gîte de type Mississippi-Valley

CONT: Dans les environnements miogéosynclinaux cratoniques, généralement sur plateforme marine et à volcanisme absent ou discret et à dominante carbonatée se situent : des gisements stratiformes de plomb-zinc du type Mississippi Valley, en Australie du Nord [...] Ils deviennent surtout abondants entre le Paléozoïque inférieur et le Mio-pliocène.
OBS: Les gîtes doivent leur nom couramment accepté au fait que plusieurs districts classiques renfermant de telles minéralisations existent dans le bassin hydrographique du fleuve Mississippi, dans la région centrale des États-unis.

CONT: Mississippi Valley-Type (MVT) Lead-Zinc. ... Prior to the opening of the Pine Point mine in 1965, deposits of this type contributed only negligibly to Canadian lead-zinc production. Since that time, however, about 30% of annual production has been derived from Mississippi Valley-type deposits.
OBS: The deposits owe their commonly accepted name to the fact that several classical districts occur within the drainage basin of the Mississippi River, central U.S.A.
OBS: Sangster (1976) has divided carbonate-hosted base metal deposits into two major types: (1) Mississippi Valley, and (2) Alpine. Other workers do not make this distinction and refer to all low temperature carbonate-hosted deposits as being of Mississippi Valley-type. Sangster contends that the first type, which are strata-bound, were emplaced after lithification of the host rocks and were largely controlled by pre-ore structures, whilst he considers the Alpine-type to be stratiform and syndsedimentary. ... However, because this distinction is made by some workers on a global basis, the author has avoided using the term Mississippi Valley-type for all carbonate-hosted base metal deposits.