(â ãåîëîãèè) - îáîçíà÷åíèå ïîäðàçäåëåíèÿ îáùåé ñòðàòèãðàôè÷åñêîéøêàëû, ïðèíÿòîå âìåñòî ãðóïïû ãåîëîãè÷åñêîé.
