The conjugated Holmes–Houtermans – Concordia–Discordia model has been substantiated with determination of μ (238U/204Pb), moments of U–Pb-system closure T and separation t. The model has been applied for interpretation of separated leads from ore deposits in Archean terranes of Central Asia: the Gargan block and southern margin of the Siberian craton. Leads of B-type from the former are interpreted as separated from a protolith of 4,31 Ga in a time interval of 2,35–1,40 Ga and J-type leads from the latter as separated from another protolith of  3,82 Ga in a time interval of 1,80–0,25 Ga. The former protolith (m = 11,0) is referred to the end of the initial planetary accretion and the latter one (m = 20,1) to the end of the late meteoritic bombardment of the early Earth about 3,9 Ga.