Basalt Dikes on Lord Howe Island
February 05, 2004
Lord Howe Island is located in the Tasman Sea nearly midway between Australia and New Zealand. This island is the remnant of a volcano produced by submarine volcanic activity, which began erupting about 7 million years ago. Eruptions continued for about half a million years. Small dikes are extremely common in the lower volcanics on Lord Howe Island. Fine grained dikes, of probably intermediate composition, are shown above intruding weathered basalt, on the northern end of Ned's Beach, Lord Howe Island. These dikes occur in swarms and tend to point towards the eruption centre of the volcano.