{"id":51,"date":"2022-12-27T14:50:07","date_gmt":"2022-12-27T14:50:07","guid":{"rendered":"https:\/\/books.gw-project.org\/large-aquifer-systems-around-the-world\/chapter\/geology-age-lithology-and-structural-setting\/"},"modified":"2022-12-29T01:05:26","modified_gmt":"2022-12-29T01:05:26","slug":"geology-age-lithology-and-structural-setting","status":"publish","type":"chapter","link":"https:\/\/books.gw-project.org\/large-aquifer-systems-around-the-world\/chapter\/geology-age-lithology-and-structural-setting\/","title":{"raw":"2.3 Geology: Age, Lithology and Structural Setting","rendered":"2.3 Geology: Age, Lithology and Structural Setting"},"content":{"raw":"
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Table\u00a05 summarizes the geological characteristics of each of the mega aquifer systems through two attributes: age and lithology. The aquifer units included in these systems consist mainly of sediments, among which sandstones and sands are predominant, in several cases in combination with carbonates. Most of these aquifer units form, together with interbedded clays and shales, a complex multilayer sedimentary aquifer system. The age of these sediments varies, but in most cases, their deposition spans a very long period, that began long ago. Millions of years of deposition (in some cases even 600 million years) resulted in thick sedimentary sequences, as indicated in Table\u00a04<\/a>.<\/p>\r\n

Table\u00a0<\/strong>5<\/strong>\u00a0<\/strong>-<\/strong>\u00a0<\/strong>Geological characteristics of the mega aquifer systems (after Margat and Van der Gun, 2013; modified).<\/p>\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
#<\/strong><\/td>\r\nAquifer System<\/strong><\/td>\r\nGeological Characteristics of the Aquifer Units<\/strong><\/td>\r\n<\/tr>\r\n
<\/td>\r\n<\/td>\r\nAge<\/strong><\/td>\r\nPredominant Lithology<\/strong><\/td>\r\n<\/tr>\r\n
<\/td>\r\nAFRICA<\/strong><\/td>\r\n<\/td>\r\n<\/td>\r\n<\/tr>\r\n
1<\/td>\r\nNubian Aquifer System\r\n(Nubian and Post-Nubian)<\/td>\r\nCambro-Ordovician to Oligocene<\/td>\r\nContinental sandstones<\/td>\r\n<\/tr>\r\n
2<\/td>\r\nNorth-Western Sahara Aquifer System (NWSAS)<\/td>\r\nCambro-Ordovician to Miocene<\/td>\r\nSandstones, carbonates and clastic sediments<\/td>\r\n<\/tr>\r\n
3<\/td>\r\nMurzuk-Djado Basin<\/td>\r\nCambro-Ordovician to Cretaceous<\/td>\r\nSandstones<\/td>\r\n<\/tr>\r\n
4<\/td>\r\nTaoudeni-Tanezrouft Basin<\/td>\r\nInfra-Cambrian* to Tertiary<\/td>\r\nSandstones, carbonates and clastic sediments<\/td>\r\n<\/tr>\r\n
5<\/td>\r\nSenegalo-Mauritanian Basin<\/td>\r\nCretaceous to Miocene<\/td>\r\nSands<\/td>\r\n<\/tr>\r\n
6<\/td>\r\nIullemeden-Irhazer Aquifer System<\/td>\r\nCambro-Ordovician to Eocene<\/td>\r\nSandstones and sands<\/td>\r\n<\/tr>\r\n
7<\/td>\r\nLake Chad Basin<\/td>\r\nCretaceous to Quaternary<\/td>\r\nSandstones and sands<\/td>\r\n<\/tr>\r\n
8<\/td>\r\nSudd Basin (Umm Ruwaba)<\/td>\r\nNeogene-Quaternary<\/td>\r\nSand and gravel, sandstones<\/td>\r\n<\/tr>\r\n
9<\/td>\r\nOgaden-Juba Basin<\/td>\r\nJurassic to Quaternary<\/td>\r\nLimestones, sandstones, sands<\/td>\r\n<\/tr>\r\n
10<\/td>\r\nCongo Basin<\/td>\r\nMesozoic to Quaternary<\/td>\r\nSandstones, sand and gravel<\/td>\r\n<\/tr>\r\n
11<\/td>\r\nCuvelai-Upper Zambezi Basin (Upper Kalahari)<\/td>\r\nCarboniferous to Jurassic, Late Creta\u00adceous to Neogene<\/td>\r\nSandstones, basalts and sands<\/td>\r\n<\/tr>\r\n
12<\/td>\r\nStampriet-Kalahari Basin (Lower Kalahari)<\/td>\r\nCarboniferous to Jurassic, Late Creta\u00adceous to Neogene<\/td>\r\nSandstones, basalts and sands<\/td>\r\n<\/tr>\r\n
13<\/td>\r\nKaroo Basin<\/td>\r\nLate Carboniferous to Mid Jurassic<\/td>\r\nSandstones with interbedded shales, basalt lava capping, dolerite dykes<\/td>\r\n<\/tr>\r\n
<\/td>\r\nNORTH AMERICA<\/strong><\/td>\r\n<\/td>\r\n<\/td>\r\n<\/tr>\r\n
14<\/td>\r\nNorthern Great Plains Aquifer<\/td>\r\nPalaeozoic and Cretaceous to Eocene<\/td>\r\nCarbonate rocks and sandstones<\/td>\r\n<\/tr>\r\n
15<\/td>\r\nCambrian-Ordovician Aquifer System<\/td>\r\nCambrian-Ordovician<\/td>\r\nMarine sandstones and carbonates<\/td>\r\n<\/tr>\r\n
16<\/td>\r\nCalifornia\u2019s Central Valley Aquifer System<\/td>\r\nQuaternary<\/td>\r\nSand and gravel (multi-layer)<\/td>\r\n<\/tr>\r\n
17<\/td>\r\nHigh Plains Aquifer (Ogallala)<\/td>\r\nTertiary<\/td>\r\nSand and gravel<\/td>\r\n<\/tr>\r\n
18<\/td>\r\nAtlantic and Gulf Coastal Aquifer System<\/td>\r\nJurassic to Holocene<\/td>\r\nUn-\/semi-consolidated sand and gravel & carbonate rocks<\/td>\r\n<\/tr>\r\n
<\/td>\r\nSOUTH AMERICA<\/strong><\/td>\r\n<\/td>\r\n<\/td>\r\n<\/tr>\r\n
19<\/td>\r\nAmazon Basin<\/td>\r\nOrdovician to Tertiary<\/td>\r\nSandstones (fine-grained) and sands<\/td>\r\n<\/tr>\r\n
20<\/td>\r\n<\/a>Maranh\u00e3o Basin<\/td>\r\nSilurian to Cretaceous<\/td>\r\nSandstones<\/td>\r\n<\/tr>\r\n
21<\/td>\r\nGuarani Basin<\/td>\r\nOrdovician to Cretaceous<\/td>\r\nSandstones and basalts<\/td>\r\n<\/tr>\r\n
<\/td>\r\nASIA<\/strong><\/td>\r\n<\/td>\r\n<\/td>\r\n<\/tr>\r\n
22<\/td>\r\nArabian Aquifer System<\/td>\r\nCambrian to Neogene<\/td>\r\nSandstones, limestones<\/td>\r\n<\/tr>\r\n
23<\/td>\r\nIndus Basin<\/td>\r\nMiocene to Holocene<\/td>\r\nUnconfined alluvial deposits<\/td>\r\n<\/tr>\r\n
24<\/td>\r\nGanges-Brahmaputra Basin<\/td>\r\nMiocene to Holocene<\/td>\r\nUnconfined alluvial deposits<\/td>\r\n<\/tr>\r\n
25<\/td>\r\nWest Siberian Basin<\/td>\r\nPaleozoic to Cainozoic<\/td>\r\nSediments (partly sub-permafrost)<\/td>\r\n<\/tr>\r\n
26<\/td>\r\nTungus Basin<\/td>\r\nCambrian to Triassic<\/td>\r\nSediments (sub-permafrost)<\/td>\r\n<\/tr>\r\n
27<\/td>\r\nAngara-Lena Basin<\/td>\r\nCambrian to Jurassic<\/td>\r\nSediments<\/td>\r\n<\/tr>\r\n
28<\/td>\r\nYakut Basin<\/td>\r\nUpper-Cambrian to Cretaceous<\/td>\r\nSediments (sub-permafrost)<\/td>\r\n<\/tr>\r\n
29<\/td>\r\nGreater North China Plain (Huang Huai Hai Plain)<\/td>\r\nQuaternary<\/td>\r\nConfined and unconfined alluvial deposits<\/td>\r\n<\/tr>\r\n
30<\/td>\r\nSong-Liao Plain<\/td>\r\nQuaternary<\/td>\r\nConfined and unconfined alluvial deposits<\/td>\r\n<\/tr>\r\n
31<\/td>\r\nTarim Basin<\/td>\r\nQuaternary<\/td>\r\nConfined and unconfined alluvial deposits<\/td>\r\n<\/tr>\r\n
<\/td>\r\nEUROPE<\/strong><\/td>\r\n<\/td>\r\n<\/td>\r\n<\/tr>\r\n
32<\/td>\r\nParis Basin<\/td>\r\nTriassic to Neogene<\/td>\r\nSand, chalk, sandstone<\/td>\r\n<\/tr>\r\n
33<\/td>\r\nRussian Platform Basins<\/td>\r\nInfra-Cambrian to Quaternary<\/td>\r\nSediments, part of them metamorphosed<\/td>\r\n<\/tr>\r\n
34<\/td>\r\nNorth Caucasus Basin<\/td>\r\nCarboniferous to Neogene<\/td>\r\nSediments<\/td>\r\n<\/tr>\r\n
35<\/td>\r\nPechora Basin<\/td>\r\nOrdovician to Tertiary<\/td>\r\nSediments<\/td>\r\n<\/tr>\r\n
<\/td>\r\nAUSTRALIA<\/strong><\/td>\r\n<\/td>\r\n<\/td>\r\n<\/tr>\r\n
36<\/td>\r\nGreat Artesian Basin<\/td>\r\nTriassic to Cretaceous<\/td>\r\nSandstones<\/td>\r\n<\/tr>\r\n
37<\/td>\r\nCanning Basin<\/td>\r\nDevonian to Cretaceous<\/td>\r\nSandstones<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n

* \u2018Infra-Cambrian\u2019 refers to the Late Ediacaran and Early Cambrian intervals between circa 585-530 million years ago (Al-Husseini, 2010).<\/p>\r\n

The mega aquifer systems are embedded in structural geologic units that favor the accumulation of thick sequences of sediments over large areas. Such settings include sedimentary basins, such as the Congo, Paris and Tarim basins. Other typical settings of mega aquifer systems are rifted depressions in which sediments accumulate (e.g., California\u2019s Central Valley and the North China Plain Aquifer System), and platforms covered by thick blankets of sediments deposited in piedmont, alluvial or glacial plain environments (e.g., High Plains Aquifer System, West Siberian Basin). Mixed setting types also occur. This characterization may give the impression of rather simple structural features of the mega aquifer systems but these are often much more complex.<\/p>\r\n

In the first place, complexity occurs because many of these sedimentary basins consist of several subbasins, with different degrees of hydraulic interconnection. For instance, the:<\/p>\r\n\r\n