Physical characteristics of alluvium and geochemistry of pebbles and cobbles from the alluvium in drill core above the Rabbit Creek gold deposits, Getchell mining district, Humboldt County, Nevada

1990 ◽  
Author(s):  
Dawn J. Madden-McGuire ◽  
S.M. Smith ◽  
Theodore Botinelly ◽  
M.L. Silberman ◽  
D.E. Detra
Keyword(s):  
Gold Deposits ◽  
Physical Characteristics ◽  
Mining District ◽  
Drill Core ◽  
Humboldt County

Research in exploration geoscience: The AMIRA model

1989 ◽  
Vol 20 (2) ◽  
pp. 5
Author(s):  
J.R. May ◽  
J.D. Bailey ◽  
J. Cucuzza
Keyword(s):  
Case Studies ◽  
Gold Mineralization ◽  
Structural Information ◽  
Rock Magnetism ◽  
Gold Deposits ◽  
Drill Core ◽  
Specific Research ◽  
James Cook ◽  
Research Themes ◽  
Csiro Division

The paper summarises the exploration related R&D that has been managed by AMIRA/APIRA and gives details of the complex, market oriented process used to develop new projects.The process is illustrated by three case studies taken from the more than 70 exploration projects completed.The Gold Deposits of North Queensland Project conducted by James Cook University studied the various styles of gold mineralization. The Rock Magnetism project undertaken at CSIRO Division of Exploration Geoscience allowed both general and specific research themes to be undertaken in parallel with confidential proprietary investigations on sponsors' drill core. The Palaeogeographic Mapping project undertaken at the BMR Division of Continental Geology provided sponsors with palaeogeographic maps including interpretation and structural information of 70 time slices.Some of the benefits of the AMIRA/APIRA approach are discussed as well as some of the difficulties which arise in ensuring companies obtain appropriate benefits from their sponsorship.

Gold distribution in the Val-d'Or Formation and a model for the formation of the Lamaque–Sigma mines, Val-d'Or, Quebec

1991 ◽  
Vol 28 (5) ◽  
pp. 706-720 ◽  
Author(s):  
Mehmet F. Taner ◽  
Pierre Trudel
Keyword(s):  
Gold Mineralization ◽  
Regional Metamorphism ◽  
Analytical Techniques ◽  
Shear Zones ◽  
Gold Deposits ◽  
Mining District ◽  
Volcanic Complex ◽  
Geothermal Systems ◽  
Gold Mines ◽  
Geothermal Activity

Recent lithogeochemical studies by accurate analytical techniques (e.g., instrumental and radiochemical neutron-activation analyses) have been used to explore the possibility of using gold distribution in the research for new gold deposits; these show that anomalous gold distribution occurs in some parts of the Val-d'Or Formation in the Val-d'Or mining district of Quebec. Gold lithogeochemistry in the Val-d'Or Formation has shown that it is possible to distinguish: (i) background values (1.4–3.5 ppb Au); (ii) zones of primarily anomalous gold values around the Lamaque–Sigma mines (median: 15 ppb Au); (iii) enrichment halos around gold orebodies (median: 70 ppb Au); and (iv) secondary gold enrichment in shear zones. We conclude that the Val-d'Or Formation is auriferous, i.e., anomalously rich in gold at least in some of its parts and contains the Lamaque – Sigma gold mines, representing 68% of the total gold production in the district. The Val-d'Or Formation is part of a central volcanic complex within an island-arc system. The centre of this complex is located in the main Lamaque plug, and this environment may be compared to high-temperature active geothermal systems that are commonly responsible for the formation of epithermal gold deposits. Gold mineralization at Sigma and Lamaque is considered to be related to a late hydrothermal phase or a retrograde phase of regional metamorphism. For the formation of the gold deposits, two distinct and successive events are postulated: (i) a gold-rich synvolcanic geothermal activity and (ii) a late remobilisation from the host rocks followed by deposition of gold ore within favourable structures.

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