GEUS Bulletin no 5.pmd

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73°00′N thick succession of Middle Jurassic marine sediments, mainly sandstones, was deposited in northern Jameson Land and progressively thins distally towards the south. The proximal areas in Traill Ø acted as a bypass area for much of late Middle Jurassic time and the succession is generally thinner compared with the more distal areas in Jameson Land (Surlyk 2003). The south-easternmost part of Traill Ø constituted an eastwards-tilted fault block, in contrast to other Jurassic fault blocks in East Greenland which are tilted westwards (Donovan 1953; Carr 1998; Surlyk 2003). A detailed analysis of the Middle Jurassic succession in the Vælddal area close to the crest of the eastwardstilted block was recently undertaken by Carr (1998; Fig. 1). He demonstrated that as a result of synsedimentary movements of the Vælddal Fault during Middle Jurassic time the sedimentary evolution of the Bjørnedal area differed somewhat from that of other parts of the region. The Middle Jurassic succession in this block shows palaeocurrent directions to the east in contrast to the axial, southwards-oriented palaeocur- 32 72°45′N 72°30′N ■ ■ 72°15′N Greenland GREENLAND ■ 24°W 23°W 22°W Geographical Society Ø ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Traill Ø Jameson Land ■ ■ ■ Vælddal Fault ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Bjørnedal Fig. 2 Kong Oscar Fjord Vælddal ■ ■ ■ ■ 10 km ■ ■ Mountnorris Fjord N ■ ■ Palaeogene intrusives Palaeogene extrusives Cretaceous Jurassic Triassic Upper Permian Carboniferous Devonian Pre-Devonian Fault rent directions seen elsewhere. The sandstone/mudstone ratio also decreases and the succession shows proximal to distal facies changes in the same direction (Vosgerau et al. 2004, this volume). Stratigraphy GEUS Bulletin no 5.pmd 32 29-10-2004, 11:14 Fig. 1. Simplified geological map of the Traill Ø area. Location of study area (Fig. 2) is indicated. The lithostratigraphical scheme for the Jurassic of East Greenland was erected by Surlyk et al. (1973), Surlyk (1977, 1978) and Birkelund et al. (1984). The scheme is under revision and many units have been raised in rank (see Surlyk 2003, fig. 5). In the Traill Ø area, the Middle – lower Upper Jurassic succession now includes the Bristol Elv, Pelion, Fossilbjerget and Olympen Formations in ascending order (Fig. 4). The Bristol Elv Formation is probably not exposed in Bjørnedal. It is of pre-Late Bajocian but probably still Middle Jurassic age and includes fluvial pebbly sandstones and thin coaly shales (Therkelsen & Surlyk 2004, this volume). The Pelion Formation consists of shallow-marine sand-
834 N Lycett Bjerg Barrikade Gletscher Land 3 1013 Ice-covered 2 1 Bjørnedal Steenstrup Bjerg River Sea Mountnorris Fjord Brede Gletscher 2 km Fig. 2. Map of the Bjørnedal area, Traill Ø showing locations of sections and ammonite localities. 1, Locality 1 with section JTH- 15/96; 2, Locality 2 with section JTH-14/96; 3, Locality 3. Altitude of mountains in metres. stones with bivalves, belemnites, ammonites and plant fragments. The formation rests on Triassic strata or on the Bristol Elv Formation. It is overlain by, or interfingers at the top with, offshore, dark, micaceous, silty mudstones of the Fossilbjerget Formation. A regressive wedge in the top part of the Pelion Formation interrupts the overall backstepping Pelion–Fossilbjerget couplet, and belongs to the Parnas Member of the Pelion Formation (Surlyk 2003). The Fossilbjerget Formation is overlain by the lower Upper Jurassic Olympen Formation, which also consists of shallow marine sandstones themselves quite similar to the sandstones of the Pelion Formation below, making recognition of the Olympen Formation difficult. The Middle Jurassic succession in the Bjørnedal area is poorly exposed. The area described here corresponds to the ‘northern part of Bjørnedal’ of Donovan (1953). An intensive search for ammonites was made in dark, silty, micaceous mudstones exposed in small sections along the Bjørnedal river, Locality 1, and in a small section in a gully at Locality 2 (Figs 2, 5). Three ammonite assemblages were recovered; two ammonite species have been identified, one of them previously known from Jameson Land but hitherto undescribed. The description of the Middle Jurassic succession in Bjørnedal is based mainly on Donovan (1953), since fieldwork was focused solely on the mudstones in its middle part. The succession is subdivided into five lithological units, A–E in ascending order (Figs 4, 5). Unit A belongs to the Pelion Formation and consists of about 200 m of sandstones containing Cranocephalites, which suggests correlation with the Upper Bajocian C. pompeckji Chronozone (Fig. 3) and indetermi- Middle Jurassic Lower Callovian Bathonian Bajocian NW European/ Subboreal Province Herveyi Discus Orbis Hodsoni Morrisi Subcontractus Progracilis Tenuiplicatus Zigzag Parkinsoni Garantiana Subfurcatum Zones Humphriesianum Calloviense Koenigi * Zones identified in the Bjørnedal area GEUS Bulletin no 5.pmd 33 29-10-2004, 11:14 Boreal Province *Nordenskjoeldi (Parnas Mb, wedge of upper Pelion Fm) *Apertum (Fossilbjerget Fm) Calyx Variabile Cranocephaloide Ishmae Greenlandicus Arcticus *Pompeckji (Pelion Formation) Indistinctus Borealis Fig. 3. Scheme of standard ammonite zones in the Upper Bajocian – Lower Callovian, Middle Jurassic. Due to faunal provincialism close correlation between zones in East Greenland (right column) and the NW European/Subboreal Province (left column) is not possible. The East Greenland ammonite zonation represents a secondary standard chronostratigraphical scheme for the Boreal Province. Modified from Callomon (2003). 33
Page 1 and 2: 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: Maximum Middle Jurassic transgressi
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 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 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 83 and 84:
GEUS Bulletin no 5.pmd 83 29-10-200
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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