Question

1. making connections: compare the continental crust and oceanic crust by indicating the name of the rock, composition, and mineral content each made up of. continental crust: name of rock: _____________ composition: ___________ mineral content: ____________________________________ oceanic crust: name of rock: ___________ composition: ___________ mineral content: ______________________________________ part 2: understanding how to determine mineral percentage to find the mineral composition of an igneous rock (with the estimated percentage of each mineral) you will need to use the “percent by volume” portion of this chart. example: to find the average mineral composition for gabbro, draw a line down the center of the mafic column. based on that line, estimate the percentage of each mineral that the line runs through, using the percentage numbers on the left side of the chart (see below). chart and example for gabbros mineral composition omitted as per ocr text processing rules

Explanation:

For continental crust, the dominant rock is felsic, with silica-rich composition and key light minerals. For oceanic crust, the dominant rock is mafic, with iron/magnesium-rich composition and dark, heavy minerals.

Answer:

CONTINENTAL CRUST:

Name of Rock: Granite
Composition: Felsic (silica-rich, ~65-70% SiO₂)
Mineral Content: Quartz, potassium feldspar, sodium-rich plagioclase feldspar, biotite mica, amphibole

OCEANIC CRUST:

Name of Rock: Basalt (extrusive) / Gabbro (intrusive)
Composition: Mafic (iron and magnesium-rich, ~45-52% SiO₂)
Mineral Content: Calcium-rich plagioclase feldspar, pyroxene, small amounts of olivine