Fluvio-estuarine deposits of the upper Silurian Si Ka Formation in the Dong Van Karst Plateau Geopark, Ha Giang Province, Vietnam.

2021 ◽  
Vol 79 (2) ◽  
pp. 46-46
Author(s):  
Toshifumi Komatsu ◽  
Toshihiro Yamada ◽  
Julien Legrand ◽  
Mark Williams ◽  
Anna McGairy ◽  
...  
Keyword(s):  
Upper Silurian

Stratigraphy of the Gorstian and Ludfordian (upper Silurian) Hemse Group reefs on Gotland, Sweden

GFF ◽  
2021 ◽  
pp. 1-13
Author(s):  
Olof Taromi Sandström ◽  
Peter Dahlqvist ◽  
Mikael Erlström ◽  
Lena Persson ◽  
Steve Kershaw ◽  
...  
Keyword(s):  
Upper Silurian

Notes of a Geologist in Ireland During August and September, 1857

The Geologist ◽  
1858 ◽  
Vol 1 (8) ◽  
pp. 330-335
Author(s):  
W. S. Symonds
Keyword(s):  
Lower Cambrian ◽  
Red Sandstone ◽  
Upper Silurian ◽  
Cover Up

On leaving Dublin, we travelled northwards, for the purpose of examining the carboniferous rocks, and visiting the magnificent collection of fossil-fishes in the museum of the Earl of Enniskillen; we then journeyed south for Killarney and the Dingle district, but as it may be more convenient to the reader to travel geologically, we will reverse the order of our journey, and visit the Upper Silurian and Old Red Sandstone districts before we examine the carboniferous deposits.The lower Cambrian rocks of Wales, of which the Oldhamia-schists of Ireland are believed to be the equivalents, pass upwards by insensible gradations into the Lingula-flags, to which they are altogether conformable. The Lingula-flags are reckoned to be four or five thousand feet thick, and the Llandeilo or Builth-beds, which cover up these, are probably as thick; but geologists are, as yet, uncertain whether they possess in Ireland any true equivalents either of the Lingula-flags or of the Llandeilo and Builth deposits. There are, however, fossiliferous rocks of the Bala and Caradoc age in Ireland similar to those which, in Wales, succeed conformably to the Llandeilo and Builth beds, and they may be examined at Courtown, in the county of Wicklow, and again at Tramore, south of Waterford. They are unconformable to the rocks below, which are undoubtedly Cambrian, and thence, we imagine, has arisen the suspicion that the Lingula-beds and Llandeilo-flags have never been deposited in Ireland, or that if they were, they have been denuded and swept away before the deposition of the Bala or Caradoc strata.

Additional information on Alainaspis and Boothiaspis, cyathaspidids (Agnatha: Heterostraci) from the Upper Silurian of Northwest Territories, Canada

1991 ◽  
Vol 65 (2) ◽  
pp. 308-313 ◽  
Author(s):  
David K. Elliott ◽  
David L. Dineley
Keyword(s):  
Northwest Territories ◽  
Related Species ◽  
Posterior Margin ◽  
Dorsal Shield ◽  
Filter Feeder ◽  
Closely Related Species ◽  
Additional Information ◽  
New Material ◽  
Upper Silurian ◽  
Original Interpretation

New material of the poraspid Alainaspis platyrhina Elliott and Dineley has made it possible to provide a more extensive reconstruction of this animal. It is now clear that an elongated branchial opening was present below the lateral lamina and that a well-developed post-branchial lobe was present. No branchial plate has been identified and this may have been fused to the dorsal shield, forming the ventral lamina. The lateral lamina is now seen to terminate in a rounded angle before the posterior margin of the shield. Several ventral shields with similar ornament are identified as belonging to A. platyrhina. These are broad and deep and are consistent with the original interpretation of this animal as a filter feeder. One similar shield with a coarser ornament is tentatively assigned to the closely related species Boothiaspis ovata Broad.

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