acrozone

acrozone

[′ak·rō‚zōn]
(geology)
References in periodicals archive ?
Two assemblage zones and one acrozone for Permian deposits and two assemblage zones for Triassic deposits were identified based on the emergence, decline and expanding stratigraphic accumulation index for conodonts having known elements.
Based on emergence, decline and expansion of index conodonts, one assemblage zone and one acrozone (Permian) and two assemblage zones (Triassic) were recognised as follows: