EAPS 111 Lab Exam 2

Detrital
Clastic
Marine Environments
Low Energy

Limestone

Biochemical/ Organic
Clastic
Swamp Environments
Low Energy

Coal

Biochemical
Clastic
Middle Marine Shelf
Medium Energy

Coquina

Detrital
Clastic
Middle Marine Shelf

Low energy

Claystone

Chemical
Mircocrystalline
Freshwater Lake
Low Energy

Shale

Biochemical
Crystalline
Outer marine shelf
Low energy

Oolitic Limestone

Chemical
Crystalline
Evaporite Basin
Low energy

Gypsum

Detrital
Clastic
Base of cliff
High energy

Breccia

Detrital
Clastic
River channel
High energy

Conglomerate

Detrital
Clastic
Marine shelf
Low energy

Siltstone

Felsic
Aphanitic (fine)

Light weight

Rhyolite

Mafic
Aphanitic

Basalt

Felsic
Aphanitic

Light weight

Rhyolite Tuff

Felsic
Aphanitic

Diorite

Mafic
Porphyritic

Gabbro

Mafic
Glassy

Obsidian

Felsic
Vesicular
Light weight

Pumice

Felsic
Phaneritic

Granite

Mafic
Porphyritic

Andesite

Mafic
Vesicular

Scoria

What are some of the more useful features features of these minerals that might be helpful in distinguishing them from each other?

Color Luster, Streak, Clevage

What mineral is more stable at the Earth’s surface, quartz or olivine?

Quartz would be more stable because it crystallizes at a lower temperature

What other mineral would you expect to find in a rock with Quartz?

Feldspar Potassium, Biotite

What other mineral would you expect to find in a rock with Olivine?

Pyroxene, Calcium-rich feldspar

Would you expect to find olivine and quarts in the same rock?

No because olivine is ultramafic and quartz is felsic or No because olivine and quartz crystalize at different temperatures.

The order od crystallization of minerals is illustrated by Bowen’s reaction. Since gradual cooling or melting drives this, at whra plate boundaries would you expect to find these processes?

Divergent and convergent boundaries

Explain what Bowen’s reaction series is?

Bowen’s reaction series shows what minerals appear at temperatures and which is first to crystallize. It is useful because it helps predict what conditions the mineral was formed.

What rocks are formed from rapidly cooled magma(extrusive)?

Pumice, Rhyolite, Andesite, Scoria, Basalt, Obsidian

What rocks are formed from slowly cooled magma(intrusive)?

Granite, Diorite, Gabbro

Which forms at the highest temperature, gabbro or granite? Andesite or basalt? and who you know this?

Gabbro and Basalt form at the highest temperature because they are mafic

Which of these rocks or felsic, intermediate, and mafic? Granite, Gabbro, Andesite, Diorite, Rhyolite, Basalt.

Rhyolite and Granite are Felsic

Andesite and Diorite are Intermediate

Basalt and Gabbro are Mafic

Would the rocks at the top of Bowen’s reaction series be light or darker than those at the bottom? Why?

Rocks at the top will be darker because they are ultramafic and crystallize first.

What kind of volcano is Mauna Loa and why?

Mauna Loa is a sheild volcano because of the elevation and lava flows

How explosive do you think eruptions from shield volcanoes would be?

Because shield volcanoes have lower viscosity, the explosions would not be very explosive.

What is a shield volcano?

A shield volcano is a broad, gently sloping volcano built from low-viscosity basaltic lava flows that spread before cooling, creating a shield shape.

What kind of volcano is Mount St Helens and Mount Vesuvius and why?

Because of the steep shape and multiple layers of lava flows it is a composite volcano.

How explosive do you think eruptions from composite volcanoes would be?

Because the lava is viscous the eruptions will be exposlive.

In general how does the viscosity of the lava from a volcano relate to how explosive the eruptions are?

The higher the viscosity of the lava the more explosive the eruption.

How is this related to Bowens reaction series?

As magma cools and crystallizes it’s silica content increases and viscosity increases.

What kind of volcanoes would you find at an oceanic hotspot?

shield volcanoes

What kind of volcanoes would you find at an subduction zone plate?

composite volcanoes

What is the relationship between water velocity and grain size

the lower the water velocity the smaller the grain size