Field
Travels of Early Iowa Geologists
by Jean Cutler Prior
Geology is not confined by state boundaries. Tracing the distribution of landscape features as well as soil, rock, and resources below the ground nearly always takes one beyond the political lines drawn on a map. To understand one’s home ground, it is often necessary to examine the geology of adjoining states and regions, as well as the geology of distant places that today resemble what Iowa was like in the geologic past.
Assembling our current picture of Iowa’s geologic history began with 19th Century geologists who were remarkable for the breadth of their travels and the historic significance of their journeys. There were few geologists, vast distances to cover, and a slow pace of travel. Their perspectives on science were broad-based and encompassed various fields of natural history. Many early geologists who are identified with Iowa are also known for their work in other regions of the country. Wherever they traveled, they always displayed a strong obligation to their science - to observe, collect, and record. The story of their work and how they accomplished it is preserved in a fascinating array of early drawings, historic photographs, personal letters, and publications summarizing their investigations. These glimpses into the past show us something about the times in which these early geologists lived and the historic frame of reference in which they worked.
One of the earliest exploring scientists to study the geologic record in Iowa was David Dale Owen. Beginning in the fall of 1839, Owen began the first official geologic investigation in Iowa as part of a federally sponsored reconnaissance of 11,000 square miles of mineral lands in Wisconsin, Minnesota, and Iowa. Owen was known for his organizational and logistical skills. He gathered provisions, marshaled assistants whom he instructed in the principles of geology, organized field parties and mapped every quarter-section of land in the designated tri-state area. The results of this and later investigations were published in 1852 in a 639-page monograph that is richly illustrated with sketches of landscapes, drawings of fossils, and maps of river valley cross-sections. Rivers were the principal avenues of exploration into the country’s interior, and travel was usually by canoe. Owen was a skilled artist, and most of the report’s illustrations are from sketches he and his brother Richard drew in the field (sketches below). Owen’s pioneering work and remarkable personal energy were directed not only toward the Upper Mississippi Valley, but also to later careers as State Geologist of Indiana, Kentucky, and Arkansas.
Sketches drawn in the field by David Dale Owen and his brother Richard were used to illustrate Owen’s 1852 "Report of a Geological Survey of Wisconsin, Iowa and Minnesota." Their drawings of the Upper Mississippi River region document features of the terrain and significant bedrock outcroppings, as well as provide insights into their means of travel, lodging, and acquiring food.
Another early geologist to work in Iowa was Orestes St. John, Assistant State Geologist of Iowa between 1866 and 1869. His work focused on the coal deposits of south-central Iowa and the geology and mineral resources of the western half of the state, as well as on paleontology, especially fossil fish. By the mid-1870s, however, he was engaged in similar reconnaissance field work with the historic Hayden Surveys of what were then the "western territories," first in New Mexico and Idaho, then in Wyoming and Colorado. Travel was by pack trains of Army-issue horses and sure-footed but cantankerous mules on whose backs cumbersome loads of photographic and engineering equipment were carried. These federally commissioned expeditions of exploration and resource evaluation were led by such geological luminaries as Ferdinand V. Hayden, Clarence King, John Wesley Powell, and George M. Wheeler. The documentary artists and photographers (especially William H. Jackson, photos below) who accompanied these trips brought to the rest of the country some of the first views of the grandeur of the western mountains and thus laid the groundwork for the future establishment of such national parks as Yellowstone, the Grand Tetons, and the Grand Canyon.
Field work was difficult, with few trails and maps; supplies were difficult to obtain; and hostile Indian bands were a threat. Hayden’s field parties consisted of mining engineers, anthropologists, surveyors, zoologists, and geologists in addition to cooks, packers, photographers, and artists. Photos from National Archives.
In the 1870s, while in the Black Hills of South Dakota, the Hayden Surveys discovered fossil cycads, a prominent group of plants that flourished with the dinosaurs during the Mesozoic Era, about 60 to 250 million years ago. Like stunted palm trees, they had large frond-like leaves crowning a squat, barrel-shaped trunk, usually less than 3 ft in height. Their trunks were imprinted with the patterned scars of former leaf stalks, and they bore their seeds in cones (cycad photo below). Local ranchers collected the unusual rocks as curios in the early 1890s, referring to them as "petrified pineapples." However, one of the first scientists to actually collect and publish accounts of these cycads was Thomas H. Macbride, noted botanist, educator, and later President of The University of Iowa, as well as a valued scientist with the Iowa Geological Survey. During a visit to the southern Black Hills, he saw a petrified cycad displayed as a curio in a store in Minnekahta and was directed to the Payne and Arnold ranch (photo below) where he found 40 or 50 other specimens weathering out of a nearby hillside. He explored and collected, accumulating one of the finest collections of these fossils known at the time. His notebook of expenses for a November 1893 trip listed crackers, figs, coffee grounds, candles, lamp oil and chimney, hotel room ($2.50), meals ($.25 to $.75), train tickets, "cycad" ($10 paid to Arnold) and livery costs, presumably for a horse and buckboard to transport about 25 of the heavy fossils to Hot Springs to be crated and shipped by rail to Iowa City. On this trip, Macbride was accompanied by Iowa’s State Geologist Samuel Calvin (also Chair of the University’s Dept. of Geology), who went with him to settle the questions of stratigraphic position and geologic age of the cycad beds. Calvin determined that they were Cretaceous age (Late Mesozoic). Macbride and Calvin’s work helped bring scientific attention to what became one of the world’s prime localities for cycad fossils.
 |
Some family members at the Payne and Arnold ranch where Macbride collected and purchased cycad fossils. |
 |
This petrified cycad, collected from the ranch, shows well preserved cones and leaf scars. It became the “type specimen” for a new species of these fossil plants, which resembled short, chunky, palm trees. |
Thomas Macbride, seated on a petrified log near the cycad fields of the Payne and Arnold ranch, made a substantial contribution to knowledge about ancient plant life in North America. He was one of the first to recognize that peculiar rocks collected by local ranchers were actually fossil plants called cycads. |
 |
Samuel Calvin, Thomas Macbride, and Charles Nutting were eminent
Iowa naturalists at the turn of the 20th century. They explored
the full realm of natural science, including zoology, botany, and
geology. Obtaining specimens for study and museum displays was
the purpose of expeditions that were organized by The University
of Iowa. A particularly significant trip was to islands of the
Bahamas and Dry Tortugas in 1893. Calvin, unable to go along, was
kept advised via colorfully written letters from Gilbert L.
Houser, an instructor and assistant to the expedition leader
Charles Nutting. Houser took numerous photographs of the voyage
(photos below). Also on board was Melvin F. Arey, Professor at
what later became the University of Northern Iowa and who went on
to author several county geologic reports for the Iowa Geological
Survey. The group sailed from Baltimore on the "Emily E.
Johnson," a 95-foot, two-masted schooner (photos below).
Among other tasks, the expedition examined modern coral reefs in
the warm, clear tropical waters. Equipped with primitive,
hand-operated dredging equipment, the expedition was noted for
its success in accurately locating and collecting the graceful
"sea lilies" Pentacrinus - the rare, stalked crinoids
(photo below). Their investigations into the clarity and
temperature of seawater, and the myriad of other forms of sea
life inhabiting the warm Caribbean waters improved
scientists’ understanding of the marine environments that
were required for crinoids to thrive in Iowa’s geologic
past.
Houser writes from Havana, Cuba on May 28, 1893:"We are much elated this morning over our success on the crinoid grounds; . . . the very first cast of the tangles brought up 25 beautiful specimens of Pentacrinus! What shouting! . . . At about the 200 fathoms line, crinoids are evidently as abundant as they were during the Sub-Carboniferous times [Mississippian] represented at Burlington [Iowa]; . . .".
 |
Modern crinoids were collected for research into Iowa's past populations.
|
Our present understanding of Iowa’s geology as well as the broader national geologic picture is built on a body of knowledge first assembled by these and other early geologists with widely different experiences in diverse geographic areas. Today, we are able to import data from satellites, map on computers, and locate ourselves with Global Positioning Systems; yet it remains fundamentally important to travel, observe, collect and record - to examine the geology beyond Iowa’s borders in order to better understand the geology within.
Non-credited photos are courtesy of The University of Iowa Calvin Collection.