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

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m 480 160 470 150 310 460 140 300 450 130 290 440 120 280 430 110 270 420 100 260 410 90 250 400 80 240 390 70 230 380 60 220 370 50 210 360 40 200 350 30 190 340 20 180 330 10 170 320 0 vf f m c vc f m c clay silt sand pebbles vf f m c vc f m c clay silt sand pebbles vf f m c vc f m c clay silt sand pebbles Fig. 60. Type section of the Qilakitsoq Member (Atane Formation) on the western side of the Qilakitsoq stream, central Nuussuaq. Note the higher proportion of delta front deposits compared to the Kingittoq Member (Fig. 53). For location, see Fig. 82; for legend, see Plate 1. 1991; Olsen 1991, 1993; G.K. Pedersen & Pulvertaft 1992; Boyd 1993; Dueholm & Olsen 1993; Ambirk 2000; Dam et al. 2000). The coarsening-upward successions are typically 5−25 m thick but may reach up to c. 70 m (Fig. 61). They can be traced laterally through closely spaced outcrops for up to 8 km in the Paatuut area (Fig. 46; Olsen 1991, 1993; Dueholm & Olsen1993) and also in the Qilakitsoq area. The mudstones at the base of the coarsening-upward units are dark grey, silty and weakly laminated, and may contain marine fossils (Olsen & Pedersen 1991; Nøhr- Hansen 1996). These grade up into sand streaked mudstones and heterolithic sandstones, where wave-ripples and swaley- and hummocky cross-stratification are enhanced by drapes of comminuted plant debris (Fig. 60, 33–50 m). The successions are frequently topped by medium-grained, trough cross-bedded sandstones (Fig. 60, 145-158 m). Bioturbation may locally be very intense and totally obscure primary structures. 78
sh L sh ch delta front Vaigat Formation Atane Formation 65 m Fig. 61. Outcrop of the Qilakitsoq Member on the western slope of gully immediately west of Qilakitsoq. The member is dominated by stacked delta front successions. The outcrop corresponds to the interval 200–380 m in Fig. 60; ch, channel; L, lagoon; sh, shoreface. Note that the uppermost delta front succession is abnormally thick at this locality. For location, see Fig. 82. Other sandstones are pale, friable, medium- to coarsegrained, in places with channel lags of pebbles or intraformational clasts of mudstone and coal. These sandstones are cross bedded or structureless, commonly with softsediment deformation structures. They form single-storey sandstone ribbons with a width:thickness ratio as low as 6 and a sinuosity of 1.2 (Olsen 1993) (Fig. 60: 0–11 m). Successions of carbonaceous heteroliths interbedded with cross laminated sand, sand streaked mudstones, mudstones with plant debris and coal seams occur in all outcrops of the Qilakitsoq Member. Their dark grey to black colour reflects the abundance of comminuted plant debris. Locally, root horizons or rare tree stumps are present. Numerous coal beds at Paatuut and Ataa are more than 0.8 m thick. Concretions and ‘coal balls’ are observed in several horizons, as well as silicified wood. Dirt bands in coal beds are common, mainly consisting of carbonaceous mudstones (Fig. 60: 20–32 m). Sheets of structureless or strongly bioturbated sandstone with an erosional base occur in most outcrops of the Qilakitsoq Member. They range from thin (c. 0.05 m) fine-grained sandstones to thick (c. 3 m) mediumto coarse-grained sandstones. Upwards, these sandstones may pass gradually into mudstones (Fig. 60, 180–182 m). Fossils. Plant macrofossils, spores and pollen are known from the Qilakitsoq Member (Heer 1883a, b; Seward 1926; Ehman et al. 1976; Croxton 1978a, b; Boyd 1990, 1992, 1993, 1994). Heer (1883b) described plant fossils collected from three outcrops of the Qilakitsoq Member (Alianaatsunnguaq, Ataa, and Paatuut) and referred these to the Atane and Patoot floras. Boyd (1992, 1993) recognised three or more floral communities (nearshore lacustrine, backswamp, levee and riparian vegetation) in the fossil flora from the Paatuut area (the Paatuut flora). Marine dinocysts have been identified in samples from the Qilakitsoq Member (D.J. McIntyre, personal communications 1997, 1999; Nøhr-Hansen 1996). The sparse marine invertebrates include ammonites (Clioscaphites saxitonianus septentrionalis (Birkelund), Clioscaphites sp. aff. saxitonianus (McLearn), Scaphites ventricosus, Scaphites cf. Svartenhukensis, and Baculites codyensis (Reeside)) (Birkelund 1965; Dam et al. 2000); bivalves (Sphenoceramus patootensis, S. pinniformis, Oxytoma tenuicostata) and echinoderms (Ravn 1918; Olsen & Pedersen 1991; Boyd 1993). Trace fossils are common in the Qilakitsoq and Nuuk Killeq areas. Burrows such as Planolites isp., Teichichnus isp., Dactyolidites ottoi, and Helminthopsis horizontalis occur in the coarsening-upward successions, whereas Ophiomorpha nodosa and O. irregulaire are seen in the sandstone sheets (Fig. 62; G.K. Pedersen & Rasmussen 1989; Dam et al. 2000; G.K. Pedersen & Bromley 2006). The trace fossil assemblages indicate the presence of both suspension and deposit feeders. Depositional environment. The Qilakitsoq Member is interpreted as being constructed of aggradational deltaic deposits referred to four facies associations: the marine delta front association, the distributary channel association, the delta plain association and the transgressive sand sheet association (Midtgaard 1991; Olsen 1991, 1993; G.K. Pedersen & Pulvertaft 1992; Dueholm & Olsen 1993; Dam et al. 2000). 79
Page 1 and 2:
GEOLOGICAL SURVEY OF DENMARK AND GR
Page 4 and 5:
Contents Abstract . . . . . . . . .
Page 7 and 8:
Preface The onshore Cretaceous-Pale
Page 9 and 10:
Introduction The Nuussuaq Basin bel
Page 11 and 12:
chemistry of the Nuussuaq Basin hav
Page 13 and 14:
Fig. 5. Plant fossils from the Atan
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Peak 2010 m Peak 1900 m Peak 1760 m
Page 17 and 18:
A lithostratigraphy for the marine
Page 19 and 20:
to provide further funding for stud
Page 21 and 22:
DGR Geological setting As a result
Page 23 and 24:
TSS 8 Agatdal Fm Eqalulik Fm Kangil
Page 25 and 26:
A Svartenhuk Halvø 50 km B Hinterl
Page 27 and 28: 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: Fig. 59. The Kingittoq Member at Ki
Page 81 and 82: Fig. 63. Type locality of the Itivn
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
Page 131 and 132:
Fig. 116. Basal conglomerate unit o
Page 133 and 134:
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
Page 139 and 140:
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
Page 147 and 148:
Naujât Member Atane Formation, Kin
Page 149 and 150:
The TOC [Total Organic Carbon] cont
Page 151 and 152:
Fig. 133. Correlation of the member
Page 153 and 154:
Fig. 135. Type locality of the Ping
Page 155 and 156:
Fig. 137. Lower, sharp boundary of
Page 157 and 158:
m 130 125 110 t t invasive lava low
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Fig. 141. Upper part of the Assoq M
Page 161 and 162:
Brown, R. 1875: Geological notes on
Page 163 and 164:
a rosetted spreite trace fossil: Da
Page 165 and 166:
ing bark from the Nûgssuaq peninsu
Page 167 and 168:
1998: The syn-volcanic Naajaat lake
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Appendix: Place names and localitie
Page 171:
Place name Place name P Paatuut sou
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Geological Survey of Denmark and Greenland Bulletin 19 ... - Geus

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