The processes of supply of elements to the sea floor will determine the occurrence of these deposits. Chemical elements enter seawater in a num-ber of different ways. Sometimes their ultimate source is the dissolved material in rivers draining the continents. In other cases, they are derived from hydrothermal solutions entering seawater from submarine volca-noes. …
The ‘knowledge turn’ has been accompanied by the emergence of the school curriculum as a more clearly delineated discursive object. In the past, the curriculum tended to be assumed: a natural aggregate of whatever subjects that schools were teaching. Today, due to develop-ments external and internal to education, the curriculum is argued to be of central impor…