GEUS Bulletin no 5.pmd

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E W Pb Geological setting The Late Palaeozoic – Mesozoic extensional basin complex in East Greenland is about 700 km long in a north– south direction. This complex is situated over structurally controlled en echelon troughs and forms a wedgeshaped embayment with the narrowest onshore part to the north. Jurassic sediments are present in the Wollaston Forland and Jameson Land Basins situated on the western margin of the rift complex. In both basins, sediment transport in Middle Jurassic time was mainly longitudinal from north to south along a low gradient basin floor, which was not differentiated into a shelf, slope and deep-water basin (Surlyk 1977, 1990, 1991; Surlyk et al. 1981; Surlyk & Clemmensen 1983). In the Wollaston Forland Basin, rifting was initiated in Middle Jurassic time, and marine Bajocian–Bathonian sandstones onlap weathered Caledonian basement rocks or Upper Permian carbonates. Deposition took place on the hangingwall of wide W–SW-tilted fault blocks. Jurassic rifting culminated in the Volgian with strong rotational block faulting associated with conglomeratic submarine fan sedimentation (Surlyk 1978). During this tectonic episode, the wide fault blocks originally defining the Wollaston Forland Basin were split into smaller blocks (Vischer 1943; Surlyk 1978). The Jurassic sediments on Hold with Hope occur 54 Tr LC Fig. 3. Triassic–Paleocene succession exposed at Steensby Bjerg, northern Hold with Hope, viewed towards the south. The Triassic (Tr) and Middle Jurassic (MJ) sediments dip towards the southwest and are unconformably overlain by Lower Cretaceous (LC) sediments. A post-Kimmeridgian – pre-Barremian normal fault striking north–south offsets the Triassic and Jurassic sediments by at least 30 m. View towards the south. From Larsen et al. (1998). The exposure shown is c. 200 m high and capped by Paleocene basalts (Pb). MJ Tr on the hangingwall of small fault blocks that dip mainly towards the west and south-west (Fig. 2). Bedding planes within the Triassic and Jurassic successions seem to be parallel whereas the boundary to the overlying Cretaceous succession is an angular unconformity (Fig. 3). The Jurassic succession shows marked lateral thickness variations depending on its position on the hangingwall. The thickness increases down-dip whereas it is missing up-dip due to Early Cretaceous erosion on some of the block crests. Faults locally cut the Triassic and Jurassic successions, but not the overlying Cretaceous succession showing that fault activity took place in post-Kimmeridgian, but pre-Barremian time (Fig. 3). Most faults in the area, however, were reactivated during Cretaceous and Cenozoic times. Stratigraphy and sedimentology The Jurassic succession on Hold with Hope is subdivided into lithostratigraphic units known from Wollaston Forland and Kuhn Ø (Fig. 4). Stratigraphic ages of the Jurassic succession are based on ammonites and dinoflagellate cysts (Piasecki et al. 2004, this volume). The oldest Jurassic ammonite found on northern Hold with Hope is Cranocephalites sp. indicating the Upper Bajocian C. pompeckji Chronozone (J.H. Callomon and P. Alsen, personal communications 1997). The ammonite was, however, not found in situ but in the basal Cretaceous conglomerate at Locality 4 and c. 150 m east of Locality 8 (Fig. 2). The Jurassic outcrops occur between Stensiö Plateau in the west and Diener Bjerg in the east (Fig. 2). Towards the south, the Jurassic sediments are exposed along the eastern side of the Gulelv river and on the southern side of the Sortelv river. A composite section, 360 m thick, was measured in a north–south direction along Gulelv on the hangingwall of a fault block dipping c. 15º towards the SSW and comprises segments 3A–E (Figs 5, 6). Lateral facies variations are illustrated by cross-sections oriented parallel (NE–SW) and perpendicular (NW–SE) to the overall palaeocurrent direction (Figs 2, 7, 8). Pelion Formation GEUS Bulletin no 5.pmd 54 29-10-2004, 11:14 The Pelion Formation in the Jameson Land and Wollaston Forland Basins consists of shallow marine, medium- to coarse-grained sandstones of Late Bajocian – Late Callovian age (Engkilde & Surlyk 2003). On Hold
System Ma 159.4 154.1 164.4 169.2 173 Jurassic Bajocian Bathonian Callovian Oxfordian Kimmeridgian Stage U L M U L M U L M U L Ammonite Zonation Subboreal–Boreal R. pseudocordata P. bifurcatus G. transversarium P. plicatilis M. herveyi C. discus O. orbis P. hodsoni M. morrisi T. subcontractus P. progracilis A. tenuiplicatus Z. zigzag P. parkinsoni G. garantiana N. subfurcatum A. autissiodorensis A. eudoxus A. mutabilis R. cymodoce P. baylei C. cordatum Q. mariae Q. lamberti P. athleta E. coronatum K. jason S. calloviense P. koenigi A. rosenkrantzi A. regulare A. serratum A. glosense C. tenuiserratum C. densiplicatum C. nordenskjoeldi C. apertum C. calyx C. variabile A. cranocephaloide A. ishmae A. greenlandicus A. arcticus C. pompeckji C. indistinctus C. borealis Traill Ø and Geographical Society Ø W E Bernbjerg Olympen Fossilbj Fb PP Pelion Bristol Elv Hold with Hope W E Legend Siltstone Bernbjerg Payer Dal Pelion Mudstone Sandstone Heterolithic sandstone Bernbjerg Jakobsstigen Wollaston Forland and Kuhn Ø S N Conglomerate Coal Ammonite Fig. 4. Jurassic litho- and biostratigraphy (Lower Jurassic and Volgian not included) of the Traill Ø – Geographical Society Ø region, Hold with Hope and Wollaston Forland. Based on Surlyk (1977, 1978, 1990, 1991), Price & Whitham (1997), Alsgaard et al. (2003), Alsen & Surlyk (2004, this volume), Vosgerau et al. (2004, this volume) and own observations in the Traill Ø and northern Hold with Hope areas. Fossilbj/Fb, Fossilbjerget; PP, Pelion (Parnas Mb). GEUS Bulletin no 5.pmd 55 29-10-2004, 11:14 Bernbjerg Payer Dal Pelion Bastians Dal Muslingebjerg 55
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GEOLOGICAL SURVEY OF DENMARK AND GR
Page 3 and 4: GEUS Bulletin no 5.pmd 3 29-10-2004
Page 5 and 6: Contents Preface . . . . . . . . .
Page 7 and 8: (Alsen & Surlyk 2004, this volume).
Page 9 and 10: Jurassic syn-rift sedimentation on
Page 11 and 12: NW SE m 1000 500 0 NW SE m 1000 500
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 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: 74º00'N ■■ ■■ ■■ 73º5
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 and 74: Jurassic dinoflagellate cyst strati
Page 75 and 76: 74°00'N ■■ ■■ ■■ 73°5
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 113 and 114:
GEUS Bulletin no 5.pmd 113 29-10-20
Page 115 and 116:
185 Greenland from Archaean to Quat
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GEUS Bulletin no 5.pmd

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