Page 32 - C.B.'s Geology: A Talk on the Rocks!

ISSUE : Issue 62

Published by Ronald Caplan on 1993/1/1

30 kilometers above where we are today. Now, no mountain ever gets to be 30 kilometers high because the rain and the snows will wear it away very fast. But we're looking at a moimtain range which was probably at least as high as the Himalayas are today, centred on central Cape Breton High? lands. And extending Shield in the north. We have the 600-million-year-old vol? canic arc which became a continental fragment, in the south, along the Mira terrane. Then we have another sub? duction zone arc like the Philippines, which became the Bras d'Or terrane. And then at the very end, a continental collision when the two all the way down the LOUISbOUrg HafbOUr is one of the best places continental fragments Appalachians towards Alabama, and across Newfoundland and into Britain and Norway on the other side. to see volcanic bombs • great boulders of material that erupted from volcanos and landed in the muds and the sands. (All connected?) All connected. There was no Atlantic Ocean at the time. It was all part of one mountain belt. When you start getting such a deep mountain belt, it gets very hot down there. The rocks begin to melt, and granite is pro? duced. Granite is the melted component of the roots of that mountain chain. And these plutons • those granite masses at Neil's Harbour and Margaree, and some more scattered • and all the granites down in southern Nova Scotia • were all I produced at the same time, when this mate? rial was all crumpled to? gether and a great mountain mass was pushed up. Lighthouse Electrical Services Ltd,' 155PeppettSt. NORTH SYDNEY Prop. David Mulley Let us help you Save $ on Energy! -~ Call us about energy efficiency • for your present electrical system. We now have economical & effective basic security systems. 24 HOUR EMERGENCY SERVICE Serving All Cape Breton Areas 794-2652 Well there's the framework of the story. We have the four different blocks. The old, billion- year and more, Pre-Cambrian WE'RE PROUD TO SHARE... Scottish and Acadian Festivals Hiking trails, picnic and camping parks Museums and heritage The warmest waters north of the Carolinas! Cottage crafts and works of art The Cape Breton highlands National Park Fresh and salt water fishing Horse racing, canoeing, and other sports Fine accommodations, gift shops Restaurants Wildlife The Sunset Side ' / '' of Cape Breton -T- Requests for Visitor's Guide, brochures, and general information may be made to: Inverness County Department of Recreation/Tourism P.O. Box 179. Port Hood, N.S. BOE 2W0 (902)787-2274 arrived and smashed into each other and dragged the Aspy ter? rane down into the crust, from which it has since rebounded. That melted at that time and produced all the granites that we see scattered throughout the Aspy terrane. By this time Cape Breton Island, or the Appalachian system as a whole, was really at the centre of a huge continent which stretched all the way from California on the west side of North America right across • without any ocean interrup? tion • as far as Siberia or China or East Africa. Cape Breton was far from the sea. We were in the southern latitudes, somewhere around the Tropic of Capricorn. And the climate was hot, the climate was dry. And the mountains began to wear away. And great desert sandstones and gravel depos? its were quickly laid down. Those are very visible today. They're referred to as the Horton Group, because they were first identified at Horton, near Wolf/ille. But they are ex? posed particularly around the Trans-Canada Highway at Salt Mountain near Whycocomagh. But these red sandstones are found throughout Cape Breton and mainland Nova Scotia. And these were the sandstones that were the sands and gravels that were being washed off the mountains, and were being deposited in the valleys and the basins that formed after the mountains were heaved up. I mentioned that the two continents had collided. What col? lided was probably South America with North America. The west coast of South America had collided with the east coast of North America. But the forces that had caused that colli? sion were still in operation. There were some remnant forc? es still going on. And gradually. South America was pushed sideways, towards the left. North America towards the right. And Africa moved in in place of it. Africa and South CAPE BRETON ,. n ., - Retailer of Quality Eyewear : Your Best! . Medical Plans Accepted mW0FFBUIIG2l??>l''!S FREE! Your Sign of Quality DON'T ACCEPT LESS Let our experienced staff help you with all your printing needs SPECIALISTS IN PROCESS COLOR PRINTING 180 Townsend St.. Sydney 564-8245 Fax: (902) 539-2040 539-8666

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