Stream Depletion Analysis Denver-Julesburg Basin Northeast Colorado
R.A. Engberg and A.D. Druliner Nebraska Ground-Water Quality
| Era | System | Rock Stratigraphic Units |
Hydrostratigraphic Units[1] |
Interior Seaway Cycle |
| Cenozoic | Quaternary | Unconsolidated Sediments (Loess, Dunes, Terraces) |
Alluvial Valley aquifers and High Plains Aquifer System |
Post-seaway |
| Quaternary | Quaternary Sand & Gravel Ogallala sands Arikaree Group Brule Formation | |||
| Mesozoic | Upper Cretaceous | Colorado Group | Upper Cretaceous aquitard | Greenhorn Cycle, etc. |
| Dakota Sandstone, etc. | Upper Dakota aquifer | Muddy-Mowry Cycle | ||
| Lower Cretaceous | Skull Creek/Kiowa Shale | Skull Creek-Kiowa aquitard | Skull Creek Cycle | |
| Plainview/Cheyenne Sandstone | Lower Dakota aquifer | |||
| Jurassic/Triassic | Morrison Formation Dockum Group |
Morrison-Dockum aquifer | Pre-seaway | |
| Paleozoic | Permian/ Pennsylvanian |
Permian Undifferentiated | Permian- Pennsylvanian aquitard |
|
| Cedar Hills Sandstone | Cedar Hills aquifer | |||
| Permian-Pennsylvanian Undifferentiated |
Permian- Pennsylvanian aquitard |
The Dakota Aquifer comprises those sandstone beds of the Dakota Formation/Group, and other closely associated Cretaceous sandstone units, from which water may be obtained in useful quantities.
As aquifers go in the region, the Dakota particularly noted for being hardness, salty, or sulfurous. Overall, Dakota water is of greatly ranging quality, from relatively fresh to so hard or salty as to be unusable. The Dakota Aquifer has particular qualities:
- Aside from the limited areas where water can be drawn from the Niobrara, aquifers in the overlying shale and chalk are trivial to non-existent, particularly in the deep shales of the Greenhorn, Carlie, and Pierre. Aquifers of Permian rocks below the Dakota and exposed to the east are limited to particular limestone beds, that is, "carbonate aquifers". So, early on, the location of the Dakota was of keen interest to agricultural development in the Great Plains, particularly on the eastern and southern extents of the Dakota, beyond the range of the High Plains Ogallala Aquifer.
- Dakota water is of greatly ranging quality, from fresh to so hard or salty as to be unusable.
sinuosity
With depletion of large parts of the Ogallala Aquifer interest has developed in increased use of the Dakota water.
Modern use of the Dakota Aquifer began in the latter 1800s as wells were first drilled into the sandstones for municipal and irrigation supplies. Railroads had particular interests in, and capital for development, of clean water to supply their locomotives.
The Dakota deposits were fresh water, but these deposits were made directly over marine shales and limestone with ample gypsum and salinity, in places, especially Central Kansas and extending into Nebraska and Oklahoma, having massive anhydrate and salt formations, mined in various locations.
The thick overlaying marine shales are are particularly chalky with several soucres of iron and sulfur ( pyrite, selenite)
Auquifer Charging Rian water percolating down through chalky rocks, sands ans soils naturaly hardend. the Dakota and Benton ans Nionrara were weathers back back from Eastern Kansas such that eastern extents of the Ogallala overlaid exposed Dakota, placing the two aquifers in vertical contact.
Considered as an alternative to the Overstreet Ogallala Aquifer.
Has Outcrop
intermontane basins west of the Continental DivideWhether called Benton, Greenhorn, or MancosHaving worked through ... I realize there is sufficient notability and regional variability in the Dakota Aquifer(s, et al.,) to warrant a separate article,The Dakota is is everywhere noted as artesianQuality ranges from relatively fresh to either so hard or salty as to be unusableStructure
The eastern outcrop of the Dakota in Kansas and Nebraska and Oklahoma noted for salty or mineral springs, salty rivers, and salt marshes. Zebulon Pike noted the saltiness of the Solomons and the Saline River, commenting on the occasion cooking meals from the waters and not needing to add salt rations in the preparation.
in general, Dakota water has higher mineral content , in cases qualifies as mineral water, at points unpalatable to more sensitive livestock and even to humans. As is commonly noted, the Dakota sandstones are broadly grouped into upper and lower sandstone beds internally In wide areas of the Great Plains and Southwest, the Dakota Sandstessential, if not exclusive, source of ground waterFrom the first wells drilled through overlying shales into the Dakota, the Dakota was noted as an artesian aquifers; Dakota wells naturally filled with water far above the formation, in many places quite capable of delivering water to the surface without pumping.separated by mud and shale. The lower sands (lower Dakota aquifer) tend to be massive beds of beach sands, widely deposited with wide lateral hydraulic distribution and flow. The upper sandstones (upper Dakota aquifer) are typically long and slender beds deposited by meandering rivers with little communication with the lower Dakota aquifer.
with increasing depth, hardness decreases and salinity increases Dakota Aquifer Program--Water Quality "Vertical Changes in Water Quality""Where saline waters exist in the Dakota aquifer or in underlying strata, salinity in the Dakota aquifer generally increases with depth."
Structure
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