Friday, June 25, 2010

Sedimentary Basins Meme

Post a satellite image of your favorite exposed ancient sedimentary basin.

Criteria: Do you have a good example of an ancient basin exhumed and exposed which still retains its original geometry, with its basins margins and paleo-shorelines easily identifiable?

Here is mine. The mid-late Proterozoic Cuddapah Basin of south east India. White arrows mark the eastern margin of the basin.

Where there are sediments there must have been a basin. Over time though the original shape of the depression may get obscured mainly through deformation and formation of sucessor basins which may have a different orientation and shape.

The Cuddapah basin however was an intra-cratonic basin i.e a basin which formed far away from plate margins within thick continental crust. Later what was to become India was situated in the interior of Gondwanaland and this region did not experience any Paleozoic sedimentation. And much later Mesozoic rifting was far away from this region further preserving the mid-late Proterozoic basin shape.

The eastern margin did see deformation in the late Proterozoic. The relatively undeformed western margin is still one of my favorite places to visit with exposures of the prominent unconformity between the Archean granites and metsediments and mid Proterozoic basin margin conglomerates and coarse sands representing the earliest deposits.

Here is a figure which shows the location of the Cuddapah basin along with other sedimentary basins of India.

 Source: Geotimes

Leave a link in the comments section so I can keep updating this post with links to your examples.


  1. Oooh, I call the Delaware Basin -- will try and get a post done early next week.

  2. I call the Sao Francisco Basin in Brazil, Late Proterozoic - since I don't have a blog, I could send you a doc file with illustrations, if you are interested.

    Renato Fonseca

  3. Renato- sure, I will post your illustration if you send it to me..

    suvrat underscore k at yahoo dot com

  4. this is still on my to-do list but, alas, only so much time to do it justice!