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Bedrock geological map of Ireland. Layers of Upper Carboniferous sedimentary rocks, Loop Head, County Clare. The geology of Ireland consists of the study of the rock formations on the island of Ireland. It includes rocks from every age from Proterozoic to Holocene and a large variety of different rock types is represented.
The term also applies to a line plotted on a geological map to represent a fault. These fractures tend to occur when a slip surface expands from a fault core, especially during an earthquake . This tends to occur with fault displacement, in which surfaces on both sides of a fault, known as fault blocks , separate horizontally or vertically.
A way up structure, way up criterion, or geopetal indicator is a characteristic relationship observed in a sedimentary or volcanic rock, or sequence of rocks, that makes it possible to determine whether they are the right way up (i.e. in the attitude in which they were originally deposited, also known as "stratigraphic up" or "younging upwards") or have been overturned by subsequent deformation.
The thin red circular contour line in the middle of the map indicates the top of the oil reservoir. Because gas floats above oil, the thin red contour line marks the gas/oil contact zone. Digital geologic mapping is the process by which geological features are observed, analyzed, and recorded in the field and displayed in real-time on a ...
(Click to zoom) See legend below This is the legend for the North American geological map above. Geologic map of North America. The geology of North America is a subject of regional geology and covers the North American continent, the third-largest in the world. Geologic units and processes are investigated on a large scale to reach a ...
It includes the following linear features (sorted from the north-east): The Fennoscandian Border Zone (FBZ) in Skagen and Kattegat; The Sorgenfrei-Tornquist Zone (STZ), including many parallel horsts in Scania (e.g. Linderödsåsen and Söderåsen). This zone experienced extension in the Jurassic.
In 1992, Coffin and Eldholm initially defined the term "large igneous province" as representing a variety of mafic igneous provinces with areal extent greater than 100,000 km 2 that represented "massive crustal emplacements of predominantly mafic (magnesium- and iron-rich) extrusive and intrusive rock, and originated via processes other than 'normal' seafloor spreading."
A fall line (or fall zone) is the area where an upland region and a coastal plain meet and is noticeable especially where rivers cross it, with resulting rapids or waterfalls. The uplands are relatively hard crystalline basement rock , and the coastal plain is softer sedimentary rock . [ 1 ]