The Grand Sweep of the City of Town & Country Pre-History lies beneath our feet recorded in layer upon layer of rock.

Rhyolite: 1.5 Billion years old Precambrian Era

1.5 billion years ago Missouri was a vast area of explosive volcanism. Volcanoes and fissures spewed forth upon the earth's surface thick layers of fast cooling rhyolite lava, volcanic ash and volcanic fragments. This material can be seen today as hard, blocky rocks in road cuts and on Taum Sauk Mountain about 80 miles South of St. Louis. At Longview Farm Park rhyolites lie about 2800 feet beneath the surface.

Some very primitive life forms lived in lakes that dotted the volcanic region. They were a form of algae that left structures called stromatolites and they are evidence of the earliest forms of life in this part of the country.

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Granite: 1.4 Billion years old Precambrian Era

Around 1.4 billion years ago molten rock (Magma) was injected into the earth's crust. Buried deep in the insolating crust of the earth the magma cooled slowly allowing time for crystals to grow and form coarsely crystalline granites. These granites can be seen at Elephant Rocks State Park and at Silver Mines in the Fredricktown, Missouri area. In Longview Farm Park, Granite lies about 3000 feet below the surface. Because of the way in which granite is formed no fossils are found in granite.

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Lamotte Sandstone: 550 million years old Cambrian Period

Some 550 million years ago large amounts of sand came from the North into our region. The sand formed vast sand flats which were swept by high tides. Strange creatures like Climactichnites crawled over the flats leaving trails that look like motorcycle tracks.

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Potosi Dolomite: 510 million years old Cambrian Period

Shallow seas covered much of Missouri during the Cambrian Period. Layer upon layer of a limestone-like rock called Dolomite was deposited by these seas. This seascape of the Potosi sea shows numerous cone-shaped Monoplacophorans and left coiling snails: typical life forms of this Period.

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Platin Limestone: 465 million years old Ordovician Period

Large straight shelled cephalopods, trilobites and one of the first crinoids were common inhabitants of the warm shallow seas that covered our region during the Ordovician Period.

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Burlington Limestone: 335 million years old Mississippian Period

Vast numbers of crinoids (relatives of the star fish and sea urchins) lived in the clear seas which covered our region 335 million years ago during the Mississippian Period of geologic time. One of the worlds largest concentrations of crinoid fragments make up the more than 200 feet of thickness of this limestone. Shown in this seascape are crinoids and other invertebrates of the time.

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St. Louis Limestone: 325 million years old Mississippian Period

The St. Louis Limestone lies above the Burlington Formation and forms much of the surface rock of the St. Louis metropolitan area. Like most of the Missouri strata it was deposited in shallow epicontinental seas. Rugose corals (horn corals) and colonial corals like Lithostrotionella become important parts of the marine fauna at the time these limestones were formed.

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