1
Structure and Surface

The surface features of Southern Africa, as indeed of any area, are the present expression of the continual interplay between earth movements and igneous activity on the one hand and weathering and erosion on the other. Periods of quiescence and deposition have been followed by continental uplift, mountain building, and volcanic activity while all the time the agents of destruction have been busy attacking and moulding the emerging forms and burying others. Hence, in order to understand the form and features of the present landscape it is necessary to consider briefly the geological history of the area.

The greater part of Southern Africa consists of a very old continental area which has not been submerged since early Palaeozoic times. Rocks of late Palaeozoic and Mesozoic age outcrop over considerable areas of the plateau but the geologists consider that they were laid down under freshwater or continental lagoon conditions. Apart from the so-called superficial deposits, mostly of Tertiary and Recent age, covering large areas in the Kalahari, only small areas in the coastal belts are underlain by rocks of Cretaceous and later date. Apart from epeirogenctic movements, the continental plateau area has remained little disturbed since the early Palaeozoic, but around its southern margins crustal folding extending from Permian to Triassic times produced the structures of the Cape ranges. Monoclinal flexuring took place along the line of the present-day Lebombo mountains in Jurassic times and fracturing was widespread in the coastal belt during the Cretaceous period.


The Geological Evolution of South Africa

The evolution of South Africa spans an enormous period of geological time, the radioactive content of some of the oldest rocks exposed at the surface today indicating an age exceeding 1,500 million years. Nevertheless the geological makeup of South Africa is relatively simple. The major rock formations were apparently laid down during five great geological eras, each one separated from the next by prolonged periods of erosion, earth movement, or igneous activity. These five great eras are the (1) Archaean, (2) pre-Cambrian, (3) Palaeozoic pre-Karoo, (4) Karoo, and (5) post-Karoo. Today the outcrops of the rocks of each era (Fig. 1)

-3-

Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items
Notes
Cite this page

Cited page

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Note: primary sources have slightly different requirements for citation. Please see these guidelines for more information.

Cited page

Bookmark this page
South Africa
Table of contents

Table of contents

Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen
Items saved from this book
  • Bookmarks
  • Highlights & Notes
  • Citations
/ 698

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Search by... Author
    Show... All Results Primary Sources Peer-reviewed

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.