Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Circular structures of large scale and great age on the Earth's surface

A Corrigendum to this article was published on 01 February 1978


THE Earth's surface exhibits faint circular patterns which have not been described before. These circles are characterised by near perfection of outline, by the presence of topographic highs (rims) along parts of their circumferences, by their generally large scale (diameters of from under 7 km up to approximately 700 km in the areas examined), and by their definition in various geological environments, in many rock types, and in rocks of all ages. Many of the circles are intermittent in places along their rims but about 55% of the approximately 1,170 definite circles observed to date can be visually traced around an entire 360° of arc. The circles are further characterised by the presence of fracturing and brecciation along parts of their rims and by the extraordinary control they place on regional geology in general and on ore mineralisation in particular.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout


  1. Gay, S. P., Jr Pervasive Orthogonal Fracturing in Earth's Continental Crust, 105–106 (American Stereo Map Co., Salt Lake City, 1973).

    Google Scholar 

  2. Lindsay, J. B. Geomorphology of Arizona, 1 : 1,000,000 (Salt Lake City).

  3. Mardirosian, C. A. Map of Mining Districts and Mineral Deposits of Arizona, 1 : 1,000,000 (Mineral Research Co., Albuquerque, 1973).

    Google Scholar 

  4. Wilson, E. D., Moore, R. T. & Cooper, J. R. Geologic Map of Arizona 1 : 500,000 (Arizona Bureau of Mines and US Geological Survey, 1969).

    Google Scholar 

  5. Titley, S. R. & Hicks, C. L. (eds) Geology of the Porphyry Copper Deposits—Southwestern North America, 7 (University of Arizona Press, Tucson, 1966).

  6. Kutina, J. Proc. 1st Int. Conf. Basement Tectonics, 567 (Utah Geological Association, Salt Lake City, 1976).

    Google Scholar 

  7. Emmons, W. H. Trans. Am. Inst. Min. Met. Eng. 75, 797–815 (1927).

    Google Scholar 

  8. Grew, P. C. Trans. Am. geophys. Union 57, 4 (abs.) (1976).

    Google Scholar 

  9. Godwin, C. I. Proc. Geol. Ass. Can. 25, 9–12 (1973).

    Google Scholar 

  10. Jerome, S. E. & Cook, D. R. Bull. Nev. Bur. Mines 69, (1967).

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

SAUL, J. Circular structures of large scale and great age on the Earth's surface. Nature 271, 345–349 (1978).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing