Intriguing Ground Anomaly

Here is a pic of the ground anomaly that I had found to the far northwest on King William Island, mentioned last week.  The photo was taken from about 300 to 400 feet AGL.  It really stood out from many other deformations.  

Intriguing ground anomaly

When I went around for a lower pass, there appeared to be what seemed like a small piece of battered wood partially buried there.  Note the gray rectangular gravel area that appears to have at some point been disturbed, slightly darker shade.   

Detail 1

Or it may be a grave of an Aboriginal.  Or it may be nothing.  But if a grave - Aboriginal type of graves, at least from what I have seen, have been surrounded or covered with rocks, built up above the ground.   I am not an expert in this area.  The only way to know for sure is to land nearby and hike over for a close up look, and also activate the magnetometer.  Unless of course the wood has an inscription of some kind.  

Or like I said before, it may be a false lead, nothing.