bogs as archives
Discloses the past
Many bogs in Sweden were originally lakes. Over time, they became increasingly shallow, growing thick with plants to form a fen. The growth of vegetation can continue until a bog is formed.
Dig
Digging through the layers of a bog, one finds the remains of the different stages. The deeper one digs, the further back in time one is taken.
Clay
Farthest down is clay from the time when the ice-age glacier melted away, leaving the ground bare. Fine-grained clay was carried to the lake by running water and then sank to the bottom.
Mud
On top of the clay is a layer of mud from the old lake bottom. It contains microscopic remains of plants and animals, along with bits of shell from snails and mussels and the remains of shafts and leaves from reeds.
