Stratigraphy Chart

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Aug 5, 2024, 12:24:18 PM8/5/24

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Threecharts have been prepared, one for each of the main regions of the continental shelf: the Norwegian North Sea, the Norwegian Sea and the Norwegian Barents Sea. The Norwegian Offshore Directorate requests industry and others to refer to these names in their reports to the directorate.

The 2014 NPD charts are based on the formal official lithostratigraphic nomenclature approved by the Norwegian Committee on Stratigraphy and published in the references below. These names appear in the charts in black letters.

In addition to the formal names referred to above, there are several supplementary names for lithostratigraphic units that have been proposed and published through time as need has arisen. The NPD recognizes the need for many of these names and have made a selection of such names to be used on a provisional basis as informal names. These names are included in the 2014 NPD charts in blue letters. These informal names are adopted from the publications below. Some of these publications also suggest minor adjustments of some official, formally approved formations.

Eidvin and Rundberg (2007) propose introduction of the new formations Ull og Eir in the Hordaland Group, and propose the extension of the Naust Formation into the North Sea. Eidvin et al 2013, 2014 proposes inor adjustments of rigg, Grid, Vade, Skade og Utsira Formations.

The mudstones of the Hordaland Group correlates with the Horda and Lark Formations of the Stronsay and Westray Groups of Knox and Holloway (1992) in the UK sector. For practical reasons and if need arises, the NPD suggests that the names Horda and Lark Formations be used informally as a subdivision of the Hordaland Group in the Norwegian sector. These names are indicated in blue letters and brackets in the 2014 NPD chart for the Norwegian North Sea.

Brunstad et al. (2013) propose introducing the new units Egga, Sotra, Sula, Rady and Odin in the Rogaland Group. These names appear in blue letters in the 2014 NPD chart for the Norwegian North Sea. Moreover, Brunstad et al. (2013) re-defined all sandstone units in the Rogaland Group to members, including those previously defined as formations. NPD, however, rank all these units, including the proposed new ones listed above, as formations in accordance with the formal status and customary application of the previously defined sandstone formations in the Rogaland Group.

In the southern part of the Norwegian-Danish Basin, some units may be correlated with the sandy units Kolga, Idun, Rind and Bor that are defined in the Danish sector by Schiler et al. (2007). These names are indicated in blue letters and brackets in the 2014 NPD chart for the Norwegian North Sea.

Gjelberg et al. (1999) introduced the name Egga Member for the sandy unit that forms the reservoir in the Ormen Lange Field. The name is in common use, but still informal. Considering the lateral extent and mappability of this unit, the NPD requests that the unit should have formation rank and that the informal name Egga Formation be used for this unit.

The International Commission on Stratigraphy (ICS), sometimes unofficially referred to as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphical, geological, and geochronological matters on a global scale.

It is the largest subordinate body of the International Union of Geological Sciences (IUGS). The ICS is essentially a permanent working subcommittee, which meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as a congress or membership of the whole.

One of its main aims, a project begun in 1974, is to establish a multidisciplinary standard and global geologic time scale that will ease paleontological and geobiological comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype Section and Points (GSSPs) within the fossil record. (i.e. section of the rock record as of a core sample section or accessible exposed strata, which when a core sample are usually "trayed" in long pieces, also called "sections" about a meter in length.)

Additionally the ICS defines an alternative type of benchmark and criteria called Global Standard Stratigraphic Ages (GSSAs) where the characteristics and dating criteria set solely by physical sciences methods (such as magnetic alignment sequences, radiological criteria, etcetera.) as well as encouraging an international and open debate amongst Earth scientists in the paleontology, geology, geobiology and chronostratigraphy fields, among others.

The International Commission on Stratigraphy has spawned numerous subcommittee level organizations organized and mobilized on a local country-wide or regional basis that are the true working committees of the IUGS, and these do the field work, basis comparisons in conference or co-ordination research committee meetings of local or wide-scale scope.

The ICS publishes various reports and findings as well as revised references periodically, summarized in the International Stratigraphic Chart, a combined working proposal and guideline-to-date released after the last ICS deliberations prior to the upcoming (next) meeting of the IUGS. Until the IUGS accepts the recommendations, they are unofficial since the IUGS parent approves or dismisses the individual deliberation reports of the ICS, which are presented as recommendations, and span dating and strata selection criteria, and related issues including nomenclatures. In de facto everyday matters, the deliberative results reported out of any meetings of the ICS are widely accepted and immediately enter everyday use, except in the rare cases where they result in a strong body of dissenting opinion, which matters are resolved before the full IUGS.

One such controversy arose in 2009 when the ICS deliberated and decided that the Pliocene Series of the current but unofficially named Quaternary Period should be shifted into the Neogene System and Neogene Period.[2] Despite the strong debate,[3] the Quaternary saw official ratification as a geological unit from the IUGS in June 2009, placing its lower boundary to the Gelasian Stage/Age at Monte San Nicola, Sicily, Italy (until then uppermost part of the Pliocene Series/Epoch, and thus of the Neogene System/Period), 2.58 Ma BP.[4]

In addition to publishing paper and document (PDF) versions of the International Stratigraphic Chart, the ICS also provides a machine-readable version of the chart formulated using the Web Ontology Language (OWL) and, in particular, Time Ontology in OWL. The ICS' chart web page also provides an interactive version of the chart, based on the OWL data.

The geology of Delaware includes parts of two geologic provinces: the Appalachian Piedmont Province and the Atlantic Coastal Plain Province. The Piedmont occurs in the hilly northernmost part of the state and is composed of crystalline metamorphic and igneous rocks. These include a variety of rock types that were formed deep in the earth by metamorphic processes, mostly in the early part of the Paleozoic Era (app. 400-500 million years ago), and later uplifted. The Coastal Plain, a flatter area that comprises most of the state, is underlain by a series of younger layers of sediments, ranging in age from the Cretaceous Period (app. 120 million years ago) to relatively recent. These have been slightly tilted through geologic time, with very minor faulting or folding in places. The rocks and sediment layers of both of Delaware's geologic provinces can be subdivided into geologic units called lithodemic units (for the crystalline rocks) or lithostratigraphic units (for the sedimentary units). These bodies of rock are identified by distinctive geological characteristics and are sufficiently thick and areally extensive to be mapped at the earth's surface and/or in the subsurface. The chart below summarizes the age and distribution of the geologic units that are recognized in the state by the Delaware Geological Survey.

Love, J.D., Christiansen, A.C., and Ver Ploeg, A.J., comps., 1993, Stratigraphic chart showing Phanerozoic nomenclature for the state of Wyoming: Geological Survey of Wyoming [Wyoming State Geological Survey] Map Series 41.

This Code describes how to classify and name all formally defined geologic units shown on maps and sections. It is the basis for the stratigraphic terminology used in the U.S. and compiled into Geolex.