Lava Tubes

• Kacey McCallister

Purpose

To Examine and understand:• Formation of lava tubes• Where Oregon Lava tubes came from• Features located in Oregon lava tubes

Area Map

• Lava tubes mostly south of bend but within the:

• Newberry Volcanic

Newberry volcanoErupting near bend 80,000 years ago

Horse Lava Tube System

Formation of the lava tubes

Arnold Lava tube system

Classic lava cave shape

Cutbacks/Keyhole

• A classic keyhole shape with different levels, caused by:

• Melting• Mechanical weathering

Arnold ice cave

-Due to the ability of lava tubes to be a great insulator once water percolates into the lava tubes and freezes. -Sometimes it completely fills the cave. -Used for it’s ice.

Breakdown• Breakdown is one of the

best ways to discover a lava tube.

• Area of lava tube ceiling that has collapsed– Pre cooling– Ice destruction– Water erosion

Lava bombs• Rolled on the top of

the lava tube flow• Sometime they will

exit through a window leaving these bomb like structures

Wind cave

Review

Lavacicle

• Super heated gas on top of the Lava flow

• Melts the ceiling of the lava tube

• Shark tooth – Layers of lava over time

• Splash• Tubular– Gas escapes through

the middle of tube

Sand castles

• Ash from Mount. Mazama percolates into lava caves.

• Waters drips down forming these peaks and vallys

Thousands of years to create

And now…………………………….

• Drum roll please………

Bat cave

Braided flows

• Most lava flows intertwine like braided streams

• They also interact with older flows to form layers.

• Bat cave shows two layers

Conclusion

• Lava tubes need a very basaltic flow to form• Classic flows include– Smooth even sides– Occasional breakdowns– Braided flows

• Special flows contain– Lavacilcles– Lava bombs– Sand castles