A proposal to create a Geopark in the Bosque de la Primavera has been submitted to the University of Guadalajara with the recommendation that the project be presented to Jalisco State authorities. An ad-hoc committee consisting of ecologists, geologists, Primavera Forest Staff and other interested parties worked for two years to create a plan of action which could result in the creation of a Primavera Caldera Geopark and its eventual recognition by UNESCO. The Guadalajara-based committee worked hand-in-hand with Geopark experts living as far away as Iran and China.
I have been involved in this project since its beginning and even before that. Here is an overview of what is involved and an update on progress toward establishing the park in Jalisco.
The project really began in the Sultanate of Oman where—thanks to a strange concatenation of events—I found myself attending the Third Global Geotourism Conference in the fall of 2011. While preparing for this event, I discovered the existence of the Global Geoparks Network, UNESCO’s organization of 90 Geoparks in 27 countries of the world, where tourists can see and, better yet, understand the world’s most outstanding geological phenomena.
I had planned to give a presentation at the conference on the extraordinary biodiversity and geodiversity all around the city of Guadalajara, an area I began calling “The Magic Circle” in 2010 after discovering that all five of Mexico’s eco-systems converge in close proximity to this city, the second-biggest metropolis in the county.
Naturally, I asked myself whether any of the geological features near Guadalajara might qualify for inclusion in a UNESCO Geopark. I decided to pose the question to a friend and neighbor, Canadian geologist Chris Lloyd.
“Can you think of any place in western Mexico,” I asked him, “that is geologically rare and at the same time suitable for demonstrating geological processes to the Man on the street?”
Lloyd looked at me and said, “John, you don’t have to go anywhere to find a site like that. All you have to do is step out your door and walk down the street.”
Thus, did I discover that I live right on the edge of a volcano which long ago produced one of the world’s biggest explosions. “Geologists come here from all over the world to see the Primavera Caldera,” said Lloyd, “but they usually study it from the western extension of Mariano Otero Street. Actually, the arroyo right here at the edge of Pinar de la Venta is much better for understanding the caldera and the creation of the Giant Pumice Blocks, which, of course, only occur in a few places in the whole world.”
Humongous explosion? Giant Pumice Blocks? A potential geopark in my own backyard? “It could only happen in Mexico,” I said to myself as I walked with Chris Lloyd down to the Río Seco, a deep arroyo which separates my community from the Primavera Forest. Soon we stood at the base of a vertical canyon wall about 50 meters tall. “Welcome to the Primavera Caldera,” intoned the geologist with a big smile.
Now a caldera is a most interesting phenomenon. It’s a big hole which is left after a huge volcanic explosion. The whole process happens so suddenly that there is no time for an above-surface volcano to form. This particular explosion, I learned, took place 95,000 years ago and it was no small thing. Twenty-four cubic kilometers of rock and dust were thrown up into the air, putting the Primavera Caldera solidly on the list (although not at the top) of the World’s Greatest Explosions. Eventually, the 11-kilometer-long crater filled with water and became a lake for 10,000 to 20,000 years. “See the horizontal lines on the canyon wall?” said Lloyd, “Each is a layer of sediment formed at the bottom of that lake.”
Right on top of all those strata of sediment, I could see a thick band of something completely different: a layer composed of ash and enormous chunks of pumice typically from four to six meters in diameter. It seems some 25-30,000 years ago, there was a Mt-St-Helen’s type eruption from a volcano at the southeast end of the lake, near the modern-day subdivision of Bugambilias. Giant blocks of pumice enclosed in a pyroclastic cloud were ejected into the lake where they floated for a while until sinking to the bottom, forming a thick layer which geologists now call the Giant Pumice Horizon.
Hot river, hissing fumaroles
Apart from canyon walls that show us the history of the caldera, the present-day Primavera Forest has other outstanding geological features, such as Río Caliente, a hot river which starts out with temperatures as high as 70° C (158° F) but is quickly joined by numerous hot and cold springs, providing a delightful, hot, bubbly, “natural Jacuzzi” experience to countless thousands of bathers yearly. In addition to hot rivers, the Primavera Caldera also has dramatically hissing, sputtering fumaroles. Some of these have produced miniature forests of delicate, featherlike sulfur crystals, a veritable Little Yellowstone that few visitors to the Primavera have ever seen.
Fairy footstools, magic rocks
In the western half of the Primavera Forest lie hundreds of bizarrely shaped rocks. Some of them look like giant bathtubs, sofas and armchairs, others resemble long, smooth, curving fences or walls. Most curious of all are the “Fairy Footstools” which, from a distance, look just like tree stumps but are, in fact, made of rhyolite rock. Dig a hole next to what looks like a stump and you’ll discover that they are just the tips of very long, smooth lithic cylinders. Geologists refer to them as “Fossil Fumaroles.”
Giant stone balls
Within a short distance of the Primavera Forest-Caldera, lie several other extraordinary geological sites which could easily become partners of the new Geopark. Forty kilometers to the west there is a hilltop covered with almost perfectly round stone balls up to three meters in diameter. The Piedras Bola, as they are called, so intrigued geologists that National Geographic sent a team to Jalisco to unravel the mystery of these megaspherulites’ origins and to publish the results (See their August, 1958 issue). More than 70 of these round rocks have been catalogued by a team from the University of Guadalajara (UDG) and it is thought that hundreds more lie beneath the surface.
Obsidian field, workshops
Jalisco has the fourth largest obsidian fields in the world. One of the most important of these is El Pedernal, which is found 25 kilometers west of the Primavera Forest, near Teuchitlán. Its obsidian is of a very high quality and comes in many other colors beside black.
What is thought to be the world’s largest and oldest obsidian workshop, Ixtlitlan, is today known as the former island of Las Cuevas, located 13 kilometers south of Magdalena. Archaeologists have proven that high quality obsidian was worked here continuously for 2,000 years and tools from here made their way as far north as what is today the US state of Arizona.
Three major volcano types
The Primavera is an outstanding example of a Caldera Volcano. Only 30 kilometers away, Geopark visitors can walk through the picturesque crater of the Tequila Volcano, a stratovolcano featuring one of the world’s best examples of an uplifted volcanic plug. A safe, yet exciting via ferrata can be constructed up to the very top. Good examples of the third type of volcanoes, scoria cones, are found just east of Guadalajara. This means that all three of the major types of volcanoes can easily be visited in one day.
Opal mines
Hundreds of opal mines lie 50 kilometers northwest of the Primavera Caldera, near Magdalena. Wielding a miner’s pick, visitors can find their own opals or purchase finely crafted opal jewelry in Magdalena.
Jalisco, it seems, has an abundance of outstanding geological phenomena which fit the requirements for a UNESCO Geopark. Primavera Forest authorities are excited about locating the park within the confines of the Bosque. As this is an official Protected Area it meets one of the crucial requirements for a Geopark. Another requirement for acceptance by UNESCO is participation in the park’s projects by local people, which again coincides with the strategy adopted by Primavera Park officials.
Participation in the Global Geoparks Network would guarantee an influx of tourists from all over the world interested in geology and ecology. “Once here,” says Juan Pedro Hernandez, Chairman of the Ad-hoc Committee, tourists who came to see natural phenomena will, of course, discover many of the other attractions of Jalisco, such as beautifully restored Haciendas, the strikingly unusual archaeological ruins of the Teuchitlán Nation, and, of course, the Paisaje Agavero.”
Hernández says that the proposal for a Jalisco Geopark is now in the hands of Raul Padilla López, former Rector of the University of Guadalajara and that he hopes a reply will soon be forthcoming.
More information on the Global Geopark Network can be found at www.globalgeopark.org.