Properties and Features of Volcanic Rocks

Shona from Geoscience Australia introduces various volcanic rocks found in their Education Centre. She explains the characteristics of rocks like vesicular lava, pahoehoe, a'a, volcanic bombs, pumice, and obsidian. Each rock type is described in terms of its formation, appearance, and unique properties. The video also touches on the historical volcanic activity in Australia, encouraging viewers to explore their local landscapes for volcanic evidence.

What are the holes in volcanic rocks called?

• Cavities

• Vesicles

• Pores

• Crystals

What is the name for the smooth, rope-like lava?

• A'a

• Pahoehoe

• Basalt

• Scoria

What is a breadcrust bomb?

• A volcanic bomb with a cracked surface

• A type of pumice

• A type of obsidian

• A smooth lava rock

What mineral is found inside some volcanic bombs?

• Quartz

• Olivine

• Feldspar

• Mica

Why does pumice float on water?

• It is made of lightweight minerals

• It has a high density

• It contains numerous gas bubbles

• It is hollow inside

Where can pumice be found after a volcanic eruption?

• Floating on the ocean surface

• In caves

• On the ocean floor

• In the mountains

What is another name for obsidian?

• Scoria

• Granite

• Basalt

• Dragonglass

What is a unique feature of obsidian when it breaks?

• It becomes powdery

• It forms sharp edges

• It melts

• It changes color

What historical use does obsidian have?

• Fuel

• Jewelry

• Building material

• Stone tools

How long ago did the last volcanic eruptions occur in South Australia?

• 1000 years ago

• 10,000 years ago

• 500 years ago

• 4600 years ago