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The programme demonstrates how, from a periodite mantle, the other rock types found in the Earth's crust can be derived.
Metadata describing this Open University video programme
Module code and title: S101, Science: a foundation course
Item code: S101; 27
First transmission date: 11-09-1979
Published: 1979
Rights Statement:
Restrictions on use:
Duration: 00:24:00
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Producer: Patricia McCurry
Contributor: John Wright
Publisher: BBC Open University
Keyword(s): Peridotite; Silicate structures
Subject terms: Geological mapping; Granite; Meteorites; Volcanoes
Footage description: John Wright, sitting on a simulated meteorite against a background of stars, introduces the programme. Then, with the aid of a meteorite fragment, thin sections of a meteorite, and animated diagrams, he explains how evidence from meteorites allows geologists to derive information on the composition of the Earth's interior, particularly the mantle. Shots of silicate rock crystals. With the aid of molecular models of various silicates, John Wright lists the several silicate structures found in rocks and discusses their properties, Wright examines olivines, pyroxenes, amphibole and mica. Wright goes on, with the aid of rock samples, animations, and models, to explain how the strucures of the various silicate minerals affect their melting temperatures and how these in turn result in volcanic eruptions. Shots of 'fire fountain' volcano in Hawaii and of a less vigorous eruption on the Isle of Skye. Unique film shots of a volcanic eruption under the sea resulting in the formation of pillow lavas. Commentary by Wright. Wright examines thin sections of basalts and gabbro and shows an animation which demonstrates how the pillow lavas, basalt dykes and gabbros form the oceanic crust. Animated diagrams are used by Wright to show what happens to the lithosphere at a destructive plate margin. This process, in time, results in continental accretion. Over a thin section of a granite specimen, Wright explains how granites are formed in continental masses. Again, using animations, Wright explains how metamorphic rocks are formed from erosion produced sediments deposited on the continental margins. Shots of several metamorphic rock specimens as well as thin sections. Repeating the animated sequences shown in the programme, Wright sums up the stages by which the various rocks found on the earth's lithosphere were formed from the original peridotite mantle.
Master spool number: HOU2894
Production number: FOUS027R
Videofinder number: 1202
Available to public: no