An interesting PowerPoint presented by the Kansas Department of Health and Environment at the Kansas Dam Safety Conference in 2010 on old brine well sinkholes in central Kansas and northwest Oklahoma. You can view the PowerPoint online at the State Library of Kansas' KGI Online Library.
WORD OF WARNING!! For some strange reason the graphic first page of the document does not show up in the KGI record. You can still view the full record though by clicking on the two opposing arrows icon below the title at the top of the record. If you still have problems contact Bill Sowers at the State Library of Kansas (ksdocs@ks.gov)
From the presentation:
WHAT IS A SINKHOLE?
--A sinkhole is a surface depression caused by subsidence of rock layers into a cavern in the underlying rock.
--The rate of subsidence can occur gradually or catastrophically.
--The rate of subsidence is dependent upon such factors as cavern size, cavern geometry, roof span diameter, and strength of overlying rock layers.
The report is technical in nature but it is a good resource in the basics of sinkholes.
Read the presentation here:
Old Brine Well Sinkholes: A Mining Legacy