Changing perspectives on Cambrian chronostratigraphy and progress toward subdivision of the Cambrian system

More than one kind of rock, as we learn from Dr. H. Hicks and other writers, occurs in the conglomerate which forms a well-marked base to the Cambrian system at St. Davids. Sometimes the pebbles are mainly vein quartz, sometimes felstone predominates, but occasionally, as in the neighbourhood of Nun's Chapel Bay, quartzites (using the term rather generally) are not uncommon. At one place, not far from a quartz-felsite dyke, these are rather large, occasionally about a foot in diameter. From this locality, while spending a few days at St. Davids in 1882, I brought away specimens of three of the most marked varieties of quartzite, of which I had slices prepared, thinking that as examples of rocks which were probably far from modern at the beginning of the Cambrian age, their structures might be instructive.

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Palaeozoic studies in honour of Sir James Stubblefield

Geological Magazine ◽

10.1017/s0016756800033811 ◽

1981 ◽

Vol 118 (6) ◽

pp. 581-589 ◽

Cited By ~ 1

Author(s):

James Stubblefield

Keyword(s):

Royal College ◽

New Genus ◽

Science And Technology ◽

Field Work ◽

Imperial College ◽

Geological Survey ◽

Current Survey ◽

Lower Palaeozoic ◽

Cambrian System

Sir James was born on 6 September 1901 at Cambridge where he attended the Perse School. He received his geological education at Chelsea Polytechnic and the Royal College of Science. In 1923 he was appointed demonstrator in geology at the Imperial College of Science and Technology, London University, where he stayed until 1928; for his last two years there he also served as Warden at the pioneer Imperial College hostel. While at Imperial College he studied the Shineton Shales of the Wrekin district of Shropshire under the guidance of W. W. Watts and in collaboration with his life-long friend O. M. B. Bulman, and was awarded a Ph.D. in 1925. This work in Shropshire provided the stimulus for his continuing contribution on the Cambrian system and its faunas, and on trilobites of all ages. During this period he also recorded his observations on Tertiary crabs from Zanzibar, a group he was to return to in later years. In 1928 he obtained one of the two posts offered by the Geological Survey, being appointed Geologist. He undertook field work in the Dorking district as a prelude to an intended posting to the Survey office at York, but the death of G. W. Lee, then palaeontologist in Edinburgh, determined that Stubblefield should remain at the headquarters of the Survey at Jermyn Street in London. Internal transfers of the palaeontological staff left no member available to determine the fossils then accumulating from the current survey of the Shrewsbury district, and Stubblefield was asked by the Director to undertake this task because of his knowledge of the Lower Palaeozoic faunas of Shropshire. This transfer became long-term and thus began his association with, and eventual leadership of, the Palaeontological Department of the Survey, and secured the continuation of his notable contributions to palaeontology. The Shrewsbury commitment led to visits to the area during which new faunal horizons were discovered in the local Cambrian and Ordovician, including the Nemagraptus gracilis fauna from the Breidden Hills; other finds included the then earliest British eurypterid subsequently described by L. Størmer as the type of a new genus under the name of Brachyopterus stubblefieldi.

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Ecdysozoan-like sclerites among Ediacaran microfossils

Geological Magazine ◽

10.1017/s001675681500045x ◽

2015 ◽

Vol 152 (6) ◽

pp. 1145-1148 ◽

Cited By ~ 8

Author(s):

MAŁGORZATA MOCZYDŁOWSKA ◽

GRAHAM E. BUDD ◽

HEDA AGIĆ

Keyword(s):

Fossil Record ◽

East European Platform ◽

Cambrian Explosion ◽

East European ◽

Stratigraphic Position ◽

Cambrian System

AbstractWe report the occurrence of organically preserved microfossils from the subsurface Ediacaran strata overlying the East European Platform in Poland, in the form of sclerites and cuticle fragments of larger organisms. They are morphologically similar to those known from Cambrian strata and associated with various metazoan fossils of recognized phyla. The Ediacaran age of the microfossils is evident from the stratigraphic position below the base of the Cambrian System and above the isotopically dated tuff layers at c. 551±4Ma. Within this strata interval, other characteristic Ediacaran microorganisms co-occur such as cyanobacteria, vendotaenids, microalgae, Ceratophyton, Valkyria and macroscopic annelidan Sabellidites. The recent contributions of organic sclerites in revealing the scope of the Cambrian explosion are therefore also potentially extendable back to the Ediacaran Period when animals first appear in the fossil record.

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