| Popis: |
Algal boring is abundant in shallow shelf carbonate sediments from the Florida-Bahamas region, but comparatively rare in deeper shelf carbonates from the northern part of the Great Barrier Reef. Available evidence suggests an abrupt decrease in abundance of algal boring in carbonate sediments at a depth of 60 feet. Should this relationship prove consistent, algal boring in ancient rocks, indicated possibly by “micrite envelopes” around carbonate grains, could provide depth information for environmental analysis. At present, abundant algal boring indicates deposition at less than 120 feet, and probably less than 60 feet, provided sediment reworking is not involved. |
