Take a Virtual tour of the IPFW Geogarden
This self-guided tour is designed to increase your knowledge of common rocks
found in the Fort Wayne, Indiana area. All of the specimens in the Geogarden
(which is located adjacent to Kettler Hall on the IPFW campus) were collected
in the Ardmore Avenue Quarry of France Stone and in the Lower Huntington Road
Pit of Brudi Stone and Gravel. The specimens were donated to the campus by
With two exceptions, all of the rocks shown in the geogarden originated in Canada. They formed during Precambrian time and were transported into northern Indiana during the Late Wisconsinan Stage of the Pleistocene Ice Ages, about 10,000 to 20,000 years ago. The main transporting agents were the enormous glaciers of the Pleistocene, but the last transportation and deposition of some of the boulders was accomplished by meltwater streams that issued from the glaciers. Most of the larger rocks were found in clayey glacial till, deposited directly from the ice itself, but some of the smaller rounded boulders were found in outwash gravel.
Click on the map to jump to the numbered sample.
The IPFW Geogarden is located in an area adjacent to Kettler Hall. It is a pleasant space for students, staff and faculty and serves as a valuable teaching resource for students in our introductory geology classes, as well as area schools. Signage for the geogarden was purchased with generous donations from the friends and former students of Jack Sunderman, founding member of the Geosciences Department, on the occasion of his retirement in 1994.
Some Background on Rocks and Minerals
Rocks are composed of minerals, mineraloids, glass and organic debris. Composition and texture [shape, size, arrangement] serve as the basis for the classification of all rocks. In all the world there are only three general types of rock: Igneous, Sedimentary and Metamorphic. Examples of all three are found within the IPFW geogarden.
Igneous rocks [Latin ignis, fire] are formed by the crystallization of minerals from a mass of melted rock [magma] either deep within the Earth, or from magma that reaches the Earth's surface [lava]. Igneous rocks which have mineral grains coarse enough to see without the use of a microscope form slowly deep within the Earth and are termed Intrusive or Plutonic rocks. Igneous rocks with very fine grained mineral crystals (or even glass) form quickly at the Earth's surface and are known as Extrusive or Volcanic rocks. Rock samples 1, 2, 3, 4, 5, 6, 7, 10 and 11 are examples of intrusive igneous rocks. Rock sample 8 is an example of an extrusive igneous rock.
Sedimentary rocks are formed at the Earth's surface from the products
of physical and chemical weathering. Sedimentary rocks form in places you are
familiar with: rivers, beaches, lakes, reefs, deserts as well as many other
There are two types of sedimentary rock: clastic and chemical/biochemical. This classification reflects the nature of weathering processes which produced the material comprising these rocks. Clastic rocks [Greek, klastos, to break form from the products of physical weathering: boulders, cobbles, sand, silt, and clay. The processes by which these mineral and rock particles are deposited to form a rock are physical in nature: wind, waves, stream currents and glaciers. Chemical and biochemical sedimentary rocks are the products of chemical reactions and biological processes. Familiar rocks such as rock salt, gypsum and coal are examples of chemical/biochemical sedimentary rocks, and commonly form in environments such as salty lakes, swamps, reefs and lagoons. Rock samples 15, 16, 17and 18 are clastic sedimentary rocks deposited by an ancient glacier, while samples 12, 13 and the sundial pedestal are examples of chemical and biochemical sedimentary rocks.
Metamorphic rocks [Greek meta, change, and morphe form] are created by the mineralogical and textural transformation of preexisting rocks under conditions of high temperature and pressure. Most metamorphic rocks are formed during the creation of mountain ranges when conditions of elevated temperature and pressure are achieved. There are two general types of metamorphic rocks, foliated and non-foliated.
Foliated metamorphic rocks are characterized by a distinct orientation of mineral grains to form flat or wavy planes [foliations, Latin foliatus, leafy] which are produced by folding of the rock under conditions of directed pressure. Non-foliated rocks are characterized by a uniform granular texture, lack a pronounced foliation, and are formed under conditions of non-directed pressure. Rock samples 9, 14, 20, 22, 24, 25 and 26 are examples of foliated metamorphic rocks. Samples 19, 21, 23, 27 and 28 are examples of non-foliated metamorphic rocks.
Two of the rocks deserve special mention. Rocks numbered 12 and 13 were collected from sedimentary bedrock in the France Stone Quarry, and thus are local rocks. One of them (no. 13) is a part of an ancient barrier reef that extended across northern Indiana during Late Silurian time (about 410 million years ago). It contains at least three prominent fossils, including a typical Silurian coral. The other (no. 12 ) is a slightly younger rock from Devonian strata at the top of the bedrock in the quarry, and exhibits typical brachiopod fossils that lived in the shallow Devonian seas.
Another feature of the geogarden is the sundial on the north edge of the exhibit. The sundial is constructed from one of the most famous building stones of the world, the Salem Limestone. Other commercial and popular names for this rock are the "Indiana Limestone," the "Bedford Stone," (after the town of Bedford at the south end of the Bloomington- Bedford quarry district, and the "Oolitic Stone," after small spherical mineral bodies that occur in the rock. Most of the spherical bodies in the Salem Limestone, however, are actually small fossil shells coated with extra layers of calcite. Note that some of the walls of Kettler Hall are faced with granite, and that the columns of the building are of Salem Limestone.
Stop by the Science Building (SB 230).
Or call 260-481-6249 if you have questions.