Impact Structures of the World

About my list of impact structures

Database v1.0 (rebuilt database engine and minor data update, July 2009)
Here is some information what you will find in different pages of this database.

 

An impact structure = A geological structure which is formed due to hypervelocity impact of celestial body. This includes all craters (or their remains) formed by explosive impact of big comet or asterdoid and craters larger than 5 meters in diameter by non-explosion impact of meteorite. Also known airblasts and impact related geological (ejecta) layers are listed.

 

ALL

This option shows all entries in database except discredited structures.

MAIN LIST

Includes all CONFIRMED impact structures, airblasts and craters over 5 meters in diameter. The main list of impact structures which origin of hypervelocity impact are scientifically confirmed and widely accepted or presented evidences seems to favour impact origin strongly enough. Usually I expect to see some presented evidence of shock metamorphosis in rocks. That often means planar deformation features (pdf) or well developed shatter cones at least. However, there has been some scientific studies claiming that these evidences has been found in some structures, but closer looks by other scientist has revealed that identification or conclusion were not correct. So there may still be some structures here which identification is not correct.

FULLY PROVED

These are also in the main list. These are impact structures which evidences are so strong that there is no or very little question about impact origin of these structures.

IMPACT RELATED LAYERS

These are NOT listed in the main list.
Some oldest known traces of impacts are layers of distal ejecta in geological strata. The impact crater causing the layer may have been destroyed long ago due to erosion and plate tectonics. These layers are important traces of ancient catastrophes. However, since this is supposed to be a list of impact structures, I have not listed these layers in the main list. Note, layer is not listed if an impact structure causing the layer has been identified (like K/T layer which is linked to Chicxulub structure). Some of these layers are not fully confirmed. An impact related geological layer is hard to identify for sure.

CANDITATES

Includes structures which has shown at least some evidence of impact origin. Usually confirmation of any of these structures needs more evidences. Structures which are recognized by shatter cones only are especially problematic since there is no othern known method to identify shatter cones than comparing samples visually. Some of these possible structures are under heavy depate and usually somebody agrees impact origin and somebody does not. I hope that most of these will be confirmed some day, but I am sure that some of these never will be confirmed.

SUGGESTED

Suggested structures are those which impact origin has been only suggested by somebody, but nobody has studied them closely enough to make any decision if the structure is an impact structure or not. These structures may become confirmed or discredited after future studies.

DISCREDITED

Because some impact crater looking structures are not impact structures and people keep asking about them, I have collect also some of these non-impact structures into my database. So here you can find if the structure you are about to ask is already discredited. However, there is always a possibility that some of these structures are impact structures after all. To confirm an impact structure is not an easy task.

GM LINK

In the very last column there is GM link which will show the structure in Google Maps. Not all structures are linked if there is problems to locate them like some deedly buried impact structures and submarine structures. All links are checked to point the right structure, however, coordinates in list may be different than in these links because several different coordinate systems used for structure coordinates.

REMARKS

Original list was based on list of 139 craters courtesy of Dave Stephenson, Geodetic Survey of California.

TECHNICAL NOTES

This database is made by mysql and php.
Use of any material without permission is forbidden. Jarmo Moilanen - 2009
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