See Article History Mississippi River, the longest river of North Americadraining with its major tributaries an area of approximately 1.
Mississippi Valley type The central plains of North Americarunning from the Appalachian Mountains on the east to the Rocky Mountains on the west, are underlain by nearly flat sedimentary rocks that were laid down on a now-covered basement of igneous and metamorphic rocks.
The cover of sedimentary rocks, which have been little changed since they were deposited, contains numerous strata of limestoneand within the limestones near the bottom of the pile is found a distinctive class of mineral deposit. Because the central plains coincide closely with the drainage basin of the Mississippi Riverthis class of deposit has come to be called the Mississippi Valley type MVT.
MVT deposits are always in limestones and are generally located near the edges of sedimentary basins or around the edges of what were islands or high points in the seafloor when the limestone was deposited. The hydrothermal solutions that introduced the ore minerals principally the lead mineral galena and the zinc mineral sphalerite apparently flowed through the sandstones and conglomerates that commonly underlie the limestones.
Where they met a barrier to flow, such as a basement high or a basin edge, the solutions moved and reacted with the limestone, depositing ore minerals. The relationship between Mississippi Valley-type deposits, the edges of sedimentary basins, and the flow of hydrothermal solutions.
Stratiform deposits A final class of hydrothermal deposit is called stratiform because the ore minerals are always confined within specific strata and are distributed in a manner that resembles particles in a sedimentary rock. Because stratiform deposits so closely resemble sedimentary rocks, controversy surrounds their origin.
In certain cases, such as the White Pine copper deposits of Michigan, the historic Kupferschiefer deposits of Germany and Poland, and the important copper deposits of Zambiaresearch has demonstrated that the origin is similar to that of MVT deposits—that is, a hydrothermal solution moves through a porous aquifer at the base of a pile of sedimentary strata and, at certain places, deposits ore minerals in the overlying shales.
The major difference between stratiform deposits and MVT deposits is that, in the case of stratiform deposits, the host rocks are generally shales fine-grained, clastic sedimentary rocks containing significant amounts of organic matter and fine-grained pyrite.
Three examples are in Australia: Another example is the famous Canadian lead-zinc deposit at Sullivan, British Columbia. At Broken Hill, metamorphism has almost completely obscured the original geologic environmentbut in the other three cases evidence suggests that hydrothermal fluids moved upward along a fault from deeper within a sedimentary basin, then reacted with a shale while it was still a mud on the seafloor.
Details of the actual processes involved remain controversial. Groundwater Groundwater is that part of subsurface water that is below the water table—that is, water in the zone of saturation. For the purpose of the present discussion, the difference between groundwater and hydrothermal solutions is that groundwater retains many of its original chemical characteristics and remains within one kilometre or less of the surface.
Such waters form two important classes of deposit.CLICK HERE for a PDF version of the conference brochure.. The conference will be held at Stoney Creek Hotel & Conference Center, Moline, Illinois.
Select the REGISTRATION tab above for registration fees and hotel reservation information. Visitors Guide to the Middle Mississippi River Valley T he Great River Road is one of America’s national treasures.
plombier-nemours.com's coverage extends from the Keokuk, Iowa and Nauvoo, Illinois region to the areas in Missouri, past Southern Illinois where the Ohio River joins the Mississippi River, and through the Upper Delta region of Kentucky, Arkansas and Tennessee.
plombier-nemours.com The term Middle Mississippian is also used to describe the core of the classic Mississippian culture area. This area covers the central Mississippi River Valley, the lower Ohio River Valley, and most of the Mid-South area, including western and central Kentucky, western Tennessee, and northern Alabama and .
Mississippi River, the longest river of North America, draining with its major tributaries an area of approximately million square miles ( million square km), or about one-eighth of the entire continent. The Mississippi River lies entirely within the United States.
Rising in Lake Itasca in. The central Mississippi River valley has experienced numerous changes during the late Quaternary (Schumm and Brakenridge, , Autin et al., , Saucier, , Rittenour et al., ).A particularly interesting period in this history is preserved in the Quaternary sediments of the Western and Eastern Lowlands between 35° and 37° N latitude near Memphis, TN ().
The Central Mississippi Valley, defined as the region along the Mississippi River from where the Ohio River joins in the north to its confluence with the Arkansas River in the south, lies between the two most important archaeological areas of the Southeast: American Bottom/Cahokia and the Lower Yazoo Basin.