by John Dvorak
His nighttime routine was almost as unconventional as his daytime one. He seldom returned to camp before darkness—his camp defined by wherever he had left his car, a Ford coupe. Then he had his major meal of the day: a slice of bread, a half can of beans, a few leaves pulled from a head of lettuce, several cups of water, and finally a cup of coffee. He then proceeded to prepare his bed. He pulled out a wooden plank and laid it across the front seat of his coupe so that part of the plank extended outside the open door on the driver’s side of his coupe. He then stretched out and fell asleep: The bottom half of the steering wheel was sawed off so that he could turn without waking himself up.
Dibblee was only half of the equation that would lead to the discovery of a major oil reservoir for Richfield executives—and that would lead to uncovering compelling evidence for hundreds of miles of movement along the San Andreas Fault. The other half was similarly quiet and highly capable young field geologist Mason Lowell Hill.
Hill was also a Californian, born in Pomona, east of Los Angeles and about 20 miles south of the San Andreas Fault. He attended the University of California at Berkeley for one year, where, according to Hill, he “suffered” through one of Lawson’s classes. He thought Lawson was “opinionated and intolerant,” though Hill admitted that Lawson was “a highly competitive and competent geologist.”
After his single year at Berkeley, Hill enrolled at the University of Wisconsin, where he became fascinated—and obsessed—with earthquake faults, focusing on how to recognize them in the field and how they worked.
Hill was hired by Richfield Oil Company to join Dibblee and a half dozen other young geologists to search for oil in the Coast Ranges between Bakersfield and Santa Barbara. As was common practice, Richfield Oil employed a few local ranchers as “scouts” to keep company executives informed in case anyone started to drill a well and to send a message immediately if something important was found. On New Year’s Eve, 1947, one of the “scouts” sent a message to a Richfield executive.
A few months earlier, the Norris Oil Company, an independent operator and one of Richfield’s rivals, had commenced drilling a well close to an oil seepage on the side of Chalk Mountain at the northern end of Cuyama Valley. Norris, so the scout told the Richfield executive, had hit “an oily sand” at a depth of a few thousand feet.
That set the Richfield Oil Company in motion. The executives were all in Pasadena, planning to attend the Rose Bowl game, when the call came from the scout. They abandoned their plans, and by driving cars and flying in chartered airplanes, they fanned out across the country, making personal contact with the owners of the various land plots in Cuyama Valley (most were absentee landlords who leased their lands to local ranchers). Within two weeks, to the shock of their competitors, Richfield had acquired oil leases to over 150,000 acres of land, almost the entire valley. The executives then sent Dibblee and Hill to decide exactly where to drill.
For the next few weeks the two men studied the area, Hill recalling that he did “some reconnaissance work” while Dibblee “did some semi-detailed geologic mapping of quite a big area.” Finally, by early February they had decided—though they could never explain how they made their decision, which is part of the continuing mystery of exploring for oil—where their company should drill: four miles south of the well drilled by the Norris Oil Company, on the Russell Ranch at the north end of Cuyama Valley.
Four tense months followed. Executives at Richfield had bet the company’s financial resources—and its future—on the recommendation of two young unorthodox geologists. On June 13, 1948, several executives were at the drill site evaluating the progress. They were with the ranch owner, Hubbard “Hub” Russell, a barrel of a man who said early that day he had his doubts whether anything dramatic would ever happen. What followed was a scene reminiscent of a Hollywood movie.
By then, the oil well had reached 2,800 feet below the ground surface and drillers were trying to punch through a hardened layer of sandstone. When they did, on that day the well quickly sank through a thick layer of loose oily sand. Those who were there heard the liquid crude come rumbling up, under pressure, and watched as liquid oil gushed out of the top of the well like a giant fountain. One of the executives who was present, a Mr. Charles Jones, would later tell others he had never been sprayed by a “finer cologne.”
Hubbard Russell, who was standing next to Jones when the oil gushed, asked, “What does it mean?”
Jones responded, “It means you are a very rich man.”
And the Richfield Oil Company was rich as well. With this discovery, the company more than doubled its oil reserves. Moreover, while most oil wells in California produce at the rate of 100 or so barrels a day, this first well in the Russell Ranch oil field at its peak would produce more than 500 barrels a day. Also it was what was called “sweet” crude, which means it had a low-sulfur content and would be easy and inexpensive to refine.
On more than one occasion I have stood along State Highway 166, which runs along the edge of the Russell Ranch oil field, and wondered why Dibblee and Hill chose this spot. By their own admission, there was nothing specific that attracted their attention. On the surface is a layer of boulders and sand washed down from the Caliente Mountains to the east. The field seems to be beneath a featureless plain. And yet later work would show that they hit the exact center of the oil field, a field five miles long and barely a half mile wide. If they had selected a spot just a quarter mile to the west or to the east, the exploratory well would have missed the reservoir. So it might have been a lucky hit, but less than a year later Dibblee and Hill did it again, this time along the south edge of Cuyama Valley, where a larger and more productive field was found.
For the next few years, Dibblee and Hill continued to search for oil in the Coast Ranges, extending their work eastward from Cuyama Valley into Carrizo Plain and closer to the San Andreas Fault. No more oil reservoirs were found.
A few years after the discovery of oil beneath the Russell Ranch—the layer that contains the oil is now locally known by oilmen as the “Dibblee Sand”—Thomas Dibblee left Richfield Oil Company and accepted a position as a geologist working for the federal government, extending his study of California’s geology into the Mojave Desert. His first assignment—this was the early 1950s—was to search for borate deposits that could be used to make solid rocket fuel. He also continued to focus his attention on the San Andreas Fault.
In all, Dibblee’s career as a field geologist lasted 68 years. During that time, he prepared more than 400 detailed geologic maps of California that cover more than 40,000 square miles—more than half of the state. It was a phenomenal achievement, and some of his maps, including the one that shows the San Andreas Fault running through Carrizo Plain, are regarded by some of his admirers as works of “art.” I have seen that particular map framed and hung in private homes.
He never explained—and no one has ever duplicated—his ability to use his eyes to decipher quickly the geology that lay beneath his feet. But this much is sure: Thomas Dibblee, the skinny and somewhat awkward man who could be seen roaming California’s landscapes, and who seemed to have a less than industrious approach to field geology, managed to cover and to understand more of California’s geology than anyone ever had or probably ever will.
Hill continued to work for Richfield. In 1957, he was part of the team of geologists who found the first oil reserves in Alaska, along the Swanson River on the Kenai Peninsula, a discovery that helped persuade Congress to admit Alaska two years later as the 50th state. In the 1960s, he led the team that discovered oil along the North Slope at Prudhoe Bay in Alaska, the largest oil field yet discovered in North America. In 1966, Hill’s company, the Richfield Oil Company, merged with the East Coast–based Atlantic Refining Company to form ARCO. And in 2000, ARCO was acquired by British Petroleum, today known as BP.
Regardless of their achievements in the oil industry, late in their lives when both men wer
e asked what they regarded as their most important scientific accomplishment, they gave the same answer: It was providing a new and radically different perspective of the San Andreas Fault.
As late as the 1950s, anyone who seriously suggested the San Andreas Fault had more than a mile of accumulated horizontal movement—Levi Noble’s work, by then, had been largely dismissed and ignored—exposed oneself to ridicule and derision. As a case in point, Don Wilhelms, who was then a geology student at the university at Berkeley—and who would go on to be one of the pioneers of the not-yet-established field of astrogeology, producing some of the first geologic maps of the moon—recalled how one of his professors, Nicholas Taliaferro, “didn’t believe that the San Andreas had any strike slip,” that is, any geologically important horizontal movement. Furthermore, as Wilhelms remembered, to make such a suggestion in front of Taliaferro was to subject oneself to a measure of loathing and, in some cases, to being called “a jerk.”
Despite the name-calling, Taliaferro, who was a first-rate field geologist though apparently deficient in the art of effective rhetoric and in inspiring students, was voicing a long-held tenet in geology: The net effect of many earthquakes was to either raise or lower the land. It was simply impossible for huge rock masses to slide sideways any appreciable amount. Or so the thinking of the time maintained. Yet Hill and Dibblee knew that Taliaferro and those who held his opinion—and that was the vast majority of geologists—were wrong.
Hill and Dibblee, as well as Taliaferro, knew of Noble’s claim that he had evidence for 25 miles of horizontal movement near Valyermo, but as early as the 1930s even Noble was beginning to question whether the Mormon Rocks and the seemingly identical rocks of the Punchbowl Formation had once been a single and continuous geologic unit, spliced and slid apart by the San Andreas Fault. Instead, Hill’s initial attention was attracted to the long-forgotten work done decades earlier by a Berkeley student called Frederick Vickery.
In the 1920s, Vickery had studied a segment of the Calaveras Fault, one of the faults that splays off the San Andreas Fault south of San Francisco and runs into the mountains east of San Jose. Here, near Dublin, Vickery found an exposed section of sandstones and fossil-rich beds on the west side of the Calaveras Fault. Twelve miles to the south, on the east side of the Calaveras, he found an identical section, complete with the same diagnostic fossils. To Vickery, the conclusion was obvious: The two exposed sections of sandstones and fossil-rich beds had been sliced through by the Calaveras Fault, then after a series of major earthquakes slid to their present positions. Moreover, as Vickery mentioned—and Hill certainly noted—the direction of sliding along the Calaveras Fault was in the same direction as for the San Andreas Fault in 1906: offset to the right. But Vickery’s conclusion did not sway Taliaferro or apparently anyone else because it was ignored as soon as it was published in 1925 and, according to Hill, “received no reaction.” But it did influence him.
Of greater influence to Hill was a pair of scientific papers, both published in the 1920s, which Hill first read in the 1940s as he was searching for areas that might contain oil, which described two geologic sections on opposite sides of the San Andreas Fault: One was in the Gabilan Range near San Juan Bautista, close to the southern end of the 1906 rupture, and the other was far to the south in the San Emigdio Mountains north of Los Angeles. In reading these two papers, Hill realized that the two sections were identical, that they had probably once been the same geologic unit. In both cases, at the bottom of each section were layers of siltstones and sandstones. And in both cases, above the siltstones and sandstones was a red bed of the Miocene Epoch that contained a distinctive type of fossilized clam—Mactromeris rushi.
Above each of the red beds, whether at San Juan Bautista or in the San Emigdio Mountains, were dacitic and andesitic volcanic rocks. The reason these two papers that described these two geologic sections attracted Hill’s attention was that the Gabilan Range near San Juan Bautista and the San Emigdio Mountains lie on opposite sides of the San Andreas. Furthermore—and this is the remarkable part—these two identical geologic sections, which locally are only a few miles in extent, are 175 miles apart! That is comparable to the distance between San Francisco and Fresno, or between Fresno and Los Angeles.
But one or two examples are not enough evidence to overturn a widely held belief, so Hill knew he had to find additional ones. For that, he turned to Dibblee and his detailed maps.
To draw a geologic map in the days before aerial imaging—either by aircraft or by satellite—can be likened to being a flea that tries to comprehend an elephant. Never can the totality be seen, yet using empirical knowledge, such as Steno’s laws of superposition,* the expectation of facies patterns,* and other droll principles, and employing the use of various colors, patterns, and line weights as well as a host of hieroglyphic symbols, it is possible to depict, in abstract form, the pattern of rocks that lie beneath one’s feet.
The deciphering of a geologic map also requires special skills such as the ability to smooth out folds and slide rock masses along faults and to perceive how the rock units originated and how they have evolved. In that regard, Hill and Dibblee were a complementary pair: Dibblee could produce the maps as he roamed the countryside, and Hill could decipher them and understand the long geologic history of a region and put it into something the layperson (especially the oil executives) could understand. When Hill mentioned his idea about the fossils in the Gabilan and San Emigdio Mountains and whether they indicated that these two widely separated geologic units might in fact have once been connected as a single unit, Dibblee gave his usual noncommittal answer: “No reason why it shouldn’t be.” Thus, these two men came to understand how the San Andreas Fault actually worked—how it moved and shaped the landscape around them.
In all, from Dibblee’s maps and from reports published in scientific journals, they identified a dozen pairs of rock units that had once been single units but had been divided and displaced by the San Andreas Fault. These units ranged from monotonous gravels in the Santa Cruz, Temblor, and San Gabriel Mountains to giant blocks of granite found all along the fault.
Hill announced their findings in 1952 at an annual meeting of the Pacific Section of the American Association of Petroleum Geologists. The meeting was held at the Statler Hotel on Wilshire Boulevard, then the grandest and one of the newest hotels in Los Angeles with more than 1,000 spacious rooms, each one, so it was boasted, equipped with a new amenity—a television set.
Hill gave his presentation on the morning of October 30, the third presenter of the day. He explained how rock units on opposite sides of the fault could be correlated if they were slid long distances horizontally along the San Andreas Fault. Moreover, he showed that the older the paired rock units, the greater the amount of offset: Gravels that had formed 1,000,000 years ago had been offset tens of miles, while blocks of granite, which had been sliding for tens of millions of years, were offset more than 300 miles.
More than 1,000 people attended Hill’s presentation. One was Henry Walrond, a recent college graduate who was beginning a career as an oil geologist. “My response to Hill’s talk was not arbitrary or based on youthful brashness,” Walrond would remember, “but was a reaction to a proposal that conflicted with my geologic experience.” And that seemed to be true of everyone in the room.
Walrond remembered that after Hill’s presentation, the mediator took the unusual step of asking for a show of hands of those who had been impressed by Hill’s presentation. Most of those in the audience responded favorably. Walrond did not raise his hand. Then the mediator asked who actually agreed with Hill’s conclusion. No one raised a hand.
Even Hill, evaluating the reaction years later, would say that his presentation had “shocked” the audience, and so he wasn’t surprised that no one immediately rushed to agree with him so publicly. It also generated interest and controversy and caused others to reevaluate their work.
More than 60 ye
ars have now passed, and the Statler Hotel is gone. But the evidence introduced by Hill and Dibblee and their proposal that there is geologic evidence for tens to hundreds of miles of horizontal slip along the San Andreas Fault have been confirmed at scores of sites. Most sites are difficult for a nongeologist to visit and examine and be convinced that, indeed, the land has slid by large amounts. But there are a few notable ones.
The place to start is the first example Hill gave in his presentation—the basin immediately east of Cuyama Valley where he and Dibblee made their oil discoveries: the Carrizo Plain.
In the Coast Ranges, midway between San Francisco and Los Angeles, is a desolate, semi-arid, landlocked basin that is favored by birdwatchers and botanists. Migratory birds stop here semi-annually. The basin contains the longest stretch of native grass that still exists in California. For those interested in prehistoric cultures, there is a remarkable concentration of multicolored paintings done hundreds to thousands of years ago by native peoples who lived, hunted, and traded in the area. And for those who seek evidence of Earth’s episodic internal forces, few places offer a clearer example than Carrizo Plain.
For someone making a first trip to Carrizo Plain, I advise climbing a central hill, Overlook Hill, to get a view of the entire expanse. To the west is the Caliente Range, and beyond it is Cuyama Valley. Turning to the east, the first major feature is Soda Lake, its harsh white surface blinding to the eyes. And beyond Soda Lake, forming the horizon is a second range of mountains, the Temblor Range.