Under the influence of weather the young, soft rocks were swiftly worn away, thus exposing, as a range of steep and dramatic hills, the core of ancient ocean floor and dragged-down sediments from the dinosaur-era age of the Middle Jurassic. Mount Diablo was born. The soft rocks, which in one particular case were thick with abundant layers of soft coal, were to be found on the flanks of the hills; the unyieldingly hard and relatively ancient rocks, which were good for road stone but not at all rich in the kind of minerals that make men wealthy, were left in the middle.
The crucial element of this long and complicated story is the relatively uncomplicated but still somewhat mysterious event that took place almost exactly 20 million years ago: the moment when the onward press of the ocean crust suddenly, and for a reason that long remained a mystery, translated itself into a northward, sliding motionâas when an army suddenly wearies of charging head-on at the enemy and begins to execute a mysterious, somewhat cunning motion to one side that appears to be an attempt to outflank the foe. At this pointâwhich took place in the middle of the period of world history known as the Mioceneâeverything that now in essence defines seismic California was brought into being.
This was the moment of makingâwhen the earthshaking, city-killing, history-creating, epoch-changing linear system, 750 miles in length, and known since the beginning of the nineteenth century, broadly and generically, as the San Andreas Fault, was created. That the oncoming plateâs change of direction also helped to create this hill, the massif that rises so formidably in the picture windows of the residents of the towns of Clayton, Pittsburg, and Pleasant Hill and their like, reinforces the view that I started to hold in the tent that breezy night: that Mount Diablo is more connected and interlinked with the events of the San Francisco tragedy than almost all those who live beside it and below it have ever properly supposed.
BY NOW I WAS READY to sleep. I stepped briefly out of the tent and looked up at a sky ablaze with stars: Cassiopeia and Gemini unusually bright, Castor and Pollux winking down from the roof of the universe. There seemed to be a gathering of clouds rolling onshore from over the faraway Pacific. The loom of lights from the cities spread a blush of orange-pink on the underside, making them glow bright against the velvet of the coastal night.
DAWN CAME UP all too early that next morning, and from where I was camped, close to the top on the western side of the mountain, the day and its morning sky were pale blue and clear as crystal. There had evidently been a shower in the small hours: The fire was out, the ashes were damp and cold, the pine needles glistened with more than the usual dew. I walked up along the empty road (the gates below would not open for another hour, and so I could revel in the knowledge that I still had the mountaintop entirely to myself) to the summit. At the top is a immense octagonal stone buildingâa onetime aircraft beacon, * a uniquely visible landmark and, as it happens, a memorial to one of the defining periods in recent American history, the Great Depression. The building, fashioned from a highly fossiliferous sandstone quarried locally, had been erected in the 1930s, using the brawn and muscle of scores of out-of-work men who had been organized into a local chapter of the federally funded Civilian Conservation Corps, and who hadlived for two years in a camp close to where I had slept the night before. I climbed the steps up to the parapet and gazed, silently and dumbstruck, at one of the most stupendous views in all America.
William Brewer, when he first surveyed the mountain in 1862, estimated that 80,000 square miles could be seen from the summit. âI made an estimate,â he wrote in his report for the Geological Survey, for which he was principal assistant, âthat in tolerably
The crucial element of this long and complicated story is the relatively uncomplicated but still somewhat mysterious event that took place almost exactly 20 million years ago: the moment when the onward press of the ocean crust suddenly, and for a reason that long remained a mystery, translated itself into a northward, sliding motionâas when an army suddenly wearies of charging head-on at the enemy and begins to execute a mysterious, somewhat cunning motion to one side that appears to be an attempt to outflank the foe. At this pointâwhich took place in the middle of the period of world history known as the Mioceneâeverything that now in essence defines seismic California was brought into being.
This was the moment of makingâwhen the earthshaking, city-killing, history-creating, epoch-changing linear system, 750 miles in length, and known since the beginning of the nineteenth century, broadly and generically, as the San Andreas Fault, was created. That the oncoming plateâs change of direction also helped to create this hill, the massif that rises so formidably in the picture windows of the residents of the towns of Clayton, Pittsburg, and Pleasant Hill and their like, reinforces the view that I started to hold in the tent that breezy night: that Mount Diablo is more connected and interlinked with the events of the San Francisco tragedy than almost all those who live beside it and below it have ever properly supposed.
BY NOW I WAS READY to sleep. I stepped briefly out of the tent and looked up at a sky ablaze with stars: Cassiopeia and Gemini unusually bright, Castor and Pollux winking down from the roof of the universe. There seemed to be a gathering of clouds rolling onshore from over the faraway Pacific. The loom of lights from the cities spread a blush of orange-pink on the underside, making them glow bright against the velvet of the coastal night.
DAWN CAME UP all too early that next morning, and from where I was camped, close to the top on the western side of the mountain, the day and its morning sky were pale blue and clear as crystal. There had evidently been a shower in the small hours: The fire was out, the ashes were damp and cold, the pine needles glistened with more than the usual dew. I walked up along the empty road (the gates below would not open for another hour, and so I could revel in the knowledge that I still had the mountaintop entirely to myself) to the summit. At the top is a immense octagonal stone buildingâa onetime aircraft beacon, * a uniquely visible landmark and, as it happens, a memorial to one of the defining periods in recent American history, the Great Depression. The building, fashioned from a highly fossiliferous sandstone quarried locally, had been erected in the 1930s, using the brawn and muscle of scores of out-of-work men who had been organized into a local chapter of the federally funded Civilian Conservation Corps, and who hadlived for two years in a camp close to where I had slept the night before. I climbed the steps up to the parapet and gazed, silently and dumbstruck, at one of the most stupendous views in all America.
William Brewer, when he first surveyed the mountain in 1862, estimated that 80,000 square miles could be seen from the summit. âI made an estimate,â he wrote in his report for the Geological Survey, for which he was principal assistant, âthat in tolerably
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