Available online
Description
The Red Sea is geologically the youngest sea on the Earth, in the sense that it started to form only some 20 million years ago as a result of seafloor spreading. It is therefore an instructive case...-study of the mechanism of seafloor spreading and plate tectonics. This programme looks at the geology of the Red Sea, and from surface and geophysical data illustrates the formation and history of the Red Sea.
The Red Sea is geologically the youngest sea on the Earth, in the sense that it started to form only some 20 million years ago as a result of seafloor spreading. It is therefore an instructive case...-study of the mechanism of seafloor spreading and plate tectonics. This programme looks at the geology of the Red Sea, and from surface and geophysical data illustrates the formation and history of the Red Sea.
| Module code and title: | S237, "The Earth, structure, composition and evolution" |
|---|---|
| Item code: | S237; 13 |
| First transmission date: | 16-05-1981 |
| Published: | 1981 |
| Rights Statement: | Rights owned or controlled by The Open University |
| Restrictions on use: | This material can be used in accordance with The Open University conditions of use. A link to the conditions can be found at the bottom of all OUDA web pages. |
| Duration: | 00:24:00 |
| + Show more... | |
| Producer: | Nick Brenton |
| Contributors: | Ian Gass; John Wright |
| Publisher: | BBC Open University |
| Keyword(s): | Evaporites; Grabens; Magnetic anomalies; Millstone grit; Piedmont fans; Plate tectonics; Red Sea; Shales |
| Footage description: | Over an animated map showing the movement of continents over geologic time, John Wright introduces the programme. Ian Gass explains why it is impossible to gather direct data on why continents split. He cites as an example the split of South America from Africa. Gass goes on to point out that a study of a very young protoocean such as the Red Sea may explain how the older oceans originated. Using a model of the Red Sea area, he points out that it is intuitively obvious that Arabia and Africa formed a single continent at one time Gass speculates briefly on one or two processes which may have been involved in the splitting of the African continent to form the Red Sea. Shots of desert rocks, a basement outcrop and the Red Sea model as he talks. John Wright, with the aid of animated diagrams, examines the sedimentary record for the region for a 500 million year period and explains what this indicates about the region's topology. Gass, with the aid of his Red Sea model and animated diagrams of the region, discusses several problems which arise when trying to make the two coastlines meet. He explains away the Afar triangle anomaly in the south but concedes that there are still problems in the north. Douglas Shearman, makes use of several Gemini satellite photographs of the Red Sea and surrounding area to discuss the evidence which explains away the anomalies such as coastal overlap in the northern Red Sea. The discussion finally leads to a simulated satellite photograph of the Red Sea as it must have looked 20 million years ago. Ian Gass summarises the geological events in the Red Sea area over the past 30 million years. Gass goes on to list some of the evidence from cores drilled during the Glomar Challenger deep sea drilling project and from magnetic surveys which show that the Red Sea is underlain by a constructive margin. John Wright joins in with a closer look at evidence from magnetic anomaly surveys. Finally, Gass reviews the geological evidence which indicates why the continent of Africa split along the line of the Red Sea. Animated diagrams and maps help to illustrate his points. Credits. |
| Production number: | FOUS172D |
| Videofinder number: | 1601 |
| Available to public: | no |
