Contents of Volume 48/1
Finch, A.A., Mansfeld, J. & Andersen, T.:
U-Pb radiometric age of Nunarsuit pegmatite, Greenland: constraints on the timing of Gardar magmatism
Rose-Hansen, J. & Sørensen, H.:
Minor intrusions of peralkaline microsyenite in the Ilímaussaq alkaline complex, South Greenland.
Davydov, Vladimir I., Nilson, I. & Stemmerik, L.:
Fusulinid zonation of the Upper Carboniferous Kap Jungersen and Foldedal Formations, southern Amdrup Land, eastern North Greenland
Schnetler, K. I., Lozouet, P. & Pacaud, J.–M.:
Revision of the gastropod family Scissurellidae from the Middle Danian (Paleocene) of Denmark
Note
Abrahamsen, H., Pesonen, L. & van der Voo, R.:
Palaeomagnetic Databases: 4 th Nordic Palaeomagnetic Workshop
Contents of Volume 48/2
Surlyk, F. & Håkansson, E.:The Oscar Volume.
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https://doi.org/10.37570/bgsd-2001-48-14
Friderichsen, J. D.:Oscar
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https://doi.org/10.37570/bgsd-2001-48-15
Reading, H.G.:
Clastic facies models, a personal perspective
Funder, S, Bennike, O., Böcher, J., Israelson, C., Petersen, K.S. & Símonarson, L. A.:
Late Pliocene Greenland – The Kap København Formation in North Greenland.
Skovsted, C. B. & Peel, J. S.:
The problematic fossil Mongolitubulus from the Lower Cambrian of Greenland
Håkansson, E. & Pedersen, S.A.S.:
The Wandel Hav Strike-Slip Mobile Belt – A Mesozoic plate boundary in North Greenland
Stemmerik, L., Bendix-Almgreen, S.E. & Piasecki, S.:
The Permian–Triassic boundary in central East Greenland: past and present views.
Surlyk, F. & Noe-Nygaard, N.:
Sand remobilisation and intrusion in the Upper Jurassic Hareelv Formation of East Greenland
Dam, G. & Nøhr-Hansen, H.:
Mantle plumes and sequence stratigraphy; Late Maastrichtian- Early Paleocene of West Greenland
Clemmensen, L.B., Lisborg, T., Fornós, J.J. & Bromley, R.G.:
Cliff-front aeolian and colluvial deposits, Mallorca, Western Mediterranean: a record of climatic and environmental change during the last glacial period
U-Pb radiometric age of Nunarsuit pegmatite, Greenland: constraints on the timing of Gardar magmatism
Finch, A.A., Mansfeld, J. & Andersen, T.: U-Pb radiometric age of Nunarsuit pegmatite, Greenland: constraints on the timing of Gardar magmatism. Bulletin of the Geological Society of Denmark, Vol. 48, pp. 1–7, Copenhagen.
https://doi.org/10.37570/bgsd-2001-48-01
Abstract: A precise U-Pb radiometric age of 1171±5 Ma has been obtained from zircons from a pegmatite in the Nunarsuit (previously spelt Nunarssuit) complex, Gardar Province, South Greenland. This age is slightly older than a corresponding Rb-Sr isochron determination. Since Nunarsuit is believed to be among the youngest Gardar centres, this radiometric age date more closely delimits the end of magmatism in the Gardar rift province. A comparison of our data with other published isotopic work may suggest that Gardar magmatism was a continuous rather than a punctuated process.
Keywords: Nunarsuit complex, Gardar province, Mid-Proterozoic, alkaline rocks, zircons, cathodoluminescence.
Addresses:
Adrian A. Finch [ aaf1 [at] st-and [dot] ac [dot] uk ], Crustal Geodynamics Group, School of Geography and Geosciences, University of St Andrews, St Andrews, Fife KY16 9AL, UK. Joakim Mansfeld [joakim [dot] mansfeld [at] ngu [dot] no] Mineralogical-Petrological Museum, University of Oslo, Sars Gate 1, N-0562 Oslo, Norway, now at: Geological Survey of Norway, N-7491 Trondheim, Norway. Tom Andersen [t [dot] h [dot] andersen [at] toyen [dot] uio [dot] no] Mineralogical- Petrological Museum, University of Oslo, Sars Gate 1, N-0562 Oslo, Norway. 16 August 2000.
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Minor intrusions of peralkaline microsyenite in the Ilímaussaq alkaline complex, South Greenland
Rose-Hansen, J. & Sørensen, H.: Minor intrusions of peralkaline microsyenite in the Ilímaussaq alkaline complex, South Greenland. Bulletin of the Geological Society of Denmark, Vol. 48, pp. 9–29, Copenhagen. https://doi.org/10.37570/bgsd-2001-48-02
Abstract: The agpaitic part of the Ilímaussaq alkaline complex, South Greenland, is made up of a roof zone, an intermediate zone and a floor zone. Dykes and sills of peralkaline microsyenite intersect the rocks of the roof and floor zones, but do not appear to intersect the lujavritic nepheline syenites which make up the intermediate zone. The microsyenites consist of Na-poor microcline, K-poor albite, aegirine and arfvedsonite which are practically identical to those of the agpaitic nepheline syenites of the complex. Neptunite and pectolite are the commonest minor minerals. The microsyenites are silica-saturated, –oversaturated, or, more rarely, undersaturated. The agpaitic part of the Ilímaussaq complex is considered to have been formed in a closed magma chamber; the lujavrites of the intermediate zone representing residual melts left after the consolidation of the roof and floor zones. That the microsyenite intrusions intersect the roof and floor zones but not the youngest lujavrites lying between these zones presents a geometrical problem which is discussed at some length. It is difficult to explain the microsyenites as products of fractionation or contamination of melts within the agpaitic magma chamber. Furthermore, the microsyenites differ mineralogically and chemically from the abundant microsyenitic dykes of the regional Tugtutôq-Ilímaussaq dyke swarm. It is therefore proposed that they originated in the source region which fed the agpaitic melts of the Ilímaussaq complex and that their emplacement in fractures was accompanied by a loss of volatiles and incompatible elements.
Keywords: agpaitic, Ilímaussaq, lujavrites, microsyenites.
Addresses:
J. Rose-Hansen & H. Sørensen, Geological Institute, University of Copenhagen, Øster Voldgade 10, DK- 1350 Copenhagen K, Denmark. 12 January 2001.
Fusulinid zonation of the Upper Carboniferous Kap Jungersen and Foldedal Formations, southern Amdrup Land, eastern North Greenland
Davydov, Vladimir I., Nilson, I. & Stemmerik, L.: Fusulinid zonation of the Upper Carboniferous Kap Jungersen and Foldedal Formations, southern Amdrup Land, eastern North Greenland. Bulletin of the Geological Society of Denmark, Vol. 48, pp. 31–77, Copenhagen. https://doi.org/10.37570/bgsd-2001-48-03
Abstract: New fusulinid data from the Kap Jungersen and Foldedal Formations in southern Amdrup Land, eastern North Greenland allow the establishment of a detailed fusulinid-based zonation of the Upper Carboniferous succession in the Wandel Sea Basin. The fusulinid fauna is quite similar to that of the Russian Platform, the Ural Mountains, Spitsbergen, Bjørnøya, and the offshore areas of the Barents Sea, and therefore the Greenland strata are confidently correlated to the these regions. The Kap Jungersen Formation and the lower part of the Foldedal Formation are dated as late early Moscovian to latest Moscovian in age. The locally more than 450 m thick Moscovian part of the succession comprises four fusulinid zones: the Profusulinella prisca – Neostaffella subquadrata Zone and the Citrinoides paraozawai Zone of early Moscovian age, and the Fusulinella bocki – Pseduofusulinella pulchra Zone and the Protriticites ovatus Zone of late Moscovian age. Lower and middle Kasimovian deposits, characterized by two fusulinid assemblages of the Obsoletes obsoletus – Protriticites pseudomontiparus Zone and the Montiparus paramontiparus Zone, are recognised for the first time in Amdrup Land. The thin lower Gzelian succession is represented by two fusulinid assemblages that definine the Rugosofusulina flexuosa Zone and the Daixina crispa – Rauserites stuckenbergi Zone. The youngest Carboniferous strata, belonging to the Orenburgian part of the Gzelian are characterised by an assemblage of the Schellwienia ulukensis Zone.
Keywords: Biostratigraphy, Fusulinid zonation, Upper Carboniferous, Wandel Sea Basin.
Addresses:
V.I. Davydov, Permian Research Institute, Department of Geosciences, Boise State University, Boise, Idaho, USA. I. Nilsson, Norsk Hydro ASA, N-9480 Harstad, Norway. L. Stemmerik, Geological Survey of Denmark and Greenland, Thoravej 8, DK-2400 Copenhagen NV, Denmark. 21 September 2000.
Revision of the gastropod family Scissurellidae from the Middle Danian (Paleocene) of Denmark
Schnetler, K. I., Lozouet, P. & Pacaud, J.–M.: Revision of the gastropod family Scissurellidae from the Middle Danian (Paleocene) of Denmark. Bulletin of the Geological Society of Denmark, Vol. 48, pp. 79–90. Copenhagen. https://doi.org/10.37570/bgsd-2001-48-04
Abstract: The rich molluscan fauna from the Middle Danian (Early Paleocene) of Fakse contains five species of the gastropod family Scissurellidae Gray, 1847. This revision recognizes three new species, viz. Anatoma rosenkrantzi sp. nov., Praescissurella? ravni sp. nov. and Scissurella (s. l.) aliceae sp. nov. Anatoma danica Bandel, 1998 is considered a junior synonym of Leptomaria niloticiformis (von Schlotheim, 1820). The palaeoecoelogy of this scissurellid and pleurotomarid fauna and the associated mollusc fauna is noted.
Keywords: Gastropods, Scissurellidae, palaeoecoelogy, Paleocene, Middle Danian, Fakse, Denmark.
Addresses:
K.I. Schnetler [ ingemann [dot] schnetler [at] skolekom [dot] dk ], Fuglebakken 14, Stevnstrup, DK-8870 Langå, Denmark. P. Lozouet [ lozouet [at] cimrs1 [dot] mnhn [dot] fr ], BIMM, Muséum National d’Histoire Naturelle, 55 rue Buffon, F- 75005, Paris, France. J.-M. Pacaud [ pacaud [at] cimrs1 [dot] mnhn [dot] fr ], Laboratoire de Paleontologie, Muséum National d’Histoire Naturelle, UMR 8569 CNRS, 8 rue Buffon, F-75005, Paris, France. 24 October 2000.
Clastic facies models, a personal perspective
Reading, H.G.: Clastic facies models, a personal perspective. Bulletin of the Geological Society of Denmark Vol. 48, pp. 101–115. Copenhagen. https://doi.org/10.37570/bgsd-2001-48-05
Abstract: Facies models evolved from classifications that were mainly descriptive, based on observable, measureable features such as the composition and texture of sedimentary rocks. As our understanding of sedimentary processes expanded, genetic facies models were developed based on the inferred process of formation. Since individual facies cannot be interpreted in isolation, they must be studied with reference to their neighbours, emphasizing the association of facies and sequences, in particular those that coarsen and fine upward. Environmental facies models are based on the interaction of studies on modern environments and ancient rock facies. Earlier facies models tended to invoke intrinsic, autocyclic controls. The advent of sequence stratigraphy led to greater emphasis on the surfaces that separate sequences and to external allocyclic controls. These were, initially, sea-level changes; later, changes in climate, tectonic movements and sediment supply were invoked. Over time, simple, all embracing models have given way to increasingly complex ones as our knowledge of the variability of nature has increased. Complex though these models are, they are only simplifications of reality. In nature there are no models and the majority of past environments differed in some respect from any modern environment. Each environment and rock sequence is unique.
Keywords: Sedimentary facies, process and environmental facies models, sequence stratigraphy.
Addresses:
Harold G. Reading, Department of Earth Sciences, Parks Road, Oxford OX1 3PR, UK. 17 April 2001.
Late Pliocene Greenland – The Kap København Formation in North Greenland
Funder, S, Bennike, O., Böcher, J., Israelson, C., Petersen, K.S. & Símonarson, L. A.: Late Pliocene Greenland – The Kap København Formation in North Greenland. Bulletin of the Geological Society of Denmark, Vol. 48, pp. 117–134. Copenhagen.
https://doi.org/10.37570/bgsd-2001-48-06
Abstract: The Kap København Formation, North Greenland, is a 100-m thick succession of predominantly shallow marine nearshore sediments, dated to c. 2.4 ma. The abundant well preserved remains of mosses, land plants, foraminifers, ostracodes, insects, cladocers, molluscs, and a few vertebrates enable a detailed reconstruction of terrestrial and marine environments and climate. The sediments indicate a complex sea-level history implying combined glacioisostatic and -eustatic control. This is supported by the faunal and floral development from arctic to subarctic and boreal conditions, and the record probably reflects the demise of the first major Cenozoic ice sheet, the Praetiglian, over the area, and the onset of the succeeding Tiglian A interglacial. The record ends with the attainment of the interglacial sea-level highstand and climate optimum when forest tundra reached the world’s northernmost coasts. It is inferred that the duration of sedimentation was a half obliquity cycle, i.e. 20,000 yr, at the most.
Keywords: Pliocene, Praetiglian, Tiglian, palaeoenvironments, sea-level change, Greenland
Addresses:
S. Funder [ svf [at] savik [dot] geomus [dot] ku [dot] dk ], Geological Museum, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark. O. Bennike, Geological Survey of Denmark and Greenland, Thoravej 8, DK-2400 Copenhagen NV, Denmark. J. Böcher, Zoological Museum, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen Ø, Denmark. C. Israelson, Statens Institut for Strålehygiejne, Knapholm 7, DK-2730 Herlev, Denmark. K.S. Petersen, Geological Survey of Denmark and Greenland, Thoravej 8, DK-2400 Copenhagen NV, Denmark & L. A. Símonarson, Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavík, Iceland. 14 May 2001.
The problematic fossil Mongolitubulus from the Lower Cambrian of Greenland
Skovsted, C. B. & Peel, J. S.: The problematic fossil Mongolitubulus from the Lower Cambrian of Greenland. Bulletin of the Geological Society of Denmark, vol. 48, pp. 135–147, Copenhagen. https://doi.org/10.37570/bgsd-2001-48-07
Abstract: Spines referred to the problematic phosphatic Small Shelly Fossil Mongolitubulus Missarzhevsky, 1977 are described from the Lower Cambrian of Greenland. The type species, M. squamifer, is reported from the Henson Gletscher Formation of North Greenland, while M. henrikseni sp. nov. is described from the Bastion Formation of North-East Greenland. Co-occurring small plates with broken spine bases suggest that Mongolitubulus henrikseni may have been a bivalved(?) arthropod with a carapace bearing multiple spines, but it is uncertain if this restoration can be extended to the type species.
Keywords: Small Shelly Fossils, problematica, Cambrian, Greenland.
Addresses:
Christian B. Skovsted [ christian [dot] skovsted [at] geo [dot] uu [dot] se ] & John S. Peel [ john [dot] peel [at] pal [dot] uu [dot] se ], Department of Earth Sciences (Historical Geology & Palaeontology), Uppsala University, Norbyvägen 22, SE-752 36 Uppsala, Sweden. 6 April 2001.
The Wandel Hav Strike-Slip Mobile Belt – A Mesozoic plate boundary in North Greenland
Håkansson, E. & Pedersen, S.A.S.: The Wandel Hav Strike-Slip Mobile Belt – A Mesozoic plate boundary in North Greenland. Bulletin of the Geological Society of Denmark, Vol. 48, pp. 149–158, Copenhagen. https://doi.org/10.37570/bgsd-2001-48-08
Abstract: The historical ‘de Geer Line’ between Svalbard and Greenland is shown to have had a Mesozoic precursor now residing well within the continental Greenland plate, where it coincides with the Wandel Hav Strike-Slip Mobile Belt. Well-constrained phases in relative plate motion reflected in the mobile belt are discernible back to the mid Jurassic, with more obscure phases dating even further back. There is evidence that the Wandel Hav Strike-Slip Mobile Belt may have been formed already in Late Palaeozoic time during onset of Pangean break-up; evidence for strike-slip movements of this age is, however, largely circumstantial, due to severe overprinting during the later phases. Wrench tectonics along the ‘fossil’ plate boundary culminated around the Cretaceous – Palaeogene boundary in the major right-lateral, transpressional Kronprins Christian Land Orogeny. Thus, the Wandel Hav Strike-Slip Mobile Belt may constitute the geological/structural expression of the Mesozoic Laurentian – Eurasian plate boundary all the way up to initiation of actual seafloor spreading at chron 24 in Palaeogene time.
Keywords: de Geer Line, North Greenland, plate boundary, strike-slip, wrench tectonic.
Addresses:
E. Håkansson, Geological Institute, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark. S.A.S. Pedersen, Geological Survey of Denmark and Greenland, Thoravej 8, DK-2400 Copenhagen NV, Denmark. 1 May 2001.
The Permian–Triassic boundary in central East Greenland: past and present views
Stemmerik, L., Bendix-Almgreen, S.E. & Piasecki, S.: The Permian–Triassic boundary in central East Greenland: past and present views. Bulletin of the Geological Society of Denmark, Vol. 48, pp. 159–167, Copenhagen. https://doi.org/10.37570/bgsd-2001-48-09
Abstract: The latest Permian, Changhsingian fauna in East Greenland is a typical northern cool-water fauna, dominated by a low diversity assemblage of boreal brachiopods and lacking fusulinids, small foraminifers and fish. Continuous sedimentation across the Permian–Triassic boundary is recorded at the Fiskegrav locality, southwestern Jameson Land but the precise location of the boundary is disputable within an interval covering the uppermost few metres of the Schuchert Dal Formation and the lowermost 23.5 m of the Wordie Creek Formation. Based on palynological data the boundary is best placed 50 cm below the top of the Schuchert Dal Formation at Fiskegrav, in a monotonous interval of bioturbated, grey offshore marine siltstone characterised by a marked drop in the ä13C of organic carbon. ä13C of carbonate from brachiopods shows a temporary drop of 2‰, 4–5 m below the top of the Schuchert Dal Formation, while the ä13C of whole rock carbonate reaches a minimum in the lowermost part of the Wordie Creek Formation. Comparisons to the ä13C carbonate curves from the boundary stratotype section at Meishan, China are therefore highly subjective and allow the boundary to be placed within a 24–27 m thick interval in the topmost Schuchert Dal Formation and the lowermost Wordie Creek Formation, – here termed as the Permian–Triassic boundary interval. The lower part of this interval, below the palynological boundary includes a low diversity Permian-type fauna of two brachiopod and four agglutinated foraminifer genera. Above the palynological boundary, in the uppermost 50 cm of the Schuchert Dal Formation remains of the Triassic-type fish Bobasatrania occur together with agglutinated foraminifers, and at the base of the Wordie Creek Formation a more diverse, Triassic-type fish fauna with five genera is present. In the stratotype section at Meishan the first Triassic-type faunal elements appear above the negative ä13C anomaly in what is regarded as a topmost Permian mixed fauna interval. A similar situation may possibly exist in East Greenland so the old East Greenland issue of faunal mixing with Permian-type fauna in the Triassic may turn out to be a matter of having Triassic faunal elements in the Permian.
Keywords: Permian–Triassic boundary, East Greenland, ä13C variations, faunal changes.
Addresses:
L. Stemmerik & S. Piasecki, Geological Survey of Denmark and Greenland, Thoravej 8, DK-2400 Copenhagen NV, Denmark. S.E. Bendix-Almgreen, Geological Museum, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark. 1 March 2001
Sand remobilisation and intrusion in the Upper Jurassic Hareelv Formation of East Greenland
Surlyk, F. & Noe-Nygaard, N.: Sand remobilisation and intrusion in the Upper Jurassic Hareelv Formation of East Greenland. Bulletin of the Geological Society of Denmark, Vol. 48, pp. 169– 188. Copenhagen. https://doi.org/10.37570/bgsd-2001-48-10
Abstract: An extensive Late Jurassic intrusive sandstone complex is exposed in Jameson land, East Greenland. The sandstones and the host mudstones form the Upper Oxfordian – Volgian Hareelv Formation. The formation covers an area of 55×70 km, is 200–400 m thick and consists of black basinal mudstones and highly irregular sandstone bodies, dykes and sills. Failure of shelf-margin sandbodies resulted in downslope sediment gravity flows and deposition of massive sands on the slope, at the base-of-slope and in the basin. The sands flowed in steep-sided gullies formed by retrogressive slumping of slope muds or loaded directly into the muds. Sandbodies deposited within the gullies have steep commonly stepped margins while those deposited at the downslope termination of gullies have a sheet-like geometry. All sandbodies underwent some degree of fluidization and liquefaction subsequent to burial and sand was intruded into the surrounding black mudstones. Remobilisation and intrusion took place over a long time interval ranging from almost syndepositional to relatively deep burial and primary sediment structures were lost in most cases. Sandstone dykes and sills are ubiquitous and were emplaced by all combinations of stoping and dilation. The intrusive sandbodies range in dimensions from centimetres to many hundreds of metres. The degree of post-burial remobilisation ranges from rather small-scale modifications to wholesale fluidization, liquefaction and out-of-place intrusion of the sand over tens to hundreds of metres. The Hareelv Formation was deposited during the most important Mesozoic rift event in East Greenland and the pervasive remobilisation of all sandbodies in the formation is interpreted as caused mainly by cyclic loading by seismic shocks. Additional important factors were slope shear stress, build up of pore pressure due to loading, slumping, upwards movement of pore waters expelled from the compacting muds and possibly also of biogenic and thermogenic gas. The Hareelv Formation is an excellent field analogue for deeply buried hydrocarbon reservoirs, which have been modified by remobilisation and injection of the sands.
Keywords: Sediment remobilisation, intrusion and injection, sandstone dykes and sills, Upper Jurassic, Hareelv Formation, East Greenland.
Addresses:
Finn Surlyk [ finns [at] geo [dot] geol [dot] ku [dot] dk ] & Nanna Noe-Nygaard [ nanan [at] geo [dot] geol [dot] ku [dot] dk ], Geological Institute, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark. 4 October 2001
Mantle plumes and sequence stratigraphy; Late Maastrichtian- Early Paleocene of West Greenland
Dam, G. & Nøhr-Hansen, H. Mantle plumes and sequence stratigraphy; Late Maastrichtian- Early Paleocene of West Greenland. Bulletin of the Geological Society of Denmark, Vol. 48, pp. 189–207. Copenhagen. https://doi.org/10.37570/bgsd-2001-48-11
Abstract: The sedimentary history of the upper Maastrichtian–Paleocene succession underneath the extensive Paleocene flood basalts in central West Greenland supports models for the generation of flood basalt provinces in response to rising, hot mantle plumes. The rise of the North Atlantic mantle plume was associated with deposition of at least three sedimentary sequences; each associated with incision of submarine canyons and valleys. Relative sea-level changes were caused by plumerelated tectonics and generation of sequence boundaries was in general associated with catastrophic sedimentation and very rapid development of sequences. As such the late Maastrichtian–early Paleocene sequences record a spectacular and significant but rare geological event.
Keywords: Mantle plumes, sequence stratigraphy, Late Maastrichtian-Early Paleocene, West Greenland.
Addresses:
Gregers Dam, Geological Survey of Denmark and Grenland, Thoravej 8, DK-2400 Copenhagen NV, Denmark. Present address: DONG E & P, Agern Alle 24–26, DK-2970 Hørsholm, Denmark. Henrik Nøhr- Hansen, Geological Survey of Denmark and Greenland, Thoravej 8, DK-2400 NV, Denmark. 1 May 2001
Tetrapod tracks deeply set in unsuitable substrates: Recent musk oxen in fluid earth (East Greenland) and Pleistocene caprines in aeolian sand (Mallorca)
Bromley, R. G.: Tetrapod tracks deeply set in unsuitable substrates: Recent musk oxen in fluid earth (East Greenland) and Pleistocene caprines in aeolian sand (Mallorca). Bulletin of the Geological Society of Denmark, Vol. 48, pp. 209–215, Copenhagen.
https://doi.org/10.37570/bgsd-2001-48-12
Abstract: A plea is made for greater attention to be paid to the ugly traces produced by tetrapods in excessively soft sediments. These rather formless structures are difficult to describe, but they have the potential for providing much information on depositional environments. Two examples are given. (1) The death-march of a musk ox (Ovibos moscatus) that blundered into soil liquified by solifluction in Jameson Land, East Greenland; and (2) Pleistocene trackways made by the extinct ruminant goat Myotragus balearicus in aeolianites on Mallorca, Balearic Islands. Ichnological evidence shows both to be examples of animals struggling through unsuitable, hazardous substrates. Parallels are drawn with escape structures made by buried invertebrate trace-makers.
Keywords: Trace fossil, musk ox, Ovibos moscatus, Myotragus balearicus, aeolian sand, hazardous substrate, escape trace, East Greenland, Mallorca, Pleistocene.
Addresses:
R. G. Bromley, Geological Institute, University of Copenhagen, Øster Voldgade 10, 1350 Copenhagen K, Denmark. 10 April 2001.
Cliff-front aeolian and colluvial deposits, Mallorca, Western Mediterranean: a record of climatic and environmental change during the last glacial period
Clemmensen, L.B., Lisborg, T., Fornós, J.J. & Bromley, R.G.: Cliff-front aeolian and colluvial deposits, Mallorca, Western Mediterranean: a record of climatic and environmental change during the last glacial period. Bulletin of the Geological Society of Denmark 48, pp. 217–232. Copenhagen. https://doi.org/10.37570/bgsd-2001-48-13
Abstract: Large, cliff-front accumulations of Late Pleistocene aeolian and colluvial deposits on southeast Mallorca provide a terrestrial record of climatic and environmental change in the Western Mediterranean during the last glacial period. The cliff-front deposits are lithified and form ramps sloping toward the southeast (i.e. seaward). Radiocarbon dating suggests that the deposits formed in Oxygen Isope Stage 3, when sea level was about 50 m lower than today, and the fossil sea-cliff situated 1.5 to 2 km from the palaeo-shore. The aeolian deposits are composed of marine carbonate sand that was transported inland episodically and accumulated in embayments along the fossil sea-cliff. The sand initially formed steadily growing and forward-moving dunes, then sloping sand ramps and finally relatively small ascending dunes. Aeolian accumulation was interrupted by erosion and colluvial ramp formation, and the cliff-front sediments can be divided into two sedimentary cycles each composed of basal colluvial deposits overlain by aeolian deposits. Colluvial deposition probably records relatively humid climatic intervals, whereas aeolian accumulation probably reflects relatively arid climatic intervals. It appears that climatic and environmental changes were rapid, and it is speculated that the dynamics of the cliff-front system on Mallorca were tied to North Atlantic millennial-scale climate oscillations.
Keywords: Aeolian sediments, colluvial sediments, climate cycles, Mallorca, Upper Pleistocene.
Addresses:
Lars B. Clemmensen [ larsc [at] geo [dot] geol [dot] ku [dot] dk ], Thomas Lisborg & Richard G. Bromley, Geological Institute, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark; Joan J. Fornós, Departament de Ciències de la Terra, Universitat de les Illes Balears, E-07071 Palma de Mallorca, Spain. 7 April 2001.