diastem


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diastem

[′dī·ə‚stem]
(geology)
A temporal break between adjacent geologic strata that represents nondeposition or local erosion but not a change in the general regimen of deposition.
References in periodicals archive ?
Fragments of detrital material as silty and clayey material including elongated pebbles and breccias of the surrounding basement and young basalt are incorporated in channels troughs which form small unconformity surfaces or diastems within the tufa.
The contact between the top of the gypsum in unit 2 and the overlying shale is a diastem. Lenses of sandstone, which contain the coprolites and cololites of this study, occur along this contact (Figure 2).
Abrupt shifts in microfacies in this interval reflect diastems due to discontinuous sedimentation.