Geo 102 Lecture 14Outline of Last Lecture I. Geologic timeOutline of Current Lecture II. Minerals to RocksIII.Rock TypesIV. Types of Sedimentary rocksV. WeatheringCurrent LectureMinerals to Rocks- Minerals form rockso Some are simple with one mineralo Others are complex with many mineralsRock Types- Igneouso From magma or lava- Metamorphico Altered through and/or pressure- Sedimentaryo Reformed bits of other rocks, broken down or from a solution- Rocks linked to tectonicsSo why the differences?- Time- Energy- Distance- MineralsTransitionsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Parent rock to sediment, sediment to sedimentary rockTypes of Sedimentary Rocks- Clastic: a sedimentary rock made from pieces of pre-existing rock that weathered and erodedo Also called detrital- Chemical: sedimentary rock derived from minerals that precipitate from a fluid (often water)Life cycle of a clastic rock- Let’s assume we begin with graniteo Quartzo Feldsparo Mica- How does that fit with sedimentary rocks we know?o Conglomerateo Sandstone (siltstone)o ShaleWeathering- Rocks break down according to their environmento The wetter, the faster it breaks down- All rain is acid raino Weak carbonic acido This is key to the carbon cycle and climate- Some minerals break down fastero Quartz is tougho Feldspar is less tough- Sometimes the process leads to new mineralso Clays form from feldspar- Soil is a weathering product- Rock weathered in situ is called
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