Examine the model of a hand sample from site 6 in Pedestal3D below. Click on the < button to hide the side menu and give you more space to view the sample. Choose 'High' instead of 'Medium' from the drop down menu to maximise the quality of the sample image.

Task: Please choose an informative view direction in the Pedestal3D model and make a sketch in your field note book. You may zoom into interesting features and make multiple sketches rather than sketching the whole hand sample if needed. Please use the tools in Pedestal3D to measure grain size etc. for your sketches. It is important to recognise the difference between a fresh and weathered face of a sample. Sometimes weathering can conceal important features and the fresh face gives the best view, however the opposite can also be true. Study both faces in these samples to see which gives you the best view of the rock's microstructures.

Question 3: These rocks were originally sedimentary and they have preserved some of their bedding features which can be identified by layers with different colours/compositions or grain sizes. Site 6 is good for practicing taking a strike and dip measurement of the orientation of the layers. These rocks display bedding, so it is an opportunity for the field geologist to learn about the structural geology of the region where at the larger scale one might map folds.

Note that the minerals in very fine grained rocks are very difficult to confidently identify without making a thin section and examining the sample under a microscope. Two photomicrographs are presented in plane polarised light (PPL) and crossed polarised light (XPL). The white dashed line marks a change in grain size, a key indicator of bedding planes in the original sedimentary rock. Veins are marked by white arrows that cut the sample a various angles to bedding. With further training in the identification of minerals under a petrographic microscope, a student could recognise that the vein is filled with a mineral called epidote (bright colours in XPL).