Highlights—The Rise and Fall of Lakes

Rapid tectonic and climate changes can markedly influence lake extent and character, with distinct expression along- and across-strike. Ghinassi et al. suggest that although the morphological along-strike variability of lacustrine coasts is relatively well understood, the nature and signature of this variability on the sedimentological and stratigraphic record of lacustrine systems is poorly documented. This study documents how lacustrine water-level oscillations are recorded in different depositional systems along strike in late Holocene shoreline deposits of Lake Hayk of Ethiopia. The results illustrate low-relief margins with fluvial-deltaic systems and high-relief margins with collvial fan deltas and stromatolitic biostromes. The data reveal possible pitfalls of classical stratigraphic approaches used to establish along-strike correlation between lacustrine sedimentary successions, important for paleoenvironmental studies, subsurface exploration and stratigraphic investigations.

Lacustrine facies in response to millennial-century scale climate changes (Lake Hayk, northern Ethiopia) by Massimiliano Ghinassi, Filippo D’Oriano, Marco Benvenuti, Mariaelena Fedi and Stanley Awramik