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GEOL 1301 Name:____________________ Metamorphic Rock Lab a Learning and Lab objectives: This is our final lab on identification of samples that record sections of the rock cycle. In this lab, you will focus on metamorphic rocks, which are rocks that have undergone changes in their mineral assemblage (i.e., the minerals that make up the rock) due to an increase in pressure and temperature. For example, if shale is exposed to temperatures greater than 200-300°C, the clay minerals will turn into white mica. Critically, this change occurs entirely in the solid state (without the rock becoming molten) as the crystalline minerals are restructured. a Terminology and lab instructions: At the beginning of the lab your lab instructor will review the important terminology below. Observe and record the properties of the metamorphic rock samples and use them to identify the samples. Lists of properties can be found below, as well as links to rock identification keys and online resources. Please complete Table 1 on page 2 of this lab and the fill-in-the-blanks exercise on page 3 and submit it to your instructor. Don’t forget to put your name on the worksheets! a Important notice: In this lab you will be using hydrochloric acid (HCl). This is a dangerous liquid for skin and eyes, and it can also damage clothes. By starting to work on this lab, you acknowledge that you have read and understood the dangers associated with the use of HCl. If you don’t want to use it, ask your instructor for help. a Grain size (refers to the size of crystals in the rock) Foliation Composition Other observation s Gravel > 2 mm Sand 0.06-2 mm Silt 0.004-0.06 mm Clay < 0.004 mm Foliated Non-foliated Can you identify any minerals in the rock? Also called “mineral assemblage”. Color Banding Cleavage … a We have also included two online identification resources: http://geology.about.com/od/rocks/a/Rock-Tables.htm http://en.wikipedia.org/wiki/Metamorphism a Samples included in the lab:

Amphibolite, Gneiss, Marble, Phyllite, Quartzite, Schist, Serpentinite, Slate 1 Name:____________________________ Part 1: Observations and classifications of rock samples. Table 1: Metamorphic rock samples Sample Number Foliatio n Grain Size Composition Other Observations Rock Name 1 F Sand Amphibole Mostly hornblende Amphiboli te 2 F Sand Mica, Quartz Shiny, crinkly foliation Phyllite 3 F Mud Clay, mica Soft, strong cleavage Slate 4 F Gravel Garnet, mica, quartz Large crystal, mix color. Schist 5 NF Mud Calcite Soft, light color Marble 6 F Gravel Quartz, feldspar, mica Banded,mixed color Gneiss 7 NF Mud Serpentine Shiny, mottled surface Serpentinit e 8 NF Gravel Quartz Light color Quartzite 1 Name:_________________________ a Part 2: Increase in grade during metamorphism a

Rock name: gneiss Change in mineralogy: shale, granitic HIGHEST GRADE 1