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Filmed on location at Mt. Etna and the Earth Science laboratories at the Open University, the programme examines the different lava types which make up the volcano and how these were formed.
Metadata describing this Open University video programme
Module code and title: S237, "The Earth, structure, composition and evolution"
Item code: S237; 07
First transmission date: 13-06-1981
Published: 1981
Rights Statement:
Restrictions on use:
Duration: 00:24:00
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Producer: Stuart Carter
Contributor: John Wright
Publisher: BBC Open University
Keyword(s): Etna; Geochemistry; Lava; Volcano
Footage description: Shots of Mt Etna and of John Wright near its summit. He introduces the programme. More shots of Etna and of eruptions showing lava flows. Also shots of a cross section diagram of Etna. Commentary explains how the volcano was formed and evolved. Shots of several different lava flows. Commentary by John Wright points out some of the differences between them, particularly their ages. More shots of lava flows. John Wright points out their distinguishing features. Shots of cinder cones. John Wright over shots of Etna explains that volcanoes are not simple tubes to the upper mantle, but complex networks of fissures which allow the lava to pass to the surface. John Wright looks at several lava specimens. He points out the different phenocrysts found in each and explains that they form a representative sample of the lavas found on Etna. Shots of the Adrano scarp and the lavas found there. Wright explains that these are some of the oldest lavas on Etna and then points out some of their features. Shots of thin section basalt specimens from Etna. This and animated diagrams help to explain the process of fractional crystallisation. A method for determining the chemical composition of phenocrysts within the lava by electron microprobe is demonstrated. Shots of the instrument. Then, using animated graphs, commentary by John Wright explains how the information is plotted and compares the results for younger and older lavas. He goes on to explain how these lavas must have evolved. Shots of an experiment with the mass spectrometer in which the ratios of strontium isotopes (Sr86 and Sr87) are determined. Commentary explains what can be inferred from this data on composition and origins of the lavas. John Wright, standing on a cinder cone on Etna, summarises the programme.
Production number: FOUS169W
Videofinder number: 1594
Available to public: no