The Hawk Beach Island, not what you think! EarthCache

The Hawk Beach Island, not what you think!

Cape Sable Island, locally referred to as Cape Island, is a small island at the southernmost point of Nova Scotia. The island is situated in Shelburne County south of Barrington Head, separated from the mainland by the narrow strait of Barrington Passage, but has been connected since 1949 by a causeway. Cape Sable Island was inhabited by the Mi'kmaq people who knew it as Kespoogwitk meaning "land's end".

Hawk Beach is considered one of the most beautiful beaches in Nova Scotia, and is a popular place for bird watchers, as all of Hawk Point is a centre for migratory birds. You can walk this white sandy beach and explore the 1500 year old drowned forest; a broad area of three stumps still rooted in the original soil .A great birding destination as it is part of the Cape Sable Important Bird Area which makes it one of the best birding areas in Nova Scotia. The beach at this site is designated a Protected Beach under the provincial law. From the beach you can view the Cape Sable Lighthouse, the tallest lighthouse in Nova Scotia, standing at 101 feet tall to the south.

At the coordinates you will find an outcrop which provides a glimpse of metamorphic conditions seen at just a few locations in the province. Conditions so extreme they caused parts of the rock to melt.

Rock that was once partly solid and partly moltlen is known as migmatite, a name derived from a Greek word meaning mixture”.  Sometimes migmatite  forms across an entire region, for example, if the plate collision pushes continental crust to great depths.  In this case, though, the effect was localized. Meguma’s  sedimentary rocks were metamorphosed but still solid until a nearby igneous intrusion heated them further.

Each mineral has a specific temperature at which it begins to melt.  For quartz and feldspar, the threshold is low, about 600-700 degrees. Because they are made of quartz and feldspar, the one milten portions of the rick are light and color. Making it easy to see what happened. Broken boulders on the outcrop provide a detailed look at the effects of partial melting. Here, fine, millimeter-scale layering is cut by larger, irregular veins of quartz and feldspar that have melted.

Below note the layering in the migmatite. Because light colored minerals melt most readily and because the melted material tends to gather together migmatite consists of distinct light and dark areas. Here the process took place on several different scales. Thin layers melt just millimeters wide sweated out of the rock as the temperature rose. In addition larger amounts of melt were squeezed into zones of weakness forming irregular cross cutting veins. 

All the while as melting took place the rock was being deformed by tectonic forces acting on the region.High temperatures and partial melting both weakened the rock. For that reason, you will see many folds,kinks, and swirls in the layering.

At ground zero you can park and walk over the rocks to the beach. On your left you will see the island, which is connected by a short tombolo when the tide is out. The best time to view is just before, during and after low tide, approximately 2hr either side of low tide.

To log this Earthcache visit the viewing location.  Please answer the following questions and send in a timely manner to my geocaching profile or email. Answers not received will result in deleted logs.

Questions:

1. How far is the island from the shore?

2. Count the number of melted zones/rocks you found?

3. What causes the coloured zones in the rocks?

4. Post a picture in your log with a personal item or hand in picture to prove you were there.

[REQUIRED] In accordance with the updated guidelines from Geocaching Headquarters published in June 2019, photos are now an acceptable logging requirement and WILL BE REQUIRED TO LOG THIS CACHE. Please provide a photo of yourself or a personal item in the picture to prove you visited the site.