Geological Survey of Denmark and Greenland Bulletin 19 ... - Geus

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Fig. 62. The trace fossil Ophiomorpha irregulare is characteristic of transgressive shoreface sandstones in the Qilakitsoq Member, especially at Qilakitsoq and Nuuk Killeq. For location, see Fig. 2. The marine delta front association comprises coarsening-upward units where mudstones with marine fossils deposited below storm-wave base are overlain by heterolithic mudstones and sandstones which pass up into shallower water facies. These units are interpreted as the result of delta front progradation of shelf deltas. The distributary channel association consists of crossbedded, medium- to coarse-grained sandstones, which are interpreted as having been deposited within almost straight to slightly sinuous fluvial channels (Olsen 1991, 1993). Small fluvial channels are included in the delta plain association, which is characterised by carbonaceous mudstones, sandstones and coal beds, interpreted as having formed through vertical aggradation of subaerial to freshwater lacustrine or swamp deposits on the lower and upper delta plain. The coal beds are interpreted as the in situ accumulations of plant remains in both freshand brackish-water environments. The transgressive sand sheet association includes thin beds of sand with erosive bases and often with numerous marine trace fossils, indicating deposition on a marine shoreface (G.K. Pedersen & Rasmussen 1989; Midtgaard 1991; Olsen 1991; Olsen & Pedersen 1991; G.K. Pedersen & Pulvertaft 1992; G.K. Pedersen & Bromley 2006). The erosional bases represent ravinement surfaces. Boundaries. The lower boundary of the Qilakitsoq Member is not exposed. The upper boundary, which corresponds to the upper boundary of the Atane For - mation, is everywhere an erosional unconformity. Dif - ferent units overlie the member throughout the region; these include the Itilli, Kangilia, Quikavsak and Atanikerluk Formations as well as volcanic rocks of the Vaigat Formation (Fig. 16). Geological age. The geological age of the Qilakitsoq Member is Middle Turonian to Santonian at Ataata Kuua, Coniacian at Alianaatsunnguaq (Birkelund 1965), San - tonian − earliest Campanian at Paatuut, Nuuk Killeq and on central Nuussuaq (Koch 1964; Boyd 1990, 1992; Olsen & Pedersen 1991; G.K. Pedersen & Pulvertaft 1992; Nøhr-Hansen 1996; D.J. McIntyre, personal communication 1997). Stable carbon isotopes in wood fragments suggest a Middle to Late Santonian age (Ambirk 2000). Correlation. The Qilakitsoq Member correlates with part of the Itilli Formation (western Nuussuaq and Svartenhuk Halvø). Subdivision. The Qilakitsoq Member includes the Itivnera Bed in the Aaffarsuaq valley near Tunoqqu. Itivnera Bed revised bed History. The Itivnera beds were described by Dam et al. (2000) as fluvial sandstones incised into the top of the Qilakitsoq Member (Atane Formation) at two widely separated localities: Itivnera and Ataata Kuua (Figs 40, 82). The erosional, lower boundary was interpreted as a sequence boundary. At Itivnera, the fluvial deposits are 80
Fig. 63. Type locality of the Itivnera Bed in central Nuussuaq (for location, see Fig. 82). The bed comprises three channellised sandstone units up to 38 m thick that cut down into Santonian deltaic deposits of the Qilakitsoq Member (Atane Formation). The Itivnera Bed is overlain by submarine fan deposits of the Itilli Formation (Aaffarsuaq Member). The sandstone cliffs are about 16 m high and the spacing between the valleys is less than 100 m (see Dam et al. 2000). m 15 10 5 0 cl si sand pb Fig. 64. Type section of the Itivnera Bed. Neither the base nor the top of the fluvial sandstone unit is exposed (from Dam et al. 2000). For legend, see Plate 1; for location, see Fig. 82. overlain by deep marine deposits belonging to the Aaffarsuaq Member of the Itilli Formation. At Ataata Kuua, a valley incised into the Atane Formation is filled by turbidite mudstones, sandstones and conglomerates referred to the late Maastrichtian to earliest Paleocene Kangilia Formation; the Itilli Formation is not present at Ataata Kuua (Figs 14, 15, 16). The Qilakitsoq Member here is of Turonian–Santonian age. Fine-grained organicrich sediments preserved in the top of a small fluvial channel contain palynomorphs indicating a Coniacian age. The fluvial channel deposits at Ataata Kuua that were previously referred to as Itivnera beds are now assigned to the Qilakitsoq Member on the basis of photogrammetric mapping (A.K. Pedersen et al. 2007b) and dating of the fine-grained channel fill, which lies within the age range of the Qilakitsoq Member at this locality. The presence of Early Campanian fluvial deposits at Ataata Kuua cannot be demonstrated. The Itivnera beds sensu Dam et al. (2000) constituted the basal part of the Itilli Formation. In the present paper, this unit is restricted to the cemented channel sandstones at Itivnera which are defined here as the Itivnera Bed of the Qilakitsoq Member. Name. The strata are named after the saddle feature named Itivnera between Nalluarissat and Tunoqqu (Fig. 82). The name was derived from a nearby locality shown on the geodetic map from 1966 (Geodætisk Institut 1966); the spelling has not been changed to modern Greenlandic orthography because the locality is not shown on later geodetic maps. 81
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GEOLOGICAL SURVEY OF DENMARK AND GR
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Contents Abstract . . . . . . . . .
Page 7 and 8:
Preface The onshore Cretaceous-Pale
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Introduction The Nuussuaq Basin bel
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chemistry of the Nuussuaq Basin hav
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Fig. 5. Plant fossils from the Atan
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Peak 2010 m Peak 1900 m Peak 1760 m
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A lithostratigraphy for the marine
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to provide further funding for stud
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DGR Geological setting As a result
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TSS 8 Agatdal Fm Eqalulik Fm Kangil
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A Svartenhuk Halvø 50 km B Hinterl
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Nuussuaq Group new group History. T
Page 29 and 30: ley (Figs 2, 40, 65). The section a
Page 31 and 32: Central Nuussuaq Agatdalen South co
Page 33 and 34: 3 10 4 6 5 Qorlortorssuaq Slibesten
Page 35 and 36: volcanic sediments are referred to
Page 37 and 38: Fig. 20. View from Uummannaq toward
Page 39 and 40: In the Kuuk area, the sediments ove
Page 41 and 42: m m 15 14 14 13 12 11 10 9 8 7 6 5
Page 43 and 44: Kome Formation m 40 30 20 D tial re
Page 45 and 46: Fig. 28. Reference locality of the
Page 47 and 48: Vaigat Fm Vesterfjeld Slibestensfje
Page 49 and 50: Gilbert delta in the Ikorfat area (
Page 51 and 52: 150 300 450 100 250 400 m 550 50 20
Page 53 and 54: Fig. 36. Outcrop of the Upernivik N
Page 55 and 56: Correlation. The Upernivik Næs flo
Page 57 and 58: 12’ 09’ 15’ 06’ 03’ Saqqa
Page 59 and 60: m 0 GGU 247801 200 400 247815 ★
Page 61 and 62: wave-rippled sand streaked mudstone
Page 63 and 64: the formation in the marine mudston
Page 65 and 66: d d Fig. 47. Type locality of the S
Page 67 and 68: Fig. 49. Cross-bedded medium- to co
Page 69 and 70: and Qaarsut (Fig. 22). Its wider di
Page 71 and 72: Fig. 52. Two closely spaced section
Page 73 and 74: Type section. The type section of t
Page 75 and 76: Fig. 56. Delta front succession of
Page 77 and 78: Fig. 59. The Kingittoq Member at Ki
Page 79: sh L sh ch delta front Vaigat Forma
Page 83 and 84: 782 Quaternary cover 54° 888 Malig
Page 85 and 86: Kuugannguaq-Qunnilik Fault and is o
Page 87 and 88: and include clasts of intraformatio
Page 89 and 90: deposited in a base-of-slope and ba
Page 91 and 92: VK 53°30’ 53°15’ Niaqornat Tu
Page 93 and 94: Umiivik-1 m Overburden ★ ★ No p
Page 95 and 96: 76). Heavily bioturbated interbedde
Page 97 and 98: Fig. 78. Type locality of the Kussi
Page 99 and 100: A B Itilli Formation Kussinerujuk M
Page 101 and 102: 160 140 120 100 Vaigat Formation Eq
Page 103 and 104: Fig. 85. Mudstones and conglomerati
Page 105 and 106: Fig. 87. Type section of the Kangil
Page 107 and 108: m 150 140 130 120 110 100 90 Kangil
Page 109 and 110: channellised, high-density currents
Page 111 and 112: Thickness. The Annertuneq Conglomer
Page 113 and 114: Fig. 96. A: Type locality of the Oy
Page 115 and 116: On Svartenhuk Halvø, on the east s
Page 117 and 118: Fig. 100. Reference locality of the
Page 119 and 120: Tupaasat Member Atane Formation Fig
Page 121 and 122: ever, have a fluvio-lacustrine orig
Page 123 and 124: etween Tupaasat and Nuuk Qiterleq a
Page 125 and 126: Vaigat Formation sill Quikavsak For
Page 127 and 128: Fig. 112. The sharp boundary betwee
Page 129 and 130: Agatdal Formation Eqalulik Formatio
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Fig. 116. Basal conglomerate unit o
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heterolithic deposits of the Kangil
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GANE#1 Vaigat Fm Anaanaa Mb m Hyalo
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Fig. 121. Well reference section of
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Pedersen 1978). The beds are usuall
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In detail, however, the boundary be
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Fig. 126. Composite type section of
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m m 240 340 m Pingu Member 230 230
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Naujât Member Atane Formation, Kin
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The TOC [Total Organic Carbon] cont
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Fig. 133. Correlation of the member
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Fig. 135. Type locality of the Ping
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Fig. 137. Lower, sharp boundary of
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m 130 125 110 t t invasive lava low
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Fig. 141. Upper part of the Assoq M
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Brown, R. 1875: Geological notes on
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a rosetted spreite trace fossil: Da
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ing bark from the Nûgssuaq peninsu
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1998: The syn-volcanic Naajaat lake
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Appendix: Place names and localitie
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Place name Place name P Paatuut sou
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Geological Survey of Denmark and Greenland Bulletin 19 ... - Geus

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