TCNJ Physics 120 Introduction to Geology

Transcription

1 TCNJ Physics 120 Introduction to Geology Laboratory Manual Professor Gregory C. Herman Sources notes within GCH

2 GCH

3 TCNJ Physics 120 Introduction to Geology Lab Manual GCH Laboratory 1. Time-Life-Man.jpg One page, hand-written essay on your interpretation of the handout. 3

4 and Spectroscopy This lab is an introduction to minerals and spectroscopy, the latter being the scientific study of how light interacts with solid matter. The Ward s mineral sets contain different mineral samples that are found in all different rock types, including those formed during 1)the cooling of molten magma into igneous rock, and others from 2)the precipitation of minerals from a) saturated, briny fluids or b) biological processes. By the end of this lab you should have a working familiarity with the 5 most common rock-forming minerals (quartz, feldspar, mica, amphibole, and pyroxene) and be able to identify them separately from other minerals that appear similar but are usually softer and formed from precipitation ((b) above) 4

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8 Carbonates(CO 3 )-2 derived from the shells and hard parts of marine organisms or are precipitated as seawater evaporates Calcite (CaCO 3 ) is the main constituent in the sedimentary rock limestone Sulfates (SO 4 )-2 derived from hydrothermal activity or are precipitated as saline-water evaporates Gypsum (CaSO 4. H 4 O) is a main constituent in drywall Phosphates(PO 4 )-3 derived from hydrothermal activity and igneous processes Turquoise CuAl 6 (PO 4 ) 4 (OH) 8 5H 2 O 8

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12 Laboratory 2. Mineral Cleavage Types 12

13 TCNJ Physics 120 Introduction to Geology Lab Manual Laboratory 2. Minerals From Cronin, V. S., and Tasa, D., 11 th Laboratory Manual in Physical Geology: Pearson, New York, NY, 426 p. 13

14 Mohs Hardness Scale 14

15 Laboratory 2. Minerals Adapted from Cronin, V. S., and Tasa, D., 11 th Laboratory Manual in Physical Geology: Pearson, New York, NY, 426 p. 15

16 Silicate Minerals 16

17 Quartz No. 2 of the 5 most common rock-forming (silicate) minerals GCH Rev

18 Identify quartz, calcite, and gypsum by checking the type of habit, cleavage, and visual aspects that you observe NOTES: Quartz (silica SiO4) Calcite (carbonate CaCO3) Gypsum (sulfate SiO4) 18

19 FELDSPAR No. 1 of the 5 most common rock-forming (silicate) minerals Group of rock-forming tectosilicate minerals which make up as much as 60% of the Earth's crust. Two cleavage directions at Hardness of Will not scratch glass or quartz. Alkali feldspars (K,Na)AlSi 3 O 8 Microcline and orthoclase Not usually clear. Often salmon pink or white and milky. Can also be aqua blue. Can have wavy stripes of similar color that go through the mineral. Plagioclasefeldspars (Na,Ca)AlSi 3 O 8 Albite to Anorthite solid-solution series Individual crystals a range of colors between white and dark gray. Exhibits striations Can have wavy stripes of similar color that go through the mineral. 19

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22 Identify plagioclase and alkali feldspar by color, microscopic twinning, and mineral habit, hardness with respect to quartz and metal. Note any visual and physical aspects that you observe. NOTES: Plagioclase feldspar (silicate (Na,Ca)AlSi 3 O 8 ) Twinning seen on face of large plagioclase sample Alkali feldspar (K,Na)AlSi 3 O 8 ) 22

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26 Identify the following minerals by color,and mineral habit, hardness with respect to quartz and metal and one another. Note any distinctive visual and physical aspects that you observe. NOTES: Mica (biotite and muscovite) Pyroxene Amphibole Olivine/peridotite 26

27 1) Igneous are derived from the hardening of molten magma (intrusive or volcanic, with felsic, intermediate, and mafic varieties) 2) Sedimentary are derived from detrital or chemical sediment, the products of mechanical and chemical weathering and chemical precipitation. 3) Metamorphic are the result of burial, increasing temperature and pressure, and fluid transfer processes during recrystallization (low, medium, and high grade) Igneous rockforms when hot magma cools and solidifies. Sedimentary rocksform when sediment iscompacted and cemented together (lithified), or when minerals precipitate from solutions. Mechanical weathering and physical breakdown of a parent material (usually rock) produces clastic or detrital sediment, whereas chemical sediment is accreted through biological processes or precipitates directly from hydrothermal or briny waters. Metamorphic rocks are compacted, heated, pressurized, and altered from burial, thermal contact, and fluid transfer during recrystallization and alteration. 27