Applied mineral exploration methods, hydrothermal fluids, baro-acoustic decrepitation, CO2 rich fluids #
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Exploration of the Mt. Boppy Au deposit, NSW

Forensic tests on soil samples

Gold at Okote, Ethiopia

Viewpoints:

Do IOCG deposits form from CO2 fluids?

How CO2 inclusions form from aqueous fluids (UPDATED)

Understanding heterogeneous fluids : why gold is not transported in CO2-only fluids

Gold-quartz deposits form from aqueous - CO2 fluids: NOT from CO2-only fluids


Discussions why H2 analysis by mass spectrometry is wrong



News:

Kalgoorlie Au data

Sangan skarn Fe deposits, Iran

New models 205 & 216 decreptiometer

Studies of 6 Pegmatite deposits

A study of the Gejiu tin mine, China


Exploration using palaeo-hydrothermal fluids

Using opaque minerals to understand ore fluids


Understanding baro-acoustic decrepitation.

An introduction to fluid inclusions and mineral exploration applications.



 Interesting Conferences:

-----2021-----

ECROFI 2021, Reykjavik, Iceland

SGA, Rotorua NZ, RESCHEDULED to march 28-31 2022
-----2022-----
6th Archean, Perth, W.Aust. RESCHEDULED unknown date 2022


Comprehensive Geology Conference Calendar


A bicycle tour loop around Kakadu park, NT., August 2020

725 Km in 6 days

With all the travel restrictions caused by the Covid19 virus pandemic in 2020, it was appropriate to avoid international or even interstate travel within Australia. However I still felt the need to go cycle touring. Many touring cyclists who have stayed with me here in Darwin wish to travel to Kakadu park and ask me about cycling there. Despite having worked there years ago, and living just 220Km from the town of Jabiru in the park, I have never attempted to cycle there - until now! I have always relied on frequent townships for food, drinks and commercial accommodation on my bicycle tours but such infrastructure is not present in Kakadu park where there is little support and even less drinking water! There is water in many billabongs, but these are occupied by hungry crocodiles so swimming, bathing at the edge or even camping nearby is seriously dangerous. (A few years ago a German tourist was eaten while swimming in a supposedly safe billabong to cool off. If you are hot, and you will be even in the cool season, avoid swimming and find an air-conditioned bungalow!)

To survive a tour of Kakadu park, I would need to go camping and carry water so I had to use my gravel bike with fat tyres and lots of luggage. My plan was to attempt to reach Jabiru in one day, a distance of 220Km, and then continue on the Kakadu Highway to Pine Creek. I did not wish to ride back north on the main Stuart highway on which there are many triple trailer road trains, but could use the "northern goldfields loop" and an old superseded section of the Stuart Highway to travel north to Adelaide River. This would leave only about 60 Km where I would have to ride on the main Stuart Highway. This page is about cycling through the park and not a tourist description or pictures of the park,  which you can find elsewhere.

My route map around Kakadu park

Kakadu bicycle
          tour route map

The first section from my home at Humpty Doo to Jabiru would be 220Km, so I started just before dawn at 6am. I could barely see the road for the first half hour but I was on familiar back-roads at this stage. It was 60 Km to Corroboree roadhouse, the only support point all day, so I stopped briefly for a drink. There was no support available at the Mary river crossing at 90 Km as the Inn was closed due to the pandemic. At 140Km I stopped to rest at a park information centre which had a toilet and picnic tables. I opened my handlebar bag and took out a food bar to eat while i checked for water in the toilet. The water was labeled as "undrinkable" but it was OK. As I returned to the bike I noticed 2 crows eating the food in my handlebar bag and ran to chase them away. One of them carried off an energy bar and as i chased it in vain, the other crow started to eat my banana. Beware of winged thieves! I rode onwards through the unremarkable monotonous scrublands reaching 170 Km where I heard a strange regular tick sound. Was it a loose pedal? But then I had a puncture - the sound must have been something stuck in the tyre but it was gone by the time I stopped and replaced the tube. At about 180Km I reached the South Alligator resort where I hoped to get some water - but the resort was closed and fenced off due to the pandemic. I still had some water, but I was now feeling weary and quite hot and had to rest under a spindly tree for a while. It was about 4pm and I was about 190Km from home but still 30 Km short of Jabiru when a motorist stopped ahead of me and opened the rear door of his vehicle as I approached. It was an invitation for a lift to Jabiru, which I gratefully accepted and we loaded my heavy bike into his car. So I failed to achieve my goal of riding 220Km to Jabiru in one day, but survival felt better than reaching an artificial goal! Barry also invited me to stay at his house for the night, how kind!

After the marathon ride to Jabiru, I deliberately rode only a short 90 Km next day north to Cahill's crossing to see the East Alligator river and back. There I saw some 15 crocodiles waiting for a feed of barramundi on the change of tide. That evening I camped in the caravan/camping park at jabiru and noticed that most caravans had bicycles attached, but no-one except me was cycling. When I queried the caravan tourists, they all admitted they had not used their bikes at all. Are their bikes merely caravan decorations?  I was apparently the only crazy cyclist there! To travel south on the Kakadu highway I needed to plan an overnight stop at the Maguk (Barramundi Gorge) campground which was 110Km from Jabiru. Although there was a walk-in swimming hole at Maguk, there was no drinking water. Unless I chose to drink the "uncertified" water from the swimming hole. I took the short side trip to visit Cooinda where there was a small shop and I had some lunch before continuing. Eventually after 100Km I reached the turnoff to Maguk campground, which is 10Km off the highway. But this 10Km was the first dirt road of my tour and it was really rough, badly corrugated and sometimes too sandy for me to ride so I had to walk some short sections. Walking while pushing my heavy bike through the sand was very difficult. It took almost an hour to travel this 10Km to reach the camping area where I chose a spot to camp. I did have some water, and other campers did help with some water, but I wanted to go to the swimming hole and I had a collapsible water container to collect more water. However the campground is about 2 km distant from the walking track to the swimming hole, followed by a 1Km scramble across and through slippery granite boulders. It was late when I arrived and no-one else was present and I wondered if there really were no crocodiles here? I swam briefly and collected some 5 litres of water and commenced my return to camp. But my cleated cycling shoes were not ideal for clambering across rocks and the sole of one shoe came loose. I tied it up with some string and I hurried to return before dark when the trail markers i was following would become invisible. Returning to camp near dusk, I assembled my small mosquito-net tent and ate a small meal of canned tuna while fighting off the flies. Now i noticed that my power-bank which i needed to recharge my phone battery was missing - it must have fallen off on the corrugated road to the campground and I hoped i might find it next morning. As night approached the flies disappeared and the mosquitoes took their place, so I crawled into my tent at 7pm and stayed there all night. I was quite tired and the long sleep was appropriate.

Next morning I had a small breakfast, packed my tent and bike and departed on the 120Km ride to Pine Creek. I dreaded the 10 Km of bad road to exit the campground, but after 45 minutes I was back on the paved road although I did not find my missing power-bank and I would have to hope my phone battery would last another day. Although I had maps on the phone, you don’t really need maps in Kakadu as there is essentially just one road and very few places of interest to visit. As I traveled south there were some hills, not too serious, but the first I had encountered in the 4 days so far. But even before midday I was starting to fade and drinking a lot of water - hot water, there is nothing cold on a bicycle camping tour in the tropics! At the Mary River crossing I stopped at the roadhouse, currently closed due to the pandemic yet again, but I rested, ate lots of cake and was able to refill my water bottles - with too-warm water! Continuing, the scenery was still monotonous and dry and burnt out by recent fires as I pedaled ever more slowly through undulating terrain. I was tiring - I had not eaten enough food last night or this morning and the energy gels and cake I was eating now were not acting fast enough to keep me fueled! After 100 Km I had to take rest stops under small trees despite the lack of shade. My cycle computer has a temperature sensor and it told me it was 49C. That is in the sunshine of course, but I was definitely feeling the heat which does not usually affect me until it is about 35C in the shade. Two motorists stopped to ask if I was OK and I appreciated their thoughtfulness, but I eventually reached Pine Creek township after 120 Km on a tiring and rather warm day and I checked into the motel. Even after a rest and some food I still felt uncomfortable and while talking at the hotel bar some people suggested I should take a rest day before continuing. We also discussed where I could obtain water and camp on the next section to Adelaide River which was some 170Km away and too far to ride in a single day as much of the road was unpaved.

Next morning I felt much better and decided to continue. The dirt road northwards was in good condition and riding it was much more interesting than the paved highway, with curves and creek crossings and short steep climbs and more interesting scenery along the way. I was enjoying my ride when after 33Km I realised my camping gear had come loose and my mattress had fallen off somewhere. I turned back and found my mattress on the road 3 Km back and tied the luggage more securely. This road passes through some now-deserted settlements established in the late 1800's and at one of these, Grove Hill, there is a hotel, currently closed due to the pandemic yet again, but I was able to refill my water bottles as there was a publically accessible water tap, much appreciated. This was a pleasant 90 Km dirt ride with almost no traffic, just 3 vehicles all day, one of which was a motorcyclist who had noticed my wheel tracks and who gave me some more water. Back on the paved road I crossed the Stuart highway to use Dorat road (the now superseded old highway)  and reached the Cosmo Howley minesite. Here I spoke to the gate attendant to ask for water and one of the staff helped me. It was sunday and he was not busy and offered to drive me about 50 Km north to Adelaide River which avoided the alternative of camping wild that night. I was very grateful - I could have camped, but why not stay in a comfortable hotel room when possible!

Refreshed, next day I rode the Stuart Highway with a detour into Batchelor township. There was not too much traffic and there was often (not always) a narrow shoulder on the road so it was not as dangerous as I had feared, although one road-train did come too close and ran me off the road into the dirt. I was very glad of my rear-view mirror to monitor potentially dangerous traffic. At Acacia hills store I was just 30 Km from home and I was able to use the back roads, which I often ride, to avoid the traffic and the Stuart highway for the rest of the day. After 100Km I arrived home in the early afternoon, pleasantly weary after my "backyard" 6 day tour of Kakadu. The first time I have cycle-toured this region despite having lived here for 40 years!

It is possible to cycle-tour Kakadu park, but it is a challenge with lack of services, lack of water and long monotonous distances between the few points of interest in the park. The Arnhem and Kakadu highways are paved, but the best cycling was on the unpaved back road north from Pine creek through the old gold mining areas. And although many of the triple trailer roadtrains were careful when passing me, two were not - you can never trust them. I encountered helpful motorists and friendly tourists in the campgrounds, but flies, mosquitoes and crocodiles are ever-present. Cold drinks are rarely available and expensive when they are. I carried some 4 litres of water which might have been enough but I always topped-up whenever possible. The 220Km distance from Humpty Doo to Jabiru is almost possible in a single day, but very difficult and could be split into 2 days of 90Km and 130Km by stopping near the Mary River crossing on the Arnhem highway and if you are lucky the inn located there will be operational.

The cool season is June to August. Daytime temperatures are still around 32C but hotter in the sun on the paved road. By october it is very humid and hotter and unpleasant to cycle in this region until april-may.

My loaded bike

loaded
          touring gravel bike