Branch Come Home Year

August 9-19, 2007

The Fossils Of Branch

Submitted by: Terry Fletcher

 

 

    Since the description of the Cambrian trilobite Paradoxides bennetti Salter, 1859 from the Wester Cove, Branch has become well known for the remains of primitive animals in the rocks of the Cove. The most notable feature of these rocks is their bright red and green layering. Such layering represents the vertical pile of iron-rich sand, silt and mud layers deposited on the bed of an ocean during the Cambrian Period of Earth history. These layers contain the buried skeletal remains of animals that lived on the sea bed, as well as those that swam around in the overlying waters about 500 million years ago. Because it took hundreds to thousands of years to accumulate a layer of sediment and animal communities change through time, the fossil remains in every layer are different. Thus, the succession of fossiliferous layered rocks provides a record of the evolutionary animal changes in that Cambrian ocean. When the succession of different animal assemblages was established by collecting layer-by-layer, geologists were able to use those individual fossil assemblages as time markers when examining rocks elsewhere of similar age. In this way, the different fossil layers may be interpreted as numbered pages in the book of Earth history.

 

The oldest rocks in Branch Cove occur in the base of the cliff below Chris Mooney’s new house in the Easter Cove. To the north and south, the rock layers are successively younger and the same succession of layers north to Beckford Head is repeated south through the Wester Cove as far as Branch Head. Those who have collected fossils in the Wester Cove will have noticed the difference between the trilobites from green rocks near the Gut and those younger ones from higher green levels at the Green Gulch waterfall and the yet younger ones on the northern side of Branch Head.

 

The importance of the succession around Branch Cove is that the rocks are the only ones in Newfoundland that represent the complete record of time for this particular interval of Earth history.  When first studied in 1959, it was considered to be the first place in the world where this interval of time was recognized in a rock sequence, i.e., a sort of missing link between known older sequences and known younger sequences. However, by 1966, other sections in Siberia and in New York State were found to have some of the same Branch fossils. Although not now as unique as first thought, the Branch Cove succession of fossiliferous rocks remains a major sequence of international importance to which many references will continue to be made

 

Hopefully, the Branch fossils will always be available for study and that no massive excavations will destroy the important sections of rock in both the Easter and Wester coves. Probably the best part of  Branch Cove for seeing fossils is close to the Green Gulch waterfall in the Wester Cove, where excavations are unnecessary, because fossils are continually falling out of the cliffs on to beach level, where they may be removed as souvenirs without affecting the scientific or touristic potential of the site. The important fossils in the Easter Cove are difficult to find, because they are so tiny and occur in cliff sections much affected by high tidal waters in layers older than those exposed in the Wester Cove.