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MAC
Nevada, USA
Main commodities: Au


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The MAC gold deposit is an area of low grade oxide gold mineralisation located to the north-west of, and less than 300 m from Gold Quarry in Eureka County of Nevada, USA. It is within the Carlin Window of the Carlin Trend andis exploited as part of the Newmont Carlin / Gold Quarry mine.

The mineralisation at MAC was discovered in 1985 during exploration of the Maggie Creek area and by 1993 was in the pre-mining planning stage (Rota, 1991/93). MAC is also 750 m from Tusc, although the two are not connected (Arkell, 1991).

The published reserve is: 5.2 Mt @ 0.55 g/t Au = 2.8 t Au (Proven+Probable Reserve, 31/12/92, Christensen, 1993)

The geology of the Carlin Window is described in detailin the 'Gold Quarry' record, while the regional setting is outlined in the 'Carlin Trend - Geology' and 'Carlin Trend - Mineralisation' records.

Finely disseminated gold is hosted by siliceous sediments of the Vinini Formation (Rota, 1991). Arkell (1991) however, places these sediments within the Rodeo Creek Unit and the underlying sequence of grey to black, laminated, thick bedded, silty limestone and siltstone, with interbeds of massive micritic limestone. This latter unit may be either the James Creek Member of the Rodeo Creek Unit, or the Un-named Formation (equivalent to the Popovich Formation in the Lynn Window).

The hosts in the upper part of the orebody are typically laminated to thin-bedded siltstone and siliceous siltstone with thin argillaceous chert interbeds. The deposit is located approximately 500 m to the south-west of the 45 to 60° north-east dipping Good Hope Fault. All of the strata are intensely folded and fractured (Rota, 1991). This deformation is interpreted to have provided excellent ground preparation for the subsequent mineralisation (Arkell, 1991). Several low angle north-easterly striking faults run through the prospect and have apparently played some role in controlling the distribution of mineralisation.

Gold bearing media have been interpreted to have emanated from the north-easterly set of faults and migrated outwards along sub-parallel fractures and bedding planes (Rota, 1991). This presumably is the pattern of distribution of mineralisation.

The most recent source geological information used to prepare this decription was dated: 1996.    
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd.   Unauthorised copying, reproduction, storage or dissemination prohibited.


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Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge.   It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published.   While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo, its employees and servants:   i). do not warrant, or make any representation regarding the use, or results of the use of the information contained herein as to its correctness, accuracy, currency, or otherwise; and   ii). expressly disclaim all liability or responsibility to any person using the information or conclusions contained herein.

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