Acid mine drainage spilling from a collapsed mine tunnel at outcrop of the so-called Fundy seam<sup id="cite_ref-quann_1-0" class="reference"><a href="#cite_note-quann-1">[1]</a></sup> (middle part of Joggins Formation, lower Pennsylvanian) north of Joggins, Nova Scotia.
<a href="//commons.wikimedia.org/wiki/User:Rygel,_M.C." title="User:Rygel, M.C.">Michael C. Rygel</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>