Metamorphic Rock Lab

Next, we can see that the rock displays a subtle porphyritic texture with plagioclase comprising the phenocrysts. The overall texture of the surrounding groundmass is granoblastic equigranular. Under thin section we also see a weakly defined foliation evidenced in the preferential alignment of actinolite grains and to a lesser extent chlorite grains. Undulose extinction is also observed in quartz indicating the rock was subject to deformation. The normalized quartz, alkali-feldspar, and plagioclase (QAP) values of this rock indicate that it is classified as a grano-diorite according to the IUGS QAPF classification system which is consistent with the hand sample interpretation.

“What happens when you put acid on different minerals?” (Formoso, Acid Test: How to tell Minerals Apart , 2013)

9. Select one of the following terms to describe the crystal shape, or habit, or each specimen shown in Figure 1.8 (p. 6 lab book): cubic crystals, hexagonal crystals, fibrous habit, banded habit, blocky habit, bladed habit, tabular habit.

Christopher and Kate noticed that after a rainstorm some of the rocks in their yard appear to shrink. They wondered how the mass of the rocks changed when dissolved in water. To

Due to Guillermo’s low reading level, he will likely struggle with the student activity that requires him to read the textbook to learn about rock characteristics.

Explain how the type of rock can affect the formation of stalactites when impacted with rainfall in Princess Margaret Rose Cave?

Define lithogeneous, biogenous, hydrogenous, and cosmogenous sediments. Why do you think it is important to be able to differentiate between these?

On the first side of the outcrop the rock when examined was greenish and had small black grains indicative of diorite with hornblende giving the green color. The rock was similar to the outcrop encountered at Hollow rock which also had several fractures parallel although not as many, and that outcrop was also highly weathered. On the other side of the outcrop, the rock was incredibly different. This side was not weathered beyond recognition but

4. Choose one of the geological periods listed in figure 3.8 and find out all you can about it. How are rock formations from that period identified? What are its most characteristic fossils? Where are the best samples of rock from your chosen period?

Answer the lab questions for this week and summarize the lab experience using this form.

Some rock’s in the Earth’s interior that are solid, are so hot that, if the pressure on these were released, or they are convected into a lower pressure zone, they could begin to melt

At the nearby valley wall, there is a distribution of rock lithology including mostly Limestone. The roundness of the samples is all angular, with a mean size of 8.325 cm in diameter. However, the stream bank has more clastic rock samples which have a rounder shape and a smaller mean size of 7.975 cm. These contrasting sections are between alluvium and colluvium data where the alluvium

The Granite rock is an intrusive rock that formed from magma coming from beneath the earth’s surface. It went through a slow cooling process that allowed the minerals; mainly quartz and feldspar to form where the result is the coarse texture. The granite went through hydrothermal metamorphism (involves hot fluid) and contact metamorphism. The gneiss, however, being able to withstand high temperatures came from a large country rock. This piece of gneiss broke off from the country rock and got trapped in between as the granite cooled. The gneiss then became the xenolith. This shows that the granite is the younger rock and the gneiss the older. The striations on the Gneiss were caused by faults. A slick-en- side fault caused the horizontal striations

Metamorphic rocks change based upon heat, pressure, and chemical processes. Sedimentary rocks change into metamorphic rocks by withstanding heat, pressure, or by chemical action. Igneous rocks change by weathering and erosion. Metamorphic rocks can change into igneous rocks by experiencing melting and cooling. Sedimentary rocks change by weathering and erosion. Sedimentary rocks are formed by the accumulation of sediments and other fragments. When utilizing the rock cycle igneous rocks can change into both sedimentary rocks and metamorphic rocks when experiencing weathering and erosion. Igneous rocks are formed from the volcanic magma that cools and hardens on the surface of the earth.

     Rocks are classified to make it easier on people to identify them in the future. This can be done by a numerous amount of ways. Each rock type has their own specific ways, but there are two distinct characteristics that apply to all. These are texture and composition. These two, along with many others helps to classify igneous, sedimentary, and metamorphic rocks.