-
Difficulty:
-
-
Terrain:
-
Size: 
(not chosen)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
This is a very lovely park as you are entering Goderich (or exiting depending on which direction you are coming from). There is a nice lookout over the water plus some trail maps of all the trails in town. Have a look around this beautiful area.
Although he was prospecting for oil in 1866, Mr. Sam Platt's drilling rig hit paydirt of a different kind when it struck rock salt almost 1,000 feet beneath Goderich Harbour. The claim that he was only mildly surprised at the discovery is probably correct as native peoples of the area had earlier told him of the evidence of salt deposits throughout the region. His findings became the first recorded discovery of a salt bed in North America. By year's end, rock salt was being used as a source of brine for salt production.
Sam Platt proved to be a successful businessman when his company declared a 51 percent dividend the next years, the same year Canada became a nation.
Little did he realize, moreover, that his salt discovery was near the edge of a huge geological formation called the Michigan Salt Basin. His discovery initiated a salt rush. By late 1867, 12 independent salt wells were dotting the Maitland River valley down to its confluence with Goderich Harbour and Lake Huron. Salt fever had hit the area! San Platt had made salt, for centuries one of the world's most sought after commodities, synonymous with " the prettiest town in Canada."
The Michigan Basin is a geologic basin centered on the Lower Peninsula of the US state of Michigan. The feature is represented by a nearly circular pattern of geologic sedimentary strata in the area with a nearly uniform structural dip toward the center of the peninsula.
The basin is centered in Gladwin County where the Precambrian basement rocks are 16,000 feet (4,900 m) deep. Around the margins, such as under Mackinaw City, Michigan, the Precambrian surface is around 4,000 feet (1,200 m) down. This 4,000-foot (1,200 m) contour on the bedrock clips the northern part of the lower peninsula and continues under Lake Michigan along the west. It crosses the southern counties of Michigan and continues on to the north beneath Lake Huron.
On the north in the Canadian Shield and Michigan's Upper Peninsula, Precambrian rocks are exposed at the surface. The eastern margins of Wisconsin along Green Bay are along the margins of the basin, while Precambrian rocks crop out to the west in central Wisconsin. The northeastern margin of Illinois around Chicago are on the southwestern margin of the basin. The southeast striking Kankakee Arch continuation of the Cincinnati Arch forms the southwest boundary of the basin underlying northeastern Illinois and northern Indiana. To the east, the Findlay Arch forms the southeast margin of the basin as it strikes to the northeast across northwestern Ohio, under the bed of Lake Erie and on as the Algonquin Arch through the southwestern prong of Ontario. The Wisconsin Arch forms the western boundary of the basin.
The rocks of the basin include Cambrian-Ordovician sandstones and carbonate rocks around the margins and at depth. Above or basinward are found the Silurian-Devonian dolostones and limestones with Carboniferous (Mississippian and Pennsylvanian) strata filling the center. A relatively thin veneer of Jurassic sediments are found in the center of the basin at the surface.
The basin appears to have subsided concurrently with basin filling as the sediments within the basin are all relatively shallow water sediments, many of which are richly fossiliferous. The location was located on a geologically passive portion of crust. The development of the basin and the surrounding arches were likely affected by the tectonic activity of the long term Appalachian orogeny several hundred miles to the south and east.
Paleogeographic reconstruction showing the Michigan Basin area during the Middle Devonian period.
Within the Precambrian rocks beneath and just west of the center of the basin lies a generally north to northwest trending linear feature that appears to be an ancient rift in the Earth's crust. This rift appears to be contiguous with the rift zone under Lake Superior. This, the Midcontinent Rift System, turns west under Lake Superior and then southwest through southern Minnesota, central and western Iowa and on through southeastern Nebraska and into eastern Kansas.
The rocks of the Michigan Basin are the source of commercial quantities of petroleum. The most actively drilled-for source of natural gas in recent years has been shale gas from the Devonian Antrim Shale in the northern part of the basin.
Gypsum has been mined from rocks in the basin. Halite (rock salt) occurs in beds of the Salina Formation (Silurian) and the Detroit River Group (Devonian). The Detroit salt mine has mined rock salt from beneath the Detroit metropolitan area since 1906. Brine recovered from wells in the Michigan basin has been used as a commercial source of potassium salts, bromine, iodine, calcium chloride, and magnesium salts.
His 1866 discovery, furthermore, distributed the seeds for the eventual creation of a major North American company destined to become, by the late 1990s, one of the world's largest suppliers of salt.
Offering access to transportation by road, rail and water, the plant site was built-up, largely from fill, in Goderich harbor. Sifto's first mine shaft is circular, measures 4.88 m (16 feet) across and is completely concrete lined; it extends from the surface down to the bottom of the salt beds a distance of 549 m (1,800 feet); a second shaft, also 4.88 m (16 feet) in diameter, is located 61 m (200 feet) away. The first shaft is used for hoisting salt to the surface, the second shaft is for ventilation, personnel and equipment.
In 1981 construction started on an expansion program to increase capacity from 2,000,000 t (2,250,000 tons) to 3,150,000 t (3,500,000 tons) annually. The objective could not have been achieved without sinking a third shaft and increasing significantly the quantity of ventilating air introduced into the mine. Like No. 2, this shaft is also circular and concrete-lined but is 6.7 m (22 feet) in diameter. The reason for the increase in size is to make the cross-sectional area approximately equal to the combined total of the other two shafts, thus keeping the velocity of the ventilating air flow within tolerable limits.
In the mining operation a 12.7 cm (5 inch) gap, (or undercut) about 3.7 m (12 feet) deep is cut across the width of the mining face; the whole face, from floor to roof and side to side is then drilled with holes. The holes are filled with explosive and blasted. The undercut allows the blasted salt to fall to the floor where it can be loaded by giant loading machines. Approximately 1,620 t (1,800 tons) of salt fall from each blast.
As safety precautions the roof must be "scaled", to remove any loose salt or rock that didn't fall in the blast, and bolted to ensure that no future cracks or falls occur. These operations are carried out by men working from a "giraffe" (opposite page), that can reach to the 13.7 m (45 feet) high roof. The fallen rock salt is loaded by machine into giant diesel trucks and conveyed by them to an underground processing mill. Here the salt is crushed and screened into its various sizes and stored underground until required for shipping when it is hoisted to the surface.
In the underground maintenance shop mobile equipment is repaired, including overhaul of diesel engines, torque converters, and other power-train components. Electric power is carried down the shaft to the shop, mill, and electric powered production machines.
There is another processing mill on the surface where the salt can be screened again, if desired, and where it is packaged into the various sizes and grades in which it is shipped. There are also bulk storage bins and silos on the surface that store sufficient salt to allow prompt service in loading large boats, trucks, or railroad cars. This is a most modern salt mine, highly automated, producing nearly 50% of the rock salt produced in Canada.
To log this cache please answer the following questions and post a picture of yourself in front of the Salt Pillar.
1) Estimate how many pounds of salt are contained with this pillar of salt.
2) Who was the Minister of Mines in October 1966?
3) When facing the pillar with your back to the main road, what direction are you facing?
Additional Hints
(No hints available.)