Golconda

North East Tasmania Geology

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Philski
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Location: Sheffield Tasmania
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Golconda

Postby Philski » Mon May 05, 2014 1:54 pm

North East

I have another go in the North East this week in the Golconda district. It was my 3rd trip into the districts the last 12 months and have covered Panama, Denison and cradle creek areas. This is the only place in the Scottsdale batholith 100km+ pluton area i have tried, The lay of eluvium and sediments to the South looks to be shallow marine environment and was the most productive with shotty gold large enough and shallow enough to be found with a metal/gold detector. Siltstone/Sandstone and underlying alluvium layer. Just like you would find the layers on our northern beaches. A foot or two of sand then cobbles. In the cradle creek area. This rests on soft light green and mottled tan slate. The dip is consistent and approx 20 degree. Gold is found through the wash and clays and is more concentrated in the cobble layers and where there can also be found jet black and quite large and waterworn spinel fragments 13mm was the largest. There is a note about a meteoric glass found further south in Lislie that many be an impactite or ejectite. The spinel i found could be mistaken for a tektite, in its shape and form, Anyway, its a great indicator for gold in that area.

Most important find for me was some highly folded sandstone in the talus that may lead to the main ore body, if one exists still. running on the south side of the ridge about halfway up T creek.

ratters
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Re: Golconda

Postby ratters » Mon May 05, 2014 10:54 pm

Ive prospected around Golconda and Lisle many times now and up tobacco and cradle creeks. For a bit of casual panning its hard going there with so much clay around but I have found a few areas of cleaner wash and the gold up tobacco is generally course but water worn. A very popular spot and Ive come across other folks or their diggings a few times now. The bottom half of cradle and tobacco are under lease/tenement last time I checked but the top end of tobacco is not, and thats where Charles Bessel won most of his gold according to the historical records. Your right about the Spinel, I have personally found plenty but mostly in Lisle. Still waiting for a big bit though, seen a few around 10mm.

Lisle is another story altogether, I love poking around there, so many areas to explore. Every time I go out there I surprise myself with what I find.

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Philski
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Re: Golconda

Postby Philski » Thu May 08, 2014 12:46 am

Hi Ratters, so many places so little time,, There is a vast amount of gold bearing ground opened up under ERA right now in the NE and so much of the North East is only pegged where the road goes and not where the gold is! crazy stuff. Ive never seen it so open. Pipers river is 100% free from gold temements, as an example. ! Warrintinna south has gold and its open for a small scale prospector. All the way to Waterhouse. unpegged or open to us.. The ground you need to be on i think, is adjacent to the granite outcrops. 3-4km out, its zonal all the way to the North coast. almost, The Mathinna beds are the go. The mottled slate was cooked by the Later Devonian granite and the slate contains gold, (sometimes rich) garnet and a few other minerals and gemstones. The sedimentary rocks are Silurian and Ordovician in age and the granite is underlain with granitodite? at approx 9km depth. with later basalt. As Tasmania hit this shallow area from the west the thin Pacific plate rammed into our plate and started to drop below us these sediments got tilted up, folded, cracked and intruded. The impact zone is our continental shelf. What i find interesting is just about every single gold mine in the Scottsdale batholith follows this zone, from the below era area to Fingal in the mathinna bed and a few km away from the granite. If you see granite, move away from it. basalt ditto.
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i removed exploration tenements but there are very few in gold country. They pegged the highway instead :) Anything in Yellow is open ground for us and the pink squares are mines.

im happy to come home with a bag of tin as much as gold in that area.

Lisle - denison area is under exploration tenement and some mines.

Also opened up under ERA. right behind Beconsfield! The same Mathinna beds exist in Beaconsfield. Im not sure how far west they go but will try and find out.

The ERA (exploration release area) is a 60 day window for small scale prospectors. i work 4 on 3 off so any Monday Tuesday Wednesday im good to go if you want a day or three prospecting

have a great night
Phillip

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