There's a great explanation for this block here:
http://www.quiltingboard.com/picture...22-t89525.html
You combine four quarter log cabin blocks, adjusting whether the small log is in the middle or pointing out. The middle four has the small logs all together to make what looks like one big square. Hope that makes sense, it's a simple block with a clever layout to make it look impressive.
Thanks for all the kind comments!