|
Goodall |
|
|
Northern Territory, NT, Australia |
| Main commodities:
Au
|
|
 |
|
|
 |
Super Porphyry Cu and Au
|
IOCG Deposits - 70 papers
|
All papers now Open Access.
Available as Full Text for direct download or on request. |
|
|
The Goodall gold deposit is located about 30 km east of Adelaide River township in the Northern Territory, Australia (#Location: 13° 12' 42"S, 131° 22' 23"E).
The deposit had a pre-mining resource of 4.25 Mt @ 2.35 g/t Au. It was mined between 1988 and 1993, producing 7.1 t of gold from 4.095 Mt @ 1.99 g/t Au (Quick 1994).
The deposit lies within the the Burrell Creek Formation of the Palaeoproterozoic Pine Creek Orogen. The Pine Creek Orogen covers an area of ~47 500 km2 and comprises a thick (>4 km) succession of Palaeoproterozoic 2200 to 1870 Ma supracrustal carbonate and carbonaceous sedimentary and volcanic rocks, unconformably overlying Neoarchaean ~2670 to 2500 Ma granitic and gneissic basement. This succession was subjected to regional metamorphism and deformation of varying grades and intensities in different parts of the orogen in the period ~1867 to 1850 Ma, and syn to post-tectonic granite emplacement at ~1830 to 1800 Ma (Ahmad and Hollis, 2013).
Structurally the deposit is located in the northern extension of the major Howley Anticline, which has a complex internal structure. The auriferous quartz veins are hosted by the Burrell Creek Formation and controlled by an upright anticline striking 320° and plunging 30 to 35° to the northwest.
In the main open pit, the host rock is a greywacke dominated succession, with common small zones of shale-dominated units, including a prominent 30 to 35 m thick shale band that can be traced across the open pit.
Hydrothermal alteration associated with the mineralised zone includes sericite, carbonate, K feldspar, tourmaline and apatite. Six strongly altered 060° striking, SE dipping pre-mineralised lamprophyre dykes cut across the fold axis.
The gold mineralisation occurs within a north-trending zone zone of quartz stockwork, consisting of sub-parallel thin veins. The mineralised zone is 750 m long, up to 50 m wide and at least 400 m deep, with grades diminishing with depth. It is sub-parallel to the fold and is centred about 60 m east of the anticlinal axis.
Quartz veins within the mineralised zone are thin (centimetre to millimetre scale), and are both discordant and concordant. Gold mainly occurs in pyrite and arsenopyrite as 5 to 10 µm blebs. Minor gold also occurs in quartz and chlorite. Other sulphide minerals include sphalerite, galena, chalcopyrite and pyrrhotite, as well as minor tetrahedrite, tennantite, bismuthinite, native bismuth and gersdorffite. In the oxide zone, minerals include digenite, chalcocite, covellite, bornite, scorodite and wittichenite. Gangue minerals are quartz, chlorite, sericite, carbonates, K-feldspar, tourmaline and apatite.
Geochronology of monazite associated with the gold veins has yielded a mean SHRIMP 207Pb-206Pb age of 1751±15 Ma, is considered to be the age of gold mineralisation (Sener et al., 2003; Sener, 2004). This age is younger than the El Sherana/Edith River/Katherine River groups that overlie the Burrell Creek Formation. It is also about 100 Ma younger than granites intruding the Pine Creek Orogen, and as such is ambiguous, possibly affected by later alteration processes.
This summary is paraphrased from: "Ahmad M and Hollis JA, 2013. Chapter 5: Pine Creek Orogen: in Ahmad M and Munson TJ (compilers). Geology and mineral resources of the Northern Territory. Northern Territory Geological Survey, Special Publication 5."
The most recent source geological information used to prepare this decription was dated: 2013.
Record last updated: 3/12/2015
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.
Goodall
|
|
|
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.
|
Top | Search Again | PGC Home | Terms & Conditions
|
|
