The Kimmeridgian ammonite faunas of Milne Land, central East Greenland ppt

[...]... member They belong to faunas 20-24 indicating the Eudoxus and Autissiodorensis Zones of the Kimmeridgian (20-23), and, at least in the eastern part of the area, the Ekgans Zone of the Lower Volgian (24) AMMONITE ZONATION The separation of ammonites into fauna1 provinces reached a peak in the Upper Oxfordian As a result it has become necessary to set up three independent schemes of standard ammonite. .. unnecessary, at least at present, to go beyond the stage of characterizing the faunas and their sequences The levels of the faunas will therefore be treated here as merely horizons within the framework of the standard NW European Sub-Boreal zonation The Kimmeridgian faunas from Milne Land are lislted in table 1 Their positions within the NW European zonal scheme is shown in fig 5, which includes also the zonal... Shales' of Aldinger, 1935 and Spath, 1935; Amoebites Shales (pars) of Spath, 1935; fully described in Birkelund, Callomon & Fiirsich, 1984) Type-locality in the well-exposed sections on the north bank of the stream in the gorge of Grikloft (section 8), on the east coast of Milne Land Parts of the member are also well exposed in the other gorges on the east coast (sections 10,13,17) and extensively along the. .. took this level to mark the base of q e Cymodoce Zone, but a formal definition of the zone in terms of a marker in a tw-section has not yet been finally proposed If drawn at the base of the Cymodoce qorizon, fauna 17 in Milne Land, it would leave the horizons with Rusenia inconsrPpts, faunas 15 and 16, still in the Baylei Zone There remain some other faunas Rusenia known from England, well characterized... exposures During the exceptionally cold winter of 1981-82 the sea froze locally and cleared the shores of seaweed The Jurassic beds were therefore unusually well exposed in the spring of 1982 and a re-examination clarified the succession The basic outline of the top beds, 35-39, given in Sykes & Callornon (1979, p 899) remains unchanged, but the classification has to be modified The top 1-2 m of bed 35 contain... 30-35 mm these become heavier, more pointed, and more ar less separated from the ribs On the youngest part of the shell the nodes are spaced independently of the ribs, but are often almost as dense, the ratio of nodes to ribs per half-whorl at diameters of 53-71 mm being between 1:l and 2:3 In specimens with the shell preserved it can be seen that the ribs extend from the nodes or clavi across the ventral... penetrated much further than Normandy and the northern parts of the Paris and Aquitaine Basins To the north it included Milne Land and, in the Kimmeridgian, extended as far as the Barents Shelf and northern Siberia Fauna1 successions tend locally to be disjointed and fragmentary, and this was historically the reason behind the rather numerous generic and familial names coined in the past The boundaries... Fig 5 The levels of faunas 14-23 of Milne Land in the framework of the standard Kimmeridgian zonation of NW Europe and northern Siberia Amoeboceras (Amoebites) bayi sp nov PI 1 , figs 1-12; pl 4, figs 4,5 1979 Amoeboceras bauhini (Oppel): Sykes & Callornon, pl 121, figs 2,3 Holofype MGUH 16659 (JHC 836) (PI 1, fig 6) Locus fypicus Milne Land, Bays Elv in Bays Fjelde, section 31 The microconchs of A... flank of the whorl-side, to be replaced by short, faint vestigial secondaries There is a strong resemblance to earlier cardioceratids, e.g C (Plasmatoceras) (m) of the Cordatum Zone, C (Miticardioceras) (m) of the Tenuiserratum Zone, and Amoeboceras koldeweyeme (m) of the Serratum Zone The dimorphic status of the present forms is, however, not clear The holotype of A ernesti has an adult diameter of 23... two-thirds of the wgy up the flanks Usually the ribs form weak clavi on the ventro-lateral shoulder The venter is poorly preserved The serration of the keel is fine, and the keel is sfiarply separated from the ribs on each side by a smooth band Sutures are not prqserved Macroconch One indeterminate fragment of a macroconch belonging to the A kitchini group has been found at the same level aslthe microconchs . on the north bank of the stream in the gorge of Grikloft (section 8), on the east coast of Milne Land. Parts of the member are also well exposed in the other gorges on the east coast (sections. indicating the Eudoxus and Autissiodorensis Zones of the Kimmeridgian (20-23), and, at least in the eastern part of the area, the Ekgans Zone of the Lower Volgian (24). AMMONITE ZONATION The separation. ent, to go beyond the stage of characterizing the faunas and their sequences. The levels of the faunas will therefore be treated here as merely horizons within the fra- mework of the standard NW