I Died and Went to Han’s (Rock Heaven): a field trip to Big Bend, Texas
by Dale Engler
This is an unusual title for an article, even for me, but somehow it seems appropriate. As I am sure you are tired of hearing, we had a field trip to Big Bend country in Texas over the holidays. It was a trip months in the planning, and that planning paid off in a big way. I just wish more of you could have made the trip. I arranged for Teri Smith (Rolling Rock Club) of Alpine, TX. to lead the first two days of the trip to two ranches she has access to. We would not have been able to collect on these ranches without her. In the process we met rockhounds from the Dallas – Ft. Worth area and thus it became a joint field trip of four clubs. Rolling Rock, Arlington Rock Club, Martin Marietta Club and Playground Gem and Mineral (us).
The first day, Monday Dec 28th, we went to the Singleton Ranch south of Marfa, Tx. to collect what is called Marfa bouquet, a type of plume agate that comes in a number of colors ranging from black to green to pastel pinks and golds and creams. This material weathers out of the lava beds as nodules that formed in the “bubbles” in the lava.
The silica source for the agate was from volcanic ash overlying the lava beds. As water percolated down through the ash, silica dissolved, was transported into the holes in the lava and the nodules were created. This is a recurring theme throughout this area and that seems to be how much of the tremendous agate and jaspers were formed. Ash supplying the silica. Water being the facilitator. Seams, holes and voids being the repository for the quartz that formed. The Big Bend area is also known for petrified wood of various sorts, with probably the same mechanism in place, only the “wood” being where the silica would end up!
Back to Singleton Ranch. Most of the material was on a slope just below a ridge top littering the surface.
Don’t get me wrong, it was not everywhere. You had to look, but everyone found nice material. I got a 5 lb. bucket and Dave got more than I did. Will every piece be a prize? No, but I am sure we each got many more that one! The best of this material, polished and in rock shops in the area had prices well in excess of $100 per cab! We also found a number of pseudomorphs. This best one was a great chalcedony after dog-toothed calcite found by Tommie Boyd, one of our new friends. The weather was great. Cold in the morning … high 20’s, but high 50’s to low 60’sby mid day.
The next day we were hit with rain, changing to sleet, and then snow. We decided to be wimps and bail. We went to a couple of “rock shops.” I put that in quotation marks because the first place was not a traditional rock shop. We drove about 75 miles, just down the road in this part of the country, to a place owned by an elderly couple and 15 – 20 dogs. They had 5 or 6 adult dogs and the rest were about 8 week old puppies. Of course the puppies had to help everyone do everything except walk .. they only help trip you with regards to walking. The “rock shop” was a series of boards set up like benches covered with rocks. They had 1 gallon nursery containers filled with pieces for $5 and the individual rocks were priced by the piece, generally by size, without much respect to what they were. In addition to the rocks, which were very reasonable, the puppies were free … please take a couple we kept hearing. It was great.
We then went to a conventional shop in Marfa. They had not only good material of the area but nice material in general. I believe Dave got some very nice turquoise at a good price.
Teri was not able to move the day 2 trip(Tues.) to Wed because she had other commitments but agreed to do it on Thurs. Wednesday was now open, so along with our new friends from the Martin-Marietta and Arlington Clubs, we collected a number of road cuts
and went to Woodward Ranch to see Trey and Jason Woodward, visit their rock shop and see Trey’s amazing fireplace. The fireplace is amazing because its entire face is made of rocks and minerals from that part of the country, much from their ranch and from the Needle Peak area. The prize piece is a pseudomorph of chalcedony after blocky calcite (rhombohedral) from the Needle Peak area that was over a foot in each dimension with the individual crystals about 1 inch in each dimension.
On Thursday Dave and I went with Teri to the Richie Ranch while our new friends went down to Stillwell Ranch where we would meet them later that day. Richie Ranch, actually T & W Ranch owned by the Richies, has large seams of agate and jasper in reds, greens, golds and black with moss, brecciated and orbicular patterns found. When I say large seam I am talking about 2 feet thick which can run across the landscape. There are also nodules found. Teri showed us one bolder and said we could break pieces from it if we wanted to, I did, but another she showed us was off limits. It had been used by Native Americans as a source of knapping material for tools and weapons and was being preserved!
We also went to a “gravel pit” on the property where road material had been dug. This area had a mixture of materials that had been transported from the surrounding hills. We each found a little material. One piece about a foot in diameter looks like it will produce good slabs.
We then traveled to Stillwell Ranch where we joined the Dallas/Ft Worth group. Stillwell Ranch is remote, with a gas pump, a very small store and camping area. It is on the ranch of Hallie Stillwell, a famous woman pioneer of that area. It is run by her granddaughter. When we “checked in” we were told that there would be a party that afternoon (It was New Year’s Eve). Everyone who lived within 50 miles was there, about 50 people enjoying a covered dish and live music.
What a treat! There was even a fireworks display at midnight. The next day we went to a rock shop in Study Butte, Tx. run by a gentleman named Hans. We had heard about this place for days. It was not a disappointment. In fact it exceeded all expectation. The material was amazing, ranging from moss and plum agates to petrified woods of a few varieties just to name a few. Bob, one of the guys from the Martin Marietta club coined the phrase, “ when I die i want to goto Hans”. Overall it was an extraordinary trip. This part of Texas had some of the most spectacular geology. There are Dikes crisscrossing the landscape.
Road cuts have intrusions very visible.
as well as layers of volcanic deposits. Lava “necks” form mountain tops when the surrounding rock is eroded away. I just wish more of the club had been able to go.