Igneous Rock Regents Questions

Name______Reference Table Activity: Igneous Rocks

Using your knowledge of rock properties and the “Scheme for Igneous Rock Identification” From the ESRT answer the following questions:

1)______According to the ESRT, as you move to the right from granite to gabbro, the general color of the minerals making up the rock become………… 2)______According to the ESRT, as you move downward from Basaltic glass to Gabbro the texture of the of the rock becomes (finer/coarser). 3)______According to the ESRT, a fine textured, light colored igneous rock would best be called (granite, pegmatite, rhyolite, diorite). 4)______Which of the following rocks from the chart would probably be densest? (Granite, andesite, scoria, pumice, diorite) 5)______Which of the following rocks would probably be made up of the largest mineral grains? (granite, scoria, pumice, basalt) 6) According to the ESRT, the characteristics of rocks that contain Potassium feldspar and quartz are: ______color ______density ______composition 7) According to the ESRT, the characteristics of rocks that contain Pyroxene and olivine are: ______color ______density ______composition 8) ______According to the ESRT, very coarse grained intrusive rocks are called….. 9)______According to the ESRT, which of the following rocks must contain quartz? (Gabbro, diorite, andesite, rhyolite) 10)______According to the ESRT, which of the following rocks must contain Pyroxene? (granite, diorite, basalt, obsidian) 11)______According to the ESRT, as granite becomes darker in color, the amount of plagioclase feldspar content generally (increases, decreases, remains the same) 12)______A fine grained igneous rock contains plagioclase feldspars and pyroxene but no quartz. The rock most likely is (granite, rhyolite, diorite, gabbro, basalt) 13)______A coarse grained igneous rock contains Plagioclase feldspar, biotite mica, but no olivine. The rock is most likely (gabbro, rhyolite, andesite, granite) 14)______A glassy textured igneous rock contains approximately twice as much Amphibole as biotite and over 50% plagioclase feldspar. This rock is most likely (granite, gabbro, obsidian, diorite basalt) 15)______Name an igneous rock which has crystallized deep within the earth’s crust which has the following approximate mineral composition: Plagioclase feldspar 20% Quartz 40% Potassium Feldspar 20% Biotite Mica 10%

16)______Name an igneous rock which has crystallized at or near the earth’s surface which has the following approximate mineral composition: Pyroxene 60% Plagioclase Feldspar 30% Olivine 5% Amphibole 5% 17)______A vesicular, glassy textured igneous rock made of mostly Pyroxene and Plagioclase Feldspar would most likely be called….