How To Identify Igneous Rocks In Thin Section Hand Sample Geo Girl The first 30 minutes of the lab will be an assessment on felsic rocks. you will be given an unknown felsic rock thin section to describe and categorize. material needed: a) lab 5 manual printed off the course website; b) polished stained and unstained hand specimens. introduction: this lab emphasizes the skills of rock classification of macro. Thin sections for gel 3160 lab 5 felsic igneous rocks at wayne state university.
Granodiorite In Thin Section Intrusive Felsic Igneous Rock Under Lab activity 5.2 crystal textures of igneous rocks in activity 5.2, you explored the properties and formation conditions of various crystal textures of igneous rocks. in this exercise, you will compare and contrast these textures to each other, and then relate their appearances to the locations of the formations of rocks with these textures. Igneous petrology eosc 321 laboratory 5: conoscopy. felsic plutonic rocks learning goals. after this lab, you should be able: •!use conoscopic obervations to determine the uniaxial or biaxial character of a mineral •!determine optic sign of anisotropic minerals •!identify the key rock forming minerals in felsic plutonic rocks. To go beyond simply identifying a rock as igneous and learn some specific igneous rock types. figure 4.1 –thin section view with crossed polarizers showing interlocking crystals of pyroxene (colorful grains), biotite (dark brown) and plagioclase feldspar (white to black striped grains) in a coarse grained igneous rock. see also figure 2.5. Bubble textures. 1. 2. pumice, made of about 90% gas bubbles. the glass colorless to light brown, and hard to see with all the air bubbles entrained in the epoxy mounting material (bubbles in epoxy have thin, birefringent rims). there are several phenocrysts of brown to green pyroxene, magnetite, and plagioclase.
5 Petrographic Characterisation Of The Felsic Gneiss The Thin To go beyond simply identifying a rock as igneous and learn some specific igneous rock types. figure 4.1 –thin section view with crossed polarizers showing interlocking crystals of pyroxene (colorful grains), biotite (dark brown) and plagioclase feldspar (white to black striped grains) in a coarse grained igneous rock. see also figure 2.5. Bubble textures. 1. 2. pumice, made of about 90% gas bubbles. the glass colorless to light brown, and hard to see with all the air bubbles entrained in the epoxy mounting material (bubbles in epoxy have thin, birefringent rims). there are several phenocrysts of brown to green pyroxene, magnetite, and plagioclase. Lab 5 igneous rocks. there are lots of terms here that you should review before lab . look closely at figures 5.2 and 5.3 before coming to lab. igneous rocks form when a molten lava, or magma cools and solidifies into a body of rock. rock cycle pg. 78. two main kinds of igneous rocks . when magma within the earth solidifies it forms an intrusive. Figure 6. rhyolite is a felsic, extrusive igneous rock. it has the same chemistry & mineralogy as granite, but is very finely crystalline (aphanitic texture; crystals <1 mm in size) due to cooling of high viscosity lava. rhyolites are often light gray to pinkish to somewhat reddish in color.
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