Friday, August 9, 2013

Longhorn Caverns, Texas


    My husband and I wanted to have a weekend break while my one son was away at camp.  This has been a tradition of ours since we started to send the kids away to camp.   We like to go to places that we have not been to before or its been a long long while since we were last there.  We decided on Fredericksburg and the hill country of  Texas to check out its vineyards and thought it would be a romantic place visit plus we could drive to it.  However we did not want to drive it all in one shot and planned on staying in Georgetown  for that Friday night.
    I'm so glad we decided to do that because the next day we wanted to avoid Austin Texas traffic and had heard about the Enchanted rock.  So we planned on taking Texas 29 to Llano and then going down Texas 16 to Enchanted rock which was off of Tx 965.  While we were in the hotel in Georgetown we saw some brochures for some caverns.  We thought that might be a fun thing to do in the morning since it look like it might be raining and we might not be able to do Enchanted rock.  We pulled out the map to look up the one cavern and how to get to it, but while looking at the map we noticed a place called Longhorn Caverns was on our way and had more information about it plus it was a State Park.  We changed our minds again and decided to go there first instead of Enchanted rock.  A decision I did not regret at all.  Lets just say these are fantastic caverns to visit. Because the lighting was so good in them  I was able to take lots and lots of pictures which I'm going to write about now.
Here's what the state sign had to say about it.((and here's some other links about it (Wikipedia -Longhorn_Cavern_State_Park . Texas State Parks tx.us/state-parks/longhorn-cavern, & Longhorn Caverns website longhorncaverns  )
   It looked interesting enough to buy the ticket and go see it.  We were told the cave was 1 1/4 miles long and the tour can take up to two hours to see and was easily accessible for most people.
    As soon as I started to the cavern entrance I knew I was going to enjoy it.   And here's why.  As we were walking to the entrance I could tell this was a sink hole.  That right away let me know that the surrounding rock was limestone.  I could tell that this sink hole they had reinforced the walls so they wouldn't cave in on people.  
 We kept on walking and came to another sink hole area only this one they made it into a park like setting.  It lead the way to the entrance.  
 The guide stopped to talk to use and I could see some natural bridges that we were going under and had just been under.   No wonder they reinforced thing. 
 You could see how the cavern was formed by water eating away at the weaker bedding planes.
I know this isn't the best photo but this was taken looking straight up and being under one of the natural bridges.  You can see another sink hole that had opened up and was letting the moisture and stuff come down into it.
Here's another sink hole that was in the natural bridge with the light shining through.
Part of the natural bridge.
Here was another hole that had started to form in the roof of the rock.  I couldn't believe I was seeing all these neat features and hadn't even made it into the cave.
    At one time there was water flowing through this area with a pretty swift current.  The water was able to carry some debris in it that was able to wear this matrix material  away in whirlpool like spots when it was trapped and couldn't get out.
We finally made it to the Sam Bass entrance.  There we gave the guide our tickets and he counted us and then called it in before locking the gate behind us. 
I tried taking this picture of the softer shaleier beds that had been eaten away and some of the calcium carbonate rock or I should say travertine was starting to be deposited on it. I realized my camera wasn't going to get good pictures hear after going deeper and having nothing turn out.  It reminded me when I was in St Michaels cave in Gibraltar where all I could do was just walk with the tour and enjoy it. 
As we were walking I was noticing that the lighting was pretty good for a cave.  I tried taking some more photos with my camera and they didn't turn out.  Just for the heck of it I decided to get my cellphone out and took a few of some of the same stuff that my camera didn't capture.  I got a whole lot better results with my cell than my camera.  Trouble was I knew the stuff on my cell I couldn't print it up but I also knew that I could download them to my computer and use them in this blog.  Since I probably wasn't going to print any of these anyway but just blog about it I thought I might just as well use the cell phone the whole time.
 This cave looked different to me from other caves I've seen.   For one thing I was noticing a lot of rounded features. 
Here some dripstones.  You can see the joint in which the water would come out and drip down.
On the walls you could see where large clasts were ripped up and deposited again in different locations.
A small column that formed.  Notice the two different colors of the rocks.  The more whitish one is an actively growing feature while the reddish one has dried up and is not still being formed.
Some stalactites coming down from the ceiling.  That was one thing I noticed about this cave was there were not a lot of stalactites or stalagmites present.  We found out that was because in the olden days when this place was a speak easy the patrons used to come and break them off and take them home as souvenirs.  That was before people realized how long it takes to form one.  Now everything in the cave is protected and you are not allowed to take anything from it.  The said in the lower caverns there are more stalactites and stalagmites but due to the water table they are harder to get to.
It was so neat to see all the erosion along the weaker bedding planes and the fallen structures.
This area was so incredible.  It's one of two area's that is called the Crystal rooms.  The reason it's called that is because the walls are covered with calcite crystals.  At one time this area was filled with water that had a very high calcium carbonate content.  The area got sealed off when a sink whole collapsed inward.  The water was trapped in the area and couldn't escape.  The crystals started to precipitate out from the brine with one atom attaching to the next atom allowing a crystal to grow with a reflection of that internal arrangement of atoms. With time the water went away leaving these incredible crystals.   I was like Oh Gosh I'm in a huge GEODE.  I couldn't believe I was actually walking around in an area that was just like how a geode is formed.   This was so different from the travertine that was on the other walls.  Travertine forms when there is calcium carbonate in solution as it drips from the Limestone around it.  The water evaporates off and the calcium carbonate stays building up in a layered fashion and not reflecting the internal structure of the atoms involved. 


Calcite crystals in the Crystal Room, Longhorn Caverns
This was just an interesting dripstone feature but it kinda look like a dinosaur face to me.
Sometimes when I take a picture I later wondered why I took it and this was one of them and then it was like oh yeah see the water in it it must because of the way you could see the water still being active and the erosion that is occurring here.  There was a band of white and the upper part was more reddish.
In some of the limestone there were chert nodules that the Indians used to come in and collect and then used them for their tools.  The nobby things is chert.  Chert is a cryptocrystalline form of SiO2 ie you can't see the crystal grains in it (quartz is made of SiO2 too but it has a crystalline form)  It is very hard and fractures by hitting it at angles.  When it breaks its usually has conchoidal fracture ie it circular like a sea shell. Because of the way it fractures sharp edges can be made with it and that's why they make such great tools.
Along the way they had names for different features.  This wasn't the best photo of it but these feature was called the Liberty Bell Dome.  When you look at it - its a dome feature in the ceiling that looks like an inside of a bell.  Because of the crack in it - it got the name of the Liberty Bell.  Geologically this feature is an inverted pothole.  At one time this part was totally filled with water and some sediments got trapped in this area and wore the matrix away when it would whirl around in a whirlpool motion.


Near the Queens throne stood this unique sculpture.  These are the best images of it so you don't get its full shape.  But its called the Queen's Watch Dog.  At first it was thought that it was carved by Indians but then when it got broken it was removed to be fixed and studied and it was realized that it was all naturally made.  There was no evidence of any tool marks on it. 
The Queen's Watchdog, Longhorn Caverns
Here's a side view of it with the guides flash light shining on it. Too bad the lights beam wasn't wide enough to cover all of it.
One of the bigger areas where people could stand and gather had this feature.  It quickly got known as the Queens Throne.  Through the years many a person has sat on it and did damage too it.  It is considered a flowstone deposit.
The Queen's throne- flowstone, Longhorn Cavern
Another view of the Queens Throne.
and a more distant image of the Queen's throne.

An inverted pot hole.
This may be what they call Sam Bass's footprint.
Just look at this unique weathering and the flowstone deposits on it. 
Another inverted pothole with what looks like bat dropping on it.  
During the civil war the Confederate army used this place to make their war ammunition.  They would use the bat dropping or guano for the nitrates they had in them.   Because the material was unstable they would store it in back nooks and crannies of the cave.   I think this area was one of the places that they stored things.  
One of the rooms was called the Cathedral room because of its high ceiling. And the fact that the room was so white.  The guide told us the rock matrix was dolomite and was more resistant to weathering and thus giving the cave more unique features to it.  This was taken as we got into the room. 
But then he switched on more lighting and it was truly spectacular what we were seeing.
Again this was more guano from bats. 
Look at how smooth and rounded everything was in this area. You could tell that the waters must have been flowing though this area quite a bit in order to scour it out like it has.  I thought that dark ring looked almost like a bathtub ring of where some water had been left in the cave for awhile.
I think this area was called the attic because the ceiling had collapsed down.

Another area where the roof had collapsed down.  Apparently there was a lot of debris in the cave and during the Great Depression this area was a CCC work site.  This was a prime location to work because the cave keeps at a constant 68 degrees and in Texas in the summer before air conditioning you couldn't beat that for a work environment.   The CCC workers cleared away the loose materials and used it to build the road beds around the area.  Everything else was left as it was.  In looking at this section those striations look like they may have come from one of the tools used to clear the debris away. 
Here's some more smaller inverted potholes with guano on it.   Apparently there used to be a lot of  migratory bats that hanged out in the caves. But when the CCC workers started to do the work they closed up some of the entrances and when those bats came back they couldn't find there way back in.  We did see some bats in the cave but not the numbers that they used to have.
Some of the material was so pretty with the way it was sculpted it was hard to believe it was all done by mother nature.
There is an area called Lumbago Alley because it is only 5 feet high but it doesn't go for too long and most people can walk through it without too much trouble. The next two photos are of it.
Lumbago Alley, Longhorn Cavern


I thought this was an interesting thing.  The light was placed behind it and so it looked like a jack-o-lantern.
Lumbago alley opened up to the hall of marble and that was where you could really see the dolomite all worn away with a shine to it.
   There used to be a stalactite here that had been removed.  Here you cans see the circular growth rings that shows the way it grows like a tree. 
More inverted potholes.
This was one of my favorite things.  Seeing the flowstones coming from this inverted pothole in the hall of marble.
I think this was the frozen giant icicle 
And this is the Eagle Wings.
This was looking up.  The guide said the dark looking things were chert that is weathering out. And to look really carefully at it.
Then he asked us if we could see Abraham Lincolns profile?
To help us out he used this laser pointer- do you see the red dot in the center of the photo? Its on it.
Here's how it looks when I cropped another picture of it.
This was very close to the end of the tunnel that the tour goes to.  We then headed back.
I think this might have peen the Viking prow.


A good shot of how the Hall of Marble look.
The guide saved the best for last.  Its called the Hall of wonders and then this was the Hall of Diamonds.  We were running late and he hurried us through here but it was pretty special to see.
The lights were moving on the crystals of calcite.  Again they formed like the crystals in the crystal room.   These crystals were more clearer than the other room and that was why they called it the hall of diamonds.


And I liked this one where you could see some drapes. 

One of the things I learned about while there was that during the cold war if a nuclear bomb were to go off this site would be used as a bomb shelter and as such they had taken precautions to make sure it was well stocked with food and things needed for people to live in for awhile.  Then when LBJ became President since his ranch was so close by this would have been the place he would have retreated to.  Since it was of such a military interest they made sure the cavern was well wired and there was a lot of light in it to get around.  This was nice for us because it was easy to see the paths which is not always the case when you are in a cave.  
     It was probably a good thing this cave never had to become a nuclear bomb shelter because later on the guide told us about a flash flood that occurred a couple of years ago and 7 people got caught in the cave and had to be rescued.   While we were in the cave we saw the fire department trainees go by.  They were learning about the cave and how to rescue people in it if they should ever have another flash flood like it.  From looking at the deposits on the walls you can tell that the water is still active in the cavern and its good training to have.    

When I left the cave I was able to obtain a copy of the 'The Geologic Story of Longhorn Cavern' Guidebook 4  Bureau of Economic Geology by William H. Matthews III (1963).  This is an excellent guide book and I did copy a couple of diagrams to help understand the geology of the caverns better.
     This shows the age of the rocks to be Ordovician and in the Ellenburger Group. 
The Geologic Story of Longhorn Cavern (Guide book 4 Bureau of Economic Geology)  by William H. Matthews III (1963) pg 7
 This is one of the best cross sections I've ever run across where it ties the underneath geology to the surface structures.  The two faults that lift up the area is so noticeable when drive through the area.  You can just see how this outcrop is just so much more resistant to erosion than the other rocks that surround it.  And how it was uplifted with the Llano uplift.
The Geologic Story of Longhorn Cavern (Guide book 4 Bureau of Economic Geology)  by William H. Matthews III (1963) pg12
 This was a very good diagram explaining how the caverns formed.
The Geologic Story of Longhorn Cavern (Guide book 4 Bureau of Economic Geology)  by William H. Matthews III (1963) pg 15


The Geologic Story of Longhorn Cavern (Guide book 4 Bureau of Economic Geology)  by William H. Matthews III (1963) pg 3

I was going to include the State Park section in this post but I feel like this is long enough and will have the State Park (http://rockhoundingaround.blogspot.com/2013/08/longhorn-caverns-state-park.html )  in a different post along with the rest of the trip. 

I must also apologize for the lack of using scales in this post.  Most of the photo's were taken of the ceiling and the walls and a scale just could not be placed with it. Also so many of the photo's were taken while we were walking through the cavern and if you dallied too long the guide would turn of the light that was there so we would keep on moving with the group since there was more than one group in the cave at a time. That was  not conducive for placing a scale or for getting images in good focus.   For so much of the cavern- if the area was really wide open with  high ceilings then the lighting was poor and a good picture was not obtained.   Most of the paths were such that people could walk through with out discomfort by being able to stand up straight but they were not very wide with people being able to go single file or 2-3 abreast.   Again I am sorry for the lack of scales. 

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