Jake M. Hancock
Imperial College London
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Publications 27
#1C W WrightH-Index: 9
#2William James Kennedy (University of Oxford)H-Index: 38
Last. Andrew S. Gale (University of Portsmouth)H-Index: 42
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ABSTRACTPart 7 presents the stratigraphical results of the revision of the Ammonoidea of the Lower Chalk. Localities key to the establishment of the revised zonal and subzonal scheme are described and discussed. The limits of the Cenomanian Stage are reviewed, as is the global correlation of Cenomanian ammonite faunas.
2 CitationsSource
#1Andrew S. Gale (University of Portsmouth)H-Index: 42
#2Jake M. HancockH-Index: 16
Last. David Wray (University of Greenwich)H-Index: 31
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The spillway of Lake Waxahachie, Ellis County (Texas), exposes a > 17 m section of the Hutchins Member of the Austin Chalk Group, un-conformably overlain by Taylor Clay. The Austin sequence was regarded as a potential Global Stratotype Section for the base of the Campanian Stage at the 1995 Brussels meeting on Cretaceous Stage boundaries, with the last occurrence of the crinoid Marsupites testudinarius (von Schlotheim, 1820) as the potential boundary marker. An integrated study of the geochemist...
60 CitationsSource
#1William James Kennedy (University of Oxford)H-Index: 38
#2William A. CobbanH-Index: 6
Last. Andrew S. Gale (University of Greenwich)H-Index: 42
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The ammonite faunas of the Main Street Limestone, Grayson Marl and Del Rio Clay form the basis for a revised upper Upper Albian to lower Lower Cenomanian zonal sequence in northeast Texas. A Mortoniceras (Subschloenbachia) rostratum Zone, previously known to be well-represented in the Denton Clay, Weno Limestone, and Pawpaw Shale, extends into the lower Main Street Limestone. A M. (S.) perinflatum Zone is also recognised in the Main Street on the basis of the occurrence of the index species, alt...
28 CitationsSource
#2Jake M. Hancock (Imperial College London)H-Index: 16
Last. Neil H. LandmanH-Index: 28
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The type material orthe ammonites described in F. ROEMER'S 'Die Kreidebildungen von Texas und ihre organischen Einschlusse' (1852) is revised, and referred to Nowakites flaccidicosta (ROEMER, 1852), Texasia denlatocarinata (ROEMER, 1852), Placenticeras syrtale (MORTON, 1834), Texanites ( Texanites ) texanus texanus (ROEMER, 1852), Tetaniles ( Texanites ) roemeri (YABE & SHIMIZU, 1923), Mariella ( Wintonia ) brazoensis (ROEMER, 1852), Baculites asperoanceps Lasswitz, 1904, Bacufiles sp., and Scap...
4 Citations
#1Jake M. Hancock (Imperial College London)H-Index: 16
#2Ireneusz Walaszczyk (University of Warsaw)H-Index: 21
Abstract Improved dating by ammonites and inoceramids of the upper part of the Eagle Ford Shales (Middle and Upper Turonian) and the lower part of the Austin Chalk (top Turonian to Coniacian) in the Dallas area has given more accurate timing of sea-level changes. The broad rise in sea level from the Turonian into the Coniacian was a Texan tectonic effect. Individual regressive troughs, in cycles of the order of 100 kyr to 1 myr, seem to be a mainly eustatic effect. The pattern is very different ...
18 CitationsSource
#1Michael G. Bassett (Cardiff University)H-Index: 23
#2John C. W. Cope (Cardiff University)H-Index: 16
Last. Charles Hepworth Holland (Trinity College, Dublin)H-Index: 11
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[Zalasiewicz et al. (2004)][1] have proposed fundamental changes in the definition and application of stratigraphic terminology involving time-rock and geologic-time units that fly in the face of widely accepted principles that have been tried and tested in establishing an international unified
1 CitationsSource
#1Jake M. Hancock (Imperial College London)H-Index: 16
It has been known since the 1970's that the relatively high sea levels during the Cenomanian in southern England and northern France were interrupted by a strong fall in sea level early in the Middle Cenomanian. This was a eustatic trough whose effects can be found not only in north-west Europe, but also from western Kazakhstan in central Asia to Texas, Colorado and South Dakota in the U.S.A.
13 CitationsSource
#1Jake M. Hancock (Imperial College London)H-Index: 16
Abstract The Aptian/Albian boundary, as currently placed, presents problems which have not yet been solved and possibly never will be. No detailed definition of recent years can be applied on a world-wide scale, which will be needed for any definition acceptable to the Subcommission on Cretaceous Stratigraphy. The only satisfactory and workable solution is to choose a completely new position. It is suggested that this should be at the base of the Zone of Lyelliceras lyelli . This would change th...
17 CitationsSource
Synopsis In the Inner Hebrides the Gribun Conglomerate Formation (possibly Maastrichtian in age) lies above the Cretaceous Chalk and below the Palaeocene basalts. It is best developed on the Island of Mull, but is also found further north in Skye. The Gribun Formation and the Chalk record several episodes of widespread silicification during the Late Cretaceous and possibly again very early in the Palaeocene. This silicification is evidence of arid or semi-arid terrestrial conditions. The possibl...
9 CitationsSource
#1Jake M. Hancock (Imperial College London)H-Index: 16
The large body of data on the Mesozoic and Cenozoic sequence stratigraphy of European basins can be used as solid evidence to test the EXXON curve. The use of numbers to distinguish sequences leads to ambiguities, anomalies, and confusion. Different authors tend to use different numbers for the same sequences, often because there is disagreement on how many sequences there are. If a mistake occurs, all the other numbers for succeeding sequences have to be changed. There are also the problems of ...
3 CitationsSource