Topeka High School is a landmark in Topeka, Kansas. It opened in the 1930’s and cost 1.75 million dollars to construct. Designed by Thomas Williamson, the project was completed in 18 months. One of the impressive aspects of this structure is the collection of rocks and minerals used in construction.
Limestone
The base of the building is faced in native Kansas limestone, which was quarried in the southeastern part of the state. Limestone is a sedimentary rock that generally forms from marine deposits and is composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate.
Like most other sedimentary rocks, most limestone is composed of grains. These grains are often the skeletal fragments of marine organisms such as coral or foraminifera. Other carbonate grains comprising limestones are ooids, peloids, intraclasts, and extraclasts. These organisms secrete shells made of aragonite or calcite, and leave these shells behind after the organisms die. The rice-like objects within the stone of this structure are fusalinids, a marine organism that inhabited the seas covering Kansas during the Mesozoic Era. These are even more prominently visible in the limestone found at the Statehouse, two blocks east of the school.
The weathering of limestone is inevitable. Moisture and acidity in the air dissolves the calcium carbonate from which the stone is made. The result is a flakey appearance.
Slate
The portions of the roof facing the streets are covered with slate. It was quarried in slabs of a quarter to an inch think and was attached with over a ton of copper nails. The amount of slate in this roof weighs a total of 157 tons. Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism.
Slate is particularly useful as a roofing material because it has an extremely low water absorption index (less than 0.4%). This low tendency to absorb water makes it resistant to frost damage and breakage due to freezing.
Brick
There are 500,000 face bricks used in this building. They were hand-made in Carlinsville, Illinois using the clay of Illinois. These types of bricks were also used in the most expensive homes in St Louis at the time. Clay minerals are typically formed over long periods of time by the gradual chemical weathering of rocks, usually silicate-bearing, by low concentrations of carbonic acid and other diluted solvents. These solvents, usually acidic, migrate through the weathering rock are formed as the result of a secondary sedimentary deposition process after they have been eroded and transported from their original location of formation. Clay deposits are typically associated with very low energy depositional after leaching through upper weathered layers. In addtion to the weathering process, some clay minerals are formed by hydrothermal activity. Clay deposits may be formed in place as redisual deposits in soil, but thick deposits usually environments such as large lakes and marine basins. Primary clays, also known as kaolins, are located at the site of formation. Secondary clay deposits have been moved by erosion and water from their primary location.
Marble
Marble lines the hallways on the first floor of the building. Marble is a non-foliated metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. The rock used here was quarried in Tennessee and represents the total supply of a small pocket of the quarry. There was great care in selecting and matching the patterns.
Granite
There is a bench setting in the front foyer that is made of granite, an igneous rock. This bench was a gift from Sarah McNeive’s 1949 classmates honoring all of the work she had done for her class. It was made by the Carthage Marble Corporation in Kansas City, MO.
Granite is a widely occurring type of intrusive, felsic, igneous rock which is granular and crystalline in texture. This rock consists mainly of quartz, mica, and feldspar. Occasionally some individual crystals (phenocrysts) are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic texture is sometimes known as a porphyry. Granites can be pink to gray in color, depending on their chemistry and mineralogy. By definition, granite is an igneous rock with at least 20% quartz by volume. Granite differs from granodiorite in that at least 35% of the feldspar in granite is alkali feldspar as opposed to plagioclase; it is the alkali feldspar that gives many granites a distinctive pink color. Outcrops of granite tend to form tors and rounded massifs. Granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels. Granite is usually found in the continental plates of the Earth's crust.
To Log This Cache
1) Describe the coloring of the slate tiles on the roof.
2) What is the elevation at GZ?
3) Describe the coloring of the brick.
4) Can you detect any weathering in the limestone? Describe such.