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Joseph Thomas Pardee (1871-1960) played a key role in the Spokane Flood controversy, in which the cataclysmic flood origins of the Channeled Scabland were intensely debated during the decades of the 1920s, 1930s, 1940s, and 1950s. Pardee first drew attention to glacial Lake Missoula in 1910. He suggested it to J Harlen Bretz as a source of the cataclysmic flooding, just prior to Bretz's famous presentation of the flood hypothesis to the January 12, 1927, meeting of the Washington Academy of Sciences. Though Pardee did not publicly advocate the cataclysmic flood hypothesis, his 1940 revelation of the evidence for rapid draining of glacial Lake Missoula, including giant current ripples and immense flood bars, proved to play a pivotal role in the eventual acceptance of the cataclysmic flooding hypothesis by the scientific community.
INTRODUCTION [point to (do not click on) figure to open, click beside figure to close]
The debate over the origin of the Channeled Scabland region of eastern Washington is one of the great controversies in the history of geology. The story, as generally recounted (Baker, 1978, 1981; Gould, 1980), centers on the singular role of Harlen Bretz of the University of Chicago, but there was another major participant in that debate, Joseph Thomas Pardee.
Bretz (1978, personal communication) recalled that his interest in the scabland problem was first piqued by looking at the newly published Quincy topographic map. This map shows the great Potholes Cataract, now recognized as the product of cataclysmic flooding (Bretz et al., 1956). The year was 1910. In that same year Pardee (1910) described the geomorphological evidence for a great glacial lake occupying the intermontane basins of western Montana during the late Pleistocene. He described the prominent strandlines of the lake Fig.1 and the evidence for lake impoundment behind a glacial lobe in the basin of modern Lake Pend Oreille in northern Idaho. These relations were well known. Pardee (1910, p. 376) even credited T. C. Chamberlin with the discovery of the lake strandlines: "Chamberlin conceived the idea of a glacial dam and furthermore tentatively suggested that its location was in the Pend Oreille region with outflow by way of Spokane." The glacial lake was named for Missoula, Montana, where its strandlines were particularly prominent (Fig. 1).
HYPOTHESIZING THE SPOKANE FLOOD
In the summer of 1922, J Harlen Bretz began his field research with small field parties of advanced students in the Channeled Scabland. His scabland studies continued over the next seven field seasons. During those years Bretz traversed the entire region first on foot and later in his trusty Dodge 4, an early enclosed-body car. He did this with parties of students and his wife, son, daughter, and collie dog.
Bretz's first paper on the Channeled Scabland was the text of an oral presentation to the Geological Society of America (Bretz, 1923a). In that paper he took special care not to call upon cataclysmic origins. The paper provided a detailed description of physiographic relations in the region. He did note, however, that the indicated channel erosion required prodigious quantities of water. Referring to the three outlets at the south end of the Hartline Basin (Dry Coulee, Lenore Canyon, and Long Lake Canyon), Bretz (1923a, p. 593 594) stated, "... these are truly distributary canyons. They mark a distributive or braided course of the Spokane glacial flood over a basalt surface which possessed no adequate pre-Spokane valleys."
The idea of a truly catastrophic flood appeared in Bretz's second scab-land paper (Bretz, 1923b). His interpretation of the mounded scabland gravel deposits as subfluvial bars led directly to the requirement for great water depths. This paper also included the first detailed geomorphic map of the entire Channeled Scabland, showing the overall anastomosing pattern assumed by a great flood of water.
Much of the 1920s research in the scabland region centered around Spokane, Washington, where the glacial margin was presumed to be located. Bretz named the hypothesized cataclysm the Spokane Flood because the flood source seemed to lie near that city. A year prior to Bretz's first scab-land work, W. C. Alden, chief of Pleistocene geology at the U.S. Geological Survey, sent a junior Survey geologist, J. T. Pardee, to study the scabland region near Spokane. The result was a brief article (Pardee, 1922) proposing that the Cheney-Palouse scabland tract was created by glaciation of rather unusual character. Bretz visited Pardee's field locations a season or two later and found that Pardee's "glacial" deposits were actually flood bars (Bretz, 1974).
Various correspondence in the 1920s led Bretz to believe (Bretz, 1978, personal communication) that Pardee was actually considering flooding from a glacial Lake Missoula as a cause for the scabland topography. Bretz (1974) speculated that Alden dissuaded Pardee from the idea. Bretz saw a memorandum of September 25, 1922, to David White, chief geologist of the U.S. Geological Survey, in which Alden noted of Pardee's work: "... very significant phenomena were discovered in the region southwest of Spokane.... The results so far ... require caution in their interpretation. The conditions warn against premature publication."
At the famous 1927 "scabland debate" at the Geological Society of Washington (Bretz, 1927) Pardee was silent on the Missoula source for the flood. Bretz believed that Pardee's superiors at the Survey, particularly Alden and Kirk Bryan, were antagonistic to the cataclysmic flood hypothesis. Did Pardee indeed first hypothesize the flooding associated with the Spokane Flood controversy? Did the critical reception accorded Bretz's hypothesis (Baker, 1978) provide a deterrent to his own theorizing?
Pardee wrote to Bretz in 1925 suggesting that Bretz consider the draining of a glacial lake as a possible source for the cataclysmic Spokane Flood. In 1926 correspondence to J. C. Merriam, Bretz wrote:
Mr. Pardee of the Federal Survey, who has seen much of the scablands, has suggested that his glacial Lake Missoula might have afforded the water for these enormous rivers if it were suddenly drained out across the plateau. This comment indicates tha[t] his former view of scablands by land ice and concomitant subglacial drainage under ordinary climatic melting has been abandoned. Even our ultra-conservative in Pleistocene geology, Dr. Alden, wrote that the phenomena I describe certainly appear to be river work "if you could only show where all the water came from in so short a time."
PARDEE'S SCABLAND HYPOTHESIS
Brian K. McDonald, grandson of Thomas Large, a confidant of both Bretz and Pardee in the 1920s, has extensively researched correspondence relating to the origins of the cataclysmic flooding hypothesis. Thomas Large wrote prolifically on various speculations concerning scabland origins. Correspondence (researched by McDonald), in the summer of 1922 to Barton W. Evermann, contains the following passages:
... One of Pardee's most interesting theories is that this broad belt of rough lava extending from Medical Lake and Cheney down through the state to Pasco is due to sub-glacial water erosion. Neither glacial nor river erosion will account for it as it has no gradient, while water under pressure under the ice could cut out a hole of any depth and rise again where resistance was least. I have as yet not been able to pick any flaws in the hypothesis. As yet we are very much in doubt as to the depth of the ice sheet. Some evidence which l have would indicate not over 200 feet between Cheney and Medical Lake. Objection will be made that this is not sufficient to cause ice movement over so large an area but it must be remembered that there is an average slope from here to Pasco of about 14 feet per mile.
... Prof. J Harlan Bretz of U. of Chicago has been to see me twice since 1 wrote you. He has a group of geology students and they have gone over some of my work. He thinks that glaciation on the "prairies" may be Wisconsin but 1 am quite sure he does not make allowance for the aridity of this climate and its effect on slowing down weathering. Furthermore he must account for the two other glacial trains at lower levels which in no way connect with the dissected plateau prairies. He says my "out-let" by way of Mica, California Creek, and North Pine will stand. Also my marginal moraine at Pantops. Thinks he may find some evidence of ground ice on south side of the Spokane Valley above the city. May leave a student here to hunt for it. I am willing he should. He goes after Pardee hard on origin of Palouse soil and glaciation farther South-west. As Pardee is a careful man and had six weeks and a "Ford" to go over the ground while Bretz had about 10 days and only "Shank's mares" it looks like a good fight in prospect.
Confirmation that Pardee's views are accurately presented in Large's letters is provided by correspondence in 1943 between Pardee and University of Michigan professor W. H. Hobbs, who proposed (Hobbs, 1943) a glacial origin for the Channeled Scabland. Hobbs wrote to Pardee about the 1922 paper and received the following reply:
... The "drift" referred to in the article in Science consists of bouldery deposits which at that time (1922) I interpreted as a gravelly till transported and deposited by glaciers that extended far over the Columbia Plateau. The principal feature of the deposits that suggested glacial action is the presence of large boulders, some of them of foreign origin. From information of the region that has been made available since 1922, however, I have concluded that the deposits are more likely the work of flood waters, such as postulated by Bretz, rather than of glacial ice. That isI do not regard them as conclusive evidence of glaciation. On the other hand the deposits are indirectly, if not directly, related to glaciation and may have been formed by streams that gouged out the channels and basins under an ice cover as you suggest.
Though Pardee may not have advocated the cataclysmic flood origin of the scablands, Bretz was not its first proponent. McMacken (1937) attributed a "Flood Theory" to a teacher at Lewis and Clark High School, Alonzo P. Troth, who apparently never published his hypothesis.
Whatever the origins of the cataclysmic flooding hypothesis, J. T. Pardee played a major role in the resolution of the Spokane Flood controversy. His contribution came in rather dramatic fashion at a 1940 meeting of the American Association for the Advancement of Science in Seattle, Washington. Howard Meyerhoff (1978, written communication), who attended that meeting, recalls a key moment in a session organized to debate various proposed origins of the Channeled Scabland. The session, held on Tuesday afternoon, June 18, was entitled "Quaternary Geology of the Pacific." The session paper titles suggested that non-flood origins of the Channeled Scab-land would be strongly advocated. A postmeeting field trip had been organized during which Richard Foster Flint of Yale University would demonstrate the evidence for a noncataclysmic origin of the Channeled Scabland. Bretz was invited to participate, but he refused, noting that all of his ideas were in print and that the field evidence would speak for itself.
Early in the session Flint gave a well-prepared synopsis of his complex arguments (Flint, 1938) of proglacial outwash stream aggradation and incision. Flint had proposed that the surface form of the scabland flood bars was that of "non-paired stream-cut terraces in various states of dissection" (Flint, 1938, p. 475). This was an idea that Bretz (1923a) had introduced, but rejected after further study. Flint (1938) proposed that the normal process of channel aggradation by proglacial out-wash streams was followed by dissection to leave remnants of a fill that locally resembled bar forms.
Subsequent papers at the 1940 meeting reiterated various hypotheses for the origin of the Channeled Scabland. E. T. Hodge (1940) presented his scenario involving glacial erosion in the scablands associated with complex damming and diversions by river ice.
I. S. Allison (1940) presented a synopsis of Flint's fill hypothesis and contrasted it with his own ice-jam theory. In a later paper Allison (1941) pointed to key shortcomings in the Flint hypothesis.
The eighth speaker in the session was Joseph Thomas Pardee, who rose to speak on "Ripple Marks(?) in Glacial Lake Missoula.' The modest title and the low-key delivery were deceiving. Pardee quietly described the "ripple marks" at Calllas Prairie Fig.2, an intermontane basin in northwestern Montana. He described their size as "extraordinary," heights of up to 15 m and spacings of as much as 150 m (Pardee, 1940). His written discussion (Pardee, 1942) also had an understated title, "Unusual Currents in Lake Missoula." His work, dating back to before Bretz's studies, clearly demonstrated that Lake Missoula was the source of catastrophic floods through the Channeled Scabland. He noted that about 2000 km3 of water were held in the lake. Moreover, the glacial dam impounding this lake had clearly failed suddenly, with a resultant rapid draining of the lake. Evidence for this failure included severely scoured constrictions in the lake basin, huge bars of current-transported debris Fig.3, and the giant current ripple marks. However, Pardee (1942) did not state the connection to the Channeled Scabland. Perhaps he generously left that point to Bretz.
In the summer of 1952, Bretz, then nearly 70 years old, returned for his last summer of fieldwork in the Channeled Scabland. The purpose was to investigate new data that had been obtained in surveys for the Bureau of Reclamation's Columbia Basin project. H. T. U. Smith accompanied him, acting in the field as "skeptic for all identifications and interpretations" (Bretz et al., 1956, p. 761). George E. Neff of the Bureau of Reclamation pointed out many new exposures of flood sediments.
Bretz returned from the 1952 field season with a wealth of new data. The U.S. Bureau of Reclamation had been especially generous in supplying maps, aerial photographs, and sedimentological information. Bretz wrote the extensive report over the next year. In that paper (Bretz et al., 1956), the most convincing evidence for cataclysmic flooding proved to be the presence of giant current ripples on bar surfaces Fig. 4. These showed clearly that bars 30-m high were completely inundated by phenomenal flows of water. Numerous examples of giant current ripples were found on the same bars that Flint had interpreted as normal river terraces. Such features could have been produced only by the flow velocities associated with truly catastrophic discharges.
J. T. Pardee may have been wrong in his 1922 interpretation of scabland flood bars, but his 1940 description of giant current ripples proved to be the key point for convincing skeptics of the cataclysmic flood hypothesis. His first paper on glacial Lake Missoula was published in 1910, only one year after he began his 32 year career with the U.S. Geological Survey. His last paper on the subject appeared in 1942, the year after his official retirement from government service on May 30, 1941, at the age of 70. His recognition of the giant current ripples of Lake Missoula was followed by the documentation of 15 scabland ripple fields by Bretz et al. (1956) and nearly 100 by Baker (1973) and Baker and Nummedal (1978) (Fig. 4). The hydraulics of the cataclysmic flows have proven to be physically consistent with the various geomorphological field evidence (e.g., O'Connor and Baker, 1992). Unresolved issues remain as to the numbers, sizes, and timing of the late-glacial floods (Baker and Bunker, 1985; Waitt, 1985), which have now been named for Lake Missoula (Bretz, 1969), the source that was so well documented by Joseph Thomas Pardee.
The Spokane Flood controversy has been cited as an illustration of the role of hypotheses in geological science.
Emphasis in previous work centered on the role of the "outrageous hypothesis" (Davis, 1926) proposed by Bretz. Formal scientific publications provided the major source for description of the controversy. However, correspondence among the participants reveals a more complex and human character to the controversy. Hypotheses in geology have a profoundly human dimension. Though often associated with single individuals, usually the authors of key scientific papers, hypotheses may emerge from exchanges with colleagues over controversial explanations. The multiple working hypotheses described by Gilbert (1886) and Chamberlin (1890) are worked out among the members of a scientific community. Similarly, the eventual acceptance of a controversial explanation by that community is also a human process. The Spokane Flood controversy provides an excellent example of the social dimension to achieving reliable scientific knowledge.
I thank Brian K. McDonald for sharing the results of his archival research into correspondence relating to the Spokane Flood controversy. Conversations with the late J Harlen Bretz provided the stimulus for my original research into the history of the controversy.
Allison, I. S., 1940, Flint's fill hypothesis of origin of scabland: Geological Society of America Bulletin, v. 51, p. 2016.
Allison, L S., 1941, Flint's fill hypothesis for channeled scabland: Journal of Geology, v. 49, p. 54-73.
Baker, V. R., 1973, Paleohydrology and sedimentology of Lake Missoula flooding in eastern Washington: Geological Society of America Special Paper 144, 79 p.
Baker, V. R., 1978, The Spokane Flood controversy and the Martian outflow channels: Science, v. 202, p. 1249-1256.
Baker, V. R., editor, 1981, Catastrophic flooding: The origin of the Channeled Scabland: Strouds burg, Pennsylvania, Dowden, Hutchinson and Ross, 360 p.
Baker, V. R., and Bunker, R.C., 1985, Cataclysmic late Pleistocene flooding from glacial Lake Missoula: A review: Quaternary Science Reviews, v. 4, p.1-41
Baker, V. R., and Nunnnedal, D., editors, 1978, The Channeled Scabland: Washington, D.C., NASA Planetary Geology Program, 186 p.
Bretz, J H., 1923a, Glacial drainage on the Columbia Plateau: Geological Society of America Bulletin, v. 34, p. 573-608.
Bretz, J H., 1923b, The Channeled Scabland of the Columbia Plateau: Journal of Geology, v. 31, p. 617-649.
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