Tertiary period

The Columbia Encyclopedia, 6th ed.

Tertiary period

Tertiary period (tûr´shēĕr´ē), name for the major portion of the Cenozoic era, the most recent of the geologic eras (see Geologic Timescale, table) from around 26 to 66 million years ago. The name Tertiary was first applied about the middle of the 18th cent. to a layer of deposits, largely unconsolidated sediments, geologically younger than, and overlying, certain other deposits then known as Primary and Secondary. Later (c.1830) a fourth division, the Quaternary, was added. Although these divisions of the earth's crust seemed adequate for the region to which the designations were originally applied (parts of the Alps and plains of Italy), when the same system was later extended to other parts of Europe and to America it proved to be inapplicable. It was realized that one scheme of classification could not be applied universally: The names Primary and Secondary were generally abandoned; Tertiary and Quaternary were, and still are, used, but other geologic literature substitutes other names, including the Palaeogene and Neogene. The main divisions of the Tertiary are the Paleocene, Eocene, Oligocene, Miocene, and Pliocene epochs. Sometimes the Paleocene is included in the Eocene. At the beginning of the Tertiary, the outlines of the North American continent were very similar to those of today; by the close of the period, Europe also had emerged substantially in its present form. Marine submergences in Europe were moderately extensive, but in North America they never went beyond the Atlantic, Gulf, and Pacific coasts and the lower Mississippi valley. These inundations took place chiefly in the Eocene, Oligocene, and Miocene epochs, the continents being generally emergent in the Pliocene epoch. The Tertiary formations of either unconsolidated sediments or quite soft rocks are widespread. In the Tertiary, Gondwanaland finally split completely apart, and India collided with the Eurasian plate (see plate tectonics). The previously existing mountain ranges of North America were again elevated, the Alps, Pyrenees, Carpathians, and other ranges were formed in Europe, and in Asia the Himalayas arose. Widespread volcanic activity was prevalent. At the beginning of the period the mammals replaced the reptiles as the dominant animals; each epoch was marked by striking developments in mammalian life. Modern types of birds, reptiles, amphibians, fishes, and invertebrates either were already numerous at the beginning of the period or appeared early in its history.

Notes for this article

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 article

Cited article

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 article

Tertiary period
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

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 article
  • Highlights & Notes
  • Citations
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

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.