Pia Glacier was but one of many glaciers that were viewed while cruising around the fjords of Tierra del Fuego. Pia Glacier is located at the head of Pia Fjord. We visited it on our first full day aboard the Terra Australis and was our first Zodiak excursion from the ship to shore.
The head of the Pia Fjord actually has two glaciers, the main Pia Glacier is a tide water glacier - the glacier terminus reaches the ocean. This glacier was calving into the fjord while we were there. The other glacier is retreating and is above sea level. Its surface is covered with glacial till (material eroded and carried by the ice in the glacier). As the ice melts the rocks, gravel, sand and silt in the glacier are exposed and left behind on the surface. While the end of the glacier looks to be mostly till, in reality there is still a lot of ice beneath it.
A stranded block of ice shows how this material is typically found within the glacier. Rocks like this one are responsible for the great erosive power of glaciers. As the glacial ice flows over the surface of the land, rocks and debris within the glacier grind away at the land. Over time this erosion can smooth the surfaces of rocks or form troughs, grooves or striations.