North Head of Bottle Cove, Newfoundland


Ophiolite Sequence
The rock sequence exposed at Bottle Cove is a portion of the ophiolite sequence seen throughout various places in Newfoundland. Newfoundland is one of the two places in the world were ophiolite sequences are clearly exposed. The top layer of the sequence is the bottom of the ocean floor and the bottom layer ranges down to the upper layers of the Earth's mantle. At Bottle Cove the top layer of the sequence, the bottome of the ocean floor is exposed.

Pillow Lavas
At Bottle Cove the pillow lavas were the prominant feature. Pillow lavas are created when basalt intrudes into a liquid. The formation of these pillow basalts occurred in the ocean, near a mid-ocean ridge. The oval shape of the pillow lavas causes the outside to cool relatively fast, at times forming a layer of obisidion. The inside, though, cools relatively slowly forming a concentric pattern that becomes larger towards the center. The gabbro at this site was intruded onto the ocean floor through a sheeted dike complex. The magma in the center of the earth heats up and then rises. When it hits the crust it plutoons and creates a magma chamber, which in turn causes fractures in the crust. These fractures allow the rising magma to intrude onto the ocean basin forming pillow lavas.
These basalts and pillow lavas were formed in the Iapides Ocean in the upper Cambrian (570 m.y.a.). This means it is older than the limestone in the surrounding areas of Newfoundland. Therefore there is a thrust fault that allowed this portion of the ophiolite sequence to be on top of the Grenville Basement. It was uplifted when North America collided with Europe.
Little Port
Just up the road from Bottle Cove there is a breccia at Litttle Port Beach. This breccia was probable created during collision and faulting. There is a fine red matrix with angular rocks in it. There are interbedded shales and carbonates. Also there are slickenslides and striation formed by the rocks grinding against each other during faulting. This area is called a mylange and it is a mixture of the oceans sediments as well as the layers it was grinding against. This is further evidence of the uplift that the ophiolite sequence went through during the collision between North America and Europe.