The meaning of bedrock is that of solid rock as opposed to loose surficial sediments. There is plenty of both types in Skaftafell. The “sandur” plains (Skeiðarársandur and Breiðamerkursandur) are excellent examples of sedimentary deposits that the great glacial rivers from Vatnajökull (and the outlet glaciers) have transported. Closer to the mountains the solid bedrock appears, such as lavas and palagonite rock (referred to in Iceland as the “moberg”). These include several rock types and which rock type initially formed often depended on the environment at the time of volcanic eruption. During ice free “interglacial” periods lavas flowed over the country but below ice during “glacials” the lavas solidified as various types of “moberg”. Inland the bedrock sticks its head where the sand deposits end, namely at the mountain foothills. Generally, the bedrock extends to the highest peaks except where covered by scree and ice. By the way “sandur” is the scientific term geologists use for fluvial deposits that glacial rivers bring or deposit enroute toward the ocean.