SENIOR FIELD SCHOOL IN CAPE BRETON ISLAND

All Geology students go to field school, but depending on when you graduated, your field school experiences will have been very varied. For many, you will remember the cold spring mornings at Crystal Cliffs with the north wind blowing off the Gulf of St. Lawrence. Others, more recently, will recall being dragged across Kings and Hants Counties, looking at rocks of the Windsor Group, and other local formations. This field school was designed to introduce students to the rudiments of field work - how to use a compass, measure a strike and dip or a geological section, or interpret a stream profile.

Up until the mid-1980's, most serious Geology students obtained summer field work with the Departments of Mines, the Geological Survey, or mineral and petroleum exploration companies. However, the enormous increase in student enrolment, combined with the down-sizing of most of these agencies, meant that fewer students were gaining geological mapping experience. Even those that did get a summer job found themselves doing mundane tasks like stream sediment sampling, or line-cutting - jobs with virtually no geological input.

To remedy this situation, we developed a second field school, taken in the fall before fourth-year classes begin, so that students could bring to it their knowledge of petrology, structural geology, sedimentology and stratigraphy. Finding a suitable area where all these subjects could be applied is not easy - especially when it needs to be near a suitable (and preferably cheap) lodging. In 1985 Sandra Barr and Rob Raeside had just completed mapping in the southeastern Cape Breton Highlands, adjacent to the Gaelic College at St. Anns. All the ingredients were there - a good mix of rock types, good exposures, sufficiently complex structures to make the exercise a challenge, comfortable(?) lodgings and lots of working space for late nights on the drafting table.

On the first day on the rocks, the whole group works up a section in the North River where they map red-bed sandstones overthrust by diorite, which in turn is faulted against a second sandstone unit sitting on granodiorite. The pace is rather leisurely - there are lots of things to see, from caliche limestones to giant hornblende crystals, and the scenery is enjoyable. So far, the water level has always been low and warm enough for us to cross the river to the fossil tree stumps. At night, students write up their day's work, and are always astonished that they had travelled only 1500 m up the river. Then they are shown the 24 square kilometres that they will map for the remaining 10 days!

For the rest of the field school students work in pairs, mapping separate areas. Recently, students from St. Francis Xavier have joined us, and the pairs are often made of one student from each university. So far we have developed five areas in the St. Anns vicinity, each with a mix of sedimentary, igneous and metamorphic rock types, and each with a suite of thin sections to help in identification of the rock types and a set of geophysical maps to match. These areas range in difficulty and accessibility, and give us the chance to adapt the exercise to individual student's abilities. Without a doubt one of the favourite streams is Goose Cove Brook, with its six waterfalls, each one higher than the last!

It has been fascinating to watch each year as different interpretations of the geology are generated. Some years the Cape Breton Highlands are thrusted over the Windsor Group, other years the Windsor is deposited on the basement rocks. The structure of the Carboniferous rocks is always a matter of great debate - is it folded (once, twice?), or is it faulted? Where does the gypsum go - it's easy to see it in the old quarry, but outcrops are very scarce elsewhere! We can't of course give out all the answers, in case next year's students are reading!

The close working conditions, the common goal, the interaction with professors ranging from crawling up the side of a waterfall to peering down a microscope, all help to build a dedication to the job at hand, as well as a realization that Geology really can be fun!