Introduction

Introduction


During the Paleozoic, eustatic transgressions and regressions of sea level resulted in the formation of Epeiric seas. This was also the case in North America, known as Laurentia at the time. The Ottawa area was covered by the Epeiric seas and this resulted in the sedimentary formations visible today. According to the theory of continental drift and plate tectonics, Laurentia was equatorial during the Cambrian to Ordovician.

The environment generated in the Ottawa area during the Ordovician caused habitats that only certain organisms could survive. The paleoclimate of the Ottawa area consisted of shallow, warm, somewhat saline waters that were excellent conditions for some creatures and detrimental for others. The many organisms that could survive the environment included the phylum Arthropoda, specifically the class Trilobita, and the phylum Brachiopoda, specifically the classes Inarticulata and Articulata.

The stratigraphy consists of Precambrian basement rocks that are overlain by Ordovician sediment. Several formations occurred during this time. The here was variation in the distribution of the organisms in different stratigraphic layers.


 

This is another photo of the Hog's Back Falls illustrating the sedimentary layering formed during the Ordovician and subsequently faulted.The faulted block is the Hog's Back Formation and the sediment in the background is the Pamelia Formation.