Table of Contents
Quantitative Thematic Maps
Qualitative Thematic Maps
Theme Maps (Fanta "Z")


Geological maps began with the examination of land surfaces and then literally went underground in portraying the underlying stratification of geologic layers.

Portrait of Martin Lister [Wikipedia].

Martin Lister, 1638?–1712

           An English naturalist and physician, Lister did not subscribe to fellow countryman William Gilbert’s influential theory that the interior of the earth was composed primarily of iron; rather, he felt that top soils and clays were indicative of underlayers of different minerals. His proposal (1683) for a “Soil or Mineral Map” first launched the idea of geological mapping. To a general map of England, divided into sections and showing basic rivers and towns, he suggested adding soil data, such as he had been collecting for many years:

The Soil might either be coloured, by variety of Lines, or Etchings; but the great care must be, very exactly to note upon the Map, where such and such Soiles are bounded. . . . Now if it were noted, how far these extended, and the limits of each Soil appeared upon a Map, something more might be comprehended from the whole, and from every part, then I can possibly foresee, which would make such a labour very well worth the pains. For I am of the opinion, such upper Soiles, if natural, infallibly produce such under Minerals, and for the most part in such order. But I leave this to the industry of future times [pp. 739–740; Lister's emphasis].

Latent in his message is the concept of geological stratification, which would be championed by William Smith in the early nineteenth century. [See his entry in this Geology section.] Apparently, Lister’s call fell upon deaf ears, for more than a half-century would pass before any geological maps appeared.


Jean Etienne Guettard, 1715–1786

           Jean Etienne Guettard’s grandfather was an apothecary and physician who taught him about plants at a young age. In Paris, he pursued botanical and medical studies and by his early thirties had become médecin botaniste to Louis, the duke of Orléans. After the duke’s death in 1752, Guettard continued to enjoy the support of the duke’s son, Louis-Philippe, with rooms in the Palais-Royal, a laboratory, and guaranteed income. By this time, he was devoted to geological study, having become intrigued with the distribution of rocks and minerals during his wide travels in France while gathering data for a national geological survey. He was the first to recognize the volcanic nature of the district of Auvergne. With Antoine Grimoald Monnet, Guettard created the first geological atlas, Atlas et description minéralogiques de la France (1780).

Portrait of Jean Etienne Guettard [Wikipedia].

“Carte minéralogique où l’on quoit la nature et la situation des terreins qui traversent la France et l’Angleterre . . . 1746.” Copperplate map, 30.6 × 26 cm, one of two maps accompanying Guettard’s “Mémoire et carte minéralogique sur la nature & la situation des terreins qui traversent la France & l’Angleterre,” dated February 19, 1746. From Histoire de l’Académie Royale des Sciences (1751): 363–392 [Rare Books Division]. Both maps were engraved by Philippe Buache (1700–1773), a leading French geographer and mapmaker.

            First maps to show bands or zones of surface geological similarity. (This map is simply an enlargement of the central section of the other.) Guettard utilizes almost fifty symbols to identify the locations of different rocks and minerals, but the main focus of the map are the three bands shown by dotted lines and shaded areas: “Bande sabloneuse” (sandy zone), which includes Paris; “Bande marneus” (marly zone), which he hypothesizes continues under the English Channel to join a similar band in England; and “Bande schiteuse ou metallique” (metalliferous zone).  Guettard states his work’s raison d’être at the very beginning of his article (which I have translated loosely):

Nothing can contribute better to a general and physical theory of the earth than collecting diverse observations of minerals and rocks, and the fossils they contain, and presenting them all at one glance [sous un coup d’oeil] in mineralogical maps [p. 363].

By viewing the maps, he argues, one can see a regularity in the distribution of certain rocks and metals and thus can extrapolate from these patterns the conclusions he has drawn about the bands.

“Carte minéralogique, où l’on voit la nature des terreins du Canada et de la Louisane . . . 1752.” Copperplate map, 25.5 × 29.6 cm, one of two maps accompanying Guettard’s “Mémoire dans lequel on compare le Canada à la Suisse, par rapport à ses minéraux,” dated June 7, 1752. From Histoire de l’Académie Royale des Sciences (1756): 189–220, 323–360 [Rare Books Division]. Both maps were engraved by Philippe Buache.

           First geological map of North America. Never having traveled to New France, Guettard examined sample rocks that had been sent back to France and also drew from the firsthand observations of other countrymen, particularly those in the landmark Histoire et description générale de la Nouvelle-France (1744) of the French Jesuit Pierre-François-Xavier de Charlevoix (1682–1761) and a memoir by Quebec physician J. F. Gautier. He found enough parallels with Europe to apply his system of three mineralogical bands to the new continent.

William Smith, 1769–1839

           Considered now the father of English geology, William Smith waited for most of his life to get the recognition he deserved. Raised by his uncle, Smith found work in 1787 as a surveyor’s assistant; later, he worked for an extended period for the Somerset Coal Canal Company. At the Mearns Pit in High Littleton, he first observed a predictable pattern of layers or strata in the vertical rock and a consistent order among them. Moreover, he noticed that each layer could be identified by its fossils and that a succession of fossil groups, from older to younger, paralleled the changes in rock strata. This principle, which he termed faunal succession, became his operative hypothesis, the consistency of which he spent years in testing around England and Wales by collecting fossil samples and mapping locations of their related strata. In time, he was known as “Strata Smith.”
            Drawing on his growing collection of fossils, Smith began publishing these findings; important titles were Geological Table of British Organized Fossils (1815) and Strata Identified by Organized Fossils (1816). In 1815, Smith also released his large-scale (five miles to the inch!) geological map of Great Britain, “A Delineation of the Strata of England and Wales with a Part of Scotland,” the first national geological map, which, in a recent biographer’s words, “changed the world.”
            But Smith’s works were quickly plagiarized; he became bankrupt and was thrown into debtor’s prison. When he emerged in 1819, he found that his home and property had been repossessed. For a number of years Smith resorted to working as an itinerant surveyor and gave lectures before his achievements began to be fully recognized and appreciated. In Scarborough, he raised money to build a rotunda-shaped museum to display fossils in their proper chronological order; today, it is called the William Smith Museum of Geology.
            In 1831, the Geological Society of London bestowed on him the first Wollaston Medal, its highest award; the following year, the British government honored him with a pension of 100 £/year. With several others, Smith was appointed by the government to make a tour (1837–1838) through England and Wales to select suitable stone for the building of the Houses of Parliament. Sand-colored magnesium limestone, from Bolsover Moor, Derbyshire, was ultimately chosen—this project was his last scientific engagement.
            Great Britain’s modern geological map is still based on Smith’s landmark 1815 work, the original of which is protected behind a blue curtain beside the main staircase at the Geological Society’s London office.

Portrait of William Smith, aged 69. From Horace B. Woodward’s The History of the Geological Society of London (London: Geological Society, 1907) [General Library Collection].


“General Map.” Copperplate map, with added color, 23.8 × 18.8 cm. The index map for John Cary’s Cary’s New Map of England and Wales . . . (London: J. Cary, 1794) [Rare Books Division]. This map is an early example of one using Greenwich as the prime meridian (0°).

            Smith chose this as his base map when he began to color in the extents of geological formations that he had developed from his notes—the beginning of his pioneer attempt to map the entire country. The resulting small-scale map, titled “General Map of Strata in England and Wales,” simply expanding on Cary’s title, was finished in 1801.

[Below] “A Delineation of the Strata of England and Wales with a Part of Scotland, Exhibiting the Collieries and Mines, the Marshes and Fen Lands Originally Overflowed by the Sea, and the Varieties of Soil According to the Variations in the Substrata, Illustrated by the Most Descriptive Names” (London: J. Cary, August 1, 1815). Reduced facsimile copy (2003) of Smith’s copperplate map, 127 by 88 cm [Map Library].

            Smith’s landmark map. Four hundred copies of the original were printed, numbered, and signed; only about forty are known to be extant. It was dedicated to the noted English naturalist and botanist Sir Joseph Banks (1743–1820), who had been Smith’s supporter and first subscriber. Among other things, the map changed the human concept of geological time.
            The map is so large—this copy is half the size of the original—that one easily can lose sight of the detailed and extensive information that Smith has provided. The coal-bearing regions are appropriately colored charcoal, and the locations of the collieries are marked with plus signs (+). Lead, copper, and tin mines are also identified.

Portrait of Baron Georges Cuvier. From vol. 2 (1833) of The Gallery of Portraits: With Memoirs (London: C. Knight, 1833–1837) [Rare Books Division].

Georges Cuvier, 1769–1832
Alexandre Brongniart, 1770–1847

           Born in Montbéliard, France, Georges Cuvier was a precocious youth who was drawn to natural history at the age of ten and acquired the animal knowledge of a first-rate naturalist by twelve. In his early twenties, he began comparing fossils with extant forms, leading, in 1796, to his presentation of two landmark papers. One, by providing his analysis of the fossils of elephants, mammoths, and other skeletal remains that he later named “mastodon,” proved that all were distinct species and, therefore, that mammoths and mastodons must be extinct. Moreover, he concluded that some kind of catastrophe had precipitated the demise of these extinct species. The other paper argued similarly about the skeleton of a large animal found in Paraguay that was related to, but different from, living sloths: here was another extinct species. As a result, Cuvier is credited with ending the debate about the extinction of speci es—most fossils were “extinct” evidence—and became a proponent of the concept of catastrophism, which claimed that past dramatic events could explain changes in geological features and the extinction of species. (Interestingly, while believing in extinct species, Cuvier rejected the idea of evolution.)

            The son of an architect, Alexandre Brongniart became a chemist and mineralogist, a combination that suited him well for a later career in ceramics. (From 1800 until his death, he directed the internationally famous Sèvres porcelain factory and founded the Musée National de Céramique-Sèvres, the national museum of ceramics.) In earlier years, he taught mineralogy in Paris, introduced a new classification scheme for reptiles, made the first arrangement of Tertiary Period geological formations, and contributed the first thorough study of trilobites, extinct arthropods that would prove useful in date-marking Paleozoic strata. In 1804, he began studying the fossil-bearing terrain of the region around Paris with Cuvier. The final version of their findings was published in 1811.

Portrait of Alexandre Brongniart. From Jules Pizzetta’s Galerie des naturalistes: Histoire des sciences naturelles depuis leur origine jusqu’a nos jours (Paris: A. Hennuyer, 1891) [General Library Collection].


[Above] “Carte géognostique des environs de Paris . . . 1810.” Copperplate map, with added color, in twelve sections backed on linen, 61.4 × 71.4 cm. From Cuvier and Brongniart’s Essai sur la géographie minéralogique des environs de Paris, avec une carte géognostique, et des coupes de terrain, 2 vols. (Paris: Baudouin, 1811) [Historic Maps Collection].

            Landmark geological map that helped establish paleontological stratigraphy, the idea that distinctive fossils found in various sedimentary strata can be used to date the rock layers. [See also William Smith in this Geology section.] Cuvier and Brongniart’s discoveries proved that the strata formations in the Paris basin had been laid down under alternating fresh and saltwater conditions—hence, there had been inland seas at various times in the remote history of the region. Dotted lines indicate the men’s travels, identifying the areas that they observed directly. Intermediate regions were characterized from accounts of others accumulated over time and from information available from architectural sites and quarries. The men had no data precise enough to label regions shown uncolored on the map. Strata identified by the colors include limestone (“craie” ) in pink, gypsum (“gypse”) in blue, and marine gypsum marls (“marnes marines de gypse”) in yellow. The green areas are labeled freshwater terrain (“terrein d’eau douce”).

“Figure 3” from the large, untitled plate containing numerous cross-section views of stratified rock, 38.3 × 74.9 cm. From Cuvier and Brongniart’s Essai sur la géographie minéralogique des environs de Paris . . . (1811) [Historic Maps Collection].

            A cross section (height in meters, distance in kilometers) of the terrain in the Versailles–Meudon region southwest of Paris. The fact that fossils of “huitres” (oysters) were found near Versailles—and about thirty meters below the surface—indicates the former presence of an ocean. Despite the separation of a valley of approximately ten kilometers in width, the strata for the two highest spots shown (Sataury and Meudon) are very similar, lending more support to the idea of a specific order of geologic layers.

Portrait of William Maclure. From Samuel George Morton’s “A Memoir of William Maclure, Esq., Late President of the Academy of Natural Sciences of Philadelphia,” in American Journal of Science and Arts 47 (1844): 1–17 [General Library Collection].

William Maclure, 1763–1840

           Called the father of American geology, William Maclure was born in Scotland. At nineteen, he traveled to New York to enter upon a commercial career, eventually becoming a partner in an American firm in London. By 1797, he had made a fortune and retired to devote himself to the study of natural history, primarily mineralogy and geology. For the next twenty years, Maclure traveled widely in Europe and the United States. His journey from Maine to Georgia in 1808 resulted in the first geological map of the new country, published in the Transactions of the American Philosophical Society in 1809. Back in the United States in 1816, accompanied by the French artist and naturalist Charles Alexandre Lesueur (1778–1846), whom he had hired as an assistant, Maclure set out again through New England and the Middle Atlantic states to make a thorough revision to his geological study, which he published in 1818 to widespread acclaim. (The general accuracy of Maclure’s geological observations was corroborated in subsequent surveys.)
            By then a resident of Philadelphia, Maclure became indelibly associated with the young Academy of Natural Sciences, financing its move to an expanded building and becoming its president, a position he held (1817–1840) until his death. His patronage was crucial to the development of American science before the creation of the Smithsonian Institution (1846). His European travels exposed him to the educational teachings of Johann Heinrich Pestalozzi (1746–1827), who championed practical education geared to the individual’s unique intuition. When Maclure met the Welsh social reformer Robert Owen (1771–1858) in 1824, he became intrigued with the socialist’s plan for a utopian community in [New] Harmony, Indiana, and agreed to invest heavily in it. In December 1825, Maclure and others recruited from the Academy of Natural Sciences traveled by boat to the new community. (Also aboard Owen’s boat was John Chappelsmith; see his entry in the Meteorology section.) There, Maclure took charge of its educational program; established a journal and a printing press, which published notable works by Lesueur on ichthyology and Thomas Say’s groundbreaking volumes, American Conchology; and continued his financial support even after the community fell apart as a result of incessant bickering.
            He retired to Mexico in 1828, where he lived the rest of his life. Unmarried, Maclure left no descendants; his estate was divided among his scientific and educational interests.


[Above] “Map of the United States of America, Designed to Illustrate the Geological Memoir of Wm. Maclure, Esqr.” Copperplate map, with added color, 31.4 × 42.7 cm. From Maclure’s article “Observations on the Geology of the United States of North America, with Remarks on the Probable Effects That May Be Produced by the Decomposition of the Different Classes of Rocks on the Nature and Fertility of Soils: Applied to the Different States of the Union, Agreeably to the Accompanying Geological Map,” which he read before the American Philosophical Society on May 16, 1817, and published in Transactions of the American Philosophical Society, Held at Philadelphia, for Promoting Useful Knowledge 1 (new ser., 1818): 1–91 [Rare Books Division].

            First geological map of the United States, published by the important, Scottish-born American mapmaker John Melish. This is the revised, larger version of the map that Maclure originally published in the Transactions in 1809. Here, in broad strokes, he identifies six different geological classes: primitive rocks, transition, secondary, alluvial, old red sandstone, and salt/gypsum. (Note that the chain of the Appalachian Mountains is correctly labeled as containing the most primitive, or oldest, rock.) Maclure avoids speculating on the origins or agents of geological change, which he believes is not productive, and instead directs his attention to making observations that will have practical uses:

A knowledge of the nature and properties of rocks, and the results of their decomposition, enables us to judge of their hardness, easy or difficult decomposition, their component parts, mode of splitting, &c., by which we judge of their fitness for house buildings, roofing, road making, burning for lime, china or pottery, brick making, glass making, hearths for forges and furnaces, &c. [p. 5].

He hopes for the day when college students will study the properties and uses of such substances to the extent they now devote to the study of “mere words.”
            After the presentation of his geological findings, Maclure takes the opportunity to draw some political conclusions from the country’s topography and to make some rather astute prognostications:

Placed on an extensive coast, accessible at all points to the depredations of a superior fleet, he [the inhabitant of the Atlantic region] is easily persuaded by his rulers to keep up a fleet and an army to protect commerce, &c. tending doubtless to involve us in all the wars of Europe, at the enormous expense it must always cost a government such as this. Taxes follow in proportion. The inhabitants of the west pay their proportion of these taxes without the same feeling or interest. The breach widens by the natural gravitation of interest arising out of situation; and nothing can long keep them together but the utmost prudence and economy in the federal rulers, by avoiding war and every cause of expense [p. 89].

Maclure foresees a bright future for the residents of the Mississippi basin, where a naturally protected country with diverse climates and easy inland navigation provides a better environment for perpetuating a free and equal representative government. For the need (excuse) to maintain a fleet or standing army, he notes, has always produced the ruin of such governments.

Bottomed on a free and equal representation of men, they [the western inhabitants] will most probably be governed by the majority; not like the greatest part of the Atlantic states, which are founded on a representation of property, and liable to be governed by the few or minority. Monopoly of property ensures monopoly of power, and the means of perpetuating it, as is proven by the experience of all other nations [p. 90].

Still, he indulges the hope that the United States will “long be governed by the positive majority, and remain a place of refuge to oppressed humanity” [ibid.].

Plate II.” Copperplate chart, with added color, plate size 20 × 26.5 cm. From Maclure’s 1818 geological article.
            The chart provides five cross sections of the United States, north to south (I to V), from the “great secondary basin of the Mississippi” River (left side) to the Atlantic seashore (right side). The colors identifying different strata correspond to those used on his map.

Edward Hitchcock, 1793–1864

            Ordained as a Congregational minister, Edward Hitchcock became a professor of chemistry and natural history, then a professor of natural theology and geology, at Amherst College in Amherst, Massachusetts. His course on geology became a requirement for graduation. From 1845 to 1854, he was president of the college (its third), overseeing a religious revival at the institution. During those years he was also leading geological surveys in Massachusetts and neighboring states. He was appointed state geologist in 1830, a post he held until 1833 and, again, from 1837 to 1841. His 1833 Report on the Geology, Mineralogy, Botany, and Zoology of Massachusetts was the first of such state-authorized reports and became a recognized standard. In 1840, he cofounded the Association of American Geologists, which would later reorganize as the American Association for the Advancement of Science (AAAS) and grow into the world’ s largest general scientific society. In both his geological and paleontological publications, he tried to reconcile his religious beliefs with his discoveries, at one point interpreting a single Hebrew character in Genesis to imply the passage of vast spans of time in the earth’s history. The collection of fossil footmarks (dinosaur tracks) begun by Hitchcock with his finds along the Connecticut River Valley is now the largest in the world and resides in the Beneski Museum of Natural History at Amherst College.

Portrait of Edward Hitchcock. From W. S. Tyler’s History of Amherst College during Its First Half Century, 1821–1871 (Springfield, Mass.: C. W. Bryan, 1873) [General Library Collection].

“A Geological Map of a Part of Massachusetts on Connecticut River, 1817.” Engraved map, with added color, 37 × 18 cm on sheet 45 × 21 cm, accompanying Hitchcock’s article “Remarks on the Geology and Mineralogy of a Section of Massachusetts on Connecticut River, with a Part of New-Hampshire and Vermont.” From American Journal of Science, More Especially of Mineralogy, Geology, and the Other Branches of Natural History; Including Also Architecture and the Ornamental as Well as Useful Arts 1, no. 2 (1819): 105–116 [Historic Maps Collection].

            Earliest detailed geological map of an American region. Included is a profile of the strata of rocks from Hoosac Mountain (in Massachusetts) to a point eleven miles east of the Connecticut River. In his article, Hitchcock notes some interesting anthropological (and other) discoveries made in the Deerfield area:

The plain on which the village of Deerfield stands, with the adjoining meadows, is sunk 50 or 60 feet below the general alluvial tract, and was undoubtedly the bed of a pond, or small lake. . . . On digging below the surface, stones are found calcified by fire. These are probably the spots where Indian wigwams formerly stood. Many vestiges of the aboriginals are frequently found in Deerfield, such as beads, stone pots, mortars, pipes, axes, and the barbs of arrows and pikes. . . . In the meadows, logs, leaves, butternuts, and walnuts are found undecayed, 15 feet below the surface; and stumps of trees are observed at that depth, standing yet firmly where once they grew. In the same meadows, a few years since, several toads were dug up from 15 feet below the surface, and three feet in gravel. They soon recovered from a torpid state and hopped away [pp. 107–108].

“Paleontological Chart.” Lithograph chart, with added color, 29.7 × 35 cm. From Hitchcock’s Elementary Geography: A New Edition, Revised, Enlarged, and Adapted to the Present Advanced State of the Science, with an Introductory Notice by John Pye Smith, 30th ed. (New York: Ivison & Phinney, 1857) [Historic Maps Collection].

            Based on Hitchcock’s Amherst teaching, this was the first truly American textbook on the subject, not merely an Americanized version of a European work. It was extremely popular and went through thirty editions before the Civil War. First appearing in the 1840 edition, the exhibited chart is the earliest known to graphically link paleontological evidence of ancient plants and animals with geological eras using the concept of a tree with branches, which was Hitchcock’s innovation. (Several years earlier, German geologist Heinrich Georg Bronn had published a similar chart, but in circular form, in his Lethæa Geognostica.) Whereas humans are shown to be the crowning achievement of animals, palm trees hold that position for plants; as Hitchcock explains, they have developed in great abundance, with more than one thousand species described.
            As a fervent Christian, Hitchcock, of course, believed that species were introduced and extinguished by a Supreme Being at appropriate times in the earth’s history, and he rejected the theory of evolution. “[T]he principles of science, rightly understood, should not contradict the statements of revelation, rightly interpreted” (Elementary Geology, 1857 ed., p. 345). Hence, after Charles Darwin published his On the Origin of Species (1859), Hitchcock dropped the chart from his textbook, for a “tree of life” then became synonymous with an evolutionary tree.

[Above] “A Geological Map of Massachusetts.” Lithograph map, with added color, 44 × 70 cm. From the atlas volume accompanying Hitchcock’s Report on the Geology, Mineralogy, Botany, and Zoology of Massachusetts (Amherst, Mass.: Press of J. S. and C. Adams, 1833) [Graphic Arts Collection].

            First geological map of a U.S. state, greatly expanding the Massachusetts part of the map of the Connecticut River Valley that he had published in the American Journal of Science and Arts in 1823.

Table of Contents
Quantitative Thematic Maps
Qualitative Thematic Maps
Theme Maps (Fanta "Z")