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Hollister, California
In the San Francisco Bay area there are three major faults, from west to east the San Andreas, the Hayward, and the Calaveras; all are part of the San Andreas fault system. All of these are "right-lateral strike-slip faults," which means that the motion is predominantly horizontal, with the land on the west side of the fault moving north.
South of the Bay Area the Hayward and Calaveras merge into the San Andreas. Hollister is located just north of where this happens, right on top of the southern end of the Calaveras fault.
What makes Hollister particularly interesting is that from San Juan Bautista to just north of Parkfield the faults in the San Andreas system are not "stuck": instead of moving only during major earthquakes, they continuously "creep." As a result of this creep, Hollister is being slowly ripped in two, for the most part along a remarkably narrow zone running right through the middle of town.
The rate of creep is inconsistent, and has been measured at between 6 and 15mm per year at various times throughout the 20th century. Underground pipes, road paving, curbing, and foundations all show signs of being gradually shifted apart. Notice how the distortion always bends structures to the right- no matter from which side of the fault the photo was taken. Also notice that the motion is horizontal: the ground is remaining level as it moves. Together, these two observations define right-lateral strike-slip motion.
On my second visit to Lake Cowal back in early December, I was told about a place that was of great interest to geologists visiting the nearby gold mine. This trip I headed out to have a look.
Following is the information I was given to explain what I was going to see.
"The outcrop is part of the Booberoi Fault and features sheared Late Silurian-Early Devonian Edols Conglomerate (Sherwin, 1996) showing stretched quartzite and vein-quartz pebbles in a quartz white mica-chlorite matrix, which was probably a muddy sandstone. Mesoscopic kinematic indicators show at least two movement episodes: a horizontal sinstral movement and a near vertical reverse (west side up) movement. The movement direction can be discerned from the asymmetry of the matrix surrounding the pebbles and the mineral elongation within the matrix."
Video - youtu.be/gFIb1JXFTb8
Ashe (The Fault Line Tour) @ 9:30 Club, Washington, DC Saturday, April 23, 2022.
The Fault Line Tour Setlist:
Me Without You
I'm Fine
Kansas / Someone to Lose
Save Myself
Not Mad Anymore
Love Is Not Enough
Taylor
When I’m Older
Another Man's Jeans
Somebody to Love(Queen Cover)
Hope You're Not Happy
Always
'Till Forever Fills Apart
Moral of the Story
On my second visit to Lake Cowal back in early December, I was told about a place that was of great interest to geologists visiting the nearby gold mine. This trip I headed out to have a look.
Following is the information I was given to explain what I was going to see.
"The outcrop is part of the Booberoi Fault and features sheared Late Silurian-Early Devonian Edols Conglomerate (Sherwin, 1996) showing stretched quartzite and vein-quartz pebbles in a quartz white mica-chlorite matrix, which was probably a muddy sandstone. Mesoscopic kinematic indicators show at least two movement episodes: a horizontal sinstral movement and a near vertical reverse (west side up) movement. The movement direction can be discerned from the asymmetry of the matrix surrounding the pebbles and the mineral elongation within the matrix."
Video - youtu.be/gFIb1JXFTb8
As far as I can see all these shots are uneven in focus/out of focus, this is due to me Dropping the camera last summer, probably the last ones I will shoot with the camera
That hill behind the row of trees? It's the fault scarp of the Alpine Fault, which experiences oblique strike-slip movement. The construction crew is building a new bridge pretty much right over it.
On my second visit to Lake Cowal back in early December, I was told about a place that was of great interest to geologists visiting the nearby gold mine. This trip I headed out to have a look.
Following is the information I was given to explain what I was going to see.
"The outcrop is part of the Booberoi Fault and features sheared Late Silurian-Early Devonian Edols Conglomerate (Sherwin, 1996) showing stretched quartzite and vein-quartz pebbles in a quartz white mica-chlorite matrix, which was probably a muddy sandstone. Mesoscopic kinematic indicators show at least two movement episodes: a horizontal sinstral movement and a near vertical reverse (west side up) movement. The movement direction can be discerned from the asymmetry of the matrix surrounding the pebbles and the mineral elongation within the matrix."
Video - youtu.be/gFIb1JXFTb8
Moab Fault
A dramatic break in the earth's surface occurred here about six million years ago. Uinder Intense pressure, unable to stretch, the crust cracked and shifted. Today, the highway (below) parallels this fracture line, called the Moab Fault.
After the rock layers shifted, the east wall of the canyon where you are standing ended up more than 2,600 feet (792 meters) lower than the west side (across the highway).
Individual rock layers no longer tine up horizontally here because of faulting. The cliff across the high-way looks much like the Entrada Sandstone, but is actually composed of Wingate Sandstone — rock deposited about forty million years before the Entrada.
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Arches National Park
Utah National Parks Trip 2021
September 4 - 10, 2021
On my second visit to Lake Cowal back in early December, I was told about a place that was of great interest to geologists visiting the nearby gold mine. This trip I headed out to have a look.
Following is the information I was given to explain what I was going to see.
"The outcrop is part of the Booberoi Fault and features sheared Late Silurian-Early Devonian Edols Conglomerate (Sherwin, 1996) showing stretched quartzite and vein-quartz pebbles in a quartz white mica-chlorite matrix, which was probably a muddy sandstone. Mesoscopic kinematic indicators show at least two movement episodes: a horizontal sinstral movement and a near vertical reverse (west side up) movement. The movement direction can be discerned from the asymmetry of the matrix surrounding the pebbles and the mineral elongation within the matrix."
Video - youtu.be/gFIb1JXFTb8
Holly " Don't blame me! I didn't make you mad and obsessed! Its within you!"
Me " Its your fault little lady, make no mistake. You stole my heart the moment I saw you in your box! You made me buy all your sisters!!!!!!!"
Holly " Hey mom if it makes you feel better to believe that, cool. But remember I told you ages ago that you were getting out of hand! Nanny Caine told you too!"
Me " Do you think I should sell some of your sisters then?"
Holly " Nooooooo you crazy woman! Over my plastic body!!!!!!!!!!!!!"
Me " Do you think I've lost the plot?"
Holly " Yes but that was established long ago, but I love you Mom inspite of your fruitloop tendencies!"