Zeolites of the Bay of Fundy

Zeolites are an important industrial mineral that are found in only a few areas around the world. They have very unusual chemical properties. The two main areas worldwide known for their rich zeolite abundances are in the Bay of Fundy and in the Poona Field in India. Zeolites are found in amygdaloids and veins in the North Mountain volcanic basalt formation. They are normally found in between zones of successive lava flows. The zeolites were deposited after the crystalization of the basalt and have a hydrothermal origin. The north mountain dates to the Jurassic Era, making it around 190 million years old. The north mountain is composed of many tilted layers dipping toward the Bay of Fundy, and the zeolites are normally found along the top layers of the lava flows. The basalt is exposed along the south side of the Bay of Fundy, especially near Parrsboro, and various local islands.

Zeolites have an interesting chemistry composed of hydrated aluminosilicates with alumina and silica linked with oxygen atoms. They also contain some calcium and/or sodium. Zeolites are framework silicates that are related to the feldspar family. However, they form under lower pressure and in more temperate environments. Zeolites contain ports, or open lattice structures in the zeolite molecules that make passageways. For example, in a half pound of zeolite, there is enough surface area from the pores to cover an entire football field. The pore diameter and characteristics are homogeneous. There are several types of zeolites found along the Bay of Fundy. These are:

1. Analcite which has a hardness of 5.5 and are found on Two Islands, Amethyst Cove, Cap d'Or, and Swan Creek.

2. Apophyllite which has a hardness of 4.5-5.0 and is found on Amethyst Cove, Sheffield Bluff, Isle haute, Port George, and Murray Brook. Apophylltes are not actually zeolites, but are closely related.

3. Chabazite which has a hardness of 4.5 and is found in Wassons Bluff, Partridge Island, and Moose Island.

4. Gmelinite which has a hardness of 4.5 and are found on Two Islands, Pinnacle Island, Wassons Bluff, and Partridge Island.

5. Heulandite which has a hardness of 3.4-4.0 and are found in Harbourville, Bennett Bay, Sheffield Bluff, and Wassons Bluff.

6. Mesolite which has a hardness of 4-5 and are found in Port George, Margaretsville, Halls Harbour, Amethyst Cove, and Cap d'Or.

These are just a few of the many zeolites that are found along the North Mountain.

(all information for this entry was taken by a handout from Dr. G. Pe-Piper in the department of Geology, as well as from Wikipedia).