Are there Pre-Variscan bedded cherts of endogenous origin in Bulgaria?

Geochemical studies of different Paleozoic intervals composed of bedded cherts, revealed in the western parts of the Srednogorie and Morava-Rhodope zones are presented: Saltar Fm; the lower and middle part of Katina Fm; the lowest part of Parchar Fm, and Tumba Fm. To determine whether the different bedded cherts intervals are hydrothermally affected, triangular diagrams of the A-F-Mn ratio were used. The low content of Fe compared to Al gives grounds to claim that the Pre-Varisian Paleozoic bedded cherts in Bulgaria are not associated with endogenous processes.