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SALTASH FORMATION
Saltash Formation - Basaltic Pyroclastic-Rock. Igneous Bedrock formed approximately 342 to 400 million years ago in the Carboniferous and Devonian Periods. Local environment previously dominated by explosive eruptions of silica-poor magma. Explosive eruptions of silica-poor magma. These rocks were formed from semi-mobile to mobile and highly gaseous silica-poor magma. It rose to the surface, where sudden pressure relief caused explosive volcanic eruptions, producing fragmentary pyroclastic material or ash.  Basaltic Lava. Igneous Bedrock formed approximately 342 to 400 million years ago in the Carboniferous and Devonian Periods. Local environment previously dominated by eruptions of silica-poor magma. Eruptions of silica-poor magma. These rocks were formed from mobile magma, poor in silica. It rose to the surface and erupted as fluid lava from shallow-sided volcanoes and fissures. These eruptions are associated with the spreading of the Earth's tectonic plates and are often accompanied by feeder dyke and sill intrusions. Saltash Formation – Slate and Siltstone Rock: Dark grey and grey silty mudstone with variable but very subordinate amounts of laminae and thin beds of siltstone and sandstone. Bioturbation is locally present, especially in the lower part. There are scattered units of thin- to thick-bedded limestone thin- to thick-bedded sandstone), basaltic lava (spilite), massive and bedded hyclastite, and bedded tuff. These rocks were formed on a deep ocean floor beyond the influence of land. They often consist of fine material from microscopic pelagic organisms. Breccia. Sedimentary Bedrock formed approximately 342 to 400 million years ago in the Carboniferous and Devonian Periods. Local environment previously dominated by shallow seas. hese rocks were formed in shallow seas with mainly siliciclastic sediments (comprising of fragments or clasts of silicate minerals) deposited as mud, silt, sand and gravel.

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