An exudate is a fluid emitted by an organism through pores or a wound, a process known as exuding. Exudate is derived from exude, to ooze, from the Latin exsÅ«dÄre, to (ooze) out like sweat (ex- out and sÅ«dÄre to sweat).
Glacial striations on bedrock. Rocks embedded in the bottom of a massive glacier scratched the rock underneath as the glacier moved along. Even though there is no ice present today, these scratched lines are evidence that glaciers were here in the geologic past.lacial striations are parallel to the handle of the hammer. Look at how the lines all go the same direction. Click to Enlarge. About : The scratch marks on the schoolyard are formed by the process shown on top -- a broom dragged along over wet tar.
Erratics are a different kind of rock than the local bedrock. Drumlins are asymmetrical hills of till or rock. Drumlins point in the direction that the ice was flowing. The composition of till reflects the geology of the region the ice has flowed over. This means that till from different parts of a large glacier will contain different types of rocks and minerals. Sometimes precious minerals in till can be traced back to their bedrock source.