Question

1. decide whether each statement is true (t) or false (f). place your answer in the blank space given.

a. oceanic crust slides under continental crust where the two meet because oceanic crust is less buoyant than continental crust.
b. the slave granite exposed along the banks of the slave river was formed in the precambrian era.
c. the precambrian era includes the present history of earth.
d. earth’s core is its densest layer.

1. match each description with the appropriate term listed. place your answer in the blank space given.

i. crustal plate ii. core iii. mantle iv. paleomagnetism v. plate tectonics vi. outcrop vii. lithosphere viii. asthenosphere
a. a part of a rock formation that appears above the surface of the surrounding land
b. the layer of earth between the crust and the core
c. the theory that earth’s outermost layer of rock consists of crustal plates that move on the mantle and interact at plate boundaries
d. a large piece of continental crust or oceanic crust that moves only on the asthenosphere
e. the innermost part of earth, consisting of two layers
f. earth’s outermost layer of rock
g. the study of the magnetic properties of rock that formed in a past geological era
h. the part of the mantle just below earth’s crust

1. describe how the movement of the semi - fluid material in a lava lamp is similar to the movement of the semi - fluid asthensophere and lower mantle in earth.

Explanation:

a. Oceanic crust is denser and less buoyant, so it sub - ducts under continental crust at convergent boundaries. So it's true.
b. Slave Granite is Precambrian in origin. So it's true.
c. The Precambrian Era ended long before the present. So it's false.
d. Earth's core, with its high - density iron and nickel composition, is the densest layer. So it's true.
For matching:
a. An outcrop is a part of a rock formation above the land surface.
b. The mantle is between the crust and the core.
c. Plate tectonics is the theory of moving crustal plates.
d. A crustal plate moves on the asthenosphere.
e. The core is the innermost part of Earth.
f. The lithosphere is Earth's outermost rock layer.
g. Paleomagnetism is the study of past rock magnetic properties.
h. The asthenosphere is just below the crust in the mantle.
For the lava lamp comparison, in both, heating causes the semi - fluid material to rise, cool, and then sink, creating a convective motion.

Answer:

4.
a. T
b. T
c. F
d. T
5.
a. vi
b. iii
c. v
d. i
e. ii
f. vii
g. iv
h. viii

1. In both a lava lamp and Earth's asthenosphere and lower mantle, heating causes the semi - fluid material to become less dense and rise. As it moves away from the heat source, it cools, becomes denser, and sinks back down, creating a convective cycle of rising and sinking material.