Unit 4: Midterm 1

Assuming an average rate of spreading along the Mid-Atlantic Ridge of 5 cm/year and knowing that the average distance across the Atlantic Ocean is about 5,000 km, how many years did it take for the Atlantic to open to its present position? (1 km=100,000 cm) 10 million years 1 million years 100 million years 0.1 million years 1,000 million years

100 million years

The radius of the core is 3,471 km. The radius of the whole Earth is 6,371 km. The formula for the volume of a sphere is 43πr3The core occupies __________ of the volume of the Earth. (π=3.14) 84% 16% 31% 55% 42%

16%

On Mohs' hardness scale, calcite has a hardness of about

3

The solar system formed about __________ years ago, whereas the universeformed about __________ years ago.

4.5 billion; 13.7 billion

A piece of sea floor representing the polarity reversal is found 65 km from a mid ocean ridge. The seafloor spreading rate is 1 cm/yr years. The age of this piece of sea floor is ______old. (1 km = 100,000 cm)

6.5 million years

Which of the following mineral is used to decrease the acidity in gardens? Calcite Quartz Garnet Gypsum Graphite

Calcite

Which mineral reacts readily with hydrochloric acid to produce visible bubbles of carbon dioxide gas? Quartz (SiO2) Fluorite (CaF₂) Plagioclase feldspar ((Na, Ca)AlSi3O8) Calcite (CaCO3) Muscovite ((KF)₂(Al₂O₃)₃(SiO₂)₆)

Calcite (CaCO3)

A Rift Valley is evidence of_____?

Divergent plate boundary

It has been determined that the oldest rocks retrieved from the Moon by Apollo astronauts were formed 4.44 billion years ago, while the oldest rocks found on Earth are less than 4 billion years old. This difference is most likely because

Earth's oldest rocks have been recycled by plate tectonics and erosion

Which of the following statements about gold and "fool's gold" is correct? Gold is denser and harder than "fool's gold" Gold is less dense and softer than "fool's gold" Gold and "fool's good' produce the same streak color Gold is less dense and more brittle than "fool's gold" Gold is denser and softer than "fool's gold"

Gold is denser and softer than "fool's gold"

Which of the following minerals is an OXIDE? Potassium-feldspar (KAlSi3O8) Calcite (CaCO3) Gypsum (CaSO4) Quartz (SiO2) Hematite (Fe2O3)

Hematite (Fe2O3)

Which of the following is NOT associated with ocean to continent convergence? Mountain building Magma formation Continental arc Subduction Trench

Mountain building

Which of the common minerals is a sulfide?

Pyrite

Which of the following minerals is formed by 3-D framework silicate structure? Quartz Halite Calcite Biotiteterm-10 Muscovite

Quartz

Which of the following provides evidence for plate tectonics? Atmospheric temperatures Seafloor topography Ocean currents Tides Ocean waves

Seafloor topography

Which of the following is a mineral? a pencil Snowflake Volcanic glass Water vapor Window glass

Snowflake

The asthenosphere is actually a part of the ________ of the Earth.

The Mantle

The boundary between the crust and mantle is marked by a seismic-velocity discontinuity called ____________.

The Moho

Formation of the Earth's layered structure resulted from _________.

The attraction of progressively denser materials by Earth's growing gravitational field.

Which of the following statements is FALSE ? The oceanic crust is denser than continental crust. The outer core is liquid and the inner core is solid. The inner core generates the Earth's magnetic field. The asthenosphere is right below the lithosphere. The chemical formula of silicon-oxygen tetrahendron structure is SiO44-.

The inner core generates the Earth's magnetic field.

Which of the following best characterizes ferromagnesian silicates? They are black to dark-green silicate minerals containing iron and magnesium. They contain iron and magnetite, are black in color, and they have metallic lusters. They contain magnetite and hematite, and they are clear to light green. They are mostly clear, colorless, and rich in the elements magnesium and potassium.

They are black to dark-green silicate minerals containing iron and magnesium.

In the terminology of Plate Tectonics, an active continental margin is______.

a continental coastline that coincides with a plate boundary

The mountains of the European Alps and the South American Andes are related to ________.

a convergent plate boundary

The island of Hawaii and the volcanoes of Yellowstone are probably caused by

a rising mantle plume from a hot spot

Which of the following features develops where plates converge and one descends into the mantle? a trench a seamount chain an oceanic fracture zone an abyssal plain a mid-oceanic rift

a trench

Subduction zones are associated with ____________.

convergent plate boundaries

Which of the following minerals is used as a source of lead? garnet gypsum galena magnetite hematite

galena

Which of the following minerals is a polymorph of diamond? copper graphite silver gold pyrite (fool's gold)

graphite

Which common nonsilicate mineral is used in drywalls?

gypsum

Polymorphs are...

minerals that have the same chemical composition but different structure

Which of the following minerals is formed by two-dimensional sheets of silicon-oxygen tetrahedra? quartz halite diamond calcite muscovite

muscovite

Linear, magnetic patterns associated with mid-ocean ridges are configured as ________.

normal and reversed magnetized strips roughly parallel to the ridge

Volcanic island arcs are associated with_______.

ocean-ocean convergence

Which of the following pairs does NOT include a characteristic of the specified mineral? magnetite / magnetism Halite/ salty biotite / 2-D sheet silicate structure quartz / single-chain silicate structure calcite / carbonate mineral that reacts strongly with acid

quartz / single-chain silicate structure

An example of a result of an ocean-ocean convergent plate boundary is_______. the Himalayas the Andes the Aleutian Islands the Cascades the Alps

the Aleutian Islands

An example of a result of continent-continent collision is_________.

the Alps

An example of a divergent plate boundary is______.

the Mid-Pacific rise

The difference between the continental and oceanic crust is that________.

the continental crust is thicker, older and less dense

The difference between the lithosphere and the asthenosphere is that_______.

the lithosphere lies above the asthenosphere and is brittle whereas the asthenosphere lies below the lithosphere and is ductile

The Icelandic volcanoes are related to plate tectonics because ________. they lie on a spreading center where two plates are converging they lie along a subduction zone where two plates move past each other they lie on a spreading center where two plates are moving apart they lie on a subduction zone where two plates are converging they lie along a subduction zone where two plates are diverging

they lie on a spreading center where two plates are moving apart