Tuesday, 4 February 2014

Microscopes and Paintbrushes

I've been busy with my samples again in the lab. I put the stubborn sample that hadn't broken down into white spirit to help dissolve it further, before leaving it in boiling water overnight. I then re-sieved it over the sink, re-filtered it and put it back in the 40 degrees centigrade oven overnight. When it is was dry, I sieved it through 1mm, 150 micrometre and 63 micrometre sieves (it still wasn't completely broken down, so there was a lot of large material, hence the larger sieve).

Large material from the stubborn sample!
I then picked through my samples for microfossils for the over 150 micrometre material. This involved putting a thin amount of material on a picking tray, putting it on a microscope, and, using a fine paintbrush, looking at every single grain, and moving the microfossils from the tray to a slide. This was a lot of hard work, as the grains and microfossils were prone to either getting stuck to the paintbrush, or flicked off into the distance!

Desk complete with microscope!

Material on picking tray

Lots of microfossils on slides
I then stuck down the microfossils onto the slides from two of the samples, as there weren't very many in either of them. I then separated the microfossils from the other two samples, specifically picking out foraminifera (forams). I am now in the process of sticking down the forams, and I will then stick down the rest of the microfossils.

Some of you may be wondering what on Earth foarms are! Well, they are marine organisms that first appeared around 540 million years ago, and are still alive today (well, not the ones that were around 540 million years ago!). They are split into two major groups - benthic (species that live on or within the seafloor sediment) and planktic (species that float in the water), and they generally have a shell, with either one or multiple chambers. I am using the forams and other fossils to determine where the samples came from - either from the deep water or near the coast. This will hopefully allow me to determine if they were affected by a tsunami.

Many different forams (courtesy of Wiki)


  1. I can just picture the scene - trainee geologist wielding a brush and variety of sieves, scampering around the lab after escaping microfossils as they ping off her slides!

    1. Yup, that's me! The problem is, they don't actually ping very far, but because you're looking at them through a microscope, it looks like they've gone miles! Very deceptive things these microfossils!

  2. Hi, where did you purchase the grid slides from ?

    1. Hi, I'm not sure sorry, the university provided them for me.