texascavers Digest 26 Jan 2010 08:34:33 -0000 Issue 953
Topics (messages 13394 through 13402):
Re: Understanding the geology behind a landslide
13394 by: Joe & Evelynn Mitchell
Mystery rocks, Chicxulub?
13395 by: BMorgan994.aol.com
Re: Climate change
13396 by: SS
13399 by: Gill Edigar
Re: CBC Emergency Petitions Filed to Close Caves and Save Bats From Extinction
13397 by: SS
Re: San Antonio sinkholes..
13398 by: SS
San Antonio slumps
13400 by: Gill Edigar
13402 by: Don Cooper
a caver party invitation / update
13401 by: David
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--- Begin Message ---
Understanding the geology behind a landslide
Reported by: Steve Linscomb
Email: [email protected]
Last Update: 6:42 pm
Landslide Close-Up (WOAI.com)
SAN ANTONIO - A number of Northwest Side homeowners are watching as
their homes are devastated as they slide down a slope. Sadly, there's
not much they can do. But many in the area -- and all across San
Antonio -- are wondering, why is it this happening?
Geologists say landslides and other types of land movments can, and
do, happen in South Central Texas for a number of different reasons.
Many times they happen in areas where construction is going on.
We talked with homeowners that could only watch their homes slide and
wonder what's happening. Travis Walston first noticed the crack in his
yard and called about it when it began to grow big enough to look down
into it.
"You could see the different layers... there's a lot of earth. There's
a lot of mother nature in this," Walston told News 4 WOAI. "I don't
understand the retaining wall. There's no rebar. There's really no
support."
So what could be happening here? We talked with Saint Mary's
University professor of geophysics Evelynn Mitchell who says it looks
to be an example of what is called "mass wasting." That's the downward
movement of earth and rock. At work are two forces.
"Your resistant forces are going to keep this slope held up over time.
The driving forces are what is encouraging the slope to move
downward," explained Professor Mitchell.
If the driving force downward is greater, you can have a collapse.
Mitchell says water collection can add more problems, expanding the
soil.
"Then the water is going to end up pushing along the slope, adding
more force and overcoming that resistant force," said Mitchell.
It could be a while before we know exactly what happened in that
Northwest Side neighborhood, but one thing's for sure; the landscape
across South Central Texas is changing... whether it be from manmade
or natural reasons.
--- End Message ---
--- Begin Message ---
Josh:
I'll buy your explanation for Jim Conrad's road cut, but my mystery rocks
are entirely different. Tell me what you think:
(Photo not shown, email me and I will send it. Is there any way to post a
resized photo on Texas caver? I see that others have occasionally posted
photos. I tried but failed)
These mystery rocks occur in broad shallow pans west of Cancun near the
airport that look superficially like dolinas, actually more like the wet
"prairies" here in Florida. It is only the top layer that is hard and has
inclusions. Beneath that is standard yucatecan crumbly white limestone. There
were occasional solution holes in the pans but no real cenotes. You are not
looking at the top or bottom of one of the flat rocks, but rather a broken
chunk, so don't infer any particular orientation.
I would have supposed that this was some form of hardpan, or perhaps
chertification as you can see in the upper left rock, but the lack of
inclusions
further down and the immediate change in hardness tells me this is a
separate formation. The surface rocks in the yucatan are generally harder than
the rocks further down, which is part of the reason why the cenotes almost
always bell out as they go down. That is normal, but when I looked carefully
at these specific rocks in the pans I discovered something very strange.
The pan rocks were in solid (though broken) sheets averaging about 8" thick,
and were composed of a matrix of hard creamy white fossiliferous limestone
in which were numerous broken jagged chunks of what looks like dark gray
dolomite to me, but I could be wrong about that. The chunks are clastic, not
rounded and weathered, and rarely touch each other. It looks like cake mix
with chunky treats mixed in. What could cause such a thing? It seems
obvious to me that a huge disaster was required to turn the limestone matrix
into
soup with jagged chunks. A conventional flood would sort the inclusions
differently and round them too.
The Yucatan is generally a wretched dry place covered with tangled scrub
that has been abused by people and fire for thousands of years. The only
places that are botanically interesting were these pans, which were
alternately
flooded then burned each year resulting in an open savanna landscape with
occasional "Logwood" trees (Haematoxylum campechianum is a cool twisted
small tree which yields a purple dye, and as a result was long sought in days
of yore).
The reason I discovered all this is because once upon a time I built a
monstrous waterfall at a hideous resort in Cancun. Most of the limestone in the
Yucatan is worthless white chalky crap unworthy of working with, but in
certain areas, such as near the Cancun airport, there were these botanically
and geologically interesting "pans" in which the surface limestone was much
harder, flatter, and more useful. So in I went with a whole tribe of
Mayans to harvest the stone by hand.
On day one I did something extra stupid. Bigger rocks are always better,
especially if someone else is lifting them, so I pointed at a big slab about
the size of a dining room table. The Mayans said "No way Jose, too big!"
But I insisted, so I said, all you little guys get on one end and I'll take
the other and we'll put it in the truck. With great effort we lifted it up
and into the truck, but in doing so I got 3/4 of an inch shorter as my
cervical vertebra collapsed. I've always been short, so getting permanently
shorter and being in pain for years didn't help! After that we collected
smaller rocks in the 100-150 lbs range, each one of which was pried up in the
scrub jungle, loaded onto the back of an individual Indian, carried to the
truck, lifted in, taken to the site, unloaded, picked up again to reload on
the back of another Indian, carried through the already occupied resort, then
lifted up the scaffolding by hand to be set. We even carried in a sixty
foot tall royal palm that weighed perhaps six tons.
I was much impressed by the fact that the Mayans were invariably smarter
than any of the tourists, who were so dumb that after months I had seen only
one reading a book so I went over to see what he was reading and it was a
Reader's digest. The only smart Gringos I met the whole time I was there
were two professional "closers" who would fly in, ply the prospective chump
with drinks and cocaine, then threaten to kill them if they didn't sign the
timeshare contract. Meanwhile back in the village otherwise illiterate Mayan
kids were learning computer aided design by candlelight. Their skill and
craftsmanship were extraordinary. The boss was an edjumacated Mexican
aristocrat. The site was gigantic, about an 1/8 of a mile across, yet his
tolerance for mistakes was only 1/8" regardless of whether the issue was a
window
frame or the entire site, but the Mayans never made mistakes. Everything
was perfect despite that fact that the entire place was a worthless piece of
shit. The monstrosity that I created can be seen _here_
(http://www.environmentaldesigns.org/Projects%20by%20type/lightscapes.html) ,
and _here_
(http://www.environmentaldesigns.org/Projects%20by%20type/lightscapes.html) .
And to think that I remember Cancun when there wasn't anything there, not
even a palapa selling cokes!
Sleazeweazel
--- End Message ---
--- Begin Message ---
Its like fleas arguing over who owns the dogs back.
At the end of the day we are having no more effect on the earth than
anything else. All the pollution in the world doesn't add up to anything
like some of the catastrophic events the earth has suffered since it was
born. Before you and I walked the earth it was struck by asteroids and
undergone volcanic activity that nearly extinguished life a hundred times
over.
If you want to be an environmentalist do so for mans sake. the earth could
care less. It can wipe us out in the blink of an eye, and ten thousand
years later you'd hardly find a trace we were ever here.
_____
From: [email protected] [mailto:[email protected]]
Sent: Sunday, January 03, 2010 11:46 AM
To: [email protected]
Subject: [Texascavers] Climate change
I am so very sick and tired of the climate change debate and of the
perversion of science that is used by both sides to justify their underlying
political agenda. No one has ever suggested that the earth's climate is
static.
There is no question but that much of current climate change is
anthropogenic and driven by fossil fuel consumption. The problem is the RATE
OF CHANGE over and above the background natural rate of change (which
changes all the time!).
The evolution of life on earth, especially that of so called "higher" life
forms, cannot keep pace with the current rate of change which is greatly
exacerbated by our rape of the planet. An increased rate of change
inevitably favors fast evolving "lower" life forms and a diminution of
biodiversity. That means that in the future we will manufacture our energy
from bioengineered pond scum and eat the byproducts thereof. That is not a
future that any responsible person would want for their children's children.
I am a fundamentally conservative person. That means that I prefer the
status quo, not the status quo of the twentieth century, but rather the
status quo of the last few million years during which time change was slow
and natural barriers prevented promiscuous intermingling. As a result of
which the biosphere increased in richness until quite recently.
Those who question anthropogenic climate change are conservative in an
entirely different way. They are directed by their inner ape to consume the
fruit right now with no regard whatsoever for either the past or the future.
They look at their ephemeral institutions as fixed in stone by some
imaginary higher power who justifies their dominance over every other life
form on earth.
As a true conservative I never thought I would see the day that I would
abandon such quaint and antiquated concepts as individual freedom, human
rights and the dignity of man, but that day has come. When I listen to the
apelike gibberings of christians, moslems, republicans, and others who deny
the reality of our impact on the earth I long for the day when our future
Chinese overlords will have the wisdom to simply shut the mouths of the
godfearing, eradicate redundant populations, dole out a gobbet of porridge
for all, and cut off the balls of those who insist upon putting their hands
into the cookie jar.
Sleazeweazel
--- End Message ---
--- Begin Message ---
On Mon, Jan 25, 2010 at 11:16 PM, SS <[email protected]> wrote:
>At the end of the day we are having no more effect on the earth than
anything else.
That statement, I feel, is important enough to reply to. Some of the others
are interesting but can wait till I have more time.
Yes, we are all a part of nature--even our man-made objects. But we, as
human beings building dams, diverting rivers, cutting down rain forests,
strip mining the surface, polluting ground water, and, subsequently wiping
out many species of plants and animals (yes, something which also happens
without our help) can not be considered as "having no more effect on the
earth than anything else." Our Earth and it's atmosphere are parts of a
(mostly & practically) closed system. Space dust and junk do regularly find
their way in, sometimes catastrophically, but that is outside the scope of
us being responsible for our own actions--for us being accountable, because
we, as human beings, can and do have a significant influence on the chemical
composition of the air and water and the soil itself, through our
machinations. If you want to pretend that that is not true I would suggest
that you find another closed environment--say your living room--and run a
hose from your idling car exhaust into the living room and then try to tell
me that pumping waste gases into a closed environment won't have any more
effect on it than whatever else goes on in there during a normal day. You
just can't pump large volumes of carbon dioxide--or anything else--into the
atmosphere and not have it change the chemistry of it. That should be
totally axiomatic. Now, what effects that change in chemistry may invoke
within the closed environment is open to debate, I'll admit.
--- End Message ---
--- Begin Message ---
Maybe they should petition the government for a caving Tax while their at
it. We can add it to the list...
Accounts Receivable Tax
Building Permit Tax
CDL license Tax
Cigarette Tax
Corporate Income Tax
Dog License Tax
Excise Taxes
Federal Income Tax
Federal Unemployment Tax (FUTA)
Fishing License Tax
Food License Tax
Fuel Permit Tax
Gasoline Tax (currently 44.75 cents per gallon)
Gross Receipts Tax
Hunting License Tax
Inheritance Tax
Inventory Tax
IRS Interest Charges IRS Penalties (tax on top of tax)
Liquor Tax
Luxury Taxes
Marriage License Tax
Medicare Tax
Personal Property Tax
Property Tax
Real Estate Tax
Service Charge T ax
Social Security Tax
Road Usage Tax
Sales Tax
Recreational Vehicle Tax
School Tax
State Income Tax
State Unemployment Tax (SUTA)
Telephone Federal Excise Tax
Telephone Federal Universal Service Fee Tax
Telephone Federal, State and Local Surcharge Taxes
Telephone Minimum Usage Surcharge=2 0Tax
Telephone Recurring and Non-recurring Charges Tax
Telephone State and Local Tax
Telephone Usage Charge Tax
Utility Taxes
Vehicle License Registration Tax
Vehicle Sales Tax
Watercraft Registration Tax
Well Permit Tax
Workers Compensation Tax
_____
From: Pete Lindsley [mailto:[email protected]]
Sent: Thursday, January 21, 2010 12:26 PM
To: New Mexico Caver Mailing List; Texas Cavers List
Subject: [Texascavers] CBC Emergency Petitions Filed to Close Caves and Save
Bats From Extinction
>From Scott House on the MoCaves List:
The Center for Biological Diversity (not a government agency!) has
petitioned the federal government to close all caves under its jurisdiction.
Do not misinterpret this for a proposed action by the federal government.
Petitions Filed to Close Caves:
http://www.biologicaldiversity.org/news/press_releases/2010/bats-01-21-2010.
html
<http://www.biologicaldiversity.org/news/press_releases/2010/bats-01-21-2010
.html> ... asks federal agencies to close all caves under their
jurisdiction...
... close all bat-inhabited caves and mines on federal lands throughout the
continental United States...
...and for the eastern small-footed bat and the northern long-eared bat...
to be protected as endangered species ...
"All Caves" is a lot more caves than the affected caves in the 9 states
mentioned...
--- End Message ---
--- Begin Message ---
The neighborhood was probably built on a landfill...lol.
That's what happens when you cut corners...I hope Centex gets sued into
bankruptcy.
-----Original Message-----
From: Geary Schindel [mailto:[email protected]]
Sent: Monday, January 25, 2010 12:48 PM
To: [email protected]; [email protected]
Cc: [email protected]
Subject: RE: [Texascavers] San Antonio sinkholes..
Folks,
This is not a sinkhole but a classic hill slope failure. Quite impressive
as slips go.
Geary
-----Original Message-----
From: [email protected] [mailto:[email protected]]
Sent: Monday, January 25, 2010 12:32 PM
To: [email protected]
Cc: [email protected]
Subject: [Texascavers] San Antonio sinkholes..
"Our backyard has shifted about 10 feet, and everything is pushed closer to
our house," said Sara Koenig, 23.
She and her husband, 27, left early Sunday to study and to volunteer at a
local hospital, respectively. She said neighbors called her at 11 a.m. to
report their back fence had collapsed but her two Chihuahuas were safe.
Near helotes.
http://www.mysanantonio.com/news/82553087.html
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--- End Message ---
--- Begin Message ---
It is often said and there is a widespread misconception that the "Balcones
Fault" is "inactive", meaning that it no longer moves. First, the idea that
it is only one fault is inaccurate; it is more correctly a "fault zone" made
up of probably millions of smaller, local faults, some mere meters long,
others well up on the order of dozens of kilometers. And they move; the
seismograph says so. Consider that there are many pre-existing joints and
faults and that would otherwise appear to be 'inactive'. These joints are
filled with mud which dissolves the surfaces of these rocks. As the rocks
are dissolved their center of gravity and their contacts with adjoining
rocks changes or goes away, or rains wash away or introduce clay or other
material. Rains and drouths will alter the mud and moisture content.
Seasonal heating and cooling of the near-surface rocks will affect their
stability. The rock's immediate environment changes over time and it must
adjust itself accordingly. It moves. And that movement, if large enough,
will register on a seismograph; it's a mini-earthquake. There are thousands
of them every day along the length of the (seemingly inactive) Balcones
Fault Zone.
It is entirely possible, and even likely, that the slumping going on in San
Antonio is a mass of rock spalling along a joint or fault after a lower
side-supporting member has been removed through natural processes or
quarrying and the recent rains have washed out and/or lubricated any clay
binders in the joint.
--Ediger
on Mon, Jan 25, 2010 at 11:38 PM, SS <[email protected]> wrote:
> The neighborhood was probably built on a landfill...lol.
>
> That's what happens when you cut corners...I hope Centex gets sued into
> bankruptcy.
>
>
> -----Original Message-----
> From: Geary Schindel [mailto:[email protected]]
> Sent: Monday, January 25, 2010 12:48 PM
> To: [email protected]; [email protected]
> Cc: [email protected]
> Subject: RE: [Texascavers] San Antonio sinkholes..
>
> Folks,
>
> This is not a sinkhole but a classic hill slope failure. Quite impressive
> as slips go.
>
> Geary
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> Sent: Monday, January 25, 2010 12:32 PM
> To: [email protected]
> Cc: [email protected]
> Subject: [Texascavers] San Antonio sinkholes..
>
>
> "Our backyard has shifted about 10 feet, and everything is pushed closer to
> our house," said Sara Koenig, 23.
>
> She and her husband, 27, left early Sunday to study and to volunteer at a
> local hospital, respectively. She said neighbors called her at 11 a.m. to
> report their back fence had collapsed but her two Chihuahuas were safe.
>
>
>
> Near helotes.
>
> http://www.mysanantonio.com/news/82553087.html
>
>
> ---------------------------------------------------------------------
> Visit our website: http://texascavers.com
> To unsubscribe, e-mail: [email protected]
> For additional commands, e-mail: [email protected]
>
>
>
> ---------------------------------------------------------------------
> Visit our website: http://texascavers.com
> To unsubscribe, e-mail: [email protected]
> For additional commands, e-mail: [email protected]
>
>
--- End Message ---
--- Begin Message ---
More rains coming soon! This could turn into a real big mess.
-WaV
On Tue, Jan 26, 2010 at 12:43 AM, Gill Edigar <[email protected]> wrote:
> It is often said and there is a widespread misconception that the "Balcones
> Fault" is "inactive", meaning that it no longer moves. First, the idea that
> it is only one fault is inaccurate; it is more correctly a "fault zone" made
> up of probably millions of smaller, local faults, some mere meters long,
> others well up on the order of dozens of kilometers. And they move; the
> seismograph says so. Consider that there are many pre-existing joints and
> faults and that would otherwise appear to be 'inactive'. These joints are
> filled with mud which dissolves the surfaces of these rocks. As the rocks
> are dissolved their center of gravity and their contacts with adjoining
> rocks changes or goes away, or rains wash away or introduce clay or other
> material. Rains and drouths will alter the mud and moisture content.
> Seasonal heating and cooling of the near-surface rocks will affect their
> stability. The rock's immediate environment changes over time and it must
> adjust itself accordingly. It moves. And that movement, if large enough,
> will register on a seismograph; it's a mini-earthquake. There are thousands
> of them every day along the length of the (seemingly inactive) Balcones
> Fault Zone.
>
> It is entirely possible, and even likely, that the slumping going on in San
> Antonio is a mass of rock spalling along a joint or fault after a lower
> side-supporting member has been removed through natural processes or
> quarrying and the recent rains have washed out and/or lubricated any clay
> binders in the joint.
> --Ediger
>
>
> on Mon, Jan 25, 2010 at 11:38 PM, SS <[email protected]> wrote:
>
>> The neighborhood was probably built on a landfill...lol.
>>
>> That's what happens when you cut corners...I hope Centex gets sued into
>> bankruptcy.
>>
>>
>> -----Original Message-----
>> From: Geary Schindel [mailto:[email protected]]
>> Sent: Monday, January 25, 2010 12:48 PM
>> To: [email protected]; [email protected]
>> Cc: [email protected]
>> Subject: RE: [Texascavers] San Antonio sinkholes..
>>
>> Folks,
>>
>> This is not a sinkhole but a classic hill slope failure. Quite impressive
>> as slips go.
>>
>> Geary
>>
>> -----Original Message-----
>> From: [email protected] [mailto:[email protected]]
>> Sent: Monday, January 25, 2010 12:32 PM
>> To: [email protected]
>> Cc: [email protected]
>> Subject: [Texascavers] San Antonio sinkholes..
>>
>>
>> "Our backyard has shifted about 10 feet, and everything is pushed closer
>> to
>> our house," said Sara Koenig, 23.
>>
>> She and her husband, 27, left early Sunday to study and to volunteer at a
>> local hospital, respectively. She said neighbors called her at 11 a.m. to
>> report their back fence had collapsed but her two Chihuahuas were safe.
>>
>>
>>
>> Near helotes.
>>
>> http://www.mysanantonio.com/news/82553087.html
>>
>>
>> ---------------------------------------------------------------------
>> Visit our website: http://texascavers.com
>> To unsubscribe, e-mail: [email protected]
>> For additional commands, e-mail: [email protected]
>>
>>
>>
>> ---------------------------------------------------------------------
>> Visit our website: http://texascavers.com
>> To unsubscribe, e-mail: [email protected]
>> For additional commands, e-mail: [email protected]
>>
>>
>
--- End Message ---
--- Begin Message ---
As of 01-26-10, my plan to host a cook-out in east Texas is still on.
http://www.facebook.com/group.php?gid=306448097728&ref=ts
For those of you who can't view that, the date is May 22, and the location
is Burton, Texas, about 1 1/4 hour east of Bastrop.
Try this link for a map showing location in relation to landmarks:
http://www.mapquest.com/mq/1-wq6T
David Locklear
281-960-0687
P.S. May 22, is the Saturday on the weekend before
Memorial Day Weekend.
--- End Message ---
