Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/619545
Bill Langer is a consulting research geologist who spent 41 years with the U.S. Geological Survey before starting his own business. He can be reached at Bill_Langer@hotmail.com CARVED IN STONE 44 AGGREGATES MANAGER / January 2016 D uring my career as a geologist, I have been fortunate to see some fasci- nating geology. This year, I would like to share some of those geologic experiences with you: some truly magnificent, others simply a curiosity. One outstanding experience was a trip to Portorož, Slovenia, where I was an invited instructor at a NATO Advanced Research Workshop on Sustainable Mineral Resource Management in Karst Areas. The term karst refers to areas charac- terized by sinkholes, caverns, caves, tunnels (also called conduits), and other under- ground drainage, formed by the dissolution of limestone or other soluble rocks. I was at the workshop to describe how to identify and characterize potential im- pacts from aggregate mining in areas of karst, and how to avoid or mitigate those impacts. What better place to hold a workshop on karst than in Slovenia, almost half of which is karst terrain. In fact, the term karst is derived from the name of the Slo- venian region Kras. It is no coincidence that karst research has its origin in this very part of Slovenia, which is scientifically referred to as "Classical Karst." One of the highlights of the workshop was a visit to the Škocjan Caves, one of the natural treasures of planet Earth. Because of its exceptional significance, Škocjan Caves is on UNESCO's list of natural and cultural world heritage sites. People have been attracted to the magnificent caves from time immemorial. The channels and caverns of Škocjan Caves were cut into a 1,000-foot-thick layer of Cretaceous and Paleocene limestone by the Reka River. Before disappearing into the karst underground, the river passes through a vast, picturesque channel about 500 feet high and about 400 feet wide, often as dramatically roaring rapids and waterfalls. At Velika Dolina (Big Collapse Doline), the Reka River sinks under a rocky wall and disappears underground into Škocjan Caves. From Velika Dolina, the water flows underground for 21 miles surfacing near Monfalcone where it discharges into the Timavo River, increasing the flow of the river by 50 percent. The Timavo River then flows to the Adriatic Sea. The Škocjan Caves consist of about 3.9 miles of explored caves. The vast underground halls and chambers of the cave sys- tem expose stunning variations of limestone bedrock and secondary cave formations. It is the exceptional volume of the un- derground caverns that distinguishes Škocjan Caves from other caves. The largest of these is Martel's Chamber with a volume of 2.8 million cubic yards, about the size of an average domed football stadium. It is considered the largest discovered under- ground chamber in Europe and one of the largest in the world. The massive underground cave system has beautiful stalactite, stalagmite, and other structures, as well as a bridge over the gorge that looks like something out of The Lord of the Rings. Beyond its geologic and visual appeal, the Škocjan Caves are home to noteworthy species that thrive in the world of the underground environment. The caves support many endemic and endangered species, including invertebrates and crusta- ceans. Likewise, the peculiar environmental conditions of the collapsed dolines provide a habitat for rare and threatened flora and fauna. Visiting the Škocjan Caves should be on your bucket list of geologic wonders. It is an experience you will never forget. If you can't make it in person, go to www.park-skocjanske-jame.si/en/gallery/foto/skocjanske-jame_3 for a photo tour. A visit to these channels and caverns, cut into a 1,000-foot-thick layer of Cretaceous and Paleocene limestone by the Reka River, should be on your bucket list. Škocjan Caves