Could the crown of thorns described in Mark 15:17 be an attempt by the writer to strengthen the relationship between Christ as the second Adam and the first Adam who is cursed in Genesis 3:18 with an earth growing thorns?
Mark 15:17 (NRSV)
And they clothed him in a purple cloak; and after twisting some thorns into a crown, they put it on him.
Genesis 3:18 (NRSV)
thorns and thistles it shall bring forth for you; and you shall eat the plants of the field.