Tilted, eroded rock cliffs allow scientists to observe rock layers.
Orillia, Ontario, sits on a large rock formation known in the science community as the Niagara Escarpment. This rock formation is composed entirely of sedimentary rock, which has formed over the last 400 million years. Shale is found at great depths while dolostone is closest to the surface.
Orillia, Ontario
The City of Orillia is directly north of Toronto. It sits on Lake Simcoe and Lake Couchiching and is proud for being directly in the middle of Ontario's lake country. Tourist attractions in Orillia include the city's downtown district, accessible lake beaches and nearby Stephen Leacock Museum. Lake users can take advantage of Orillia's plentiful boat launches. Many visitors to Orillia also stroll through the city using its 9.5-kilometer paved trail.
Niagara Escarpment
The Niagara Escarpment is prominent in the Orillia area and, in fact, covers nearly all of southern Ontario. Scientists discovered this rock formation from areas where it tilted and shifted to the surface. Steady, gradual erosion then exposed each layer, allowing them to understand the rocks in the area without having to dig. The reason for massive erosion in this area remains unknown, but there is speculation that is could have been caused by slow weathering or by a catastrophic local event. Geologists found that the layer closest to the surface was primarily composed of dolostone. Underneath the dolostone is a thick layer of shale.
Dolostone
Dolostone is naturally occurring rock people commonly use in driveways or walkways as gravel. It is also frequently mixed with concrete and asphalt for roadways. Dolostones are light gray rocks primarily composed of the mineral dolomite. It should not be confused with limestone, which looks similar. Geologists can differentiate between limestone and dolostone using vinegar. When vinegar contacts limestone, it bubbles. When it contacts dolostone, it is stagnant. Dolostone was formed from the fossils of ancient animals that inhabited a vast sea that covered North America over 400 million years ago.
Shale
Shale, like dolostone, is a sedimentary rock, meaning it forms from the accumulation of ground sediments. If properly pressurized, silt and clay, commonly known as mud, can form shale. Therefore, shale is classified into a group of sedimentary rock known as mudstones. Shale can be easily recognized by two distinct features. It is fissile, which means it easily breaks. Shale is also laminated, meaning that each layer of shale is extremely thin. Shale and its products have significant industrial importance. Throughout history, the organic materials in black shale have broken down and formed large deposits of natural gas and oil. Certain shales can also be mixed with water to form a variety of useful clays.
Tags: Niagara Escarpment, Orillia Ontario, rock formation, sedimentary rock, closest surface
