Marine fossils in Colombia’s Eastern Cordillera
Our Colombian trip ended in Bogotá, in the Eastern Cordillera. The active volcanoes associated with the offshore subduction zone are farther west, in the Central Cordillera. For maps of the plate tectonic setting, see my first Colombian post: https://landscapes-revealed.net/bienvenidos-a-colombia-welcome-to-the-northwest-corner-of-south-america. The landward position of the Eastern Cordillera, east of the active volcanoes, is a region geologists refer to as the back-arc—that...
Trekking through an ancient sea in the Italian Dolomites
The main purpose of our August–September trip to Italy was to explore the much-lauded Dolomite Mountains, located in northeastern Italy (Trentino-Alto Adige province) just a few hours north of Venice. The gleaming steep-sloped white mountain blocks separated by verdant valleys were just as spectacular as we had been led to believe! This view is northeastward from Piz Boe (see 3-D...
Discovering what killed the dinosaurs in Gubbio, Italy
Our 4-week trip to Italy in August and September was mainly focused on trekking in the Dolomite Mountains—those posts to come later! During the planning process, I realized the town of Gubbio is located just 4.5 hours south of Venice, where we were flying in and out of. We had to go there! A rock outcrop just east of Gubbio...
Rock architects in the 9th–13th centuries: Chaco Canyon National Historic Park and World Heritage Site
There is evidence that people have been inhabiting the region we now call northern New Mexico for at least 10,000 years. But starting in the mid-800s, the Native Chaco people began to build massive, multi-story stone buildings—referred to as “great houses”—that they continued to expand for more than 300 years. In early June, we visited the Chaco Canyon historic park...
The dinosaur that went to space: the state fossil of New Mexico
Who knew that New Mexico has one of the world's most famous dinosaur species? I sure didn't until our recent visit to Ghost Ranch, located about an hour north of Santa Fe (see my last post about Georgia O'Keefe and her life in that region: https://landscapes-revealed.net/the-rocks-of-georgia-okeefe/). It turns out that a Ghost Ranch quarry has yielded hundreds of Coelophysis dinosaur...
John Day Fossil Beds National Monument—climate
My previous post about paleontology explored how plants and animals changed during the 44-million-year time period represented in the John Day Fossil Beds. The evolution of species, in general, occurs because species eventually become extinct and new species arise to take their places. Today, human activities are contributing to organisms' extinction, but there are many natural factors that have caused...
John Day Fossil Beds National Monument—paleontology
Paleontology is the study of plant and animal fossils to understand how life has evolved through geologic time. The John Day Fossil Beds are a world-class locality for such studies. According to Dr. Ralph W. Chaney, a paleontologist at the University of California Berkeley (UCB) who worked in the area from the 1920s through the 1960s: “No region in the...
John Day Fossil Beds National Monument—stratigraphy
The John Day Fossil Beds is located in north-central Oregon. It was established as a national monument in 1974. The region has one of the world's most complete records of fossils during the Age of Mammals, a period of time also known as the Cenozoic Era (past 66 million years). There will be three blog posts: (1) stratigraphy—how layers of...
Dinosaur National Monument—more public lands worth preserving
My last four posts have been about our public spaces—two national parks and two national monuments. With increased petroleum and mineral exploration and drilling in and near our preserved lands, it behooves us to learn more about the places that may be threatened by the current U.S. administration. In June we visited Dinosaur National Monument, an out-of the way park...
The Great American Biotic Interchange
With its many excellent fossil sites, Argentina has lots of evidence for how life evolved through time. One of the largest effects on how organisms evolved was the position of the continents. For example, when the continents were united into the "super continent" called Pangea at the end of the Paleozoic, land animals could migrate for huge distances. In contrast,...
Argentina—a paradise for fossils of dinosaurs and proto-mammals
We visited Parque (park) Ischigualasto, which means "the place animals go to die" in the local indigenous language. The native people saw many bones in the region, which was the reason for this name. Later, of course, these bones were recognized as animals that have long been extinct. We also visited the Museo de Ciencias Naturales (museum of natural sciences)...
Fossils fossils everywhere (and Sintra update)
The previous post got "published" before it was finished, so this post is going out to announce the update of the prior post and to include some fossil photos. Everywhere you step or look in Lisbon there are fossils—interior floors and walls are often covered with fossiliferous limestone. This rock was quarried from a place where oysters were once very...
About the Blogger
Karen (here with Mt. Shasta in background) is a geology professor emerita who aims to provide a "pocket geologist" for world travelers. Follow the blog to explore the landscapes of our planet and figure out what causes them to look the way they do.