Lake systems and their economic importance

Geologically significant lake sequences can be found throughout the Phanerozoic rock record, and examples of lake sequences occur on all continents. Lakes that developed in large tectonic extensional or compressional basins are by far most significant, large-scale and economically important. However, the distribution of many present-day lakes is very much a reflection of Pleistocene glaciations. Within most tectonic lake basins, the main basin-filling megasequence contains three parts reflecting the early stages (initiation), climax and then late-stages (decline) of either the extension or compression that created accommodation space. Three factors of (1) subsidence versus sedimentation rate, (2) climate, and (3) hinterland geology consistently recur as key controls on sequence development, sediment composition, and facies architecture. Lake deposits record much information useful for palaeoclimatic reconstructions. Lake sequences frequently contain significant petroleum, coals and minerals, making them especially relevant to global economic development.