▁south ▁sides ▁of ▁the ▁mountain ▁d rain ▁into ▁the ▁Matt ab es ett ▁River , ▁then ▁to ▁the ▁Connecticut ▁River , ▁th ence ▁to ▁Long ▁Island ▁Sound . ▁ ▁Ge ology ▁and ▁e col ogy ▁Brad ley ▁Mountain , ▁like ▁much ▁of ▁the ▁Meta com et ▁R idge , ▁is ▁composed ▁of ▁bas alt , ▁also ▁called ▁tra pro ck , ▁a ▁vol can ic ▁rock . ▁The ▁mountain ▁formed ▁near ▁the ▁end ▁of ▁the ▁Tri ass ic ▁Period ▁with ▁the ▁rif ting ▁apart ▁of ▁the ▁North ▁American ▁continent ▁from ▁Africa ▁and ▁E uras ia . ▁L ava ▁wel led ▁up ▁from ▁the ▁r ift ▁and ▁solid ified ▁into ▁sheets ▁of ▁str ata ▁hundreds ▁of ▁feet ▁thick . ▁Sub sequ ent ▁fault ing ▁and ▁earth qu ake ▁activity ▁t ilt ed ▁the ▁str ata , ▁creating ▁the ▁cl iffs ▁and ▁rid g eline ▁of ▁Brad ley ▁Mountain . ▁Hot , ▁dry ▁upper ▁s lop es , ▁cool , ▁mo ist ▁rav ines , ▁and ▁min eral - rich ▁led ges ▁of ▁bas alt ▁tal us ▁produce ▁a ▁combination ▁of ▁micro cl imate ▁e cos ystem s ▁on ▁the ▁mountain ▁that ▁support ▁plant ▁and ▁animal ▁species ▁un common ▁in ▁greater ▁Connecticut . ▁Brad ley ▁Mountain ▁is ▁an ▁important ▁ra pt or ▁migration ▁path . ▁( See ▁Meta com et ▁R idge ▁for ▁more ▁information ▁on ▁the ▁ge ology ▁and ▁e cos ystem ▁of ▁Brad ley ▁Mountain ). ▁ ▁Rec re ation ▁and ▁conservation ▁Despite ▁the ▁development ▁on ▁its ▁lower ▁s lop es ▁and ▁the