John's New England Minerals and General Geology Blog: January 2014

Friday 31 January 2014

FRENCHIES SWAMP CREEK NEAR GLEN INNES NSW AUSTRALIA

FRENCHIES SWAMP CREEK

NEAR GLEN INNES NSW AUSTRALIA

The Yarrow Creek junction 2013

Frenchies Swamp Creek is one of only two tributaries of Yarrow Creek over the entire length of the two properties we have regularly fossicked. The other one is a mere trickle and hardly noticeable. Just who Frenchie was I have no idea, but the swamp bearing his name covers a swathe of country between Yarrow Creek and the Mt Slow road near the Henry River bridge.

You might think that swamps are unlikely places to find gemstones, but it has been the swampiest ground at Pretty Valley that has been the most productive, so it doesn’t pay to jump to conclusions. In the case of Frenchies Swamp, the creek flows through some rocky areas along its course and gemstones have been found in all these places. I have followed the main creek up to the limit of the last swamp (about 4km from Yarrow Creek)

3 carat zircon

and gemstones are to be found in the gullies running into the swamp there. There are more small tributaries running into the swamp around its margin but I never had the opportunity to check these out.

The junction with Yarrow Creek is not obvious except when water levels are high. It can be followed up to the first swamp (about 400m) through rocky ground with quite a bit of typical quartz gravel in places. How this got there through kilometres of swamp is one of those little mysteries. The junction is at “Sue’s Favourite Spot”, just below the "Glory Hole" section.

The gemstones are identical to those in Yarrow, with perhaps a lower

Corundum fragment 1998

garnet percentage. The fact that there is any garnet at all is significant, because it implies that the source of the mineral must be in the catchments of both creeks. There is another possibility, that the swampy ground represents a former course of the Yarrow and that there are in fact large gemstone deposits present under the swampy areas.

It’s been quite a while since I checked out anything but the lowest part of the creek. In fact, it’s been 12 years since I went much further than that. Access is complicated by the fact that we never had a 4 wheel drive vehicle and relied on others on the few times we went there. Walking from The Crossing is the best bet, allowing 20 minutes to the point where the track crosses the creek.

I’m looking forward to hearing of good finds there one day. The landowner certainly believes that Frenchies Swamp Creek has more potential than Yarrow Creek. I hope he proves to be correct.

Check out the videos and blogs of Sue's Favourite Spot and the Glory Hole for more information and ideas.

Photographs are unfortunately rather few. Sorry about that. The only one of a day's best finds was done on a scanner. Be assured that there were many good finds made over the years.

https://johnsbluemountainsblog.blogspot.com/2013/12/links-to-all-blog-entries-and-relevant.html All Blue Mountains blogs and videos

https://johnsnewenglandminerals.blogspot.com/2013/12/list-of-all-blog-entries-to-date.html

All New England and other Geology blogs and videos

https://www.blogger.com/blog/posts/1325599670344725659?pli=1

Limestone Caves of NSW

https://www.blogger.com/blog/post/edit/1147003616874115974/2430103125095714141

Song Studies. Bible studies based on hymns and songs

https://www.blogger.com/blog/posts/1515863000684737715

Shoalhaven District Geology.

Best finds from an outing in 2006

Monday 6 January 2014

“DOWN THE HILL” YARROW CREEK, NEAR GLEN INNES NSW AUSTRALIA

LIST OF ALL BLOG ENTRIES TO DATE

10.2 and 4.9 carat sapphires

Thanks to Google Earth. "Down the Hill" is in the centre

Many visitors to Glen Innes have enjoyed a day’s fossicking at “Down the Hill”, both on our Wednesday Baptist Church trips and during Minerama. I’ve written about the place in two previous blog entries (Quartz at Down the Hill and The Big Sapphire). Several videos have also covered the area (one, two and three). Click on the links to go there.

“Down the Hill” lies downstream of “Through the Fence” and upstream of “Underground River”.

Down the Hill is an area with many rocky outcrops and, most notably, an abandoned channel through which the creek only flows in flood. At one time this was the most productive area, but the old diggings have mostly filled with sand and no-one seems too keen to spend the day removing it when they could search among the rocks. At the lower end of the channel the wash was at least two metres below the overlying sand. The last we saw of it, there was lots of black jack and

Cliff O'Brien digging in the old channel 1998

presumably gems, but we were beaten by inflowing water and finally by a flood which filled up the hole with sand. Maybe one day, during a drought, fossickers will get another chance to experience the thrill of working this spot.

At some time, probably in the 1960’s, a small mining operation operated at Down the Hill. There was the remains of a shed or hut when I first visited the place in 1988 but hardly any sign of actual mining. This was on the flat immediately below where we parked. The only other sign of previous visitation was a Tamworth 1 pint milk bottle I found in the creek just below old hut site.

4.3 carat sapphire, 11.6 carat zircon (July 2008)

One day's small finds - December 2009

The gemstones are the usual ones for Yarrow Creek – sapphire, zircon, pyrope garnet, the occasional topaz and enstatite and, of course, quartz. My one and only cuttable ruby came from here, as well as my largest sapphire, best dog’s tooth crystal and biggest quartz