GEOL111_Rocks2Lab

Geology 111: Rocks and Environments Name: _____Anya Donders ______________________ Lab Partner(s): ______________________ Lab Instructor: ______________________ Lab Day (Circle One): M T W R F

Metamorphic Environments: Match the images with possible types of metamorphic environments. Options: impact metamorphism, regional metamorphism, contact metamorphism, hydrothermal metamorphism. Some options can be used more than once. A D (entire ridge) B E (image is underwater) C F For each image, describe the type of plate tectonic boundary, where the point is located relative to the boundary, the intensity of pressure and temperature possible, and the metamorphic environment from the list above. Fill in your responses in the table below. Points Plate Likely Likely Metamorphic

c) Provide an image of the rock, either as a photo you took yourself (take your own photo, please) or a sketch. Draw arrows indicating the directions of pressure. d) What type of rock is it? What was it’s protolith? Why do you think that? The rock is marble It’s protolith is block stone because it has a rectangular shape. 2. Our field trip now takes us to the Delta terminal at a California airport, where I came across this beauty of a rock many years ago on my way home. a) Using arrows in Microsoft word, google docs, etc. alter this image by drawing arrows on the direction of pressure you think this rock was under during the formation of its features.

b) Zoom in to the image and describe the two major types of minerals here- the lighter and darker bands. Were they felsic? Mafic? Which one- the darker or lighter bands- seems to be more “bent”? The lighter ones are felsic and the darker ones are mafic. The felsic is more bent. c) Take your knowledge of Bowen’s reaction series. Is it common for these two types of materials to be present in the same type of rock? Yes or no and why? Do you think the two materials are from the same source (i.e., parent rock, etc.) or not-why? It is not common for those two to be present in the same rock because mafic cools at a higher temperature than felsic rock. Therefore I don’t think they are from the same parent rock/ same source. d) Knowing what you know about felsic and mafic composition and properties, discuss how viscosity would relate to how the material folds. Which one likely flowed more easily and which one not- which one would have folded more, then, and why? Felsic has a higher viscosity because it doesn’t flow easily

Specimen Minerals Present (Compositional Group) Texture (Grain Size, Shape, Foliation) Metamorphic type (contact, regional, etc) /Possible geologic environment Metamorphic Grade (Low, Medium, or High) Rock Name Possible protolith 3A Clay grains and biotite (from mica) Distinct layers, very few and small foliations Regional metamorphis m, oceanic- continental convergent plate boundary low slate shale 3B Silica, quartz Small grain size with angular minerals throughout. Some lighter pinkish areas (more felsic) and very fine layers Hydrothermal metamorphis m at hot spots and underwater vents high Quartzite Quartz sandstone 3C Quartz, mica, chlorite Fine, straight layers made of fine grains. Slight oily shine Regional metamorphis m at a convergent plate boundary low phyllite Shale, slate 3D Biotite, feldspar, quartz, hornblende Distinct alternating layers of felsic and mafic materials. Small grains sizes and minerals Regional metamorphis m at a convergent plate high gneiss Shale, slate, phyllite, garnet schist, garnet gneiss 3E Hornblende Very fine grains with Regional high Amphibolit basalt

(amphibole), feldspar small minerals. Nonfloated with mineral all laying in a parallel position to each other metamorphis m at a convergent plate boundary e 3F Mica, biotite, quartz, olivine Green color with some lighter green lines throughout. Some white and cream-colored mineral sparsely scattered. Fine grains Hydrothermal metamorphis m, most likely in the ocean low serpentine Dunnite, peridotite, possibly other ultramafic rocks 3G Calcite or dolomite (carbonates) White colored rock with medium grains. Some tan colored material scattered throughout. Few grey lines of more mafic materials Regional metamorphis m at convergent plate boundaries high marble limestone 3H Hornblende, plagioclase feldspar, garnet Medium minerals and garnets scattered throughout a mafic rock with some small felsic areas Regional metamorphis m at convergent plate boundaries high Garnet gneiss Shale, slate, phyllite, garnet schist 3I Chlorite, talc, silicates, carbonates, magnesium Distinct layers with slight foliation. Mostly tan material with some mafic material. Angular with rounded edges and small garnets formed throughout Regional metamorphis m at a convergent plate boundary Low-medium Soap stone Basalt 3J Garnet, mica, feldspar, Mostly felsic material, Regional high Garnet Shale, slate, phyllite