Waipara gorge

Last Friday, Nicola and I went with Catherine Reid to look at some areas of the Waipara river, where Nicola’s school does a field trip. This was an opportunity for us to have a look at some of the geology of the area so that we would be able to explain it to our kids at school.

 The flat parts under the forest have been formed by the debris coming down the river at a time in the past, which has been deposited and built up the landscape. This has later been cut through by the river (when it has less debris coming down from the mountains) exposing the layers and cutting out the gorge.

The earliest rocks have been tilted by plate movement causing the different angles.

The angles are noticeable in this unconformity. The lower (older) rocks are tilted. On top of them the river has deposited new layers of material, and then as its sources of material have diminished it has cut back down through all the layers exposing this unconformity.

These are old sandstones again and are on an angle. In them are fossils, and some examples of concretions.

This is a concretion. It is part of the sandstone that has become much harder than the surrounding rock because of the precipitation of minerals that hold the pieces of the rock together.

Concretions are usually mostly spherical in shape and can be seen all through the river as boulders that have been washed out of the sides of the river.

These are some from in the river.

They also have trace fossils in them. These are areas where something has been before it hardened and have left marks which then hardened with the stone.

We also found fossils in the sediment walls of the gorge.

We spent too long looking at stuff in the part of the river we were in so we didn’t make it as far as we were supposed to last week, so hopefully (if the weather clears!) we will be going up to look at the rest tomorrow.

Castle Hill Basin field trip

Yesterday I went along with my (well they will be my class when I am back at school anyway) Earth and Space Science class on their field trip to the Castle Hill area. This was done with the help of a Masters student from the geology department who was extremely useful and explained things really well to the class.

Unfortunately it was very cloudy at the top of Porters Pass so we could not see the fault there, but the weather improved down the other side and we were able to see some examples of the rocks that make up the area.

We started at Castle Hill, checking out the limestone formations there. These limestone formations appear to dominate the landscape, but there is actually very little limestone compared to the older Torlesse rocks (sandstone, mudstone, greywacke). The limestone formed on top of the older basement Torlesse rocks when they were submerged by a large, shallow inland sea, which was inhabited by many shell forming organisms. These left behind the calcium carbonate shells that formed the limestone.

Our second stop was in the Cave Stream area, where we looked at how the cave formed from the stream eroding of the limestone.

The old stream bed is clearly visible here, where the path runs now. The cave entrance is just to the right of this photo. You can see how the stream eroded a path through here, before finding an easier route through the cave it eroded.

The current stream, and some boulders of greywacke from the Torlesse rocks, against the limestone of the cave. The greywacke is much tougher and will erode less. As the rocks get further downstream they get smoother and rounder as they are tumbled in the water.

In the cave stream area there are lots of lovely exposed faces cut by the river channels that geologists can use to see what has happened to the rocks by the angles they are all on, and also what is in each layer of rock. In the background you can also see the smooth flat planes caused by glaciation.

Our final stop was Lake Pearson. Here we were looking at evidence of glaciation and postglacial erosion. The points where glaciers stopped is generally marked by a moraine, a ridge of sediment that has been pushed in front of a glacier as it advances.

When the glaciers melt, the water is left behind in depressions created by large chunks of ice. The melting also brings large amounts of sediment down, leveling out valley floors.

The erosion is always continuing, and Lake Pearson is very nearly divided in two by debris fans from the mountains either side.

It was as exceptionally beautiful day down at the lake.

Leadership Assignment 1

I have been very quiet on the blog front recently because I have been busy writing my first leadership assignment not doing exciting science things I could take photos of. All my recent photos have involved piles of books and post-it notes.

This has been my life for the last couple of weeks.

I was a bit rusty on the essay writing but I have to say that it got easier as I went along. I actually enjoyed writing about leadership and I have found myself very interested in reading about it. It will have to be something that I try to keep up when I go back to school.

I have taken the opportunity to enjoy the lovely autumn weather we were having as well (until today) and did some of my reading on the deck with a view of the trees and sheep.

This

Picking Forams

This morning I was finally able to get into helping do some lab work for my project. When we were in Brooklands, we took a core sample and Emma has been sorting samples from it and drying them. Now it is time to go through each section of the sample and look for forams.

Picking forams involves taking some of the sample and spreading it out on a tray then looking at it through a microscope and using a wet paintbrush to pick up forams and put them on a slide.

My tools.

Luckily I am pretty comfortable with a paintbrush, but once I was looking at it under the microscope I realised why I can never paint a straight line… My hand wouldn’t stop moving!

It was almost impossible to pick up a foram without grabbling bits of sand too.

My job was also made more difficult by the fact that I wasn’t very good at spreading out the sand on my try and so I didn’t have a nice thin layer.

The sand isn’t supposed to be this thick!

There were very few forams in my sample, but it turned out that the ones that were there were very easy to spot. They were bigger than the sand grains and were nice and smooth looking so they stood out.

This was a foram I found and put on the slide ready to be sorted.

On the slide there is a gel stuff that is used to thicken icing, but it dries on the slide, then when you use the damp paintbrush with a foram on it, it will make the foram stick to the slide. The good thing about this is that when you need to sort the forams into types, you can use a damp paintbrush again to move them around on the slide.

It was really interesting working with the post-grad students this morning and listening to the questions they asked, as well as the answers. It made me think that maybe part of the nature of science is the questions we ask and constantly asking why? It was also very clear that it is important to be methodical and make sure everything is very clearly labeled.

By the time I had done two hours of picking this morning, I had not even finished one sample. But I was starting to feel slightly nauseated from moving the try around under the microscope and bending my neck to look through it. I am definitely not used to using a microscope!

Last week

Well I have been rather quiet on the blog front for the last week or so. This has not been because I have not been busy, quite the opposite really. Last week we (the B(est) team) spent the week in Dunedin for our leadership course. This was a really fabulous time, and very thought-provoking. Or brain-hurty as we regularly described it. I have returned full of new enthusiasm for leadership positions and for some reason can’t wait to get started on my first leadership assignment. Im sure the feeling will pass when I start having to actually write an essay.

One of the really important parts of the course was having to work out what our values are. I realised that I have spent far too long in cadets because it is hard to go past Discipline, Respect, Integrity, and Loyalty. But then I thought more about it, and realised that the reason I am struggling to get past these is because they are essentially what I think I was taught from a young age (if not, sorry Mum and Dad but that is what I got out of all those times I was told to “mind your manners” 🙂 ).

I found it quite difficult when we had to stand up in front of every one and speak about a leader we admired. It turned out that none of us liked public speaking. But I did it and will hopefully be more confident next time I have to do it.

The leader I chose to speak about was Admiral William McRaven, not because I know anything about his leadership (although I can assume he must have leader someone well to be an Admiral), but because I was recently shown a video of him speaking and found it inspirational. It is a reminded that anyone can do anything if they want to. We have to start, take small steps, not be afraid, and not ever give up.

I think this is good advice for all of us, and sometimes you just need a little inspiration and the self belief that comes with it.

As part of the course we were also taken on a lovely tour of Dunedin. In classic Jags. 🙂

This was them parked outside the railway station.

We went to a lookout.

And attempted Baldwin St.

And saw the first church. Looking lovely and gothic as it got dimmer.

And had an amazing dinner in St Clair, at Starfish. In fact the food the whole time was amazing.

Andrea and I posing with the car… I sat in the seat that the Queen had sat in. I practiced my wave the whole way through Dunedin.

One lunch time I went for a quick walk and had a look at the geology museum at Otago and found these:

I’m quite familiar with forams now!

Rocks and a flume

Yesterday I went to a 200 level lab for the Depositional Envrionments and Stratigraphy (GEOL243) course. I had been to a lecture on Wednesday as was surprised to find that I actually understood what they were talking about. It turns out that a knowledge of the physics of waves was quite useful.

The lab started with looking at a variety of different rocks and they had to decide what processes had caused the sediment layers to look the way they did. They also had to decide if you could tell which way was up. A lot of this seemed like common sense to me, for example if a layer was eroded away and had another layer deposited in it then of course you could tell which was was up as erosion like that will always go downwards… yay for gravity. You can see an example of this in the second picture.

The third picture shows a rock where the layers have been disturbed by something burrowing through it.

Some of the rocks contained trace fossils. These were also useful in helping decide which way was up.

The second part of the lab was going to the flume to see sediment patterns being formed. When ripples are created in a current the sediment is picked up from the upstream side and deposited on the downstream side creating patterns.

You can see the ripples created by the flow of the water.

The flume with the water flowing. Up close you could see the sediment being picked up and deposited further down.

This reminded me of being at the beach as a kid and looking at the ripples forming in the shallow water and watching the sand get picked up each time a wave went over. It was quite fascinating.

Core and Forams

This morning Matt Easterbrook showed Nicky and I the work he is doing on a core from the Avon Heathcote estuary.

First we had a look at some forams he has collected through the microscope. There are lots of tiny forams in each of the black squares on each of the slides.

I tried taking photos of what we could see through the microscope, and it worked better than I expected.

This is one square, and one foram.

He also showed us how the start to separate the forams from the sample, by using liquids of a particular density so that only the forams (and a few other bits) float. This is then decanted through filter paper and the rest of the liquid filtered off.

The liquid is about $1000 per litre, so it is separated out and used again, and any that has been diluted has its water evaporated off and is also used again.

We also had a look at sand under the microscope, which is very cool! It is very rough, and you can see it is made from a wide variety of stuff.

Curriculum Days No 1

Last week we spent 3 days in Wellington at RSNZ looking at curriculum development, more specifically looking at science capability one, ‘gather and interpret data’ (http://scienceonline.tki.org.nz/Introducing-five-science-capabilities)

On the flight down I couldn’t resist taking this photo of the Brooklands lagoon (I was in an Airbus A320 so it was ok to use my phone to take a picture!), where I was the week before getting all muddy. The mouth of the Waimakariri is visible next to the lagoon, and you can see it was quite a misty morning in lower parts of the area.

While in Wellington we looked at lots of activities we could do with classes to observe and infer different things.

One of the activities was looking at what happens with skittles in water and making good observations with it.

We then got so excited we had to try it with M&Ms which was even better.

With purple skittles it was particularly good, as you could see the different colours coming out, like pen ink in chromatography.

Another activity was making playdoh circuits. Salt playdoh is able to conduct electricity so you can make cool circuits with it. If you make sugar playdoh though, it would be an insulator so could be a good way of looking at both circuits, and conductors and insulators.

This activity was shown to us by an ambassador from Future in Tech. They will come out to schools and take about careers, and will do activities.

They were very simple circuits with two AA batteries, playdoh, and LEDs. No need for resistors etc. They also work really well! Much easier than setting up electricity equipment that hardly ever works properly!

We also did an activity looking at different density liquids where we had to figure out which liquid would float on which to make a traffic light in the straw.

It took a while, but we got there in the end.

While we were looking at making observations and inference, we also looked at Cartesian divers, observing toast cooked in two ways (toaster and microwave- there is a surprising amount to observe there!), and floating paper cut different ways.

On Thursday night we were sent out on a mission to take photos of “Science”, so that we could use them the next day. We didn’t know what they were for so we all took lots of photos.

Those are some of mine.

In the end we were asked to choose a photo (I chose the plant one) and write some questions about it that help make close observation of the photo, then some that help make inferences. This was interesting as it was very quickly proven that it is very hard to stop making inferences automatically and just make some observations. We all tend to observe very quickly and leap straight to inference.

I think next time I might give this photo a go…

Brooklands Lagoon

For the last three days I have been spending my time out in Brooklands lagoon helping some Frontiers Abroad students to do a survey of the lagoon.

Brooklands lagoon is a tidal estuary at the Waimakariri river mouth. The river end of the lagoon is next to what was the suburb of Brooklands. This was badly damaged by liquifaction in the Christchurch earthquakes and was “red zoned”.

The area shows where peoples houses and gardens used to be.

The lagoon covers 270ha, is 4.5km long, and 0.8 km wide at its widest point. It is a mix of saltmarsh and tidal mudflats, and home to numerous birds.

The purpose of the survey is to see if there is evidence for subsidence in the estuary. To do this we used 5 transects to survey along to see the plants and sediments, and took measurements of the elevations and a core sample in one.

We did quadrats along each transect to see what plants were there.

This photo was taken near the Spencer park end and shows mostly jointed sedge. Four quadrats were done at each point along the transect to get a more thorough idea of what was there. However the really only cover a very tiny percentage of the whole area!

At each spot we also took a sediment sample to be tested for grain size. Each one is labeled with the transect number, which side it is on, and the point it was taken from. I got very good at the labeling and collecting for this! The trick to collecting the sample was to not dig too deep as we only wanted the surface sediment size.

Each bag had to be labelled on the outside and have a label inside. This is because sediment can be pretty rough on vivid and we didn’t want to lose the labels!

These were my tools! The bucket got pretty heavy when it was full of sediment samples.

Along one of the transects we also did a survey of the elevation, took samples for looking at the forams, and did a core.

I took a sneaky selfie of me standing in the lagoon holding the survey equipment.

The first thing we did on this part was send Nicky out to measure a straight line 100m out. We then surveyed the elevation and the plants every 10m. We also took samples of the sediment to see what forams are living there. This will be compared to the core to see how things have changed, as forams are specific to the conditions.

It was quite wet and muddy heading out along the tape measure!

This white tube was used to get the samples for the forams rather than the trowel. The key was to only take the top 2cm to get the currently living ones. There is a dowel inside the tube that pushes up as it is pushed into the ground and it has measurements on it to show how deep it is.

Then when we were just past the end of the plants we took a core. First we used a probe to see what was under the ground and see if it was a suitable place. You could hear the difference in sound as the probe pushed past mud or sand.

This picture shows Emma, one of the students trying to push the corer into the mud.

It was challenging getting the samples out of the corer at times. And very important to remember which was the top! It was like getting the worst stuck cake out of a tin.

Some of our samples. We made it a total of 3m in the end.

Below are some other photos of my time out there.

My feet got progressively muddier throughout the days. I was really glad of my tramping boots keeping my feet dry though!

The lumpy bits seen in this photo are actually the remnants of old sand volcanoes from the Christchurch Earthquake. They are only visible where the channel is.

The Basement

Today I got to have an introductory look around the basement of the Geology/Biology building.

The basement is full of samples of various types of rock for teaching and peoples research. It also has lots of bone samples, including moa bones but we couldn’t find them today. That is a mission for next time!

Just some of the bones!

Some lovely rocks. Next time I am going to look for the rocks with fossils. Watch this space for an update on that.

The basement also has the core samples taken for various things. These are one of the things I will be looking at in the estuary to see what sorts of foraminifera are present which should tell us about the water levels at different times and how the estuary has changed with earthquakes.

Cores

Watch this space for more updates from the basement!