On section nineteen, township of Summerfield, ore is formed on the borders of a marsh of about ten acres. The marsh is fed by springs and is unaffected by drought. The ore is deposited in loose, amorphous masses, mingled with shot ore. The sandy soil of the neighboring plains is much mingled with particles of shot ore resembling fine gravel. Several hundred loads might be obtained from this locality.

On section twenty-five, ore was discovered in digging a trench through a marshy swale. It is found over about an acre, principally disseminated in the state of shot through the sandy peat soil, in a stratum not exceeding six inches thickness. In the dry border some heavy mamillary ore is found, in loose pieces, some of which weigh several pounds.

On a neighboring farm ore of a similar character was thrown out in ditching. A few loads might be obtained.

Swales similar to the above abound, and other localities of ore will no doubt be found whenever sufficient inducement shall be offered for its search.

Numerous indications of bog iron were seen in township of Bedford. No valuable deposite came under my observation. A locality is said to exist, supposed to be in quantity, on section three, (township nine south, range seven east.)

Indications also exist in township of London and elsewhere.

A bed of sandy red ochre is found on section twenty-one, Bedford, covering about three square rods, with a depth of from one to three feet. It is immediately underlayed by limerock. A small quantity has been applied as a paint and tolerably answers the purpose.

Boulders.

Numerous water-worn fragments of the primary rocks are found lodged on the limestone hillocks, and accompanying the ranges of limerock throughout the country, but seldom occur elsewhere upon the surface. Similar boulders are found imbedded in the blue clay deposite.

A large boulder from the limerock formation was noticed on section four, township of Milan.

Phenomena accompanying the Limerock.

Sink-holes. In the township of Whiteford occur a number of those bowl-shaped depressions, known by the name of "sinks." The largest that came under my observation is near the northeast corner of the township. This immense basin occupies nearly one hundred acres, and at the centre is about fifteen feet below the general level. I found the bed to be composed of layers of blue clay and sand, covering at a slight depth limerock.

These sinks derive their name from the fact of their being col

lects for the waters of the surrounding region, which are here absorbed; no outlets being discovered. The waters no doubt disappear in a cavernous aperture of the limerock below. It is stated on good authority, that when the large sink is filled, a whirlpool may be seen of sufficient force to draw in rails floating near the vortex.

Marks of Diluvial Action.-Upon the surface of the broad, flat ledges of limerock at Point au Peaux, was observed a beautiful exhibition of the grooves and scratches supposed to be occasioned by attrition of hard bodies moving in a strong current. These have a uniform direction, north 60 east. In some instances the surface has been worn to a fine polish, which imparts a beautiful light color to the stone, and exhibits the markings as fresh in appearance as if done yesterday.

A similar phenomenon is observable at Brest, and is a fine illustration of the course and moving power of the current. The surface, about twenty square feet of which is exposed, is undulating and worn into curves. Two directions are here observed of the furrows, on contiguous portions of the same ledge; north 50° east and north 65 west.

Facts of this nature, which singly are of little importance, are noted because they have a bearing upon the results of scientific inquiries; a consequence which, though for a time unheeded and "darkly hid," tends to throw clearer light upon the ultimate plan of useful economy.

My acknowledgements are due to many persons in the above counties for hospitalities and assistance rendered in the prosecution of the survey.

Detroit, January 26, 1839.

BELA HUBBARD.
Assistant Geologist.

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GLOSSARY.

Including most of the Geological terms used in these reports from Lyell's Geology, and other sources.

Alluvial.

The adjective of Alluvium.

Alluvion. A synonim of Alluvium.

Alluvium. Recent deposites of earth, sand, gravel, mud, stones, peat, shell banks, shell marl, drift sand, &c., resulting from causes now in action. This term is generally applied to those deposites in which water is the principal agent.

Alum rocks. Rocks which by decomposition form Alum.
Amorphous. Bodies devoid of regular form.

Amygdaloid. A trap rock which is porous and spongy, with rounded cavities scattered through its mass. Agates and simple minerals are often contained in these cavities.

Anthracite. A species of mineral coal, hard, shining, black, and devoid of bitumen.

Anticlinal. An anticlinal ridge or axis is where the strata along a line dip contrariwise, like the sides of the roof of a house. Arenaceous. Sandy.

Argillaceous. Clayey.

Augite. A simple mineral of variable color, from black, through green and gray, to white. It is a constitutent of many volcanic and trappean rocks, and is also found in some of the granitic rocks.

Avalanche. This term is usually applied to masses of ice and snow which have slidden from the summits or sides of mountains. It is now also applied to slides of earth and clay.

Basalt. One of the common trap rocks. It is composed of Augite and feldspar, is hard, compact, and dark green or black, and has often a regular columnar form. The palisades of the Hudson show the columnar aspect of trap rocks. The Giants' Causeway is cited as an example of Basaltic rocks, and the columnar structure is there very strikingly displayed.

Bitumen. Mineral pitch, which is often seen to ooze from fossil coal when on fire.

Bitumenous shale. A slaty rock, containing bitumen, and which occurs in the coal measures.

Blende. Sulphuret of Zinc. A common shining zinc ore.

Bluffs. High banks of earth or rock with a steep front. The term is generally applied to high banks forming the boundaries of a river, or river alluvion.

Botryoidal. Resembling a bunch of grapes in form.

Boulders. Rocks which have been transported from a distance, and more or less rounded by attrition or the action of the weathcr. They lie upon the surface or loose in the soil, and generally differ from the underlying rock in the neighborhood.

Breccia. A rock composed of angular fragments cemented together by lime or other substances.

Calc Sinter. A German term for depositions of limestone from springs, and waters which contain this mineral in solution. Calcareous Rocks. A term synonimous with limestones. Calcareous Spar. Crystalized carbonate of lime. Carbon. The combustible element of coal.

Carbonates. Chemical compounds containing carbonic acid, which is composed of oxygen and carbon.

Carbonic Acid. An acid gaseous compound, incapable of supporting combustion, and deleterious to animal life. It is common in caves and wells, and many incautious persons lose their lives

in consequence of descending, without first ascertaining its presence by letting down a lighted candle. Man cannot live where a candle will not burn freely.

Carboniferous. Coal bearing rocks. This term has been applied to formations belonging to an ancient group of secondary rocks which contains coal. The term is now used in a more enlarged sense, and may be applied to any rocks containing coal. Chalybeate. Impregnated with iron.

Chert. A siliceous mineral, approaching to chalcedony, flint and hornstone. It is usually found in limestone.

Chlorite. A soft green scaly mineral, slightly unctuous.
Chloritic Slate. Slate containing chlorite.

Clinkstone. A slaty feldspathic or basaltic rock, which is sonorous when struck.

Cleavage. The separation of the laminae of rocks and minerals in certain constant directions. They are not always parallel to the planes of stratification, but are often mistaken for them. Coal formation. Coal measures. These terms are considered synonymous, and refer to the great deposite of coal in the older secondary rocks, which has been called the "independent coal formation." There are, however, deposites of carbonaceous matter in all the geological periods, and several of them might also be called coal formations.

Conformable. When strata are arranged parallel to each other, like the leaves of a book, they are said to be conformable. Other strata lying across the edges of these may be conformable among themselves, but unconformable to the first set of strata. Conglomerate, or Puddingstone. Rocks composed of rounded masses, pebbles and gravel cemented together by a siliceous, calcareous, or argillaceous cement.

Cretaceous. Belonging to the chalk formation.

Crop out and out crop. Terms employed by geologists and mining engineers, to express the emergence of rock, in place, on the surface of the earth at the locality where it is said to crop

out.

Crystaline. An assemblage of imperfectly defined crystals, like loaf sugar and common white marble.

Delta. Alluvial land formed at the mouths of rivers.

Denudation. A term used to express the bare state of the rocks over which currents of water have formerly swept, and laid the rocks bare, or excavated them to form valleys of denu

dation.

Deoxidize. To separate oxygen from a body.

Detritus. Broken and removed portions of rock which have been operated upon by waters or the atmosphere; frequently transported by currents to great distances.

Dykes. A kind of vein intersecting the strata, and usually fill

ed with some unstratified igneous rock, such as granite, trap or lava. These materials are supposed to have been injected in a melted state into great rents or fissures in the rocks.

Diluvium and Diluvion. Deposites of boulders, pebbles and gravel, which many geologists have supposed were produced by a diluvial wave or deluge sweeping over the surface of the earth. Dip. Where strata are not horizontal, the direction in which their planes sink or plunge, is called the direction of the dip, and the angle of inclination, the angle of dip.

Dolomite. A magnesian limestone belonging to the primary class. It is usually granular in its structure, and of a friable tex

ture.

Dunes. Sand raised into hills and drifts by the wind.

Earth's Crust. The superficial parts of our planet which are

accessible to human observation.

Eocene. The strata deposited during the oldest of the tertiary epochs, as, for example, the Paris Basin.

Estuaries. Inlets of sea into the land. water streams mingle and flow into them.

The tides and fresh They include not only the portion of the sea adjacent to the mouths of rivers, but extend to the limit of tide water on these streams.

Exuvia. In Geology, fossil remains.

Fault. A dislocation of strata, at which the layers on one side of a dyke or fissure have slidden past the corresponding ones on the other. These dislocations are often accompanied by a dyke. They vary from a few lines to several hundred feet.

Feldspar. One of the simple minerals, and next to quartz, one of the most abundant in nature.

Ferruginous. Containing iron.
Fluviatile. Belonging to a river.

Formation. A group of rocks which were formed during a particular period, or which are referred to a common origin.

Fossils. The remains of animals and plants found buried in the earth, or enclosed in rocks. Some of these are but slightly changed, others are petrified and the organic replaced by mineral matter; some have decayed and left the impression of the bodies, while others have been formed by mineral matter deposited in the cavities left by the decay of the organic body. These last are called casts. The term petrifaction is applied to those cases in which organic matter has been replaced by mineral substances. The form and structure of the original body both remain. In casts the exterior form alone is preserved. Fossils are also called organic remains.

Fossiliferous. Containing organic remains.

Galena. An ore of lead composed of lead and sulphur.

Garnet. A simple mineral, which is usually red and crystal- . lised. It is abundant in most primitive rocks.