Stratigraphic notes, 1994: Three short papers propose changes in stratigraphic nomenclature in Virginia, Kentucky, and Alaska

10.3133/b2135 ◽  
1995 ◽  
Keyword(s):  
Stratigraphic Nomenclature

scholarly journals A revised lithostratigraphy for the Palaeogene – lower Neogene of the Danish North Sea

2005 ◽  
Vol 7 ◽  
pp. 21-24
Author(s):  
Poul Schiøler ◽  
Jan Andsbjerg ◽  
Ole R. Clausen ◽  
Gregers Dam ◽  
Karen Dybkjær ◽  
...  
Keyword(s):  
North Sea ◽  
Energy Agency ◽  
Sequence Stratigraphic ◽  
Oil Companies ◽  
The North ◽  
Reference Sections ◽  
Stratigraphic Model ◽  
Lithostratigraphic Units ◽  
The North Sea ◽  
Stratigraphic Nomenclature

Intense drilling activity following the discovery of the Siri Field in 1995 has resulted in an improved understanding of the siliciclastic Palaeogene succession in the Danish North Sea sector (Fig. 1). Many of the new wells were drilled in the search for oil reservoirs in sand bodies of Paleocene–Eocene age. The existing lithostratigraphy was based on data from a generation of wells that were drilled with deeper stratigraphic targets, with little or no interest in the overlying Palaeogene sediments, and thus did not adequately consider the significance of the Palaeogene sandstone units in the Danish sector. In order to improve the understanding of the distribution, morphology and age of the Palaeogene sediments, in particular the economically important sandstone bodies, a detailed study of this succession in the Danish North Sea has recently been undertaken. An important aim of the project was to update the lithostratigraphic framework on the basis of the new data.The project was carried out at the Geological Survey of Denmark and Greenland (GEUS) with participants from the University of Aarhus, DONG E&P and Statoil Norway, and was supported by the Danish Energy Agency. Most scientific results cannot be released until September 2006, but a revised lithostratigraphic scheme may be published prior to that date. Formal definition of new units and revision of the lithostratigraphy are in preparation. All of the widespread Palaeogene mudstone units in the North Sea have previously been formally established in Norwegian or British wells, and no reference sections exist in the Danish sector. As the lithology of a stratigraphic unit may vary slightly from one area to another, Danish reference wells have been identified during the present project, and the lithological descriptions of the formations have been expanded to include the appearance of the units in the Danish sector. Many of the sandstone bodies recently discovered in the Danish sector have a limited spatial distribution and were sourced from other areas than their contemporaneous counterparts in the Norwegian and British sectors. These sandstone bodies are therefore defined as new lithostratigraphic units in the Danish sector, and are assigned Danish type and reference sections. There is a high degree of lithological similarity between the Palaeogene–Neogene mudstone succession from Danish offshore boreholes and that from onshore exposures and boreholes, and some of the mudstone units indeed seem identical. However, in order to acknowledge the traditional distinction between offshore and onshore stratigraphic nomenclature, the two sets of nomenclature are kept separate herein. In recent years oil companies operating in the North Sea have developed various in-house lithostratigraphic charts for the Paleocene–Eocene sand and mudstone successions in the Danish and Norwegian sectors. A number of informal lithostratigraphic units have been adopted and widely used. In the present project, these units have been formally defined and described, maintaining their original names whenever feasible, with the aim of providing an unequivocal nomenclature for the Palaeogene – lower Neogene succession in the Danish sector. It has not been the intention to establish a sequence stratigraphic model for this succession in the North Sea; the reader is referred to the comprehensive works of Michelsen (1993), Neal et al. (1994), Mudge & Bujak (1994, 1996a, b), Michelsen et al. (1995, 1998), Danielsen et al. (1997) and Rasmussen (2004).

scholarly journals Benin and Western Nigeria Offshore Basins: A Stratigraphic Nomenclature Comparison

2016 ◽  
Vol 07 (02) ◽  
pp. 177-188 ◽  
Author(s):  
Gérard Alfred Franck d’Almeida ◽  
Christophe Kaki ◽  
James Adejimi Adeoye
Keyword(s):  
Stratigraphic Nomenclature

scholarly journals Overview of Cordilleran oceanic terranes and their significance for the tectonic evolution of the northern Cordillera

2021 ◽  
Author(s):  
A Zagorevski ◽  
C R van Staal ◽  
J H Bédard ◽  
A Bogatu ◽  
D Canil ◽  
...  
Keyword(s):  
Continental Margin ◽  
Tectonic Evolution ◽  
Middle Triassic ◽  
Passive Margin ◽  
Suprasubduction Zone ◽  
Ophiolitic Rocks ◽  
Juvenile Crust ◽  
Tectonic Framework ◽  
Tectonic Reconstructions ◽  
Stratigraphic Nomenclature

Ophiolite complexes are an important component of oceanic terranes in the northern Cordillera and constitute a significant amount of juvenile crust added to the Mesozoic Laurentian continental margin during Cordilleran orogenesis. Despite their tectonic importance, few systematic studies of these complexes have been conducted. Detailed studies of the pseudostratigraphy, age, geochemistry, and structural setting of ophiolitic rocks in the northern Cordillera indicate that ophiolites formed in Permian to Middle Triassic suprasubduction zone settings and were obducted onto passive margin sequences. Re-evaluation of ophiolite complexes highlights fundamental gaps in the understanding of the tectonic framework of the northern Cordillera. The previous inclusion of ophiolite complexes into generic 'oceanic' terranes resulted in significant challenges for stratigraphic nomenclature, led to incorrect terrane definitions, and resulted in flawed tectonic reconstructions.

Middle, Upper Jurassic and Lower Cretaceous sedimentary environments of the Djebel Nefusa region, northwestern Libya

1977 ◽  
Vol 8 ◽  
pp. 45-49
Author(s):  
Richard J. Hodgkinson ◽  
Christopher D. Walley
Keyword(s):  
Sedimentary Basin ◽  
Upper Jurassic ◽  
Fault Scarp ◽  
The West ◽  
Sedimentary Environments ◽  
The North ◽  
Clastic Sediments ◽  
Stratigraphic Nomenclature ◽  
Saharan Platform ◽  
North Western

Carbonate and clastic sediments of Jurassic and Cretaceous age are exposed along the fault-scarp of Djebel Nefusa in north-western Libya. Previous geological investigations have been mainly restricted to the eastern sector of the scarp. Recent studies by the authors in the western sector of Djebel Nefusa and on equivalent sediments in southern Tunisia have allowed the first regional interpretation of these rocks.The area studied lies geographically and geologically at the edge of the Saharan Platform, a large cratonic block, composed of rocks of Precambrian-Palaeozoic age. To the north and east lies a downfaulted sedimentary basin (Gabes-Sabratha Basin) containing a large thickness of Mesozoic sediments. The location of the sections measured along Djebel Nefusa are depicted in Fig.1.The stratigraphic nomenclature of the rock succession of Djebel Nefusa was first established in the east and continued laterally towards the west by later workers. Difficulties in the application of this nomenclature are presented by the recognition of facies changes previously overlooked by earlier investigators. However, as a framework for understanding these changes and the sedimentary processes which caused them, the stratigraphy erected by Magnier (1963) is adopted.

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