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Introduction for Educators
LITHOPROBE is "probing" the "litho" sphere of our continent, the ground we are living on, the basis of our ecosphere. How earth scientists are investigating the unseen depths of the continent, and the often startling discoveries they have made, is described in 80 slides and 35 pages of fairly captivating text. This teaching aid aims at the serious senior-high school and undergraduate university student. Teachers may wish to read this text to students verbatim or paraphrase it. Either way, we are quite certain of the students' interest in what we present here.
In the LITHOPROBE project, earth scientists have pooled their resources to unravel the puzzle that is the history and makeup of Canada's, and our continent's, growth over longer than four billion (that is 4,000,000,000 or 4,000 million) years, searching our continental roots to well beyond 50 km depth, often below 100 km.

These scientists share a mission: to understand the makeup and dynamics of our continent's "inner space". Such a national, and multidisciplinary, voyage along Earth's hidden frontiers has never been undertaken before. Canadian scientists have been leading the way into the unseen depths of Earth. More than 600 have participated in the project so far.

So, what is underground, and what does it take to find and describe it? Who are these scientists, and what do they do?

We describe LITHOPROBE's discoveries across the width and the depts of Canada in about 23 of the 35 pages of text; we highlight the sciences and methods used in the remainder. We don't talk down to students. What our scientists are seeing is not trivial; it is exciting and revealing of nature's processes and powers. Also, LITHOPROBE has a gripping story to tell, and this mustn't be lost either.

It shouldn't necessarily take a calamitous earthquake to kindle an interest in the earth sciences, although feeling earth move and shake under our feet might persuade us that terra firma isn't always as firm as we expect it to be.

Indeed, continents move, and so do ocean floors. These changes cause enormous events: the disappearance of oceans, for instance, the creation of majestic mountain chains, the eruption of volcanoes, and, of course, earthquakes.

Through the package, we ease the viewer into the physical processes and history of the growth of our continent, the tectonic and other natural forces which have formed and deformed it, and hwo we go about finding out what has happened and how it happened.

In the process, and again in the concluding third of the package, we introduce and describe the various earth-science disciplines which let us see where eyes cannot look, and record where and how pas creations and events have evolved. Thus, a complex project, operating at the frontiers of the earth sciences, is being introduced in appropriate stages and bites, but also is shown in all its complexity.

We begin our journey of discovery into Canada's inner space at Long Beach on Vancouver Island, observing how a plate of the shrinking Pacific Ocean floor subducts under the advancing North American continent. Next we investigate the east coast at the widening Atlantic, taking a more detailed look at the phenomenon of ocean rifting and closures.

Now we are ready for the even more complex history of the oldest part of the continent, the Canadian Shield. We explain its growth from individual building blocks of microcontinents to their titanic agglomeration into the crystalline patchwork of the Shield.

Often at teh surface, but largely at depth, this old continent contains the roots and traces of several, now eroded, major mountain chains, obliterated and consumed oceans, faults, rifts, ore belts, and the tell-tale magnetic and chemical markings of their places of origin. To this Canadian Shield, nature added the Appalachians in the east and the Cordilleran system in the west.

Already having discussed a fair measure of the earth sciences during the previous voyage, we then turn our attention to the multidisciplinary aspects of LITHOPROBE: i.e., how it's done. This third chapter contains subchapters on seismic reflection and refraction surveys (or sonar eyes and ears), gravity and magnetic studies, electromagnetic geophysics, heat flow and geothermal studies, geological mapping, structural geology, igneous and metamorphic petrology, stratigraphy and sedimentology, geochemistry, geochronology, paleomagnetism, physical properties of rocks, and a summary of the earth-science disciplines used. An attached glossary explains terms used in the text.


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