Visible rock formation (7)
I believe the answer is:
outcrop
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">visible rock formation</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for outcrop that I've seen before include "Rock formation at the earth's surface" , "Surface eruption of rock" , "Rocks projecting from ground" , "Sudden emergence" , "rock appearance" .)