EOSC 326 Study Guide - Midterm Guide: Cambrian Explosion, Conodont, Cyanobacteria

299 views2 pages

Document Summary

Rigid reef structures that grow very slowly (about 5 cm in 100 years) --> corals grow 10 times faster. Only microscopic evidence of life between first appearance of life (3500 million years ago) and the appearance of first plants and animals (600 million years ago) Formed by communities of microbes that live on sediment surface. Microbes (cyanobacteria) able to trap and bind sediment grains together to form cohesive mats. Mats cemented by calcium carbonate precipitate from sea water, forming stromatolites. Only form in unusual environments where slow-growing structures can gain foothold. Hamelin pool is 1 of the 3 known localities in the world where stromatolites still flourish. Salinity of hamelin pool is double that of normal seawater due of isolation by a wall of sand. 10,000 year ago, hamelin pool was dry land. 6,000 years ago, rising sea level flooded hamelin pool.

Get access

Grade+20% off
$8 USD/m$10 USD/m
Billed $96 USD annually
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
40 Verified Answers

Related Documents