Dinoflagellate cyst assemblages across the Oxfordian/Kimmeridgian boundary (Upper Jurassic) at Flodigarry, Staffin Bay, Isle of Skye, Scotland – a proposed GSSP for the base of the Kimmeridgian

2018 ◽  
Vol XV (1) ◽  
pp. 51-62 ◽  
Author(s):  
Marcin BARSKI
Keyword(s):  
Upper Jurassic ◽  
High Abundance ◽  
Green Tides ◽  
Dinoflagellate Cyst ◽  
General Terms ◽  
Two Samples ◽  
Correlation Potential ◽  
Isle Of Skye

Examination of seven ammonite-calibrated palynological samples across the Oxfordian/Kimmeridgian boundary in the Flodigarry sections at Staffin Bay, Isle of Skye, northern Scotland, has revealed dinoflagellate cyst assemblages in general terms in line with previous contributions. The sparse occurrence of Emmetrocysta sarjeantii, Perisseiasphaeridium pannosum and Senoniasphaera jurassica slightly above the proposed Oxfordian/Kimmeridgian boundary may be used as a palynological approximation of the base of the Kimmeridgian. The high abundance of tests resembling modern zygnemataceous chlorophycean alga Spirogyra in two samples above the Oxfordian/Kimmeridgian boundary horizon is probably associated with increased eutrophication and possible association with ‟green tides”. This bloom is proposed as a palynofloral proxy event for the boundary in the Flodigarry section. According to previous studies, various eutrophication events may have a correlation potential in Subboreal Europe.

Illite-smectite from the North Sea investigated by scanning tunnelling microscopy

Clay Minerals ◽  
1992 ◽  
Vol 27 (3) ◽  
pp. 331-342 ◽  
Author(s):  
H. Lindgreen ◽  
J. Garnaes ◽  
F. Besenbacher ◽  
E. Laegsgaard ◽  
I. Stensgaard
Keyword(s):  
Thickness Distribution ◽  
Particle Diameter ◽  
Upper Jurassic ◽  
Scanning Tunnelling Microscopy ◽  
Minimum Thickness ◽  
Two Samples ◽  
Scanning Tunnelling ◽  
Tunnelling Microscopy ◽  
Dimensional Growth ◽  
Particle Thickness

AbstractTwo samples of illite-smectite (I-S) isolated from Upper Jurassic clays in well 2/7-3 (3365 m) and well 2/11-1 (4548 m) have been investigated by scanning tunnelling microscopy (STM), and the particle shape and dimensions have been correlated to results from transmission electron microscopy (TEM) on shadowed specimens and results from atomic-force microscopy (AFM). By STM, lath-like and equant particles were observed in both samples, some of the particles having sharp edges. In the I-S from well 2/11-1, spiral-shaped particles were also seen. For both samples, the most frequent particle diameter was 100–200 Å. Particle-thickness distributions from STM and TEM were similar for the I-S from well 2/7-3, being dominated by 10 Å thick particles. For I-S from 2/11-1, the STM particle-thickness distribution has a predominance of 20 Å thick particles, but the TEM particle-thickness distribution is broad, with about equal amounts of 20, 30, 40, 50 and 60 Å thick particles. The AFM particle-thickness distribution for this I-S resembles the TEM thickness distribution. It is concluded that mainly thin (10 and 20 Å) particles are seen by STM. Failure of AFM to show sharp particle edges (seen in STM and TEM) might be attributed to the AFM tip movement or tip shape. In STM, I-S particles from well 2/7-3 have peaks along edges, whereas I-S particles from well 2/11-1 have rims. These rims are also seen in AFM and are therefore real geometrical features, probably a result of two-dimensional growth, whereas the spirals in the I-S from well 2/11-1 demonstrate three-dimensional growth. The minimum thickness of most particles is 10 Å.

Dinoflagellate cysts from an allochthonous block of Nordenskjöld Formation (Upper Jurassic), north-west James Ross Island

1992 ◽  
Vol 4 (3) ◽  
pp. 267-278 ◽  
Author(s):  
Michael G. Snape
Keyword(s):  
New Species ◽  
Papua New Guinea ◽  
Antarctic Peninsula ◽  
Late Jurassic ◽  
New Genus ◽  
Upper Jurassic ◽  
Dinoflagellate Cysts ◽  
Dinoflagellate Cyst ◽  
North West ◽  
James Ross Island

An allochthonous block of the Nordenskjöld Formation from north-west James Ross Island, Antarctic Peninsula has yielded a diverse marine palynoflora. Dinoflagellate cyst assemblages from the 185 m thick sequence are described and compared with similar microfloras previously described from Australia, Papua New Guinea and Madagascar. A mid Tithonian (Late Jurassic) age is suggested for the section. One new genus, Helbydinium gen. nov. and four new species, Helbydinium scabratum sp. nov., Leptodinium acneum sp. nov., Leptodinium posterosulcatum sp. nov. and Rhynchodiniopsis foveata sp. nov. are described.

scholarly journals A note on the nomenclature of some Upper Jurassic dinoflagellate cyst taxa

1982 ◽  
Vol 1 (1) ◽  
pp. 53-53 ◽  
Author(s):  
Michael J. Fisher ◽  
Leslie A. Riley
Keyword(s):  
New Species ◽  
Upper Jurassic ◽  
Dinoflagellate Cyst ◽  
Publication Delay

Abstract. In 1980, several new species of dinoflagellate cyst taxa were validly published and named from the Kimmeridge Clay of England as part of a larger study on Kimmeridgian-Valanginian dinoflagellate cyst assemblages (Fisher & Riley, 1980); this study was originally presented at the IV International Palynological Conference, Lucknow in 1976–77. This note, necessitated by the long publication delay and numerous printing errors, comprises taxonomic re-allocations, taking account of subsequent studies (Norris, 1978; Stover & Evitt, 1978; Davey, 1979; Riley, 1979) and corrects inadvertent taxonomic errors.

scholarly journals <i>Rotosphaeropsis thula</i> (Davey 1982) comb. nov., emend.: a dinoflagellate cyst from the Upper Jurassic-Lower Cretaceous of England

1989 ◽  
Vol 8 (1) ◽  
pp. 109-112 ◽  
Author(s):  
James B. Riding ◽  
Roger J. Davey
Keyword(s):  
Lower Cretaceous ◽  
Upper Jurassic ◽  
Morphological Parameters ◽  
Specific Diagnosis ◽  
Dinoflagellate Cyst

Abstract. The Upper Jurassic-Lower Cretaceous dinoflagellate cyst Cannosphaeropsis thula Davey 1982 does not conform to the morphological parameters of the genus Cannosphaeropsis O. Wetzel 1933 emend. Duxbury 1980. The species also exhibits no indications of belonging to the Spiniferites complex of Evitt (1985). The species is transferred to Rotosphaeropsis Davey 1987 by virtue of its shape, archaeopyle type, processes and trabeculae and the specific diagnosis is emended in the light of this reassessment.

scholarly journals Jurassic dinoflagellate cyst stratigraphy of Hold with Hope, North-East Greenland

2004 ◽  
Vol 5 ◽  
pp. 73-88 ◽  
Author(s):  
Stefan Piasecki ◽  
Michael Larsen ◽  
Jens Therkelsen ◽  
Henrik Vosgerau
Keyword(s):  
Upper Jurassic ◽  
Dinoflagellate Cysts ◽  
East Greenland ◽  
Dinoflagellate Cyst ◽  
North East ◽  
Lowermost Part ◽  
Early Late

Dinoflagellate cysts of the Middle–Upper Jurassic succession on northern Hold with Hope have been studied in order to establish a biostratigraphic framework and to date the succession. The Pelion Formation is characterised by abundant Chytroeisphaeridia hyalina and Sentusidinium spp., with some Ctenidodinium thulium and Paragonyaulacysta retiphragmata in the lower part. Mendicodinium groenlandicum appears higher in the formation followed by Trichodinium scarburghense in the upper part. The succeeding Payer Dal Formation contains Scriniodinium crystallinum, Rigaudella aemula and Leptodinium subtile in the lower part and Dingodinium jurassicum and Prolixosphaeridium granulosum in the uppermost part. The Bernbjerg Formation contains abundant Sirmiodinium grossii and Gonyaulacysta jurassica. Adnatospahaeridium sp., Cribroperidinium granuligerum, Glossodinium cf. dimorphum and Scriniodinium irregulare appear in the lower part of the formation, followed by Avellodinium spp. in the highest part. The dinoflagellate cyst assemblages in the Pelion Formation indicate an Early–Late Callovian age (C. apertum – P. athleta Chronozones). This is supported by ammonites in the lower part of the formation, which refer to the C. apertum and P. koenigi Chronozones. A significant hiatus, from Late Callovian to Middle Oxfordian, is present between the Pelion Formation and the overlying Payer Dal Formation. The age of the Payer Dal Formation is Middle Oxfordian to earliest Late Oxfordian (C. tenuiserratum – A. glosense Chronozones). The Payer Dal Formation is conformably overlain by the Bernbjerg Formation of Late Oxfordian to possibly earliest Kimmeridgian age (A. glosense – P. baylei Chronozones). The A. glosense Chronozone is also documented by abundant ammonites in the lowermost part of the formation.

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