æz ðə vˈæli ɡlˈeɪʃɚ mˈuːvz, ɐbɹˈeɪʒən ænd plˈʌkɪŋ ɪɹˈoʊd ðə pɹətɹˈuːdɪŋ tˈɪps ʌvðə spˈɜːz, lˈiːvɪŋ stˈiːp klˈɪflˈaɪk tɹˈʌŋkeɪɾᵻd spˈɜːz.
As the valley glacier moves, abrasion and plucking erode the protruding tips of the spurs, leaving steep cliff-like truncated spurs.