User Tools

    To create and edit articles, please register and log-in

Main Menu : categories & index etc.

Main menu
Click categories to expand

A-Z listingplugin-autotooltip__plain plugin-autotooltip_bigA-Z listing

This is an alphabetical index of all content pages.

Other categories



Also see

Importance Ratings
Curator's rationale
AI Policy

Twitter feed 𝕏

Feeds + s.e.o. etc.
rss / xml feed
sitemap file
A-Z listing (archived)

Indexed under : Earth Sciences

Wikenigma - an Encyclopedia of Unknowns Wikenigma - an Encyclopedia of the Unknown

Mima mounds

Mima Mounds are low, dome-like, roughly symmetrical natural mounds on terrestrial terrain - mainly composed of loose, unstratified, often gravelly sediment. They have a diameter of 3 to 50 m, and a height of 0.2 to 2 m.

They are found mainly in the northwestern United States - though similar structures have also been found on every continent except Antarctica. They sometimes occur in groups of thousands.

After 150 years or so of research, there are now several theories to explain their origins - none of which has been generally accepted.

As their construction tends to vary, it's currently thought that different mounds may have differing origins.

The main theories are that they were formed by ;

  • Gophers
  • Wind
  • Seismic activity
  • Clay expansion/contraction
  • Termites, ants, rodents and plant roots
  • Glacial flooding

See : BBC Earth

Also see : Drumlinsplugin-autotooltip__plain plugin-autotooltip_bigDrumlins

"Drumlins are elongated hills of glacial deposits. They can be 1 km long and 500 m wide, often occurring in groups. A group of drumlins is called a drumlin swarm or a basket of eggs, eg Vale of Eden.[UK]

Source : BBC Glacial Depostion"

They are formed from …

    Please share this page to help promote Wikenigma !

Dear reader : Do you have any suggestions for the site's content?

Ideas for new topics, and suggested additions / corrections for older ones, are always welcome.

If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !

Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.

( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)

Automatic Translation

You are currently viewing an auto-translated version of Wikenigma

Please be aware that no automatic translation engines are 100% accurate, and so the auto-translated content will very probably feature errors and omissions.

Nevertheless, Wikenigma hopes that the translated content will help to attract a wider global audience.

Show another (random) article

Further resources :