Bed 19

So many times, since we have been here, we have heard it said that Gros Morne is a geologist's Nirvana.  We have been to Western Brook Pond and seen the granite and gneiss cliffs. (I now know why this lake is called a pond. We have been told that when the Europeans came here to fish in the 1500's they did not have the vocabulary to call a body of water anything but a pond. So we have been told.)  We have seen the quartzite on the top of Gros Morne Mountain and the Long Range mountain chain. The Tablelands has peridotite which is formed in the earth's mantel.  Today we visited Green Point, in 2000 acknowledged as the stratotype for the boundary between the Cambrian and the Ordivician periods - known as "Green Point Time". 

Great rocks at Green Point. The dark colored rocks are shale, formed by mud settling in a tropical ocean over millions of years. The lighter colored rocks are limestone that form on ocean shelves from calcium from sea shells that slide over the shale, in some cases over a period of minutes, because of some catastrophic event - earthquake, for example. These layered rocks moved from a tropical location near the equator to the edge of Laurentia, ancient North America, and as Laurentia and Gondawana collided, these layers were pushed upright, even past vertical.

Here is Chris, a geologist for Parks Canada, tells us how these rocks formed and came to be here and their significance. She pointing out that the older rocks are on the top and the younger rocks are on the bottom. All this give credence to plate tectonics.

This is a particularly interesting layer of limestone formed this way because it was squeezing the water out of the underlaying shale, de-watering, (the mud laying on the bottom of the ancient Iapetus ocean), and the water pressure caused the limestone to solidify in an irregular way. 

This is the same layer of limestone from the other side. You can see how wavy its edge is.

This is the "famous" (to geologists) Bed 19 of Cow Head. What this shows is that this limestone conglomerate slid onto the shale from some catastrophic event. This one bed of limestone conglomerate can be traced for many kilometers at Gros Morne. At one end, up in Cow Head, the conglomerate is the size of houses and cars; at Broom Point the size of a beach balls; here at Green Point, it is the size of grapefruit; and, at Norris Point, it is the size of a fingernail. This shows that the farther from the source of the event, the smaller the chunks are.

Here Chris is pointing to Bed 23,  the famous layer before which there is no sign of living matter and after, the beds begin to show the first conodonts. This is the Green Point Time line, the beginning of the Ordovician Period. 

We were all invited to look for graptolites, animals like corals that only appear at the start of the Ordovician Period. 

This plaque on a stone proclaims the importance of Green Point - English on one side, French on the other.

This evening we attended another Parks program - The Fire Circle at Lobster Cove Head.  When we arrived at 7 pm, there was lightening not too far away, and you could see the rain falling in the mountains. No outdoor fire tonight! Instead we all gathered inside a small, nearby building.

The Lobster Cove Lighthouse.

This is Kevin. He is of French Mi'kmaq heritage. He talked about our connection to Mother Earth.