geo lo8

Two scientists were arguing about mineral resources of Earth, both of them state something.

The first one said that almost all of Earth’s mineral resources are on the continents.
The second one said that the water of the oceans contains huge amounts of chemical elements.

Who was right?

• 1. The first one.

• the second one

• both of them

• neither of them

Hydrothermal deposits are formed due to:

• 1. Precipitation from water- rich” juices:

• 1. That crystallize from the magma

• 1. Evaporation from sea water

• 1. Erosion and precipitation

It is not practical to “mine” minerals from the waters of the ocean because

• 1. The cost is very high, and the quality is bad

• 1.  The sediment stirred up and suspended in the water during mining

• 1. The water of the ocean contains low concentration of most chemicals

• 1. The water of the oceans contains high concentration of most chemical.

• 1.  The water of the oceans contains high concentration of most chemical.

Great areas of the deep ocean floor are covered with dark-colored, which known as:

• 1. Iron–magnesium nodules.

• 1. Iron–manganese nodules.

• 1. Iron–sulphate nodules.

• 1. Iron–phosphate nodules.

A mineral resources company decides to conduct a gravity survey of a region. Why would this be a useful method of prospecting?

• Ores produce cracks in the surrounding rock that generate inverse

  gravitational fields .

• 2.  Ores generate a smaller gravitational field than the surrounding rock

• 2.  Many ore bodies are located close to gravitational nodes .

• 2.  Many ore bodies are denser than the surrounding rock

A placer deposit forms when:

• Minerals precipitate from evaporating ocean water

• Minerals precipitate from magmatically heated water

• Minerals are deposited during metamorphic reactions

• Minerals are deposited when flowing water slows down

Scientists search for fossil fuels in many ways. Sending a sound wave into the ground (by exploding dynamite, thumping the ground with a large weight, or using an electric vibrating machine) and measuring its return to the surface at receiving stations is called ________.

• destructive surveying

• seismic surveying

• dynamite surveying

• sonar surveying

Metal enrichment in subduction zones is a result of...

• Differential melting and density stratification

• Dissolution and precipitation
  

• Magmatic segregation and mantle convection

• Hydrothermal activity and fluid enrichment

How does magnetometer work?

• 1. A-  By detecting local changes in Earth’s magnetic field.

• 1. B-  By calculating the quantity of a magnetic mineral deposits

• 1. C-  By measuring how well rocks conduct electrically.

• 1. D-  By pointing in the direction of magnetic materials.

Ore of this metal is often found in areas subjected to magma intrusions........

• 1. A-  copper

• 1. B-  lithium

• 1. C-  aluminum

• 1. D-  sodium