Wednesday, May 1, 2013

The Blue Rocks Event

Has it ever happened to you that something occurs you think is odd or at the very least out-of-the-ordinary…but you’re not really sure? You’re not sure because it’s come to your attention not because of one specific thing but rather a bunch of seemingly unrelated things. And to top it off, it relates to a field of study that’s not your own. Well here goes! 

It seems to me that ages ago, a here-to-undocumented and yet very significant geological event may have occurred…smack in the middle of the Blue Rocks peninsula in southern Nova Scotia. No, I’m not a geologist, so, there’s a tad bit of conjecture here on my part.

I’ve named it the Blue Rocks Event. (Click on the photos or maps for an enlarged view)

I’m a bit of a rock hound. I love looking for agates while walking along the shore on sunny days.
However, I had come up empty handed on and around the south shore in Lunenburg County. That is until I found a whole bunch of large Carnelian agates near the town of Blue Rocks; all within a 300 meter square, intertidal area, characterized by some eroding "older" glacial till at the water's edge and near the outflow of a fast flowing creek.

 It’s important to note for the rest of this post that most of the world’s agates develop as secondary deposits in hollow cavities called vesicles in ancient volcanic lava flows. These flows occurred when the continents were first forming.  During that time layers of molten lava pushed toward the earth's surface through rift zone cracks, volcanoes, and other geologic events. 

Finding so many agates in one place is unusual and they weren't worn down meaning they had to originate relatively close by; and after all Blue rocks is a peninsula. When I got home I sat down at my computer and looked up the area on Google Earth, to see if I could follow the creek bed further inland and spot something. I was surprised when the satellite shots on my computer screen seem to show what I perceive as possible magma flows originating in the center of the peninsula. They seemed to me to radiate outward in an unmistakable circular pattern, flowing out to cover the whole of the Blue Rock’s  peninsula and even further beyond.

I remember when I made my first visit to Blue rocks almost a year ago I thought the area had been
erode by the wind and sea thus exposing the rock formations that make Blue Rocks...well Blue Rocks. But, on visits there this week, with fresh eyes, it donned on me that at one time, this rock scape was most likely completely barren whereas now vegetation and trees have take firm hold  progressively capturing yet more wind-blown soil...indeed the inverse...this area is being overgrown.  It makes me wonder what this "mountain" of "maybe" magma looked like to the first North Americans who saw it. I am sure they would have been drawn to explore it.

I imagined that glacial, coastal, and seasonal erosion, would have been instrumental in releasing the agates from their imprisonment in this once oozing magma flow. Glacial forces in this area are from the north-east to the southwest as indicated by stria on the bedrock and the elongated Drumlin hills the glaciers left behind to the north.

In addition to agates, because of the multiple historical gold finds that have on the South shore, I have also been intrigued by the possibility, when walking on Blue Rocks, that there might be gold right under my feet. The 1891 gold rush at the Ovens was just across the bay.

The well documented events of North Africa’s collision with North America 300 or so million years ago (directly into the side of Nova Scotia), the formation of the super continent Pangaea, and the reemergence of a much larger Nova Scotia as the continents as we know them today emerged, indicates that there was some pretty dramatic shifting, folding, and sliding going on right here. The “folding” especial the anticline folds are acknowledged as central to Nova Scotia’s gold strike history.

Of course, when bedrock folds, slides, or faults the resulting friction causes great heat. That’s the
ideal scenario for hydro thermal, volcanic, or magma events and of course the concentration of gold into veins as well as the creation of agates. This recent, Bedrock Geology Map of  Lunenburg County, (OFM ME 2012-085), completed by D.H. O'Brien, and C.E. White in 2012, that I downloaded from the internet does more than highlight possible gold bearing anticline folds (dotted lines with arrows out) and syncline folds (dotted lines with arrows in), major faults, and Drumlins in the Blue Rocks area.  It also highlights, in vivid colour, that the bedrock of Blue Rocks and the bedrock peeking out in places circularly beyond, is a unique composition all its own.

Note also that the sort of tear-drop Drumlin hills you see to the North-east, deposited as the glaciers receded, seem to diminish progressively across Blue Rocks which for the most part is devoid of the kind of overburden the glaciers left behind to the north. If there were magma flows here the bedrock would have remained rather hot for millions of years; most probably during one or more of the four different glacial periods, truncating their trajectory and perhaps even augmented the more northern Drumlins in some way.

So, my agate find, the Google shots of the obvious flow pattern, the dome in the rockscape pictures, the uniqueness of the Blue Rocks bedrock, the augmented yet diminishing Drumlins, and the circular structure of the overall landscape, even beyond the peninsula, started to swirl in my head.

 I set down some rather arbitrarily circles onto a jpeg of this latest (2012) map; as a way of crystallizing my thoughts. It was incredible how well they fit.  And I deduced (My dear Watson) that those circles, and the likely hood of even more circles beyond that, should at the very least bring attention to the possibility of an important geological event, centered in Blue Rocks, that may have happened so very, very, very, long ago.

In the context of some gold claims I had secured, which ended up covering the anticline at the very center of those circles and thinking I might apply for a prospecting grant to shed more light on what I thought I had found, I shared my thoughts with some regional geological experts. They were most polite, Nova Scotians always are, but my “Event” just didn’t seem to jive with their more learned thinking.  I guess I don’t blame them. After 30 years as a professional marketing consultant I get miffed when some Dick or Jane, with no experience or training in marketing, thinks they know what marketing strategy is.

I guess it’s back to agate hunting along the shore for me…. I'll gladly put my gold prospecting on the back burner...there are too many deer ticks around in the interior during the summer anyway and I've got some sea kayaking to do.