Monday, February 6, 2012

Hot Springs AR

A couple of weeks ago, when I was transferring all the stuff we had to do to the new calendar, I noticed that we had nothing scheduled for the weekend of Feb 3-5.  This is such an usual event for us, because it seems like there is always something going on where we have something we have to do, or go.  I mentioned it to my spouse and he was amazed too, but then he remembered it was Super Bowl weekend and figured that was probably the main reason nothing had been scheduled for Sunday.  Saturday was just a fluke, and I thought nothing more of it.
    But he didn't,  after New Orleans lost in the play offs, he really wasn't interested in the Super Bowl as to which team would win - he liked certain players on both teams; so he decided to surprise me with an early Valentines day gift.  We had been talking about going up to Hot Springs Arkansas for quite awhile, but never seemed to find a good time to go.  He decided this weekend would be the perfect time for us to get away, and scheduled a stay at the Arlington Hotel. 
   The Arlington Hotel has always been a special place for us.  When my eldest child was just a baby, my husband had to go to a business meeting at that hotel, and we came along too so we could start our vacation from there. My son was teething at the time and was very fussy and was not going to sleep that night.  To quiet him down, I took him down to the lobby at 2 a.m. and was letting him crawl around in the sitting area, only problem was he finally decided he wasn't going to crawl anymore.   He took his FIRST steps there!! I was so excited.  I wished I had my camera but it was packed away in my luggage and never did get those shots.  The next morning I couldn't wait for his daddy to see what he could now do, by then he was walking all over the place and there was no stopping him.  We were so busy watching him that neither one of us thought about taking any pictures, and the opportunity was lost forever.
  That was about 24 years ago and we have only made it back there one other time - again with children.  We both felt like we were long overdue for another visit there for just the two of us.  This time it was so much nicer because we were not on such a tight budget and could take advantage of the hot baths and other amenities the place offers.  After all that was what the area was always famous for its Hot Springs and rejuvenation properties.  The Bathhouse row is now part of a National Park.
Here's a view of the Arlington hotel from Tufa Terrace Trail.
Hotel Arlington, Hot Springs National park


The Arlington Hotel lobby, Hot Springs AR
 This is the area where my son started to walk, its still basically the same except the rugs and upholstery have been updated.
  But this is what got me really excited about being there.  Is seeing this as we pulled into the parking garage.
 Look at those fold rocks.  Aren't they beautiful.  There wasn't a whole lot of geologic information that I saw which really disappointed me.  The park is big and we didn't make it to all of its attractions and I probably missed the display where they talk about the geology.  Most of the stuff we did see was all about the historical significance of the area and the way its always attracted people to the hot waters.
   From what I can figure out these rocks are Lower Paleozoic rocks of the Ouachita Mountains. According to "Geology of National Parks" 6th ed by Ann G. Harris, Ester Tuttle & Sherwood D. Tuttle (2004)  Ch 52 pgs 779-790, The rocks that outcrop in the park are: 'The Womble shale, Bigfork Chert, Polk Creek Shale of Ordovician age; the Silurian Blaylock sandstone and the Missouri Mountain Shale; and the Arksnsas Novaculite which is Devonian and Lower Mississippian in age.' 
      Here's a closer view and a different angle.  There was definitely faulting in the area and it looked like its the  overhang thrust of the Stanley Shale but I don't know it for sure. The Arlington is located in the Y of Fountain street and Park ave and Central ave.
The folded rocks behind the Arlington parking garage
   Most of the geology that I saw talked about how the Hot Springs are formed.  They mention that the rain falls onto the highly fractured Arkansas Novaculite.  It takes about 4000 years to percolate down through the rock. (though some of the waters they think make be as young as twenty years).  As it does down it gets heated by rocks of high temperature and then flows out as an artesian springs. The water comes out in the Hot Springs Sandstone outcrop along the the traces of two thrust faults that that parallels the Hot Springs mountain anticline.

Here's one of the springs anyone can get water from.
 Noble Fountain, Hot Springs AR
 Since the area was famous for its hots springs, bathhouses sprung up around them.  Now the area is not as popular as it used to be around the turn of the century and started to run into decline but people have stepped up and turned most of the bathhouses into historical landmarks.  It still is a fun area to visit.

Bath House Row, Hot Springs National park, AR; Arlington in background.

 Fordyce Bathhouse  National Park visitor center & Maurice Bathhouse to its left
 One of the more popular attractions to the park is the Hot Springs mountain tower.  In the past we were here during the tourist season and was not able to go into it and see the view from the top.  I was so glad we went when we did because this time we had no problems getting in and seeing things.  It is very much worth the effort to do.
  Here's the tower.
Hot Springs Mountain Tower
 I really liked seeing the north view. You can see the Hot springs Mountain Sandstone is right next to the Stanley Shale beds in the valley.  I really got a feel for why the springs are where they are. 

The north view from the Hot springs Mountain Tower
This picture is to the east and you see the Hot Spring mountain and the Arkansas novaculite mountain.
The one thing I don't like about the area is the vegetation is so prolific you don't get to see a lot of really fresh outcrops unless an area has been recently cleared away. 
East View from the Hot Springs Mountain tower
 
   Years and years before, I had been to the area with a friend that was a geologist.  He had been here before on a field trip.  One of the things they did was to collect quartz crystal from the Coleman mine.  He took me to this mine and we had a great time collecting some crystals.  Through the years and with moving, I either gave away or left behind most of what I collected.  I always thought that I would be back here some day and never really worried about not having the stuff anymore.
   Well with this trip I thought I would see if I couldn't find that mine again. I got on the internet and found out that there's now two Coleman mines --Jim and Ron.  It turns out they are brothers.  I remembered I could see the mine from the shop and figured I must have gone to Ron's mine.
   My husband knows how I'm with rock shops and things like that. He knew I wouldn't be happy until I went and visited the area and see if things were the way I remembered them. I wasn't so keen on going because  the night before there had been a terrible thunderstorm and the weather was foretasted to be bad all weekend long. I was hesitant about going since conditions were predicted to be so miserable and I'm to the point now I hate being cold, wet and miserable. We decided that we could at least go to the rock shops since they would be mostly inside.   So the first thing we did Saturday was head out to find them.
  Boy was I glad we decided to do that. I could not have asked for a prettier day.  It was in the high 60's, mostly cloudy sky's with the sun occasionally poking through.  Since it had rained so much the day before everything was nice and wet and easy to see.
  As we drove along Highway 7, I saw some interesting things.  Near Mountain Valley, and the Glazypeau Mountain I saw a piece of land that was cleared away and was for sale.  Since we had nothing better to do we decided to turn back and look at it.  Here's what it look like from the road.

 But then as I started to walk closer this is what I saw.  Isn't that some amazing folding and faulting. I was so glad we had stopped to look at it.

 And this is as close to it as I could get without wading through a deep, deep puddle.

  Finally we got to the Coleman rock shop.  I thought we were at Ron's but it turned out we were at Jim's.  Just look at the crystals they have sitting out front.  If you look really carefully you can see the penny on it for scale.

This one the penny didn't make it in the photo but they still were impressive to see.
Quartz Crystals in front of the Jim Coleman Rock Shop
 It took awhile but my husband was finally able to drag me away.  I couldn't wait to see Ron's mine and if it was the one I remembered or not.  I was so excited I was like a little kid in a candy store.
   Here's Ron Coleman's mine and it was just as I remembered it.  Even though it was wet.  I just had to go out and try to look for something.  When you go there you are not allowed to go into the mine itself, but you are allowed to look in the talus piles.  You are allowed to keep what ever you find and can carry out.  They give you a bag to put your stuff in. 

Ron Coleman quartz mine
Ron Coleman quartz mine, Jessieville, AR
According to the Howard's, Darcy & Mike "Collecting Crystals - the Guide to Quartz in Arkansas" (2000 pgs 13-14) the crystals are formed in the Blakely sandstone, Ouachita Mountains (Orogeny)  during the Late Pennsylvanian age (290-245 million years ago.)  During this time the seas were closing thrusting the land mass to the south up to the north and forming the massive continent Pangaea.  The sands in the area were heated and some of them melted yielding a silica rich solution that was able to precipitate out in the open fractures of the rocks. These long quartz veins formed along the fractures because that was where it was easiest for it to travel.  Eventually some of them got filled in, but not all of them and thus individual crystal can now be found in those open fractures.  It appears that the crystals were formed only during the mountain building time of the Pennsylvanian and had stopped in the Triassic.  Most of the crystals are in the crystal belt formations of Crystal Mountain  and Blakely sandstone. The Blakely sandstone was deposited during the Ordovician age (400-500 mya) based on fossil evidence.
     From my observation the sandstone is pretty fine grain and there is a lot of red clay associated with it.  All of which leads me to believe it was deposited in a fluvial to sub-aqueous environment, but I didn't have enough time to really study this and figure it out on my own.  Everything I was looking at was in the tailing piles and thus were out of place. 
Here's some rocks that lined the road to the tailing piles.
veined sandstone, Ron Coleman quartz mine
This next one gives you a really good idea of how the quartz formed along the fractures of the rocks.
quartz veins in a sandstone @ the Ron Coleman mine
 This was the area we were allowed to look in for the quartz crystal.  As you can see it doesn't give you much of a feel for how the matrix rock was deposited..
Ron Coleman quartz mine where you are allowed to hunt for quartz crystals
 I did find quite a few crystals but now I have to get them cleaned up since they are all covered in that red mud/clay.  We did find some really nice pieces but they were too heavy for us to haul out so we left them there for some other strong body person to get.
    While we were there another family was there also.  My husband and I would chuckle every time we heard the young girl scream at the top of her lungs, I've found another lucky rock.

   I mused upon the Lucky Rocks she found and realized she'll remember this the rest of her life, just like I have all those years ago when I wasn't much older than her when I first saw this mine.  I wonder if she'll become a geologist too.

  If you ever get a chance you should definitely check out the Hot Springs area, and the Coleman mines.

And I forgot to include what Wikipedia has to say about it  Hot_Springs,_Arkansas.
 Hot_Springs_National_Park
Here's the geology of it from Wikipedia

Geology

The thermal springs are situated in the Ouachita Mountains of central Arkansas. The springs emerge in a gap between Hot Springs Mountain and West Mountain in an area about 1,500 feet (460 m) long by 400 feet (120 m) wide at altitudes from 576 to 683 feet (208 m). The springs predominantly are composed of hot water from thousands of feet underground mixed with some shallow cold ground water. Currently, there are 43 thermal springs in the park that are presumed to be flowing. Thermal water from 33 of the thermal springs is collected and monitored at a central reservoir, which distributes the combined discharge for public use and consumption. Rock types in the area include shale units which generally impede ground-water movement, while fractured chert, novaculite, and sandstone units generally support ground-water movement.[10]


Conceptual diagram of thermal water flow.
The water comes from rain which falls in mountains to the north and northeast. Flowing downward through cracked rock at about one foot a year, the meteoric water migrates to estimated minimum depths of 4,500 to 7,500 ft (2,300 m) and achieves high temperatures in the deep section of the flow path before rising along fault and fracture conduits. Under artesian pressure, the thermal waters rise and emerge through the Hot Springs Sandstone between the traces of two thrust faults, along several northeast-trending lineaments. Some rainwater from near the springs mixes with the deep hot water before discharge. The trip down takes about 4,000 years while the hot water takes about a year to reach the surface.[5]
The heat comes from the natural heating of rocks as depth increases. The composition of the water indicates it is heated rainwater which has not approached a magmatic source, so no volcanic action is involved in the formation of these hot springs. The result is the mildly alkaline, pleasant tasting solution with dissolved calcium carbonate.[5]

[edit] Rock types



Remaining natural hot springs
The exposed rock types in the vicinity of the thermal springs are sedimentary rocks of Mississippian to Ordovician age, with the exception of younger igneous rocks (Cretaceous age) exposed in two small areas about 6 and 11 miles (18 km) southeast of the thermal springs (Potash Sulphur Spring and Magnet Cove, respectively), and in many small dikes and sills. Most dikes are less than 5 ft (1.5 m) wide. There have been 80 dikes noted about 4 miles (6.4 km) southeast of Hot Springs, on and near the Ouachita River. There is no indication that igneous rock occurs where the thermal springs discharge.
The sedimentary rocks in the vicinity of the thermal springs consist of shale, chert, novaculite, sandstone, and conglomerate.

  • The Stanley Shale is predominantly a clayey, thinly fissile, black to green shale, with large amounts of sandstone interbedded throughout the formation. The sandstone, when freshly exposed, is a hard, fine-grained, feldspathic, silty sandstone, but weathers easily to a soft, clayey porous material ranging from green to brown in color. Almost all of the low-lying areas in the city of Hot Springs are composed of the Stanley Shale, and it surrounds Hot Springs Mountain on the south, east, and west sides.
  • The Hot Springs Sandstone Member of the Stanley Shale, hereafter referred to as the Hot Springs Sandstone, consists of fine- to medium-grained sandstone with some shale and conglomerate. The sandstone is gray, hard and quartzitic, reaching thicknesses up to 6 ft (1.8 m) The shale predominantly occurs at the top of the unit, and the principal bed of the conglomerate occurs at the bottom.
  • The Arkansas Novaculite consists of lower, middle, and upper members. The lower member is a massive fractured novaculite, and is the dominant member on Hot Springs Mountain, with a thickness of about 275 ft (84 m) The middle member is a black clay shale interbedded with novaculite, about 10 ft (3.0 m) thick on Hot Springs Mountain. The upper member is chiefly a massive, highly calcareous light gray to black novaculite. It reaches a maximum thickness of 180 ft (55 m) in the area.
  • The Polk Creek Shale and Missouri Mountain Shale overlie the Bigfork Chert and generally consist of shale with minor thin layers of quartzitic sandstone. The Polk Creek Shale is a black, fissile, graphitic shale. The Missouri Mountain Shale varies in color, and is soft and argillaceous.
  • The Bigfork Chert overlies the Womble Shale and consists almost entirely of chert and silty chert in layers 2 to 12 inches (300 mm) thick, separated by minor thin beds of black shale. The chert is very brittle and intensely fractured from folding.
  • The Womble Shale is the oldest geologic unit that underlies all other exposed units. It is black, hard, and argillaceous shale.[10]
During most of the Paleozoic Era, what became the Ouachita Mountains was the bottom of a shallow sea, where several sedimentary layers were created. About 500 million years ago a collision of the South American Plate with the North American Plate caused the shale and sandstone layers to fracture and fissure, creating mountains of the folded rocks.[1] The thermal springs emerge from the plunging crest line of a large overturned anticline in the Zigzag Mountains of the Ouachita anticlinorium. The overturned anticline plunges toward the southwest into the Mazarn Basin. There are two recognized major thrust faults trending nearly parallel to fold axes that define the northern and southern limits of the thermal springs discharge area. The northern fault extends nearly parallel to Fountain Street northeastward about 9,200 ft (2,800 m) onto the southeast flank of North Mountain, and dips about 26 degrees north. At the northern extent of the thermal springs, this fault is suggested to form along the bedding contact of the Hot Springs Sandstone and Stanley Shale, with the Stanley Shale forming the hanging wall of the fault. The southern fault extends northeastward about 9,000 ft (2,700 m) roughly along the axis of the Hot Springs anticline, and dips about 44 degrees north. It has been proposed that a fault splits away from the southern fault, trends west and connects with the northern fault. A natural ravine trends along the location of this fault. Extensive cracks, joints, and fissures in the Bigfork Chert, Arkansas Novaculite, and the Hot Springs Sandstone allow the water to flow in the thermal springs area.[10] Dissolved minerals in the water precipitate to form the white to tan travertine or "tufa rock" seen near the openings of the hot springs.[1]

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