A comparison of alteration assemblages associated with Archean gold deposits in Western Australia and Paleozoic gold deposits in the southeast United States: Discussion

1991 ◽  
Vol 28 (11) ◽  
pp. 1883-1884
Author(s):  
Peter W. Stewart
Keyword(s):  
United States ◽  
Western Australia ◽  
Gold Deposits ◽  
Southeast United States

A comparison of alteration assemblages associated with Archean gold deposits in Western Australia and Paleozoic gold deposits in the southeast United States

1990 ◽  
Vol 27 (12) ◽  
pp. 1560-1576 ◽  
Author(s):  
G. Todd Ririe
Keyword(s):  
United States ◽  
Western Australia ◽  
Regional Metamorphism ◽  
Spatial Association ◽  
Gold Deposits ◽  
Striking Similarity ◽  
High Alumina ◽  
Acid Sulfate ◽  
Southeast United States ◽  
Hydrothermal Origin

A comparison of high-alumina mineral assemblages spatially associated with the Haile and Brewer gold deposits in the Paleozoic Carolina slate belt (CSB) of the southeast United States and the Sons of Gwalia and Mount Celia gold deposits in the Archean Norseman–Wiluna greenstone belt (NWGB) in Western Australia suggests a similar hydrothermal origin and subsequent metamorphic and deformational history. A common hydrothermal origin is supported by the striking similarity in whole-rock chemistry, even though there were probably significant variations in original unaltered protoliths. An analysis of rocks from each of the deposits that contain high-alumina minerals demonstrates that the protoliths were leached of alkalis with respect to aluminum and have a ratio of Al2O3/Na2O + CaO + K2O greater than three. Although the rocks contain abundant high-alumina minerals, the aluminum content in these rocks is not unusually high, and it does not appear that there has been any significant transport of aluminum either into or out of the rocks that were altered.The most common high-alumina minerals found in rocks affected by the feldspar destructive alteration event include andalusite, kyanite, pyrophyllite, kaolinite, and sericite. Other minerals present in variable amounts include diaspore, chloritoid, alunite, natroalunite, paragonite, and topaz. It is possible that some of these minerals formed during the early hydrothermal alteration event and were recrystallized during metamorphism. Regardless of when the high-alumina minerals formed, textural relations suggest that the rocks had been hydrothermally altered by the time the metamorphic minerals formed. A comparison of alteration from the deposits studied in the CSB and the NWGB suggests there are many similarities to acid-sulfate alteration associated with geothermal areas, such as Yellowstone Park, Wyoming, and with acid-sulfate gold deposits, such as Goldfield, Nevada. Thus, it is possible that the protolith of the metamorphosed rocks in the CSB and NWGB contained an alteration assemblage that included alunite, pyrophyllite, and kaolinite.A generalized paragenetic sequence determined from petrographic and field observations, beginning with regional metamorphism, follows: (i) formation of andalusite, kyanite, chloritoid, and topaz during prograde metamorphism, depending on whole rock chemistry, (ii) formation of pyrophyllite and quartz-rich pods during silicification of aluminosilicate-bearing rocks, (iii) bedding parallel schistosity and fracturing produced by a deformational event, (iv) fractures filled by quartz, sericite, pyrophyllite, or calcite, (v) folding of early layering in the rocks to form a crenulation cleavage accompanied by introduction of quartz veins at high angles to foliation; and (vi) retrograde metamorphism of andalusite–kyanite-pyrophyllite to produce an assemblage of kaolinite ± diaspore.The spatial association of the acid-sulfate alteration with gold mineralization, together with comparison of analogous alteration associated with younger unmetamorphosed acid-sulfate gold deposits, suggests that at least some of the gold was introduced during the early premetamorphic alteration event. The present location of gold in each deposit is a result of local changes brought about by later metamorphic and deformational events.

Stereo photo series for quantifying natural fuels. Volume XII: Post-hurricane fuels in forests of the Southeast United States.

2009 ◽  
Author(s):  
Robert E. Vihnanek ◽  
Cameron S. Balog ◽  
Clinton S. Wright ◽  
Roger D. Ottmar ◽  
Jeffrey W. Kelly
Keyword(s):  
United States ◽  
Southeast United States

Characterization of non-methane hydrocarbons in the rural southeast United States

1997 ◽  
Vol 31 (23) ◽  
pp. 4017-4038 ◽  
Author(s):  
Lisa M. Hagerman ◽  
Viney P. Aneja ◽  
William A. Lonneman
Keyword(s):  
United States ◽  
Southeast United States

Phenolic compound profile of selected vegetables frequently consumed by African Americans in the southeast United States

2007 ◽  
Vol 103 (4) ◽  
pp. 1395-1402 ◽  
Author(s):  
Zhiliang Huang ◽  
Baowu Wang ◽  
Doris H. Eaves ◽  
James M. Shikany ◽  
Ralphenia D. Pace
Keyword(s):  
United States ◽  
African Americans ◽  
Phenolic Compound ◽  
Southeast United States

scholarly journals Management of Daylily Rust With Different Fungicides and Fungicide Combinations

2017 ◽  
Vol 18 (3) ◽  
pp. 162-165 ◽  
Author(s):  
Robert S. Emmitt ◽  
James W. Buck
Keyword(s):  
United States ◽  
Disease Management ◽  
Disease Severity ◽  
Low Cost ◽  
Single Application ◽  
Southeast United States ◽  
Disease Progress Curve ◽  
Disease Progress ◽  
Progress Curve ◽  
Disease Pressure

Production nurseries and daylily hybridizers in the southeast United States rely on the use of fungicides to manage daylily rust, caused by the fungus Puccinia hemerocallidis. Foliar sprays of pyraclostrobin, flutolanil, tebuconazole, myclobutanil, chlorothalonil, mancozeb, pyraclostrobin + boscalid, flutolanil + tebuconazole, flutolanil + myclobutanil, flutolanil + chlorothalonil, and flutolanil + mancozeb applied on 14-day intervals, and a nontreated control, were evaluated under high disease pressure at three locations in Griffin, GA, in 2015. Tebuconazole or the tebuconazole + flutolanil treatment consistently had the lowest area under the disease progress curve (AUDPC) of the treatments. The addition of flutolanil to chlorothalonil or mancozeb did not improve rust control and no difference in disease severity was observed in any treatment containing contact fungicides on all assessment dates. Single application costs ranged from $10.21 to $95.96 with tebuconazole providing excellent disease management at a relatively low cost per application ($13.90).

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