The Newer Volcanics

The Newer Volcanics of the Melbourne region consist of an extensive overlay of basalt which forms part of a major geological province of Victoria. The volcanic activity which formed the rocks of the Newer Volcanics group can broadly be equated with "hot spot" volcanism, as it was not associated with a major tectonic plate boundary. In general, the activity of the Newer Volcanics was that of numerous, short-lived eruptions from relatively small vents. The lava flows of the Newer Volcanics were generally very fluid and fast flowing. Columnar jointing, developed in varying degrees, is common in the basalts of the Newer Volcanics. The Newer Volcanic activity produced both lava and pyroclastic products. The basalts of the Newer Volcanics are almost always altered to some degree, as many of the constituent minerals, such as olivine and the pyroxenes, are relatively susceptible to alteration. The Newer Volcanics are weathered by the elements in a variety of ways.