GEUS Bulletin no 5.pmd

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Fig. 1. Locality map of East Greenland and eastern North Greenland. The white region illustrates the permanent inland ice cap of Greenland, the grey areas are ice-free. Hold with Hope is located between 73ºN and 74ºN. 74 42°W 36°W 28°W 20°W 12°W Jameson Land Milne Land Scoresby Sund St. Koldewey Kuhn Ø Wollaston Forland Fig. 2 Hold with Hope Geographical Society Ø Traill Ø 28°W 20°W Hochstetter Forland 200 km 70°N improve the knowledge of Jurassic dinoflagellate cysts in this region in general. The results reported here allow correlation with corresponding assemblages from Store Koldewey and Hochstetter Forland in the north and Jameson Land – Milne Land in the south (Fig. 1). Geological setting GEUS Bulletin no 5.pmd 74 29-10-2004, 11:14 82°N 80°N 12°W 78°N 76°N 74°N 72°N The Late Palaeozoic – Mesozoic extensional basin complex in East Greenland is approximately 700 km long in a north–south direction. Jurassic sediments are present and exposed from Jameson Land in the south to Store Koldewey in the north (Surlyk 1977). In the northern part of the rift system, e.g. the Wollaston Forland Basin, rifting was initiated in Middle Jurassic time, and marine Bajocian–Bathonian sandstones onlap Caledonian basement rocks or Permian carbonates (Vischer 1943; Surlyk 1978). Deposition took place on the hangingwall of W–SW-tilted fault blocks. Jurassic rifting culminated in the Volgian with strong rotational block faulting (Surlyk 1978). During this episode the wide original fault blocks, defining the Wollaston Forland Basin, were divided into smaller blocks (Vischer 1943; Surlyk 1978). A similar tectonic development may have occurred in the Geographical Society Ø and Traill Ø area towards the south (Donovan 1957; Price & Whitham 1997). The Cretaceous period was generally characterised by subsidence controlled by thermal contraction (Surlyk et al. 1981; Price & Whitham 1997). The East Greenland rift basin complex was uplifted during the Cenozoic. Sediments of Jurassic age were first recognised on Hold with Hope by Stemmerik et al. (1997). They are limited to the north coast of Hold with Hope from Stensiö Plateau to Steensby Bjerg (Fig. 2), where they occur on the hangingwall of small fault blocks that dip mainly to the west and south-west. Bedding planes within the Triassic and Jurassic seem to be parallel, whereas the boundary with the overlying Cretaceous succession is an angular unconformity (Vosgerau et al. 2004, this volume). The thickness of the Jurassic succession varies significantly depending on its position on the hangingwall and the depth of Cretaceous erosion. The Jurassic succession includes shallow marine sandstones of the Pelion and Payer Dal Formations (Vardekløft Group), and offshore transition – lower shoreface heteroliths and offshore mudstones of the Bernbjerg Formation, Hall Bredning Group (Fig. 3). The Spath Plateau Member of the Pelion Formation was erected to accommodate sandy heteroliths and
74°00'N ■■ ■■ ■■ 73°55'N ■■ ■■ ■■ ■■ Spath Plateau ■■ ■■ 3 Stensiö Plateau ■■ ■■ ■■ Fig. 2. Geological map of the northern Hold with Hope which illustrates the distribution of the studied Jurassic succession. Localities 1, 2 and 3 are marked; the succession at Locality 1 has been compiled from a number of short laterally correlated sections (1A–1E). offshore mudstones that contrast with the generally coarse-grained sandstone facies of the Pelion Formation (Vosgerau et al. 2004, this volume). The succession on Hold with Hope resembles the well-known Jurassic succession in the Wollaston Forland and Jameson Land Basins towards the north and south. The Middle Jurassic Pelion Formation is c. 190 m thick, the Upper Jurassic Payer Dal Formation is 50–80 m thick and the Bernbjerg Formation is estimated to be c. 130 m thick (Fig. 4; Vosgerau et al. 2004, this volume). Samples and methods ■■ ■■ ■■ ■■ ■■ ■■ 21°15'W The dinoflagellate cysts have been studied in three sections (Fig. 4), in combination with a number of geographically and stratigraphically scattered samples 1A Gulelv 1B 1C 1D ■■ ■■ ■■ ■■ 1E ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ Sortelv ■■ 2 ■■ ■■ ■■ ■■ ■■ ■■ Ice Undifferentiated superficial deposits Dolerite sill Plateau basalt Paleocene Lower Cretaceous Middle and Upper Jurassic Lower Triassic Permian Crystalline basement 2 km Steensby Bjerg ■■ ■■ ■■ ■■ ■■ 21°00' Gael Hamke Bugt ■■ ■■ ■■ ■■ ■■ ■■ ■■ Normal fault Inferred fault Locality on northern Hold with Hope. The main area of exposure is located on the northern and western slopes of Steensby Bjerg towards Gael Hamke Bugt and along the Gulelv river (Fig. 2, Locality 1). Samples from a number of short, vertical sections are combined into a composite section representing the entire succession (Fig. 2, Locality 1, sections A–E). The Payer Dal Formation was also sampled at the Sortelv river, south of Steensby Bjerg (Fig. 2, Locality 2). Samples from a third section through the Pelion Formation at Stensiö Plateau (Fig. 2, Locality 3) provide good supplementary material from the lowermost part of the succession, which is poorly represented in the section at Steensby Bjerg. Most of the analysed samples are from finegrained thin beds or lamina in the otherwise coarsegrained, sandy Pelion and Payer Dal Formations. The number of samples and their stratigraphical distribu- ■■ ■■ 3 ■■ ■■ Diener Bjerg GEUS Bulletin no 5.pmd 75 29-10-2004, 11:14 ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ ■■ Hold with Hope 75
Page 1 and 2:
GEOLOGICAL SURVEY OF DENMARK AND GR
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GEUS Bulletin no 5.pmd 3 29-10-2004
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Contents Preface . . . . . . . . .
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(Alsen & Surlyk 2004, this volume).
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Jurassic syn-rift sedimentation on
Page 11 and 12:
NW SE m 1000 500 0 NW SE m 1000 500
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GEUS Bulletin no 5.pmd 13 29-10-200
Page 15 and 16:
grained than the lower parasequence
Page 17 and 18:
the Pelion Formation. The mudstone-
Page 19 and 20:
The fluviatile Bristol Elv Formatio
Page 21 and 22:
Name. After the river Bristol Elv i
Page 23 and 24: edded, and display both sheet-like
Page 25 and 26: N S Fig. 5. Coarse-grained sandston
Page 27 and 28: Fig. 7. Lacustrine deposits from th
Page 29 and 30: deposition of peat and coal. Journa
Page 31 and 32: Maximum Middle Jurassic transgressi
Page 33 and 34: 834 N Lycett Bjerg Barrikade Gletsc
Page 35 and 36: SW NE Lycett Bjerg Parnas Member Be
Page 37 and 38: Cadoceras cf. nordenskjoeldi Callom
Page 39 and 40: GEUS Bulletin no 5.pmd 39 29-10-200
Page 41 and 42: 4 C B 1 2 GEUS Bulletin no 5.pmd 41
Page 43 and 44: Fig. 1. Sketch-map of the Jameson L
Page 45 and 46: Table 1. Measurement of dimensions
Page 49 and 50: 1 2 GEUS Bulletin no 5.pmd 49 29-10
Page 51 and 52: A new Middle-Upper Jurassic success
Page 53 and 54: 74º00'N ■■ ■■ ■■ 73º5
Page 55 and 56: System Ma 159.4 154.1 164.4 169.2 1
Page 57 and 58: Sedimentary structures Biota Struct
Page 59 and 60: wards units is biogenic carbonate d
Page 61 and 62: Fig. 7. Log panel giving a broadly
Page 63 and 64: SPM LU to medium-grained and consis
Page 65 and 66: and mudstone drapes reflects varyin
Page 67 and 68: with the presence of a minor angula
Page 69 and 70: the north-east and south-west, resp
Page 71 and 72: elly mass-flow deposits. In: Koster
Page 73: Jurassic dinoflagellate cyst strati
Page 77 and 78: Bernbjerg Formation Payer Dal Forma
Page 79 and 80: Depositional environment. The prese
Page 85 and 86: Metres 30 20 10 Hold with Hope, Loc
Page 87 and 88: Correlations The Pelion Formation o
Page 89 and 90: Jurassic dinoflagellate cysts from
Page 91 and 92: Fig. 2. Sedimentological log of the
Page 93 and 94: LITHOSTRATIGRAPHY BIOSTRATIGRAPHY F
Page 95 and 96: ALPHABETICAL SPECIES LIST 41 Adnato
Page 97 and 98: References Alsgaard, P.C., Felt, V.
Page 99 and 100: Jurassic dinoflagellate cyst strati
Page 101 and 102: parties from the Geological Survey
Page 103 and 104: may indicate a hiatus in the sedime
Page 105 and 106: Metre 50 25 0 Store Koldewey Ravn P
Page 107 and 108: Fig. 6. Schematic stratigraphical c
Page 109 and 110: Chronozone) to the earliest Kimmeri
Page 111 and 112: The Upper Jurassic succession is co
Page 115 and 116: 185 Greenland from Archaean to Quat
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