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Description
The programme depicts a field trip to the island of Arran where they examine the rocks from the oldest to the youngest. Particular attention is paid to field relations and their use in ordering geo...logical events.
The programme depicts a field trip to the island of Arran where they examine the rocks from the oldest to the youngest. Particular attention is paid to field relations and their use in ordering geo...logical events.
| Module code and title: | S101, Science: a foundation course |
|---|---|
| Item code: | S101; 28 |
| First transmission date: | 18-09-1979 |
| Published: | 1979 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:00 |
| + Show more... | |
| Producer: | Patricia McCurry |
| Contributors: | Chris Wilson; John Wright |
| Publisher: | BBC Open University |
| Keyword(s): | Arran; Dalradian; Glaciation; Phyllites; Sandstones; Volcanic rocks |
| Subject terms: | Basalt; Geology; Limestone |
| Footage description: | John Wright and Chris Wilson introduce the programme. Panoramic views of the island of Arran as they talk. They examine first the rocks at Hutton's Unconformity and point out, particularly, the weakly metamorphosed phyllites found there. Wright and Wilson go on to date the rocks at this point. They estimate the sedimentary layering to have taken place 700 million years ago and the metamorphosis into phyllites about 400 million. An animation is used to illustrate the sequence of events which led to the format of Hutton's Unconformity. Wright points out a vertical basalt intrusive dyke which separates the phyllites of the Unconformity from the red sandstones above it. He and Chris Wilson then examine the composition of the sandstones a little higher up in the succession. They discuss the environments which were responsible for these sandstone depositions. Wright and Wilson next examine some volcanic agglomerate rocks higher up in the succession. They speculate on the mechanism by which the jumble of volcanic material settled out. Wright and Wilson look at some columnar point sections in the next succession layer to find more evidence for the mechanism by which the volcanic material settled out. Chris Wilson draws a sketch which represents a cross section of the rocks they have examined so far. Wilson and Wright walk along the shore. They look at some Carboniferous limestone and then at some cross bedded sandstones all of which are much young than the rocks examined so far. Chris Wilson completes the sketch of the geological cross section of his walk over the island so far. Wilson and Wright, on the south of the island, examine the effect of several basalt dykes on the sediments they cut. Wilson points out several area of contact metamorphosis. Wright and Wilson look for evidence that horizontal igneous sheets lying parallel to the bedding at the south of the island are sills. Wright and Wilson, standing in the hills of northern Arran, look at granite intrusions there and the surrounding dalradian. They speculate on how these features were formed and go on to date them. Chris Wilson ends the programme with a brief description of the effects of glaciation on Arran. Shots of a U-shaped valley while he talks. |
| Master spool number: | OU3136 |
| Production number: | FOUS028K |
| Videofinder number: | 1203 |
| Available to public: | no |
