Hydrology of the Western Arkoma basin and Ozark platform during the Ouachita orogeny: implications for Mississippi Valley‐type ore formation in the Tri‐State Zn–Pb district

Abstract

Numerical groundwater modeling was used to investigate the role of fluid flow associated with uplift of the Arkoma basin during the closing stages of the Ouachita orogeny in forming the Mississippi Valley-type Zn-Pb ores of the Tri-State district. The model hydrostratigraphy was flexurally compensated to account for the restoration of Pennsylvanian-Permian sediments removed since the close of the orogeny in estimating the regional paleotopographic gradient. Estimates of the amount of Pennsylvanian-Permian sediment that has been removed by erosion vary widely. A thick and a thin endmember case were considered, and in both cases topographydriven fluid flow was shown to have been an important mechanism for groundwater motion, with a lesser component contributed during the early stages of uplift by overpressuring created by compaction in the deep portion of the Arkoma basin. The Pennsylvanian-Permian sediments and underlying Western Interior Plains confining system acted as thick capping aquitards that caused slow rates of groundwater flow over much of the profile. As a result, meteoric water infiltration initiated during uplift was slow to flush saline formation waters, allowing MVT ore-forming salinities to persist at Tri-State on the order of at least 10 0 Myr. The slow groundwater flow rates also caused heat transport to occur primarily by conduction rather than advection. Despite this, MVT ore-forming temperatures were still reached at Tri-State for both endmember cases of Pennsylvanian-Permian aquitard thickness, though much more readily in the thick aquitard case. Faults within the Tri-State district served as a regional fluid focusing mechanism and probably played a more important role in localizing mineralization than the window in the Ozark confining unit that occurs in the district. Fluids rising along these faults could have cooled by about 8-10°C and as much as another 0.3°C km )1 as they flowed laterally northward. This temperature change alone however would not have been sufficient to precipitate the total mass of metal sulfide ore occurring at Tri-State.

What controls porosity in cherty fine-grained carbonate reservoir rocks? Impact of stratigraphy, unconformities, structural setting and hydrothermal fluid flow: Mississippian, SE Kansas

“…As is observed in many basins (e.g. Dickey 1969;Appold & Nunn 2005), salinity of aqueous fluids tends to increase with depth. Structural deformation in the shallow section could form migration pathways allowing the lower temperature, lower salinity fluids to migrate northwards (Fig.…”

A reconnaissance for signs of a Mississippi Valley-type lead-zinc mineralizing system on the eastern flank of the Rutbah Uplift, Anbar Province, Iraq

“…Several pathways that may result in interaquifer groundwater mixing zones in a stack of regionally confined carbonate and sandstone aquifers and their confining beds are shown in figure 2. The briny groundwaters that mixed to yield MVT deposits are believed to be derived from fluids recharged in collision-belt mountains before traveling down to great depths through the adjacent foreland basins, where they became hot, saline, and metals-loaded before moving toward discharge zones updip on adjacent cratonal margins (Bethke, 1986;Leach and Rowan, 1986;Appold and Nunn, 2005). That flow system explains why foreland swells are ideal locations for MVT mineralization: foreland swells are structurally high, and mineralizing fluids move upward owing to the artesian heads.…”

Dolomite Fronts and Associated Zinc-Lead Mineralization, Usa

“…These are the TriState zinc-lead district in Oklahoma, Missouri, and Kansas (e.g., Appold and Nunn, 2005), the southern Illinois-Western Kentucky fluorite-zinc district (e.g., Trace and Amos, 1984;Yancey, 1995), and the central Kentucky fluorite-barite-zinc district (e.g., Anderson et al, 1982;Kesler et al, 1996). Most of this mineralization is in Mississippian or Middle Ordovician limestone and appears principally as vein occurrences or in beddingcontrolled structures related to tensional fault systems.…”