Sedimentary rocks deposited during the Ediacaran period (∼630–542 Ma) contain carbonates whose carbon isotopic ratios show a marked negative excursion consisting of a precipitous drop from +5‰ to −12‰, followed by a sub‐linear recovery to positive δ13C values. Isotopic ages (U/Pb) and thermal subsidence modelling are combined to constrain the excursion in time and indicate an onset at ∼600 Ma, and duration of recovery of approximately 50 Myr. The excursion is widely recognized in Oman and has potential correlatives in Ediacaran strata elsewhere, and may thus represent a characteristic feature of the Ediacaran period. The amplitude of this carbon isotope excursion far exceeds those of other Neoproterozoic anomalies. The isotopic trend of negative excursion and long‐term recovery spanned at least one short‐lived glacial episode (at 580 Ma), but appears unrelated to glaciation, which indicates that negative anomalies in the Neoproterozoic marine carbon isotope record are not directly or uniquely linked to ice ages.

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The extensive shallow‐water carbonate platform deposits of the Dolomia Principale Formation (Southern Alps, northern Italy) accumulated during the Late Triassic, a time of plate‐scale reorganization and rifting. Synsedimentary tensional features such as fractures, neptunian dykes, normal faults, shatter breccias and laterally discordant intraformational breccias have been studied within a well‐preserved platform‐to‐basin transition in the Monte Pramaggiore area (Carnian Prealps). These tensional features follow three preferential orientations: N–S, E–W and NE–SW. To fully explain these different arrays it is proposed that the study area experienced during the Late Triassic the waning rifting phase connected to the westward propagation of the NeoTethys (N–S extension) and the onset of the rifting phase that led in the Middle Jurassic to the opening of the Central Atlantic (E–W extension), with a contemporaneous reactivation of Early–Middle Triassic NE–SW‐orientated faults. This palaeostress analysis reveals the good potential of tensional features as reliable palaeostress indicators.

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