Hydrogeologic units of Lundy (1978), Hydrogeologic role/unit of Richter (1981a; Hydrogeologic division of Lowry et al. (1973) Hydrogeologic role/unit of Statewide Huntoon and Lundy (1979a), Thompson (1979), Figure II-6, Table IV-2, and text) Hydrogeologic unit of Mazor (1990) Lithostratigraphic units of Love et al. (1993) [Laramie, Hanna, and Shirley Basins; Hydrogeologic role/unit of Younus (1992) Hydrogeologic unit of HydroGeo, Inc. (2003) Hydrogeologic unit of Taboga (2006) Framework Water Plan Hydrogeologic unit used in this report for SYSTEM AND SERIES Davis (1984), Western Water Consultants, Inc. [Laramie, Hanna, and Shirley Basins; and Mazor et al. (1993) in the Hanna and Laramie Basins Sierra Madre, Laramie Mountains (west flank) [Laramie area/southern Laramie Basin] [Hanna Basin] [Laramie area] (WWC Engineering et al., 2007, Figure 4-9) Hanna and Laramie Basins (1993, 1995), and WWC Engineering (2006a) Sierra Madre, Laramie Mountains (west flank) [Laramie area] ERATHEM and Saratoga Valley areas] [All of Wyoming] [Laramie area] and Saratoga Valley areas]
Holocene QUATERNARY and Alluvium and terrace deposits Unit 8 Local aquifers3 Local aquifers Major aquifer–alluvial Quaternary unconsolidated-deposit aquifers Pleistocene
Pliocene1
Miocene Miocene and Oligocene rocks Not discussed or not present Undefined Presumed aquifer(s) in investigator’s study area Conglomerate
CENOZOIC TERTIARY Oligocene White River Unit 8 Marginal aquifer White River aquifer and confining unit Formation Lower part Principal aquifer–Tertiary aquifer(s)4 Wagon Bed Formation Marginal aquifer Wagon Bed aquifer and confining unit Eocene Wind River Formation Major aquifer–sandstone Wind River aquifer
Hanna Formation Aquifer8 Marginal aquifer Hanna aquifer Paleocene 8 Ferris Formation Aquifers and confining units Aquifer Marginal aquifer Ferris aquifer Medicine Bow Formation (not divided or classified in report). Aquifer Minor aquifer Medicine Bow aquifer Lithostratigraphic units composed primarily of Fox Hills Sandstone Not discussed marine shales are regional confining units. Aquifer Major aquifer Fox Hills aquifer Sandstone beds can be aquifers. Unit 6 Confining unit with local discontinuous saturated Confining unit Major aquitard Lewis confining unit Lewis Shale (Fox Hills Sandstone not discussed) sandstone lenses Almond Formation Not discussed Pine Ridge Sandstone Not discussed Secondary aquifer–Mesaverde aquifer Interbedded aquifers and confining units8 Major aquifer Mesaverde aquifer Allen Ridge Formation Rock River Formation Haystack Mountains CRETACEOUS Mesaverde Group Upper Formation Steele Shale Cretaceous Steele Shale Leaky confining unit Confining unit Major aquitard Steele confining unit Niobrara Formation Major aquitard Niobrara confining unit Unit 5 Frontier Formation Secondary aquifer–Frontier aquifer Minor aquifer Frontier aquifer Mowry Shale Major aquitard ? Regional MESOZOIC leaky 5 Mowry-Thermopolis Muddy Sandstone Muddy Sandstone Aquifer Not discussed confining unit aquifer confining unit Lower Thermopolis Shale Major aquitard Cretaceous Cloverly Formation Principal aquifer–Cloverly aquifer Aquifer Minor aquifer Cloverly aquifer
Leaky confining unit with local discontinuous 7 Upper Morrison Formation Unit 4 saturated sandstone lenses Confining unit Minor aquifer Morrison aquifer and confining unit Jurassic JURASSIC Sundance Formation Secondary aquifer–Sundance aquifer Aquifer Marginal aquifer Sundance aquifer Middle Jurassic JURASSIC (?) AND TRIASSIC (?)
Upper Jelm Formation Aquifer3 Not discussed Not discussed Jelm aquifer Triassic TRIASSIC Chugwater Formation of Darton (1908) Lower Chugwater confining unit Triassic 7 Unit 3 Regional leaky confining unit with Redbeds Confining unit Major aquitard groundwater Goose (Forelle Limestone not discussed) Not present in locally permeable sandstone and Not present in Not present in Not present in Aquifer system/ Goose Egg Egg Forelle investigators’ fractured limestone interbeds investigator’s confining unit investigator’s investigator’s Major aquitard Limestone (WWC Engineering, 2006a) Confining unit confining unit Forelle aquifer PERMIAN Formation study area study area study area study area Satanka Shale Confining unit Confining unit7 Confining unit Major aquitard Satanka confining unit
Upper Not discussed Pennsylvanian Unit 2 Casper Formation 2 Principal aquifer–Casper aquifer Casper aquifer Casper aquifer Major aquifer–limestone Casper aquifer (Fountain Formation not discussed) Casper aquifer Confining Middle Fountain PENNSYLVANIAN unit Pennsylvanian Formation Casper aquifer/groundwater system6 Lower Pennsylvanian
Upper Mississippian MISSISSIPPIAN Lower Madison Limestone Confining unit3 Major aquifer–limestone Madison aquifer Mississippian Not discussed or not present in Not present in Not present in Not present in investigator’s study area investigator’s study area investigator’s study area Upper investigators’ study area Devonian Fremont Canyon Sandstone Not discussed Not discussed Not discussed Fremont Canyon aquifer PALEOZOIC DEVONIAN Lower Devonian SILURIAN1 Middle Silurian Upper Ordovician Not discussed or not present in investigators’ study area ORDOVICIAN1 Middle Ordovician Lower Casper aquifer6 Ordovician Upper Cambrian CAMBRIAN1 Lower Cambrian PRECAMBRIAN Precambrian rocks Unit 1 Confining unit Confining unit with locally permeable zones3 Confining unit Precambrian crystalline aquifer or Precambrian aquifer Major aquitard Precambrian basal confining unit with locally permeable zones
1Rocks of Pliocene, Silurian, Ordovician, and Cambrian age not present in Hanna and Laramie Basins. 2Casper Formation (aquifer) divided into five informally named subaquifers in Lundy (1978): alpha, beta, gamma, delta, and epsilon, in ascending order. This nomenclature is retained/used by most subsequent studies of the Casper aquifer in the Laramie area, including many of the investigators listed at the top of this column. 3Hydrogeologic role/unit inferred from description provided in “Hydrologic Properties” column (Richter, 1981a, Table IV-2). 4Each lithostratigraphic unit in”Tertiary aquifer” category is inferred to be an individual aquifer on the basis of description provided in “Hydrologic Properties” column (Richter, 1981a, Table IV-2). 5Muddy Sandstone inferred to be an aquifer within “Leaky confining unit” classification on the basis of description provided in “Hydrologic Properties” column (Richter, 1981a, Table IV-2). 6Casper aquifer composed of Casper and Fountain Formations and underlying Precambrian rocks (where locally permeable) in Mazor (1990). In contrast to Mazor (1990), Mazor et al. (1993, Figure 8, p. 198) classified the Precambrian rocks and overlying Fountain Formation as a “basal confining unit.” 7Although classified primarily as a confining unit, local sandstone beds may yield mineralized water and be classified as local aquifers (Younus, 1992, Figure 11, p. 25). 8Hydrogeologic classification inferred from description in report (HydroGeo, Inc., 2003, p. 2–4).
Plate U. Relation of lithostratigraphic units to hydrogeologic units, Hanna and Laramie Basins.