Short Answer Questions (questions are equally weighted)
The Lithospheric Plates: Plate tectonics - the notion that gigantic lithospheric plates move, separate or collide, grow or disappear - has been hailed as a major revolution in the earth sciences. The world maps below show the current configuration of major and minor lithospheric plates.
The lithospheric plates shown in the above figures are:
|
Great Plates
|
Lesser Plates
|
Pacific
American (North, South)
Eurasian
Persian subplate
African
Somalian subplate
Austal-Indian
Antarctic |
Nazca
Cocos
Philippine
Caribbean
Arabian
Juan de Fuca
Caroline
Bismark
Scotia |
The purpose of this lab assignment is to better acquaint us with this extraordinary new understanding of the Earth's dynamic crust. As geographers are always looking for patterns and relationships, we will take a geographical survey of the lithospheric plates.
Using the maps above, identify the greater or lesser plate(s) listed in the above table that satisfies each of the following descriptions.
1. It consists almost entirely of oceanic lithosphere. Its eastern boundary is largely a spreading boundary; its western boundary is largely a converging boundary.
2. Formed entirely of oceanic lithosphere, its eastern boundary is a converging boundary; its northern, western, and southern boundaries are spreading boundaries.
3. Formed almost entirely of oceanic lithosphere and volcanic island arcs, this plate is bounded almost exclusively by converging boundaries.
4. It consists of a central mass of continental lithosphere completely surrounded by a broad zone of oceanic lithosphere.
5. It consists of two widely separated masses of continental lithosphere, one of which is almost completely surrounded by oceanic lithosphere; the other bounded in the north by a converging boundary.
6. It consists largely of continental lithosphere. Oceanic lithosphere forms its western and northern border zone. Converging boundaries in the form of island arcs comprise much of its eastern and southern boundary.
7. It has two parallel transform fault boundaries, and each of these connects with a spreading boundary and a converging boundary.
8. It is about equally divided into continental lithosphere and oceanic lithosphere. Oceanic lithosphere forms the eastern part; continental, the western part.
9. Composed entirely of oceanic lithosphere, its western and southern boundaries are spreading boundaries; its northern boundary is a converging boundary.
10. Elongate in the east-west direction, its eastern boundary is a converging boundary, and both its northern and southern boundaries are transform boundaries. [two answers]
11. A small, narrow plate sandwiched between two great plates, one of which is formed of oceanic lithosphere, the other of continental lithosphere.
12. It consists of a large central core of continental lithosphere, surrounded on the west, south, and southeast by oceanic lithosphere. Its northern boundary is partly a converging boundary. Its northeastern boundary is a spreading boundary.