metamorphic-plutonic basement and unconformably overlying sedimentary and volcanic successions

Abstract The first measurements of gravity in Arctic Canada were made on Melville Island in 1819-1820 (Sabine, 1821). Gravity measurements in the Arctic did not resume until 1957 when five gravity control stations were established by the Canadian Government (Bancroft, 1958), and in 1958 about 200 gravity observations were made over Gilman Glacier in northeastern Ellesmere Island (Weber, 1961). The same year, as a contribution to the International Geophysical Year (IGY), a subtense bar and gravity traverse was carried out from Clements Markham Inlet on the Arctic coast across the United States Range to Archer Fiord on Kennedy Channel (Weber, 1961). In 1958 the Polar Continental Shelf Project (PCSP) was established, in the then Department of Mines and Technical Surveys, to coordinate most of the scientific studies carried out in the Arctic by the Canadian Government. From 1960, under the aegis of the PCSP, systematic gravity surveys have been carried out in the Arctic by the Dominion Observatory (later renamed the Earth Physics Branch [EPB], of the Department of Energy, Mines and Resources, and now part of the Geological Survey of Canada) primarily over the relatively flat areas of the Innuitian Region and adjacent continental margin (Sobczak, 1963; Sobczak et al., 1963; Picklyk, 1969; Sobczak and Weber, 1970; Sobczak and Stephens, 1974; Sobczak and Sweeney, 1978). Except for small areas completed in the southern, central, and northern parts of Ellesmere Island, gravity surveys of the mountainous areas of Axel Heiberg and Ellesmere islands have been deferred until reliable elevations can be

Abstract This chapter summarizes information on the northernmost parts of the Shield relevant to the understanding of the early history of the Innuitian region; a systematic description of the Canadian Shield and Greenland can be found in another volume of this series (Hoffman et al., in prep.). From a stratigraphic point of view, the Shield is divisible into crystalline basement, metamorphosed in Archean and/or Early Proterozoic time, and unconformably overlying sedimentary and volcanic successions of Proterozoic age that are only slightly deformed. The following section describes briefly the crystalline basement rocks at the margin of the Arctic Platform, proceeding from southwest to northeast. Regional metamorphic facies of the Canadian part have been compiled by Fraser et al. (1978). Victoria Island . Granodiorite on the northeast side of the Minto Arch yielded a’ K-Ar age of 2391 ± 125 Ma (recalculated from Lowdon et al., 1963), suggesting that it may be part of the original Slave Province. This interpretation is supported by the inferred Early Proterozoic age of unconformably overlying sediments (Campbell, 1981; see below). A later thermal event, however, is apparent from the 1645 ± 20 Ma K-Ar age on a pegmatitic granite in the Wellington High (W.A. Gibbins, quoted by Campbell and Cecile, 1979). Boothia Peninsula, Somerset Island and Prince of Wales Island . The Precambrian core of the Boothia Uplift (Fig. 4.2, 4.3) consists of quartzofeldspathic, pelitic, calcareous, and mafic rocks metamorphosed largely in the transitional granulite facies (Blackadar, 1967; Brown et al., 1969). Structural trends are northerly on

Abstract The Franklinian Basin extended from northern Ellesmere Island across North Greenland, where its sedimentary infill is exposed from Inglefield Land and Washington Land in the west to Kronprins Christian Land in the east (Fig. 7.1–7.3). The segment of the basin exposed in North Greenland is approximately 800 km long and has a maximum preserved north-south width of 200 km. The thickness of the sedimentary column reaches about 8 km; the main part of the succession is of Cambrian-Silurian age, but it may extend down into the latest Precambrian and up into the earliest Devonian. A distinction into a shelf sequence and deep water trough sequence can be recognized in northern Ellesmere Island and in North Greenland, and the variations in facies with time in the two regions show close parallels. Correlation on group or formation level is often possible across Nares Strait (Peel and Christie, 1982; Peel et al., 1982). Detailed knowledge of the North Greenland sequences, however, permits an integrated account of shelf and trough development in the North Greenland segment of the Franklinian Basin. A craton composed of Archean and Upper Proterozoic crystalline basement rocks, overlain by Middle and Upper Proterozoic sedimentary and volcanic rocks, lies to the south of the Franklinian Basin (Chapter 6). This is now exposed intermittently along the margin of the Inland Ice, and more extensively in eastern North Greenland (Fig. 7.1). In the early Paleozoic, this craton was fringed to the north by an east-west trending shallow marine shelf, Two main facies belts

Abstract Two first-order depositional provinces are distinguished — a southeastern shelf, which encompasses nearly all of the Arctic Platform and a large part of the Franklinian mobile belt, and a northwestern deep water basin. The latter, in turn, is divisible into a southeastern sedimentary subprovince, and a northwestern sedimentary and volcanic subprovince. The unstable boundary between deep water basin and shelf migrated cratonward from late Early Cambrian to Early Devonian time. In the preceding chapter, the Cambrian to Silurian depositional history of North Greenland has been divided into seven evolutionary phases that are applicable to both shelf and deep water basin as they are based, to some extent, on shifts of their mutual boundary. This organization was feasible because in Greenland only northern parts of the shelf province, which have been affected markedly by the cratonward expansion of the basin, are exposed. Separate schemes for shelf and basin, however, are required in the Arctic Islands where both provinces are more extensive and more complex stratigraphically. It is most convenient to discuss the stratigraphy of Franklinian Shelf and Arctic Platform in terms of informal time-rock slices, and that of the deep water basin in terms of unrelated, variably diachronous, informal rock units. The basic differences in the stratigraphic record of the two provinces reflects the fact that different geological processes are important in them. Eustatic fluctuations in sea level, for example, affect primarily the shelf; tectonic events in “outboard” orogenic belts affect primarily the basin. The different classifications chosen in Chapters 7

Abstract A geological province in northernmost Ellesmere Island, named Pearya by Schuchert (1923) and interpreted as the relict of a Precambrian borderland, is now regarded as an exotic continental fragment with an internal suture, i.e. as a composite terrane (Chapter 4). This chapter outlines its late Middle Proterozoic to Late Silurian record and briefly compares it with the records of the Franklinian and Caledonian mobile belts. Special emphasis is placed on Ordovician tectonic and plutonic events, which are important for the evaluation of Pearya’s relationships with these two regions. Establishment of this history has been difficult because of sparse age control for the pre-Caradoc stratigraphic record, the effects of five orogenies, and partial ice cover. On first approach, Pearya is divisible into four major successions that differ in age and overall lithology (Fig. 9.2; for geographic names throughout this chapter see Fig. 9.1). Succession I includes sedimentary and(?) volcanic strata of uncertain age that have been deformed, metamorphosed in the amphibolite facies, and intruded by granitic plutons in late Middle Proterozoic time (1.0-1.1 Ga). Succession II, ranging in age from Late Proterozoic to Early Ordovician, consists mainly of “miogeoclinal” or “platformal” sediments (carbonates, quartzite, mudrock) with lesser proportions of mafic and siliceous volcanics, diamictite, and chert. Its concealed contact with succession I is tentatively interpreted as an angular unconformity. Succession III includes arc-type and(?) ocean floor volcanics, mudrock, chert, and carbonates, and has associated with it fault slices of ultramafic-mafic complexes of late Early Ordovician (Arenig) age. The faulted contact between

Abstract Carbonate deposition dominated the Franklinian miogeocline from Late Cambrian until earliest Middle Devonian. Following a transgression in early Eifelian (within the costatus-costatus conodont Zone), quartzose clastics replaced carbonates as the dominant sediment type and, from that time until Early Carboniferous, clastic sedimentation was widespread across the Franklinian miogeocline. During this interval an enormous clastic wedge prograded southwestward, heralding the advance of Ellesmerian deformation. Middle-Upper Devonian clastic sediments are widely preserved and are most widespread in the western Arctic, where they occur over much of Bathurst, Melville, Prince Patrick and Banks islands (Fig. 10.1). In the eastern Arctic the deposits occur mainly in a broad synclinorium which stretches from central Ellesmere Island to eastern Grinnell Peninsula. Isolated occurrences are present on northern Ellesmere Island in the Yelverton Pass region and in Tertiary grabens on Cornwallis Island (Fig. 10.1, Fig. 4 [in pocket]). Forty-two wells have penetrated the strata and numerous surface sections are described in the literature (Fig. 10.1, Fig. 1 [in pocket]). The maximum preserved thickness of the clastic wedge is about 4000 m, although thermal maturation levels of strata within and directly below the wedge suggest that original thicknesses may have been nearly twice this figure in some areas. Regional mapping studies carried out by the Geological Survey of Canada in the 1950s and 1960s established a general stratigraphic framework for these clastic sediments (McLaren, 1963; Thorsteinsson and Tozer, 1962; Tozer and Thorsteinsson, 1964; Kerr, 1974). Embry and Klovan (1976) reviewed all previous work up to 1975 and presented

Abstract As outlined above (Chapters 7, 8), the sedimentary subprovince of the Franklinian deep water basin (Hazen Trough) extends eastward from the Canadian Arctic Islands (Chapter 8C) into northern Greenland (Chapter 7), and the pulses of deformation which affected the Canadian sector (Hazen Fold Belt) in Late Silurian or Devonian to Early Carboniferous time (Chapter 12) likewise extended into Greenland producing an east-west striking mobile zone, known traditionally as the North Greenland fold belt. The fold belt has an exposed width of up to 100 km on the north coast of Greenland and is flanked to the south by the weakly deformed lower Paleozoic platform sequence described in Chapter 7. Figure 11.1 shows that several distinct tectonic zones can be recognized in the fold belt, and Figure 11.2 illustrates how these are spatially related to the geometry of the deep water basin (Hazen Trough). A southern fold and thrust zone coincides with a region which was transitional between the platform and trough for much of the Cambrian and Ordovician. It is bounded to the south by the Navarana Fjord lineament, which represents the position to which the platform margin had retreated by Early Silurian time. The structure of the southern zone is of thin skinned fold and thrust type, with an approximately east-west strike and southerly vergence. A northern orthotectonic zone is developed on the site of the trough proper with its thick fill of dominantly Lower Cambrian turbidites. It forms the mountainous regions of Johannes V. Jensen Land, Nansen Land,

Abstract In the Arctic Islands, intermittent and localized deformational phases of Late Silurian to Frasnian age were followed by the Ellesmerian Orogeny sens stricto of latest Devonian (Famennian) to Early Carboniferous age (Thorsteinsson and Tozer, 1970, p. 566), which affected the entire mobile belt. Regional metamorphism of greenschist and higher grades, and granitic plutonism were restricted to parts of northern Ellesmere and Axel Heiberg islands. The structural events and associated phases of metamorphism and granitic plutonism will be described in historical order, and, within given phases, from the oceanic side toward the craton. The most important conclusions are summarized at the end of the chapter. For an overview of the orogen, see Figures 12A. 1 and 121.1, and for geographic names, Figure 1 (in pocket). The most important event in the structural history of northern Ellesmere Island was the accretion of Pearya, which resulted in intensive deformation in Pearya and the Clements Markham Fold Belt, and possibly also in adjacent parts of the Hazen and Northern Heiberg fold belts (Fig. 12B.1). Preliminary geological maps for this region have been published by Trettin and Mayr (1981), Mayr et al. (1982a, b), Trettin (1982, 1987b), Trettin et al. (1982), and Trettin and Frisch (1987); other relevant references arequoted in Chapters 8 and 9. Available evidence strongly suggests that Pearya is an exotic terrane that was part of the Caledonides, at least until late Middle Ordovician time (Chapter 9).The Ashgill Wenlock deep water facies of Pearya are broadly comparable to those of the Franklinian

Abstract Upper Paleozoic carbonates and evaporites with associated basal redbeds, marine shales and minor chert and basic volcanic rocks form the initial fill of the Sverdrup Basin. These rocks are exposed in spectacular fiord cliff faces on northwestern Ellesmere and northern Axel Heiberg islands, and in more subdued terrain on southern Ellesmere, northwestern Devon, northern Melville, Cameron, and Helena islands (Fig. 13.1; for geographic names and regional geology see Fig. 1 and 2 [in pocket]). They also have been penetrated, totally or in part, by 35 exploratory wells, most of which are in the western sector of the basin, on and between Melville and Cameron islands. Carboniferous evaporites deposited in the centre of the basin have generated halite-cored diapirs and other linear intrusive bodies that influenced the structural development of the basin, deformation of the Mesozoic section, and localization of oil and gas accumulations. Similarity with the upper Paleozoic section on Svalbard and northern Greenland extends the regional implications of upper Paleozoic strata in the Sverdrup Basin in terms of circum-Arctic tectonics and paleoclimates. The Ellesmerian Orogeny (Chapters 10, 12) probably extended into the earliest Carboniferous (Tournaisian), but appears to have terminated before the deposition of the Visean Emma Fiord Formation. Too little of this formation is preserved to obtain a clear picture of tectonic conditions just prior to the subsidence of the Sverdrup Basin, which commenced in the Namurian and continued to the Late Cretaceous. Structures formed during the initial phase of subsidence, and geophysical evidence for crustal thinning below

Abstract Mesozoic strata are widespread in the Canadian Arctic Islands and occur in diverse tectonic-stratigraphic settings (Fig. 14.1). The Sverdrup Basin, which was a major depocentre in the Arctic Islands from Carboniferous to early Tertiary, contains the thickest and most complete Mesozoic succession in the region. In the central portion of the basin Triassic to Cretaceous deposits are up to 9 km thick (Fig. 14.1 ; for well sites and geographic names see Fig. 1, in pocket). Mesozoic rocks in eastern Sverdrup Basin were folded and faulted by regional compression in early Tertiary, and excellent exposures occur in mountainous terrain. To the west, the structures and terrain have much lower relief and outcrop is mainly Cretaceous or younger in age. Banks Basin on Banks Island (Fig. 4.3) contains a gently-dipping, 1200 m succession of Upper Jurassic to uppermost Cretaceous strata. Scattered outliers of flatlying to tilted Cretaceous strata occur in the Franklinian mobile belt, Arctic Platform and Canadian Shield geological provinces. These outliers are areally restricted and thin, and commonly lie in grabens. Cretaceous strata are also interpreted to occur beneath thick Tertiary deposits along the continental shelf northwest of the Arctic Islands, in eastern Lancaster Sound, and on the continental shelf east of Baffin Island. The nature and thickness of these offshore and deeply buried strata are unknown owing to a lack of data. The Mesozoic succession in the Arctic Islands consists almost entirely of clastic sediments. In Sverdrup Basin, sandstone units occur mainly on the basin margins with shale-siltstone

Abstract Macrofossils are extremely rare in Arctic Cenozoic sediments, apart from rare nondiagnostic gastropods and pelecypods, plus foraminifera, fish, scaphopods and land vertebrates recorded from the Strathcona Fiord area, Ellesmere Island (Westetal., 1977, 1981). These have only a local distribution and are therefore of limited chronostratigraphic value. Macroflora, particularly pine cones, occur in Neogene sediments and some are age diagnostic. Marine fossils are rare throughout the Cenozoic section, except for rare dinoflagellates, particularly in the Banks Island area, and foraminifera on Meighen Island. However, spores and pollen are abundant throughout the Cenozoic and in the Campanian-Maastrichtian sediments of similar facies that lie conformably beneath the Cenozoic section. Palynostratigraphic studies therefore form the main chronostratigraphic basis for the largely nonmarine or brackish water facies that comprise the bulk of the Cenozoic section of the Innuitian region (plus Campanian to Maastrichtian in the eastern Arctic). Many local, spot age determinations have been carried out on the Upper Cretaceous and Cenozoic section. The only thorough stratigraphic investigations are those by Doerenkamp et al. (1976) in Banks Island and Rouse (1977) in Remus Creek, Ellesmere Island, for the Maastrichtian to Early Oligocene interval. These workers established zones based on comparison with contemporaneous sections in the Northern Interior Plains, Beaufort-Mackenzie Basin, British Columbia, Alaska, Siberia and elsewhere. In addition, G. Norris and M. Head (pers. comm., 1983-1985) have examined the writer’s collections from Axel Heiberg and central Ellesmere islands, and G. Norris (pers. comm., 1987) examined the Eocene to Miocene section in the Meighen Island well

Abstract Northern Greenland underwent within-plate deformations in Tertiary time in response to a rather complex and incompletely understood displacement history associated with the opening of Labrador Sea – Baffin Bay, the Arctic Ocean basins, and the North Atlantic. Because post-Ellesmerian cover sequences are not widely preserved in the region, it is frequently difficult to differentiate these “Eurekan” structures from earlier deformations, or to establish their precise age. Nonetheless, three sets of structures and two geotectonically important magmatic events of Cretaceous-Paleogene age have been recognized Fig. 16.1. Since these have been subject to speculative and often conflicting geotectonic interpretations, in this account we concentrate on the available factual information, following the review by Soper et al. (1982) and references therein, plus new information derived from 1984 fieldwork. We allude briefly to geotectonic implications, referring the reader to the Nares Strait symposium volume (Dawes and Kerr, 1982) for fuller discussion. A dense swarm of approximately north-south trending (coast-normal) dolerite dykes occurs along the north coast of Greenland between about 38°W and 48°W (Nansen Land, westernmost Johannes V. Jensen Land and the intervening islands). Scattered examples are also present throughout Johannes V. Jensen Land. The swarm is most dense at sea level, approaching 50 per cent of the rock in places, with individual dykes up to 25 m in width and occasionally much larger. Dyke density diminishes both upward and to the south, the swarm being confined to the region north of the Harder Fjord fault zone (see below). The dykes cut lower Paleozoic

Abstract Four major phases of deformation with partly overlapping age ranges affected different parts of the Innuitian Orogen and Arctic Platform in late Mesozoic – Tertiary time: (1) Middle Jurassic (Aalenian) to Early Cretaceous (Barremian): mild uplift and extensional faulting (i.e. rifting) along the northwestern margin of the Arctic Islands; (2) Early Cretaceous (Neocomian) to earliest Oligocene: normal faulting in the southeastern part of the Arctic Platform and in the Boothia Uplift, accompanied by local transcurrent faulting; (3) Paleogene (and possibly latest Cretaceous): compressional deformation in the northeastern part of the Arctic Islands (Eurekan Orogeny); (4) Middle and Late Tertiary (Oligocene-Pliocene): widespread differential uplift, most pronounced in the eastern part of the Eurekan Orogen and around Baffin Bay, accompanied by some normal faulting. Event 1, known mainly from the stratigraphic record, is discussed in Chapter 14 by Embry, who relates it to rifting in the Amerasian Basin (Fig. 14.60). Structural treatment of this region, including Late Cretaceous and Tertiary events, will have to await systematic analysis of available geophysical information. However, normal faulting, such as on Banks Island (Miall, 1979a), recurred in the Tertiary. Event 4, inferred from limited geological and geomorphic information, is discussed in Chapter 18. This chapter is concerned with the Eurekan Orogeny (event 3) and the partly coeval but longer ranging extensional event 2. Kerr’s (1967) hypothesis that the two are related in origin — having been caused by counterclockwise rotation of Greenland — now is widely accepted, and therefore his term, Eurekan Deformation (Kerr, 1977)is

Abstract The post-Eurekan pre-Pleistocene history of the Arctic Islands is poorly known because the stratigraphic record of this interval is limited mainly to the northwestern margin of the Queen Elizabeth Islands (Chapter 15). The lack or scarcity of preserved sediments in other areas indicates uplifts, which, in interaction with erosion and eustatic sea level changes, gave rise to the present landscape (cf. Thorsteinsson and Tozer, 1970). Middle or Late Tertiary positive movements were most pronounced within the Eurekan Orogen and a belt surrounding the Labrador Basin, and of lesser magnitude in the area south of the Eurekan Orogen. The uplift of the Eurekan Orogen represents isostatic adjustments to post-Eurekan erosion; the causes of the uplifts in the other areas are uncertain although a thermal model appears to be applicable to the mountains around Labrador Basin. The positive movements have been amplified to a minor extent by an overall drop in sea level since early Tertiary time (Vail and Hardenbol, 1979). The Holocene postglacial rebound will not be considered in this context because it merely tends to restore conditions that existed before the Pleistocene. Crustal thickening during the Eurekan Orogeny resulted in high topographic relief that produced the syntectonic clastic sediments of the Eureka Sound Group (Chapter 15). Post-Eurekan erosion must have caused an isostatic disequilibrium that was compensated by upward movement. The presence of high mountain ranges and matching negative Bouguer anomalies shows that the crustal roots of the orogen have not yet been eliminated by these processes. It is generally

Abstract Quaternary geology studies in most of the Arctic Archipelago inevitably have focused on the age and extent of Pleistocene glaciations. In the islands south of Parry Channel (Fig. 19.1), repeated advances of temperate glaciers spreading from continental dispersal centres have eroded and deposited a wide range of landforms. There, till is the most widespread surficial material; marine deposits, raised with a crust rebounding from the last glaciation, are also conspicuous. In the Queen Elizabeth Islands to the north, the mountainous eastern rim (Fig. 19.2) remains half glacierized and has attracted the interest of the glacial geologist as well as glaciologist; drift landforms are scarcer than to the south. In the western islands, drift is sparse and glacial studies are retarded in comparison with the rest of the archipelago. Suitably, this area has drawn some studies of Holocene and older nonglacial deposits and processes, including the thermal history of near-surface sediments. The Quaternary of the archipelago is discussed at greater length in Fulton (1989), by Hodgson (1989) for the Queen Elizabeth Islands, by Funder (1989) for north Greenland, and, in three separate articles by Andrews (1989), Dyke and Dredge (1989), and Vincent (1989), respectively, for the islands south of Parry Channel. The Quaternary climate of the Arctic Islands is poorly understood — in particular, the polar weather patterns that resulted when continental ice domes lay to the south. The present climate of most of the northern islands is dominated year-round by the anticyclonic air of the central Arctic Ocean, and thus