The underside central zone of the sample shows a hole dug in Paleoproterozoic silt.
This hole is surrounded by a Brown flat surface.
<a href="//commons.wikimedia.org/w/index.php?title=User:Benoit_Potin&amp;action=edit&amp;redlink=1" class="new" title="User:Benoit Potin (page does not exist)">Benoit Potin</a>
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<span class="int-own-work" lang="en">Own work</span>