Paul Morris: Making the leap from hard rock to regolith geochemistry

Paul Morris, retired Chief Geochemist for GSWA, talks about his early days working for the survey when he made the leap from hard rock geochemistry to studying regolith – the unconsolidated surface material covering more than 80% of Western Australia .

Transcript

00:01 Paul

I found myself sort of kneeling in a creek looking at sand at all these weathered rocks in the bank and I thought to myself, ‘What the hell have I done?’

00:08 Julie

Welcome to The Rocks Beneath Our Feet. In this series, five geologists talk about their years devoted to working for the Geological Survey of Western Australia. From understanding early life, to the tectonic processes that shaped our planet, and making the maps that unearth our understanding of Western Australia’s geology, they reveal their shared passion for discovering the stories in the rocks beneath our feet.

I’m Julie Hollis.

In this episode Paul Morris, retired Chief Geochemist for GSWA, talks about his early days working for the survey when he made the leap from hard rock geochemistry to studying regolith – the unconsolidated surface material covering more than 80% of Western Australia.

If you just want to introduce yourself?

00:52 Paul

Okay. I'm Paul Morris. And three years ago, I retired from the Geological Survey of Western Australia. For the last 30 years of my geological career, I worked at the survey. And for the last 22 of those, I was the Chief Geochemist, looking after regolith geochemistry, and to some extent regolith mapping. So I want to talk a little bit about this, about the regolith geochemistry because for me, it was a bit of an adventure. To sort of put it in context, I'll just talk briefly about what I did before I joined the survey and the first few years at the survey.

01:30 Julie

Yep.

01:31 Paul

I was educated in New Zealand, and I worked on intraplate volcanic rocks in south of New Zealand, and to the east of New Zealand, at university. And then I went to the University of Sydney. And I worked on similar sorts of rocks in eastern Australia. And then I got a job at the geological survey. I had a brief stint in Japan in 1985, working on some young volcanic rocks there, but I joined the survey in 1988. And they very kindly gave me a job working on volcanic rocks again, but these ones were much older. They were Archean ones, so around Kalgoorlie, and Kambalda, where there was some mapping going on at the time there.

And then out of the blue in 1993, I had a fax message from the university I was at a Japan offered me a staff position there for two years. So very quickly, we managed to arrange two years leave without pay. And my wife and my then two year old daughter and I went to Japan for two years. And we had a great time there and I continued work on some pretty young volcanic rocks. They're some of them are so young, they're almost warm.

We got back in September 1995. So I was a, what is a, if you like, a confirmed hardrock geologist. And when I got back in September, my then boss Peter Dunn sat me down. And I think it was the second day I got back to the survey. And he said, “Well”, he said, “You've got a choice. If you want to work in geochemistry, you have to join the regolith program. Or if you don't want to work in geochemistry, you have to become a regional mapper.” So I had to make up my mind pretty quickly and at the time, I didn't know if I had made the right decision. But I joined the regolith geochemistry program.

The Chief Geochemist at the time, Richard Davy, had been poorly funded for doing regional work. But in 1993, just after I'd left to go to Japan, the State Government put forward quite a bit of money for regional geochemical working on the regolith. And Richard very quickly started the program, collecting some samples on a regional basis, large amounts of samples, and analyzing them. So we understood more about the regolith. And the premise of this was that regolith, which is derived by the weathering of a bedrock, can give some idea about the what the parent bedrock composition is if you know something about the chemistry.

So Western Australia, huge amounts of regolith, more than 80% of the state is covered in this material. And yet very little was known about it. They'd done two or three one to 250,000 map sheets at the time. They'd collected 1000 samples on each sheet. These sheets were in the Goldfields. So they knew the geology pretty well. There were in mineralized areas. 

In late September, probably about three weeks after I got back from Japan, we set off in the field. And I found myself kneeling in a creek up in the Gascoyne area, looking at sand and the mineralogy of sand, at all these weathered rocks in the bank and I thought to myself, ‘What the hell have I done’, you know, ‘What have I let myself in for’, but I've made a commitment.

And then later on that year in October I was given a sheet to organize and run. They were 250,000 scale sheets, an area of roughly 16,000 square kilometres and samples were collected at a density of around about one sample every 16 square kilometres, a four by four grid. And the preferred sample medium stream sediment representing that grid square. 

So, this was done by using survey vehicles. We had a contracting company who used to use our vehicles. Extra bar work was put on them because it was pretty rough in the bush. And we go out in a group supervised by the GSWA geologists. On average, it was taking about five weeks to collect 1000 samples and the vehicles came back and they were pretty knocked around. And the mental toll on some of the staff is a bit high because the driving was pretty bad.

We set off up towards up to Nabira, which is just north of Wiluna on the on a northern part of the Yilgarn Craton. Now, for all these programs, we were increasingly made aware that getting in contact with Aboriginal people was important to find out about any heritage issues. We always used to make inquiries, but usually there were very few responses. However, on this particular occasion, when we got to Wiluna, we inquired at the local Aboriginal Corporation. Oh, they were very keen to come up and they had an area of concern. So before the samplers arrived, up at the first station we were going to stay out, we drove up the road expecting to meet these people up there to have a look around. So on the way up there we stopped on the side of the road to make a radio call back to Perth to say we were okay. And as we sat there, one of the GSWA vehicles would pass with a caravan on the back, and it was the cook. And he was driving at about 80, 90 kilometers an hour on a gravel road. And when we got further up the road, the wheel had come off the caravan. There was food all over the place inside the caravan. We put a generator on it, because he had freezers in there, and we drove off to the station, and we had to go down the road and pick up this food every night. So it was all a bit hectic to begin with.

The samplers hadn't arrived. But we set off out with these Aboriginal guys. There was about eight of them turned up in two or three vehicles. And we set off with them for a couple of days. And they took us up into their country and showed us around. And they pointed out a particular area to us quite a big area, which was an important area for them. And it was an area they took young males for initiation.

06:41 Julie

Right.

06:42 Paul

And they said, ‘We really don't want you to come in here’. So it was a big area, probably 150, 200 square kilometres. So they told us why they took us around and showed us different parts of it. And we were going along the road. And occasionally we'd stop and they'd kill some poor, unsuspecting animal on the side of the road and cook for dinner that night. They showed us an area where we could get water up in the side of these hills. There was a spring up there. So when we came back, I said to the samplers, you really must not go in there to do this work. So there was a bit of disagreement about that. But I thought it was important that we do that.

So the program started and they’re pretty rough, like we used to get around about perhaps about 10 or 12 samples a day per vehicle. There were four vehicles. But some days were really quite bad. I think the worst day that I had when I was out sampling, we had 16 punctures and collected four samples. When I got back to Perth after this program, I thought there really has to be a better way of doing this. The disadvantage of using ground based vehicles is that the access is limited. You can go into some areas where you might only have to go a kilometre, but it's through a ravine or it's off the edge of a cliff or something like that and you just can't get a vehicle in there. So we thought there really has to be a better way to do it.

So after this program had finished, we still had quite a bit of money. The samples were analyzed. The analytical program we used was what's called a total analytical program. And this is where we analyze the samples using a very aggressive technique to try and dissolve the whole sample so we could get the chemistry of the whole sample, with the belief that that would tell us something about the chemistry of the of the bedrock it came from. It didn't take into account how the samples formed, what kind of weathering process it was just attacking by for acids or fusions. And we got a lot of elements. We got 50, 60 elements from it. And the idea was that this was a program that would suit a lot of geochemical explorers, regardless of what they were looking for, if it was gold, or nickel, copper, lead, zinc, heavy minerals, even, that we would have enough data there that the database could be used over and over again.

08:46 Julie

Yep.

08:47 Paul

After each map sheet, chemistry was done on the samples. There was a set of explanatory notes written up summarizing the geology, the way the samples were collected, discussion of the analysis, an interpretation of the results and some maps were created. And then these were published at a nominal price. And a small disk was put in the back which had all the geochemistry on it. And these were released to the public.

So this started off and I must sort of confess that by the time we got back from this program, and we started the analytical side, it was a bit like being in a bit of a thunderstorm. I didn't really know what was going on. This was barely six months after I'd got back from Japan. But we're planning the next program. And we decided the only real way that we were going to improve this was to get better access. We decided to use helicopters. This was another steep learning curve for all of us. The survey had not routinely used helicopters before. In the end, we picked up a company. They supplied us with two Bell Jet Rangers. These ones are really good for regional work, great carrying capacity, a good range 2, 300 kilometers, seating capacity for four passengers, widely available. So lots of pilots with experience. Lots of companies have them.

So we set off and we decided we were going to do two map sheets, two 250,000 map sheets back to back. So we're going to do 2000 samples, Mount Edgerton and Glenburgh. The director of the survey at the time, Pietro Guj, was a great fan of this, of doing it with helicopters. And I mentioned to him that we use the contract company for staff before and he said ‘Oh, no, no’. He said, ‘We'll use Geological Survey staff for this’. 

10:18 Julie

Okay.

10:19 Paul

And I said, ‘Well, I warn you this is not going to be very popular’. And he said, ‘Why not?’ I said. ‘because they’re hardrock mappers, it's going to be difficult’. He said, ‘Oh, it's not a problem’. So he actually drafted people in to do this. So we had Geological Survey geologists up there. We had, some of them were actually field assistants as well.

10:37 Julie

Yeah.

10:38 Paul

We got a cook. We got a huge vehicle from the Western Power, a four-wheel drive truck. We had to get drums of fuel sent up there. So he had all these geologists and some of these geologists now, you know, one of them is actually the director of scientific program at CSIRO. The other one is a senior research scientist in Anglo Gold Ashanti. One of them used to be the deputy director of the geological survey. So these were highly credentialed people we had coming with us. And they were being pretty much forced into looking at regolith.

So the way that we set out is that each of the helicopters would have two, two person sampling crews on them – a field assistant, and a geologist – and they would have a series of sites that they would go to each day. So the helicopter takes off in the morning pretty early on. Six o'clock is a good time. When the sun comes up the air’s nice and heavy so the helicopter can fly quite easily. And so they drop off the first crew at the designated site. They would get down there, fill a form in with all the details on there about the sample, they were going to take. The field assistant would collect the sample. The helicopter then leaves the leaves goes to the next site drops off the next sampling crew camp, takes off and comes back and picks up the first one. So they sort of bunny-hop around like this. And then after about 16,17 samples, sample weight on the helicopter running a bit low on fuel, go back, dump off the samples, pick up some fuel and do it all again.

So we had two helicopters doing this, four sampling crews plus two spare crews. We had four helicopter pilots because they can't fly continuously. We had an engineer, we had a field assistant and an offsider. So we had a camp of roughly 16, 18 people. And we were collecting, I think the best days we had we were collecting 100 samples a day. So a vast improvement on what we've been doing with vehicles before. The only thing that stops access is heavy vegetation.

12:32 Julie

Yeah.

12:33 Paul

So we're getting 100% access. And each team was spending roughly 10 minutes, 12 minutes at each site. And then helicopter would come back. I think we took 28 days, four weeks to collect 2000 samples. So it was a really a vast improvement. And by the end of it, we were exhausted.

12:50 Julie

Yeah.

12:51 Paul

We were absolutely flattened. It was full on. We never had a short day. We didn't have any bad weather. But the helicopters are so expensive to run that you can't just afford to have them sitting there doing nothing.

13:04 Julie

Yeah.

13:04 Paul

Right at the beginning of the program, when we first went up to Mount Edgerton, we were at Mount Augustus. And the samplers hadn't turned up. It was just the advanced party, which was me and a field assistant, the big truck with all the gear on it. The fuel had been put up this and drum fuel and we had to get it in further east onto the Mount Edgerton sheet because it was that was a much better position for the helicopter. But it was raining and it was pouring with rain and they'd closed the roads. So we couldn't get the fuel in there. But the helicopters were coming. So I was imagining the helicopter sitting there for two or three days and we were going to be charged a standing right for the helicopters, couldn't fly them.

We were just sort of talking about this at the Mount Augustus Tourist Park and there was this old bloke sitting there at the bar having a beer he said, “Oh,” he said, “oh probably help you out” and he was the grader driver there. And that you can't drive on these roads. If they close the roads and you drive on them, they charge you an enormous amount per wheel of your vehicle as a fine. And he said ‘Oh, we can sort this out’. So I think four o'clock in the afternoon, fired up the truck. He fired up the grader. We followed him down the road to where we wanted to drop the drop the fuel off. We dropped off the fuel and then came back and we drove ahead and he graded behind us. So we got back to Augustus and the fuel was delivered. The road was absolutely perfect. Okay, no one knew we'd been down there. And we were ready to go.

14:23 Julie

Yeah.

14:24 Paul

So I think the reason the program worked really well is that there were survey geologists on it. You know, they were really committed to doing a good job. They had a huge amount of professionalism about them. I wish I could say the same for the cook. We had to fire him halfway through the trip. A few of the people got food poisoning, you know his cooking was going off. We decided he had to go. So someone, we'd moved on from there. We were off somewhere on the Glenburgh sheet. We ran him down to Meekatharra and put them on the bus. And then everyone had to muck in and cook. So for the last half of the trip, geologists who are not up in the helicopters having their day off or cooking meals.

14:55 Julie

Right.

14:56 Paul

So we had Sandy Occhipinti, who's now at CSIRO, cooking focaccias at 10 o'clock in the morning to take out for the pilots when they changed over at midday. And

15:05 Julie

Wow.

15:06 Paul

It was great, you know, it was just really worked very, very well.

15:10 Julie

Yeah.

15:10 Paul

And this is the way it went on from there. We used the helicopters for the rest of the program. The programs had initially started on the Yilgarn Craton, where we had pretty simple geology, granite-greenstones. We knew what was mineralized. But we moved into less prospective areas. And I think this is where the power of the program really was. In that, it became pretty apparent that the people who were using our data were exploration companies who wanted to find out if some of this untenanted ground that they thought might be interesting was worth putting a tenement on. Big expense doing that, much better if you can limit the risk a little bit by having some data. So we were covering areas with geochemical data, giving them that sort of information. We were providing data at virtually no cost at all.

The program was proving, I think, to be quite popular. When people knew the data was coming up, they'd phone up, the phones start ringing, “When are you going to release the data for the sheet?” And we'd say, “Well, look, we can't actually tell you that. But there will be an advertisement in a newspaper”. So we'd say something like Tuesday, the 15th of May, the data for say the Byro one to 50,000 sheet will be released at nine o'clock on the first floor of Mineral House in East Perth. Well, there might be 10 or 15 people lined up there,

16:28 Julie

Wow.

16:29 Paul

at quarter of the nine waiting for the counter to open, and they wanted the explanatory notes with the disc in the back. I did see one guy take a copy of the notes, took it away. And as he was walking your way, pulled a disc out of the back of the notes and threw the notes in the bin. He just wanted the data. 

16:44 Julie

Yeah.

16:44 Paul

So we carried on doing these sheets. During 1998, 99 when the program finished in 2000, we were doing four sheets a year. So I had extra people working for me, we picked up two or three geologists who were working for me. And then all of a sudden it stopped. The money ran out.

17:00 Julie

You’ve been listening to The Rocks Beneath Our Feet. You can discover more about GSWA by visiting dmp.wa.gov.au/gswa or find GSWA on LinkedIn and Facebook. If you like what you’ve heard, give them a follow.