Just Another Magma Monday!

Contents of our second dredge of the expedition and our first dredge of the EPR!

Yesterday’s first dredge produced some spectacular pieces of lava pillows from a depth of over 3,200 m (10,000 feet) on the East Pacific Rise, just west of the Cocos Nazca gore tip. The lava pieces have large empty gas bubbles far bigger than could have come from within the lava itself.   Instead, the lava must have swept up seawater as it flowed out, the seawater turned to steam, blowing up the bubbles.  While this was going on, more lava came pushing into the pillows, as laminar flow, filling up the empty spaces in a ropey structure or expanding the pillows, cracking their crust and oozing out of the cracks. See examples in the photos.

 

 

 

Several broken pieces of altered pillows. Note the darker glass rinds.
Half pillow showing some alteration (the brown patches)
Ropey structure breaking out of vesicular pillow

 

We had an exciting afternoon at sea! Please check back tomorrow to learn more! Sneak peak below.

R/V Sally Ride tied off to a catamaran in the equatorial Pacific

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