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Brèches Du Grand Fond Group
The Brèches du Grand Fond Group is a group (stratigraphy), group of stratigraphic formation (stratigraphy), formations in France that were deposited between the Middle Jurassic and the Early Cretaceous. The deposition was contemporaneous to the rifting of the Valais ocean, and overlies the pre-rift rocks along an Unconformity#Angular unconformity, angular unconformity. The Brèches du Grand Fond Group is overlain by the post-rift sequences Couches de l’Aroley Formation, Couches de l’Aroley, Couches des Marmontains Formation, Couches des Marmontains and the Couches de Saint Christophe Formation, Couches de Saint Christophe. The Brèches du Grand Fond Group consists of two formations that are found in the External Valais units, the younger Pyramides Calcaires Formation and the older Dent d'Arpire Formation. The deposition of these two units was roughly contemporaneous to the deposition of the Brèches du Collet des Rousses and the Complexe Antéflysch Formation of the Internal Va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Group (stratigraphy)
In geology, a group is a lithostratigraphy, lithostratigraphic Stratigraphic unit, unit consisting of a series of related Geological formation, formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into Supergroup (geology), supergroups. Groups are useful for showing relationships between formations, and they are also useful for small-scale mapping or for studying the stratigraphy of large regions. Geologists exploring a new area have sometimes defined groups when they believe the strata within the groups can be divided into formations during subsequent investigations of the area. It is possible for only some of the strata making up a group to be divided into formations. An example of a group is the Glen Canyon Group, which includes (in ascending order) the Wingate Sandstone, the Moenave Formation, the Kayenta Formation, and the Navajo Sandstone. Each of the formations can be distingui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
