To Do:

1. Place your hands in the sand and move it around.
2. Create different formations, such as mountains and valleys.
3. Observe how and where the virtual water flows.Note the water’s direction, speed and height.

Explanation:

Sensors detect if you made a hill or scooped a canyon.  A computer and projector overlays elevation and moving water.  Superimposing computer-generated images into our real world is called augmented reality.

Application:

Topography is the study of the Earth’s surface – high and low elevations.  It helps us understand the land’s mountains and valleys, water flow into flood plains, river deltas and watersheds, and changes over time.

The Science Central Spiral Geogarden

The rocks for the Science Central Geogarden came from original bedrock sources in northeastern Indiana and Canada. Specimens 1-3 are from nearby bedrock sources in northeastern Indiana; specimens 4-6 are from bedrock in the France Stone Co. quarry on Ardmore Avenue, Fort Wayne; and specimens 7-30 are from bedrock sources in Canada. Specimens 1-3 and 7-30 were carried to Indiana by Pleistocene glaciers about 10,000 to 15,000 years ago. The specimens were provided to Science Central by The France Stone Company, StoneCo Inc., and Irving Gravel, and were transported to the geogarden site by Fox Contractors Corp.

The two geogarden spirals lead from sedimentary and igneous rocks on the outside of the spirals to metamorphic rocks in the center. Specimens 1-4 are sedimentary dolostone rocks of Silurian age, about 410 million years old. They contain marine fossils such as bryozoa, brachiopods, crinoids, and stromatoporoids. The most unusual fossils, the stromatoporoids were extremely abundant in the Silurian seas, where they substituted for modern reef-building corals.

Specimens 5 and 6 are slightly younger sedimentary dolostone rocks of Devonian age, about 380 million years old. These rocks were deposited in supersaline seas were normal marine organisms did not thrive. These rocks have no fossils. Most of specimen 5, however, has been broken into small angular pieces, then recemented, forming breccia. Halite (salt) or gypsum may have been deposited here, then dissolved, causing the rock to collapse and break apart. Glistening masses and veins of white calcite now fill openings in the breccia. Part of specimen 5 and the upper part of specimen 6 are thinly banded (laminated) brown dolostone with no fossils.

Specimens 7-30 are among the oldest rocks on earth! They are mostly igneous and metamorphic rocks of Precambrian age, between 1 and 3 billion years old. They are from the Canadian Shield, a huge expanse of bare Precambrian rock that makes up most of eastern Canada. Pleistocene glaciers picked up and transported the boulders to sites atop local bedrock, faceting and polishing them in the process. Meltwater streams further rounded the boulders.

Specimen 30, the large central rock, is a typical metamorphic gneiss, produced by metamorphism of older igneous granite or similar rock. This gneiss was buried perhaps a mile or more beneath the earth’s surface on the Canadian Shield and subjected to intense pressures and high temperatures during Precambrian mountain-building events. Upheavals of the earth’s crust, along with erosion by streams, later exposed this rock at the surface where it was extracted by Pleistocene glaciers and transported to Indiana. This huge specimen is about 10 feet long (including about 3 feet buried below the geogarden surface) and weighs 11.27 tons.

The Geogarden Rocks:

1. 1. 1. Dolostone, gray, fossils.
      2. Dolostone, gray, fossils.
      3. Dolostone, brown, fossils.
      4. Dolostone, white, fossils.
      5. Dolostone, breccia, gray & Dolostone, laminated, brown.
      6. Dolostone, gray & brown.
      7. Quartzite (?), dark gray.
      8. Sandstone, tan, coarse & quartz pebble conglomerate.
      9. Breccia, red & gray.
      10. Quartzite, white, pure.
      11. Quartzite, jasper grains.
      12. Quartzite, pink, pure.
      13. Quartzite, brown.
      14. Metaconglomerate, gray.
      15. Metaconglomerate, gray.
      16. Tillite (?), black, with angular gray clasts.
      17. Basalt, gray, spotted, white feldspar clots.
      18. Basalt, black, polished.
      19. Basalt, black, “rusted.”
      20. Diorite, gray, polished.
      21. Granite, pink, faceted.
      22. Granite, pink, porphyritic, pink, feldspar crystals.
      23. Granite, gray-pink, small pink dike.
      24. Granite, dark gray.
      25. Granite, gray-pink.
      26. Gneiss, gray, red, weathered.
      27. Migmatite, black, pink, white.
      28. Gneiss, dark gray, contorted.
      29. Gneiss, dark gray, contorted.
      30. Gneiss, light gray, banded.

Credit:  Dr. Jack A. Sunderman, October 26, 1995