In north European geology, Jotnian sediments are a group of Precambrian rocks assigned to the Mesoproterozoic Era (Riphean), albeit some might be younger. Jotnian sediments include the oldest known sediments in the Baltic area that have not been subject to metamorphism. Stratigraphically, Jotnian sediments overlie the rapakivi granites and other igneous and metamorphic rocks and are often intruded by younger diabases.
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In this Dossier
- ⭐ Core Definition: Jotnian
- Jotnian in the context of Platform (geology)
- Jotnian in the context of Wilhelm Ramsay
Jotnian in the context of Platform (geology)
In geology, platform is a craton covered with sediments. It can be classified into the following groups: a "protoplatform" of metamorphosed sediments at the bottom, a "quasiplatform" of slightly deformed sediments, a "cataplatform", and an "orthoplatform" at the top. The Mesoproterozoic Jotnian sediments of the Baltic area are examples of a "quasiplatform". The post-Ordovician rocks of the South American Platform are examples of an orthoplatform.
View the full Wikipedia page for Platform (geology)Jotnian in the context of Wilhelm Ramsay
Wilhelm Ramsay (20 January 1865 – 6 January 1928) was a Finnish geologist. He became a member of the Royal Swedish Academy of Sciences in 1914 and in 1915 was accepted into the Royal Physiographic Society in Lund. He coined the terms Fennoscandia (1900) and Postjotnian (1909). Ramsay also coined the term ijolite.
Together with Jakob Sederholm, Ramsay was a student of Fredrik Johan Wiik. Pentti Eskola was a student of Ramsay.
View the full Wikipedia page for Wilhelm Ramsay