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

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Naujât Member Qallorsuaq ‘Keglen’ Iviangernat Assoq Member invasive lava Atanikerluk Formation Umiussat Member subaerial lava flow Atane Formation Kingittoq Member Fig. 125. The coastal slope above Atanikerluk where Koch (1959) described the strata of the Atanikerluk Formation (for location, see Fig. 40). The peak at Iviangernat is 1031 m a.s.l. The Albian to Cenomanian Kingittoq Member of the Atane Formation is up to 500 m thick and is overlain by the Paleocene Atanikerluk Formation (see Figs 16, 17). scale, the formation comprises two coarsening-upward successions that may include thinner, coarsening-upward successions on a local scale (Figs 16, 131). The mudstones are grey to dark grey, with abundant silt-sized particles and with kaolinite and quartz as the dominant minerals. In addition, gibbsite in subordinate amounts has been detected consistently in samples from the Pingu Member and commonly in the Assoq Member. Locally, rows of small, yellowish brown siderite concretions occur in the mudstones (G.K. Pedersen 1989; G.K. Pedersen et al. 1998). Reworked Cretaceous palynomorphs are found in the lowest part of the Atanikerluk Formation at Akunneq (Hjortkjær 1991), suggesting that the formation also contains redeposited silt and clay. Interbedded with the mudstones are thin layers of tuff. The particles are in the coarse sand fraction and have a brownish colour that weathers to pale buff or white. The strong alteration precludes a determination of the original chemical composition of the volcanic glass. The sandstones are weakly cemented, and in several outcrops the lithology may be better described as sand. Colours range from pale grey to deep yellow, and fine coal debris is common. The sand or sandstones are generally fine- to medium-grained; coarser grain sizes occur but are volumetrically insignificant. Chert pebbles derived from Ordovician sediments occur in the coarser facies, as also seen locally in the Atane Formation. The sediments of the Atanikerluk Formation could therefore include material reworked from Cretaceous Atane Formation sand or sandstones. This is supported by the occurrences of few Paleocene palynomorphs together with more numerous Cretaceous spores and pollen in the lower part of the Akunneq Member at Pingu (Fig. 132, 285–355 m). The siliciclastic sediments are interbedded with volcanic rocks such as hyaloclastite breccias, invasive or subaqueous lava flows and tuffs. Hyaloclastite breccias comprise particles ranging from boulder-sized pillow fragments to sand-sized grains of glass; these rocks formed 142
Fig. 126. Composite type section of the Atanikerluk Formation from the Atanikerluk area between Naajaat and Umiusat, south-eastern Nuussuaq (for location, see Fig. 40). 1: Section through the Naujât Member from Saqqaqdalen at the type locality defined by Koch (1959) (Fig. 129). 2: Sections through the Umiussat Member from discontinuous outcrops in the Umiusat area (Figs 136, 137). 3: Section through the upper part of the Naujât Member and the upper part of the Assoq Member, formerly the Point 976 Member of Koch (1959) from discontinuous outcrops below Keglen (Fig. 125). For legend, see Plate 1. Atanikerluk Formation Naujât Member m 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 Quikavsak Formation 0 1 3 t 5 t 2,4,5 t 3,1,2 Atanikerluk Formation Naujât Member Umiussat Member Assoq Member ? m 50 40 30 20 10 0 50 * * 40 30 20 10 0 30 20 10 0 20 10 0 2 vf clay silt f m c vc sand vf clay silt f m c vc sand when lava flowed into water. The breccias are often foreset-bedded and the height of the foresets provides an indication of water depth (Jones & Nelson 1970; A.K. Pedersen et al. 1996; G.K. Pedersen et al. 1998). Invasive or subaqueous lava flows formed from large volumes of lava that reached the lake floor and continued into (invaded) the unconsolidated sediment without forming breccias (Schmincke 1967; Duffield et al. 1986; L.M. Larsen & Pedersen 1990; Tucker & Scott 2009). Invasive or subaqueous lava flows can be traced laterally into sub- 143
Page 1 and 2:
GEOLOGICAL SURVEY OF DENMARK AND GR
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Contents Abstract . . . . . . . . .
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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
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ley (Figs 2, 40, 65). The section a
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Central Nuussuaq Agatdalen South co
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3 10 4 6 5 Qorlortorssuaq Slibesten
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volcanic sediments are referred to
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Fig. 20. View from Uummannaq toward
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In the Kuuk area, the sediments ove
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m m 15 14 14 13 12 11 10 9 8 7 6 5
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Kome Formation m 40 30 20 D tial re
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Fig. 28. Reference locality of the
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Vaigat Fm Vesterfjeld Slibestensfje
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Gilbert delta in the Ikorfat area (
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150 300 450 100 250 400 m 550 50 20
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Fig. 36. Outcrop of the Upernivik N
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Correlation. The Upernivik Næs flo
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12’ 09’ 15’ 06’ 03’ Saqqa
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m 0 GGU 247801 200 400 247815 ★
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wave-rippled sand streaked mudstone
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the formation in the marine mudston
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d d Fig. 47. Type locality of the S
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Fig. 49. Cross-bedded medium- to co
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and Qaarsut (Fig. 22). Its wider di
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Fig. 52. Two closely spaced section
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Type section. The type section of t
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Fig. 56. Delta front succession of
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Fig. 59. The Kingittoq Member at Ki
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sh L sh ch delta front Vaigat Forma
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Fig. 63. Type locality of the Itivn
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782 Quaternary cover 54° 888 Malig
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Kuugannguaq-Qunnilik Fault and is o
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and include clasts of intraformatio
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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
Page 135 and 136: GANE#1 Vaigat Fm Anaanaa Mb m Hyalo
Page 137 and 138: Fig. 121. Well reference section of
Page 139 and 140: Pedersen 1978). The beds are usuall
Page 141: In detail, however, the boundary be
Page 145 and 146: 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
Page 159 and 160: 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
Page 169 and 170: 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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