. ▁However , ▁a ▁reasonable ▁average ▁for ▁f elsen me er ▁depth ▁is ▁approximately ▁ 1 m . ▁Ball ant y ne ▁( 1 9 9 8 ) ▁defines ▁three ▁types ▁of ▁f elsen me er ▁profiles : ▁Type ▁ 1 ▁consists ▁of ▁b ould ers ▁over lying ▁a ▁matrix ▁of ▁fin es ▁at ▁some ▁depth ▁below ▁the ▁surface . ▁Type ▁ 2 ▁consists ▁of ▁b ould ers ▁supported ▁by ▁a ▁coh es ion less ▁sand y ▁matrix ▁that ▁continues ▁from ▁the ▁surface ▁down ▁through ▁the ▁profile . ▁Type ▁ 3 ▁also ▁consists ▁of ▁b ould ers ▁supported ▁by ▁a ▁matrix , ▁but ▁diff ers ▁from ▁Type ▁ 2 ▁in ▁that ▁the ▁matrix ▁consists ▁of ▁s ilt ▁and / or ▁cl ay ▁rather ▁than ▁sand . ▁ ▁Occ urrence ▁ ▁Due ▁to ▁the ▁slope ▁requirements ▁they ▁are ▁most ▁commonly ▁found ▁on ▁plate aus . ▁Bas alt ▁and ▁sed iment ary ▁rocks ▁often ▁produce ▁larger , ▁more ▁numerous ▁f elsen me ers ▁than ▁other ▁types ▁of ▁rock . ▁Block fields ▁are ▁most ▁often ▁found ▁in ▁high ▁mountain ▁per ig la cial ▁regions ▁near ▁the ▁Ar ctic ▁Circle , ▁especially ▁in ▁I cel and , ▁the ▁Canadian ▁ar ctic ▁and ▁Norway ▁and ▁are ▁still ▁active ▁in ▁parts ▁of ▁Central ▁Europe ▁that ▁were ▁not ▁covered ▁by ▁ice ▁sheets . ▁In ▁the ▁Southern ▁Hem is phere ▁in active ▁block fields ▁can ▁be ▁found ▁in ▁the ▁Les oth o ▁High lands , ▁and ▁the ▁Prince ▁Edward ▁Islands . ▁ ▁Age ▁ ▁F elsen me ers ▁are , ▁typically