what is this???

[Cheez Dawg]

Last week my neighbor had a huge maple tree come down in a violent storm. He was cutting it up for firewood. A lot of the blcks had a grain pattern like in the picture I am attatching. It looks like the grain is going both ways on the block, but I'm not sure what it is.
Any explanations??

 

[MVPCues]

This is a common grain pattern in maple that reveals itself more often in pieces that are split than sawn pieces. The streaks are rays running through the wood that probably have slightly different properties than other tissues, causing splits to naturally follow them.

Kelly