Mineralogy and paragenesis of potassic alteration associated with late copper and iron mineralization at the Sweetwater and Viburnum 29 mines in the Viburnum Trend, southeast Missouri

Conference · Mon Mar 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:7069718

Rasberry, M A; Hagni, R D ^[1]; Walker, W T ^[2]; Childers, A G ^[3]

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1. Univ. of Missouri, Rolla, MO (United States). Dept. of Geology and Geophysics
2. ASARCO, Bunker, MO (United States). Missouri Mines Div.
3. Doe Run Co., Viburnum, MO (United States)

The mineralogy of local occurrences of fine-grained material, commonly called clay pods at the Sweetwater and Viburnum 29 mines in the viburnum Trend, has been investigated by petrographic, reflected light microscopic, XRD, SEM-EDS, and cathodoluminescence (CL) microscopic (CLM) techniques. Although the pods contain clay-size grains, only a small amount of illite is present. They are comprised principally of fine-grained sericite and adularia in an average of ratio of about 3:1. Sericite plates are 1--10 um in size, partially altered to illite, and locally observed by RLM and SEM to have formed prior to and be included within adularia. Adularia occurs as euhedral rhomb-shaped crystals, about 5 to 25 um across. CLM study has shown that about 60% of the adularia crystals, which are non-CL, contain cores of rounded, blue CL, detrital feldspar that was present as an insoluble residue from dissolution of the host Bonneterre Formation and that acted as a catalyst for adularia overgrowth deposition. This study has defined the paragenetic position of the potassic alteration to a narrow time period. It formed relatively late, during or after east-west faulting that is essentially perpendicular to the dominant trends of the orebodies, and during dissolution of earlier deposited octahedral galena. It formed prior to cubic galena, hydrothermal quartz, late chalcopyrite, late marcasite, and calcite, because sericite and/or adularia were observed to be included in those minerals. It coincides with a major period of sulfide dissolution.

• OSTI ID: 7069718
• Report Number(s): CONF-9303210--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:3
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
152002 -- Geothermal Data & Theory-- Properties of Minerals & Rocks
58 GEOSCIENCES
580000* -- Geosciences
CATHODOLUMINESCENCE
CLAYS
COHERENT SCATTERING
DEVELOPED COUNTRIES
DIFFRACTION
ELECTRON MICROSCOPY
GEOLOGIC DEPOSITS
LUMINESCENCE
MICROSCOPY
MINERALOGY
MISSOURI
NORTH AMERICA
PARAGENESIS
SCANNING ELECTRON MICROSCOPY
SCATTERING
STRUCTURAL CHEMICAL ANALYSIS
USA
X-RAY DIFFRACTION