GEO1115_2021_Activity8

THEME 8 – IGNEOUS ROCKS [ 33/44 : B+ ] A CTIVITY 8.3S – I DENTIFICATION OF IGNEOUS ROCKS SAMPLES FROM THE KIT ( /44) Reference material: - Lecture of associated theme (Brightspace) - Glossary ( https://mysite.science.uottawa.ca/dumas/ ) - Reference document “Section of the lab manual” in Brightspace Activity: You must identify the name of 11 selected igneous rocks samples from your kit. To do this, you need to study the properties of these rocks: texture (phaneritic, aphanitic, etc.), colour (light- or dark-coloured), and composition (felsic, mafic, etc.). You will need your course notes as well as the reference documents on igneous rocks (informative text on igneous rocks, igneous rocks classification table, and igneous rocks worksheets – see “Reference document: section of the Lab Manual” in Brightspace). Thus, you must associate each identified sample number in your kit (see below) with an igneous rock name from the list below . This time, we also require that you fill in and submit the igneous rocks worksheets for the various samples identified. This will help you, among other things, to make links between the different textures observed and the mode of formation of these rocks (intrusive/extrusive, slow/fast cooling, etc.). It will also allow you to associate each rock with its mineral composition (quartz, potassium feldspar, pyroxene, olivine, etc.) even if it can not (or only with difficulty) be observed on the various samples. List of the 11 igneous rocks to identify: (igneous rocks highlighted in yellow in the reference material “Section of the lab manual”) Rhyolite Basalt Granite Vesicular basalt Obsidian Gabbro Pumice Dunite (or peridotite) Pegmatite Tuff Breccia Sample numbers of the kit to identify: 17 : Dunite 19 : Rhyolite 20 : Granite 21 : Basalt 22 : Vesicular Basalt 23 : Gabbro 24 : Obsidian 25 : Pumice 26 : Pegmatite 27 : Tuff 28 : Breccia