In the geologic timescale , the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series . It spans the time between 199.5 ±0.3 Ma and 192.9 ±0.3 Ma (million years ago). The Sinemurian is preceded by the Hettangian and is followed by the Pliensbachian .
11-760: In Europe the Sinemurian age, together with the Hettangian age, saw the deposition of the lower Lias , in Great Britain known as the Blue Lias . The Sinemurian Stage was defined and introduced into scientific literature by French palaeontologist Alcide d'Orbigny in 1842. It takes its name from the French town of Semur-en-Auxois , near Dijon . The calcareous soil formed from the Jurassic limestone of
22-962: A ceratosaur theropod from Skye" . Scottish Journal of Geology . 31 (2): 177–182. Bibcode : 1995ScJG...31..177B . doi : 10.1144/sjg31020177 . ISSN 0036-9276 . Bibliography [ edit ] Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2 . Retrieved from " https://en.wikipedia.org/w/index.php?title=Broadford_Beds_Formation&oldid=1228636117 " Categories : Geologic formations of Scotland Jurassic System of Europe Jurassic United Kingdom Sinemurian Stage Limestone formations Mudstone formations Sandstone formations Siltstone formations Paleontology in Scotland Hidden categories: Pages using gadget WikiMiniAtlas Articles with short description Short description
33-699: Is often divided into Lower, Middle and Upper subgroups. In Southern England the Lias is divided into the following formations (from top to base): In the East Midlands Shelf the Lias is divided into the following formations (from top to base): In the Cleveland Basin in Yorkshire the Lias is divided into the following formations (from top to base): In South Wales only the Blue Lias
44-675: Is present. The Lias is underlain by the Late Triassic Penarth Group , and overlain by the Inferior Oolite in most of England and the Dogger Formation or Ravenscar Group in the Cleveland Basin. In some areas there is a stratigraphic hiatus , and the rocks are overlain by Cretaceous marine sediments. There are restricted outcrops of Lias rocks on the west coast of Scotland where, in
55-580: The Early Jurassic epoch of the geologic timescale . It is now more specifically known that the Lias is Rhaetian to Toarcian in age (over a period of c. 20 million years between 200 to 180 million years ago ) and thus also includes a part of the Triassic . The use of the name "Lias" for a unit of time is therefore slowly disappearing. In southern England , the Lias Group
66-531: The North Sea , the Low Countries and the north of Germany . It consists of marine limestones , shales , marls and clays . Lias is a Middle English term for hard limestone, used in this specific sense by geologists since 1833. In the past, geologists used Lias not only for the sequence of rock layers, but also for the timespan during which they were formed. It was thus an alternative name for
77-1322: The Lias Group consists of nine formations (from top to base): Broadford Beds Formation Coordinates : 57°42′N 5°42′W / 57.7°N 5.7°W / 57.7; -5.7 Geologic formation in Scotland Broadford Beds Formation Stratigraphic range : Sinemurian ~ 196–190 Ma PreꞒ Ꞓ O S D C P T J K Pg N Type Geological formation Unit of Lias Group Underlies Pabay Shale Formation Overlies Triassic rocks Thickness 50–100 metres (160–330 ft) Lithology Primary Limestone , mudstone , sandstone , siltstone Location Coordinates 57°42′N 5°42′W / 57.7°N 5.7°W / 57.7; -5.7 Approximate paleocoordinates 43°24′N 1°54′W / 43.4°N 1.9°W / 43.4; -1.9 Region Hebrides Country [REDACTED] Scotland [REDACTED] [REDACTED] Broadford Beds Formation (the United Kingdom) Show map of
88-737: The Sea of the Hebrides depositional basin on Skye , Raasay and Mull , the Broadford Beds Formation , Pabay Shale Formation and overlying Scalpay Sandstone Formation are assigned to the Lias Group. In Dutch lithostratigraphy, the name Lias has no official status, however, it is often used for the lower part of the Altena Group in the subsurface of the Netherlands and the southern North Sea. In northern Germany,
99-594: The Sinemurian (the base of the Pliensbachian) is at the first appearances of the ammonite species Bifericeras donovani and ammonite genus Apoderoceras . The Sinemurian contains six ammonite biozones in the Tethys domain : Lias Group The Lias Group or Lias is a lithostratigraphic unit (a sequence of rock strata ) found in a large area of western Europe, including the British Isles ,
110-809: The United Kingdom [REDACTED] [REDACTED] Broadford Beds Formation (Scotland) Show map of Scotland The Broadford Beds Formation is a Sinemurian geologic formation in western Scotland . An indeterminate partial tibia of a theropod dinosaur are among the fossils that have been recovered from the formation See also [ edit ] List of dinosaur-bearing rock formations List of stratigraphic units with indeterminate dinosaur fossils References [ edit ] ^ Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607. ^ Benton, M. J.; Martill, D. M.; Taylor, M. A. (1995-11-01). "The first Lower Jurassic dinosaur from Scotland: limb bone of
121-530: The region is in part responsible for the character of the classic Sancerre wines . The base of the Sinemurian Stage is at the first appearance of the ammonite genera Vermiceras and Metophioceras in the stratigraphic record. A global reference profile ( GSSP or golden spike ) for the Sinemurian Stage is located in a cliff north of the hamlet of East Quantoxhead , 6 kilometers (3.7 mi) east of Watchet , Somerset , England . The top of
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