"Scenic view from atop Twin Rock" by U.S. National Park Service , public domain

Florissant Fossil Beds

National Monument - Colorado

The Florissant Fossil Beds National Monument is located in Teller County, Colorado. The location is famous for the abundant and exceptionally preserved insect and plant fossils that are found in the mudstones and shales of the Florissant Formation. Based on argon radiometric dating, the formation is Eocene (approximately 34 million years old) in age and has been interpreted as a lake environment. The fossils have been preserved because of the interaction of the volcanic ash from the nearby Thirtynine Mile volcanic field with diatoms in the lake, causing an diatom bloom. As the diatoms fell to the bottom of the lake, any plants or animals that had recently died were preserved by the diatom falls. Fine layers of clays and muds interspersed with layers of ash form "paper shales" holding beautifully-preserved fossils.

maps

Official visitor map of Florissant Fossil Beds National Monument (NM) in Colorado. Published by the National Park Service (NPS).Florissant Fossil Beds - Visitor Map

Official visitor map of Florissant Fossil Beds National Monument (NM) in Colorado. Published by the National Park Service (NPS).

Map of the U.S. National Park System. Published by the National Park Service (NPS).National Park System - National Park Units

Map of the U.S. National Park System. Published by the National Park Service (NPS).

Map of the U.S. National Park System with Unified Regions. Published by the National Park Service (NPS).National Park System - National Park Units and Regions

Map of the U.S. National Park System with Unified Regions. Published by the National Park Service (NPS).

Map of the U.S. National Heritage Areas. Published by the National Park Service (NPS).National Park System - National Heritage Areas

Map of the U.S. National Heritage Areas. Published by the National Park Service (NPS).

https://www.nps.gov/flfo/index.htm https://en.wikipedia.org/wiki/Florissant_Fossil_Beds_National_Monument The Florissant Fossil Beds National Monument is located in Teller County, Colorado. The location is famous for the abundant and exceptionally preserved insect and plant fossils that are found in the mudstones and shales of the Florissant Formation. Based on argon radiometric dating, the formation is Eocene (approximately 34 million years old) in age and has been interpreted as a lake environment. The fossils have been preserved because of the interaction of the volcanic ash from the nearby Thirtynine Mile volcanic field with diatoms in the lake, causing an diatom bloom. As the diatoms fell to the bottom of the lake, any plants or animals that had recently died were preserved by the diatom falls. Fine layers of clays and muds interspersed with layers of ash form "paper shales" holding beautifully-preserved fossils. Beneath a grassy mountain valley in central Colorado lies one of the richest and most diverse fossil deposits in the world. Petrified redwood stumps up to 14 feet wide and thousands of detailed fossils of insects and plants reveal the story of a very different, prehistoric Colorado. Visitors traveling north/south on I-25: Exit at US 24 West, travel 35 miles to town of Florissant, then follow signs two miles south on Teller County Road 1 to the Visitor Center. Visitors traveling from town of Cripple Creek: Follow Teller County Road 1 north for 16 miles. Florissant Fossil Beds Visitor Center At this time, only the restrooms are open in the visitor center. The bookstore is open Fridays through Sundays. There is a tent and table on the front patio set up to welcome and orient visitors. Fees are being paid in a fee booth on the front patio. The indoor exhibits and theater are closed, however, the park film is online at www.nps.gov/flfo Park entrance off of Teller County Road 1, two miles south of the intersection of Teller County Road 1 and Highway 24 in Florissant, Colorado Big Stump Fossil redwood stump Walk the Petrified Trail Loop to see fossil redwood stumps Ancient Wasp Fossil palaeovespa, ancient wasp Captured 34 million years ago, this ancient wasp and other insects are on display at Florissant Fossil Beds NM. Hornbek Homestead Visitors Visitors at Hornbek Homestead Visitors explore the Hornbek Homestead, built in 1878. Junior Rangers Junior Rangers in Visitors Center Youth of all ages participate in the Junior Rangers program at the Monument. Self Guided Trails View of the Florissant valley with grassy meadows and mountains in the distance View from the top of the self-guided Geologic Trail Campers, Composers, and Cake at Florissant Fossil Beds in the Summer of 2019 Florissant Fossil Beds National Monument, for the second year in a row, offered a free geology and paleontology camp for upper elementary students. three men standing in a grassy field Paleontological Modeling Example—Redwood Trio 3D Fossilized Redwood Trio Florissant Fossil Beds National Monument, Colorado model of fossil redwood stumps National Park Getaway: Florissant Fossil Beds National Monument Set aside as a national monument in 1969, this lesser-known national park protects one of the richest fossil deposits in the world. Over the past 140 years, paleontologists have also found fossils of plants, mammals, fish, birds, snails, and mollusks. That level of diversity of fossil insects at any one locality is extraordinarily rare in the world. Fossilized wasp Checking Florissant's Vital Signs In 2007, the Rocky Mountain Inventory and Monitoring Network—a small team of NPS scientists—began monitoring natural resources, called “vital signs,” in Florissant Fossil Beds and nearby park units. Vital signs indicate park health and serve as red flags if conditions deteriorate, supporting park managers’ efforts to make science-based management decisions. Learn about the NPS Inventory and Monitoring Program and its work in Florissant Fossil Beds National Monument. petrified redwood stump on edge of a green, grassy valley with buildings and horizon in background 2012 Freeman Tilden Award Recipients In 2012, seven rangers were awarded the national and region Freeman Tilden Awards for innovative and exciting interpretive programs. Learn their stories and more about their award-winning programs. Renee Albertoli Wildland Fire in Douglas Fir: Western United States Douglas fir is widely distributed throughout the western United States, as well as southern British Columbia and northern Mexico. Douglas fir is able to survive without fire, its abundantly-produced seeds are lightweight and winged, allowing the wind to carry them to new locations where seedlings can be established. Close-up of Douglas fir bark and needles. NPS Geodiversity Atlas—Florissant Fossil Beds National Monument, Colorado Each park-specific page in the NPS Geodiversity Atlas provides basic information on the significant geologic features and processes occurring in the park. Links to products from Baseline Geologic and Soil Resources Inventories provide access to maps and reports. [Site Under Development] group of three fossil stumps 2017 Recipients: George and Helen Hartzog Awards for Outstanding Volunteer Service Meet the recipients of the 2017 George and Helen Hartzog Awards for Outstanding Volunteer Service. These award recipients are recognized for their exceptional dedication and service to parks and programs. Boy outside holding a tool onto a wooden post. Wildland Fire in Ponderosa Pine: Western United States This forest community generally exists in areas with annual rainfall of 25 inches or less. Extensive pure stands of this forest type are found in the southwestern U.S., central Washington and Oregon, southern Idaho and the Black Hills of South Dakota. Recently burned ponderosa pine forest. Florissant Fossil Beds Virtual Night Sky Junior Ranger Online Activity Florissant Fossil Beds National Monument Virtual Night Sky Junior Ranger Badge Florissant Fossil Beds National Monument Virtual Night Sky Junior Ranger Badge Draw Your Own Big Stump Face Challenge Florissant Fossil Beds protects some of the largest petrified tree stumps in the world by diameter. During the 1800s, people tried to saw the park's famous Big Stump into pieces. If you look close enough, you can make out a grumpy face on the Big Stump. Use templates to decorate Big Stump as your own artistic masterpiece without causing damage to these protected resources. Fossilized tree stump with a sad face drawn over the photograph to make the tree stump look grumpy Latinos en Capas, "Latinos in Layers" (A Poem Connecting Geology to Latino Culture) Through the poem "Latinos en Capas," Astrid Garcia and Franklin Cruz convey various aspects of Latino culture using the geology and paleontology of Florissant Fossil Beds. A multi-generational Latino family admire a large petrified Redwood stump. Series: Geologic Time Periods in the Cenozoic Era The Cenozoic Era (66 million years ago [MYA] through today) is the "Age of Mammals." North America’s characteristic landscapes began to develop during the Cenozoic. Birds and mammals rose in prominence after the extinction of giant reptiles. Common Cenozoic fossils include cat-like carnivores and early horses, as well as ice age woolly mammoths. fossils on display at a visitor center Series: Badlands Geology and Paleontology Badlands National Park is well-known for its geology and paleontology. Fossils found in the park range from 75- to 28-million years old and many are in excellent condition. The flat-lying layers of the park's formation represent classic sedimentary rock layers. a layered badlands butte's jagged edges reach into a bright blue sky. Series: National Park Service Geodiversity Atlas The servicewide Geodiversity Atlas provides information on <a href="https://www.nps.gov/subjects/geology/geoheritage-conservation.htm">geoheritage</a> and <a href="https://www.nps.gov/subjects/geology/geodiversity.htm">geodiversity</a> resources and values all across the National Park System to support science-based management and education. The <a href="https://www.nps.gov/orgs/1088/index.htm">NPS Geologic Resources Division</a> and many parks work with National and International <a href="https://www.nps.gov/subjects/geology/park-geology.htm">geoconservation</a> communities to ensure that NPS abiotic resources are managed using the highest standards and best practices available. park scene mountains Series: Park Paleontology News - Vol. 11, No. 2, Fall 2019 All across the park system, scientists, rangers, and interpreters are engaged in the important work of studying, protecting, and sharing our rich fossil heritage. <a href="https://www.nps.gov/subjects/fossils/newsletters.htm">Park Paleontology news</a> provides a close up look at the important work of caring for these irreplaceable resources. <ul><li>Contribute to Park Paleontology News by contacting the <a href="https://www.nps.gov/common/utilities/sendmail/sendemail.cfm?o=5D8CD5B898DDBB8387BA1DBBFD02A8AE4FBD489F4FF88B9049&r=/subjects/geoscientistsinparks/photo-galleries.htm">newsletter editor</a></li><li>Learn more about <a href="https://www.nps.gov/subjects/fossils/">Fossils & Paleontology</a> </li><li>Celebrate <a href="https://www.nps.gov/subjects/fossilday/">National Fossil Day</a> with events across the nation</li></ul> devils tower Series: Photogrammetry Applications and Examples Photogrammetry is the science and art of using photographs to extract three-dimensional information from a series of well-placed images. Paired with either a standard ruler or GPS locations of camera positions provides the scale in completed models. This Series provides examples of photogrammetry projects for a variety of resources in National Parks. fossil redwood stump trio Women & Paleontology in the Badlands Although Badlands National Park is proud to employ many female paleontologists today, this scientific field was not always accepting of women. In this article, learn about how women's roles in paleontology have changed over years of Badlands research. a woman in a white lab coat uses a small pick while working on a baseball-sized fossil skull. Paleogene Period—66.0 to 23.0 MYA Colorful Paleogene rocks are exposed in the hoodoos of Bryce Canyon National Park and the badlands of Badlands and Theodore Roosevelt national parks. Extraordinary Paleogene fossils are found in Fossil Butte and John Day Fossil Beds national monuments, among other parks. fossil skull with teeth expsoed Cenozoic Era The Cenozoic Era (66 million years ago [MYA] through today) is the "Age of Mammals." North America’s characteristic landscapes began to develop during the Cenozoic. Birds and mammals rose in prominence after the extinction of giant reptiles. Common Cenozoic fossils include cat-like carnivores and early horses, as well as ice age woolly mammoths. fossils on display in a visitor center
Climate Change Changes in the Earth’s climate have occurred since the planet formed 4.5 billion years ago. Eocene Florissant was at the threshold of one of the most significant climate changes since the extinction of the dinosaurs – a massive cooling event that affected life around the globe. Modern Florissant faces a similar challenge from climate change today. How can fossils help us understand climate change of the past, and how does this knowledge help us make decisions in response to modern climate change? What was Florissant like 34 million years ago? At the end of the Eocene Epoch, the time when plants and insects were falling into Lake Florissant to be preserved as fossils, Florissant was wetter and much warmer than it is today: primarily on plant fossils to determine what Eocene Florissant was like. Unlike animals, which can migrate with the seasons, plants are rooted to the ground and have specific adaptations for survival in a particular climate. One way to infer climate from fossil plants is to look at the nearest living relatives of the fossil species and the climates those plants live in Modern 4°C (39°F) 38cm (15in) today. A modern plant probably lives in a climate similar to the one its Eocene relative Eocene 11-18°C (52-64°F) 50-80cm (20-31in) lived in. Another method involves considering Today Florissant has a cool temperate climate and primarily the physical form of the fossil plant. Many plants evergreen coniferous vegetation, like pines and spruces. During have physical adaptations, especially in their the Eocene, Florissant had a warm temperate or even subtropical leaves, which help them survive more successfully in certain climate with deciduous broadleaved plants and exotic tall conifers. climates than others. The size, shape, texture, and teeth of a Although modern and Eocene Florissant had comparable summer leaf are all features that reflect the climate a plant inhabits. temperatures, winter temperatures are much colder now, A combination of multiple methods must be used restricting the types of plants that can live here. when reconstructing climate because no single method is flawless. When reconstructing Eocene How do we know what past climates were like? Florissant’s climate, scientists consider the There are many methods that scientists can use to reconstruct the physical features of fossil leaves, the climates that the climate of a past ecosystem. At Florissant, researchers rely fossils’ nearest living relatives live in, and other methods like analyzing the tree rings in Florissant’s petrified redwood and hardwood stumps. Mean Annual Temperature Mean Annual Precipitation What happened after Eocene Florissant? As the Eocene transitioned into the Oligocene Epoch 34-33 million years ago, global climate cooled significantly and rapidly. This was the result of new cold ocean currents created by continental plate movement around Antarctica. Studies have found that the North American climate cooled by as much as 8-10°C (14-18°F) in less than a million years. Florissant is one piece of the fossil record that spans the Eocene-Oligocene transition and shows how plant communities and climate changed during this time. 1cm 0.5cm Late Eocene Florissant had a warm temperate climate at high elevation, as shown by the dominance of broadleaved plants with a few conifers. In contrast, a nearby and slightly younger early Oligocene site at comparable elevation had a cool temperate climate, indicated by a dominance of conifers such as pine, fir, and spruce. A similar change is evident from fossil floras in the lowlands of the west coast, where the near-tropical forests of the late Eocene gave way to temperate deciduous forests in the Oligocene. These lowland Oligocene floras share many types of plants with Eocene Florissant, such as pines, firs, redwoods, oaks, hickories, elms, maples, and roses, indicating that these types of plants dispersed from higher to lower elevation as climate cooled. The shift from subtropical to temperate at low elevations and from warm temperate to cool temperate at high elevations is evidence of the effect global climate change can have on terrestrial ecosystems. Fossil leaves from subtropical, warm temperate, and cool temperate climates. Left to right: “Cinnamomum dilleri” (UCMP-735), Fagopsis longifolia (FLFO-11513), Sequoia affinis (FLFO-6488). UCMP image courtesy of the University of California Museum of Paleontology. What causes climate change? Data from scientific studies prove that climate is changing, as it has changed since the Earth formed, but why is this climate change concerning? Most past global climate changes are attributed to variability in solar output, the Earth’s orbit and tilt, volcanic activity, and plate tectonics. The rapid warming occurring on Earth today is caused not by any of these natural variations, but by human augmentation of the atmosphere’s natural greenhouse effect. By burning fossil fuels like coal and oil, we increase th
Florissant Fossil Beds Paleontology Program U.S. Department of the Interior National Park Service Florissant Fossil Beds National Monument The paleontology staff at Florissant Fossil Beds National Monument includes a paleontologist, a museum technician, and several interns. These specialists monitor fossil sites around the monument, curate fossils in the on-site museum, and work with scientists at other institutions conduct to research about Florissant. Is anyone still digging for fossils? Researchers from various institutions have dug for fossils at Florissant, but any excavation on National Park Service land requires a permit. There are no large excavations currently planned because there is not enough room for more fossils in the monument museum. The most recent large dig occurred over the summers of 2009 and 2010 as part of a master’s thesis. Other research has led to small digs since then. A paleontology intern splits shale. Keeping an eye on the fossils Paleontology staff have monitored the stumps and other geologic resources in the park every summer since 1992. They photograph each site from specific angles and compare photographs from different years to determine how the site has changed. An evaluation form for each site quantifies disturbances such as erosion, animal burrows, research excavations, and theft. In general, most sites change very little in a year and theft is rare, but it is important to continue monitoring the resources to ensure that adequate protection measures are in place to preserve the monument’s resources. Where are all the excavated fossils? The paleontology lab in the visitor center building includes a room for museum collections. More than ten thousand objects are cataloged in the museum, and most of these are plant or insect fossils. Other museums across the U.S. and U.K. hold tens of thousands more fossils from excavations at Florissant done before the site was protected as a national monument. Conserving Fragile Fossils The monument does ongoing and pioneering experiments to find the best ways to care for the fossils at Florissant. Petrified Wood Paleontology staff regularly monitor the the stumps behind the visitor center. These fossils were shattered when they were historically excavated with dynamite. The monument has worked Metal bands are installed to stabilize the stumps with around a cracked stump. metal retaining bands and overhead shelters. New projects are ongoing with the University of Pennsylvania to test stone masonry conservation techniques on the most fragile stumps. Paper Shale The shale containing Florissant fossils is made of paperthin layers of ash and microorganisms called diatoms. The shale splits, flakes, and cracks with temperature and humidity changes or contact with chemicals. The paleontology staff are studying ways to repair and prevent damage to the shale fossils in the monument collections. 1 What happens to the fossils after excavation? Fossil specimens easily break or become lost if they are not properly cared for. Museum staff at Florissant Fossil Beds National Monument record, photograph, and permanently store each fossil collected in the park. Some fossils are also prepared and studied for scientific research. 3 Fossils are cushioned in a small box with foam. Preparation When shale is split to reveal a fossil, often parts of the shale still cover the edges of the specimen. Paleontology preparators (people trained to care for fossils) use needle-like tools to pick the shale away, revealing the fossil underneath. The antennae (shown by arrows) of this fossil insect (FLFO-9817) were hidden before preparation (left) but visible afterwards (right). 2 Fossils are photographed to create digital database records. 4 Fossils are placed in drawers organized by the place that they were collected. The museum will keep these specimens permanently so that researchers can make new discoveries from Florissant fossils and check the quality of earlier scientific work on them. What kinds of research happen at Florissant? Research generates scientifically credible information for public outreach and visitor understanding. Scientists have studied Florissant fossil beds for more than 140 years, and several students have written master’s theses about the site. Paleontology staff collaborate with universities, museums, and other institutions to coordinate research activities like digging fossils, loaning specimens, or sharing database information. How does Florissant help other geologic sites? Florissant Fossil Beds National Monument supports national and international efforts to conserve geologic heritage. The paleontology program and Friends group for the monument have partnered with El Bosque Petrificado Piedra Chamana (The Petrified Forest Piedra Chamana) in the Andes Mountains near Sexi, Peru, to help this “sister park” protect and educate about its fossils. Like Florissant, Sexi captures a snapshot of the What are the public benefits of
Fossil Plants More than 130 plant species have been described from Florissant. These are represented by leaves, fruits, flowers, seeds, wood, and pollen, yet the only fossils most visitors see are the stumps of ancient redwood trees. Why is this? Fossilization is a complex process that can be affected by a number of factors, and multiple forms of fossilization took place during Eocene Florissant. How were the fossil plants preserved? Most of the plant diversity at Florissant comes from the abundance of plants preserved in shale. The volcanic mudflow that preserved the redwood stumps was very high-energy, meaning that only the most durable plant parts, such as trunks, cones, and seeds, survived the flow intact. More delicate plant parts like leaves and flowers were preserved poorly or not at all. Delicate plant parts were deposited at the bottom of Lake Florissant, a low-energy, low-oxygen environment. Their fine features are preserved in paper shale, a very fine grained rock produced by the deposition of volcanic ash and a kind of microscopic algae called diatoms. These delicate fossils are still trapped within layers of rock and are only revealed through natural weathering, which causes the fossils to deteriorate, or excavations by the paleontology staff. During excavations, monument paleontology staff dig out pieces of shale, split them to reveal the fossils, and bring them back to the lab where they are safe from the elements. Where did the Eocene plants live? Eocene Florissant was made up of a variety of plant habitats, ranging from the aquatic environment of Lake Florissant to the drier and harsher environments of the surrounding mountainsides. Since most of the plants represented by fossils are terrestrial species, they had to be transported into the lake from wherever they grew, facing possible destruction in the process. Therefore, the distance between a plant and the lake greatly influenced the likelihood of it being fossilized. Species like Sequoia (redwood, left) were preserved frequently because they lived in wet valley bottoms near the lake. Pine (above left), mountain mahogany (above center), and oak (above right), which are seen less frequently as fossils, lived on more distant hillsides. The abundance of certain species also plays a role in how often they are preserved. Fagopsis longifolia, the most common fossil plant found at Florissant, is an understory tree that inhabited the banks of the lake and streams. The number of these fossils relative to those of other species suggests that Fagopsis was also one of the most common species in the Eocene environment. Left: Sequoia FLFO-3661; Above left to right: Pinus FLFO-11481, Cercocarpus FLFO-4096, Quercus UCMP-3661; Right: Fagopsis YPM-30121 Why are fossil leaves so common? Plants in the fossil record are unique in how certain organs are preserved preferentially. A plant organ is a part of a plant that has a specialized function. For example, leaves are considered organs because they are responsible for collecting sunlight for photosynthesis. Other plant organs include flowers, seeds, fruits, and stems. Unlike animals, while a plant is alive it continually releases and regrows many of its organs. All plants, even evergreens, drop leaves. All plants release reproductive structures such as pollen, seeds, and fruit. This means that many isolated plant organs can be found in depositional environments like the bottom of Lake Florissant. Therefore, leaves and reproductive structures are more commonly seen in the fossil record than other plant parts that are not released from the plant during its life, such as the wood of a trunk or stem. The durability of a plant organ also affects its fossilization. Certain leaves are more likely to reach a depositional environment intact than others. Evergreen leaves, like Mahonia (a relative of holly, left), are thicker than deciduous leaves, making them better able to withstand damage during transport and more likely to be well preserved. Fossil fruits and flowers (above) like Asterocarpinus, Florissantia, and Hydrangea are rare at Florissant. This is because they are very fragile and can easily fall apart or be destroyed before being buried. Left: Mahonia UCMP-3764; Top left: Florissantia flower UCMP3619 (width 2.6 cm, 1 in); Top right: Asterocarpinus fruit UCMP-198424; Right: Hydrangea flower YPM-23931. What happened to the Eocene Florissant plants? At the end of the Eocene, there was a drop in global temperature and the Florissant climate began to change from subtropical/ warm temperate to cooler temperate. In response to the intense cooling, many plants native to the ecosystem that were not coldadapted either became extinct or dispersed to other parts of the world. The two most abundant plant fossils at Florissant, Fagopsis, a relative of beech, and Cedrelospermum, a relative of elm, became extinct. The last living species of Sequoia, the coastal redwood, lives on the US Pacific coast. Koelreuteria (g
Florissant Fossil Beds Fossil Vertebrates Giant redwood trees and buzzing insects called Florissant home, but they were not the only inhabitants. Florissant was also home to tiny horses and vibrant birds, as well as other vertebrates. Vertebrates include mammals, reptiles, birds, fish and amphibians. Vertebrate fossils are rare at Florissant due to the environment they lived in and the difficulty in preserving their bodies, as they needed to be transported to the water for preservation. How do vertebrates fossilize? There are a few ways that vertebrates can fossilize. Bones and teeth are usually the only parts that preserve since they are hard and durable. Although rarer, sometimes feather and scale impressions can be preserved. Generally the harder the body part, the greater likelihood of it being fossilized. There are a few modes of fossilization at Florissant like impressions or carbonization. It is also possible to have several forms of fossilization in one fossil. Carbonization forms the thin, black films of carbon of a fossil. This occurs when an organism’s body is compressed and decays all the organic compounds except for carbon. This bird’s feathers were carbonized after it drowned and then was rapidly buried. The thin layer of carbon still show the fine details of the feathers when they were compressed. 1 cm 1 cm Impressions form when the hard parts of an animal are imprinted in soft sediment, like mud, after burial. The hard part, which later decays away, then creates a mold. Impressions include scales, bones and feathers. This unidentified fish had its ribs pressed into the mud before becoming a rock, after which the bones were destroyed. Permineralization occurs when a buried bone is penetrated by groundwater with dissolved minerals through the bone’s pores. Dissolved minerals can be calcite, iron or silica. Over time, the dissolved water will deposit small crystals of the dissolved minerals into the tiny pores. The permineralized bone shards below still have visible pores inside the bone. 1 cm UCM-73039 What vertebrates existed in Eocene Florissant? USNM-11955 Mouse Opossum (genus Nanodelphys) These marsupials were once plentiful in North America but later became extirpated here after having migrated to the southern hemisphere, where they diversified. They typically measured 4 to 5 inches (10-13 cm) from head to tail and their diet consisted of insects and small fruits. It is likely they spent most of their time in the trees to avoid predators using their prehensile tail to aid in climbing. 1 cm Suckers (genus Amyzon) Suckers were 3 to 5 in (7-13cm) freshwater fish that lived at the bottom of the lake. Amyzon suckers were a common fish, with three specimens collected from Florissant’s deposits. They would have been omnivorous, feeding on the both plants and aquatic organisms. While the genus Amyzon died out at the end of the Paleogene (23mya), the family Catostomidae continues to this day in North America. UCM-38711 1 cm Brontotheres (genus Megacerops) The largest of the animals to walk through Lake Florissant’s forests were brontotheres. These giants were 8 feet (2.4m) tall and weighing as much as two tons(1.8 tonnes). They sported a huge bifurcated horn above their nose for protection against predators and by males to settle rivalries. They are most closely related to rhinos, but filled an ecological role similar to modern day elephants. Unable to cope with the changing climate, brontotheres went extinct at the end of the Eocene. Primitive Horses (genus Mesohippus) Considered to be transitional from the small ancestral horses to today’s large modern horses, Mesohippus evolved greater speed with longer legs and three toes. These primitive horses were only 3 feet (90cm) tall, which aided their ability to hide from predators. Based on the structure of their teeth, Mesohippus were browsers (fed on shrubs and trees), not grazers (grass eaters) like modern horses. 1 dm UCM-65951 1 cm Rail (family Rallidae) Rails were slender birds with compact bodies that measured about a foot from head to toe. Their long legs allowed them to wade through shallow water in search of food. They fed on aquatic insects and crustaceans by using their long beaks to dig prey out. Rails are still around today, inhabiting all continents except Antarctica, though they are elusive and hard to find. Are there more vertebrates? Today, the monument has identified over 30 vertebrates. The collections contain other birds including a cuckoo and a roller. A few years ago, a snake vertebra was found, which is the first reptile found at Florissant. The fish are the most abundant fossils in the Florissant fossil record. This is because fish lived and died in the water whereas other animals’ carcasses would have to be transported to the lake to be preserved. As excavations continue to take place, more bones, teeth and other hard parts may be uncovered to reveal more animals that lived in the Florissant ecosystem. Specimen photos labeled
Florissant Fossil Beds Microscopic World of Florissant Imagine walking along the shore of ancient Lake Florissant, almost 34 million years ago. What would Florissant look like? During the late Eocene epoch, the world was a much warmer place. You’d see a lush, thriving habitat—water lilies and cattails lying along the beach, willows leaning into the lake, the air thick with hundreds of swarming insects. But unless you had a microscope, you’d inevitably miss the world invisible to the naked eye. Pollen, algae and microscopic invertebrates are preserved in the fossil beds, providing a window into the environment around Lake Florissant. Fossil Pollen and Spores Pollen and spores are regularly released by plants and are carried by the wind or by pollinators. During the late Eocene, pollen from the plants in Florissant ended up either settling on the surface of the lake or washing into the lake by streams. The pollen then settled to the lake bottom, combining with dead diatoms (algae) in the mud that had bloomed from the ash from the nearby Guffey volcano. When these fossils are excavated, the rock might not show signs of containing fossils at all. This might explain why early naturalists to the area rarely documented the presence of such microfossils. In order to see the identifying characteristics, a micropaleontologist needs to isolate the individual pollen grains and spores by dissolving the rock in acid. The extracted pollen grains are then stained with dye and mounted on slides to view under a Longest dimension: 0.128 mm microscope. Pictured to the left is a fossilized pollen grain found at Florissant from a fir tree. Pollen can be identified by size, shape, and the number and location of pores and furrows. Florissant’s collection has been identified to contain over 130 different species of pollen and spores. Moreover, 25 of the plant genera at Florissant are known only by their pollen. These microfossils have been critical to defining the plant communities surrounding the lake and the climate necessary to support these plant species as seen in the figure below. Fossil Diatoms Diatoms are a type of unicellular algae that flourished in Lake Florissant that have cell walls made of silica. The exterior is typically covered in pores and unique ornamentation and can be used to identify different genera of diatoms. Like pollen, diatoms are carefully extracted from the rock matrix and then mounted on slides. A scanning electron microscope (SEM) is used to be able to view the sub -millimeter level of detail on the diatoms. The photo to right displays an SEM image of two exceptionally preserved of Florissant’s diatoms. Diatoms were critical to the preservation of the fossils at Florissant due to the mucus they produce when stressed. The silicon-rich volcanic ash from the nearby volcanoes would be deposited into the lake that acted as a fertilizer, causing algal blooms to form large mats on the surface of the lake. When the silicon was exhausted, the diatoms would become stressed and exude mucus that would eventually settle to the bottom of the lake. The mucus slowed the decay of dead organisms in the lake so they could fossilize. Fossil Ostracods Ostracods are a type of small crustacean, almost like a shrimp enclosed in a shell, which resided in Lake Florissant. The top left photo depicts a modern ostracod within its shell. They likely lived in the lake’s shallow areas, feeding on detrital remains that settled to the bottom. As they fed on detritus, they absorbed dissolved calcium and other elements from the lake water to augment to their shells. These ostracods were then fossilized, embedded in the resulting shale in their original assemblages. Scale: 1mm in length Like diatoms, ostracods are typically observed using SEM. The bottom left photo shows an ostracod shell that was extracted from the Florissant shale viewed under an SEM. Once identified, ostracods can reveal clues about their original habitat in Lake Florissant. Various elements in the shell record water quality during the ostracod’s life, like the water current, depth and salinity. Furthermore, their presence across the fossil record can be related to temperature. Ostracods can even be used to estimate the temperature at the time they were buried. Knowing this, scientists can approximate the changes in the paleoclimate, and help us better understand modern climate change. Scale: 1.11 mm in length Fossil Charophytes The most recent fossil finds at Florissant include freshwater algae called charophytes. These macro algae are considered the progenitors of land plants since they have a complex lifecycle similar to mosses. When their spores are fertilized, they surround the spores with a lime covering so that upon release, it will be protected from elements. The capsule, also called gyrogonite, keeps the spores dormant until favorable conditions to grow arise. Rarely, the gyrogonites get buried and become fossilized instead. Like ostracods, gyrogonites have un
Florissant Fossil Beds Petrified Forest National Park Service U.S. Department National Park Serviceof the Interior U.S. Department of the Interior Florissant Fossil Beds SiteNational Name and Designation Monument A tall forest grew in the valley behind the visitor center 34 million years ago. Some of the trees survived as fossils that are visible on the trails today. Scientists have studied Florissant’s fossil wood to understand changes in climate and forest composition and the process of petrification—turning wood to rock. Why are only stumps left? Are there more stumps underground? Heavy rain or rapid snowmelt can sweep rock and ash from volcanos into thick mudflows called lahars. Lahars can rush downslope at up to 120 mi/hr (190 km/hr). One lahar from the ancient Guffey Volcano flowed through the Florissant stream valleys 34 million years ago. This volcanic mudflow buried the forest there under more than 16 ft (5 m) of debris and killed the trees by preventing oxygen from reaching their roots. The lahar encased and protected the lower trunks, which are preserved as fossils. The roots and tops of the trees decayed or broke off. Researchers have searched for undiscovered stumps at Florissant in several ways. Ground-penetrating radar, which measures reflections from electromagnetic pulses, has not been effective because the upper soil of the park is rich in clay. A recent study shows promise for detecting stumps with a magnetometer instead. This is because the local magnetic field is weaker above the silica-rich stumps than above the surrounding volcanic rock, which contains the magnetic mineral magnetite. How does a tree petrify? Artistic reconstruction of the Eocene forest at Florissant. What kinds of trees lived here? Most fossil stumps at Florissant are redwoods similar to the coast redwoods now living in California and Oregon. Some of the petrified wood comes from hardwoods, including Hovenia (related to Japanese raisin trees), Koelreuteria (golden rain tree), Robinia (locust), Zelkova (related to elms), and Chadronoxylon. When mineral-rich water penetrates wood, it deposits silica on the plant cells. As the wood decays and water continues to seep in, more silica minerals (opal, quartz, and a quartz with microscopic crystals called chalcedony) form inside the cells. Most of the silica in the stumps at Florissant probably came from volcanic rock and ash. Certain types of wood, like redwood trunks, are more durable than others, which may make them more likely to petrify. Experiments show that wood can petrify in tens to hundreds of years in ideal conditions, but it likely took much longer for the stumps at Florissant to turn into rock. Some plant tissue remains after wood petrifies, which helps preserve the tree structure in cellular detail like that seen in this fossil wood of Koelreuteria (golden rain tree). Image magnified. Do the stumps have growth rings? Scientists cut thin sections of petrified wood to study growth rings and other plant features under a microscope. During petrification, minerals form in the spaces of organic tissue. This process can preserve individual plant cells. Some of the petrified redwood stumps at Florissant show clear growth rings. The Florissant fossil tree rings are wider than those of modern California redwoods, indicating a better growing season in the past. A technique called tree ring cross-dating matches the patterns of thin and thick rings among different trunks to see if the trees lived through any of the same drought or wet periods. Petrified Florissant trees have the same patterns, so it is likely that all the trees in the forest died at the same time. A single lahar probably covered the entire valley in a day. Colorful Petrified Wood You can see many colors in the petrified stumps. Cream-colored fossil wood usually contains quartz. Dark brown or grey indicates organic material, often in opal. Iron minerals make other colors, including black and dull red. Where can I see petrified stumps? Big 3 Stump N The Ponderosa Loop and Petrified Forest Loop trails pass more than a dozen petrified stumps (map at left). Some of the best stumps lie right behind the visitor center (stop 1). On the Ponderosa Loop trail, a modern forest surrounds the fossil one, and living pines grow directly on top of petrified stumps (stop 2)! The Big Stump (stop 3) on the Interpretive Pit (Seasonal Access) Petrified Forest Loop trail is completely excavated. The petrified trees are the largest fossils at Florissant. Please help protect them by staying behind railings. Law prohibits disturbing or collecting fossils in the national monument. Stump 1 Redwood Trio 0 2 Pines 0.1 mi 0.1 3 Big Stump 0.2 km Petrified Forest Loop 1 mi (1.6 km) Boulder Creeek Trail & Hans Loop Visitor Center 1 Ponderosa Loop 0.5 mi (0.8 km) Sawmill Trail 2 Hornbek Wildlife Loop Geologic Trail Explosive Excavations Early settlers knew of the stumps near Florissant, and tourists arrive
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Florissant Fossil Beds Geologic Trail Florissant Valley is an ever changing landscape, shaped by the power of erosion, uplift and eruptions over millions of years. Since the Proterozoic eon, Florissant had several episodes magmatic activity with the emplacement of Pikes Peak pluton nearly one billion years ago, to the eruption around the Thirtymile Volcanic field that ended Lake Florissant. Even today, water from Grape Creek continues to cut through the rock strata beneath. Rain and snow are constantly eroding the landscape. The Geologic Trail helps you see the tectonic history and erosive forces that have shaped Florissant valley. 1 Stop One – Eocene Lake Florissant The trailhead of the Geologic Trail begins at the junction with the Petrified Forest Loop Trail going 1,000ft (300m) northeast of the visitor center. Follow the map on the back to see each stop. As you walk to the junction, you will cross the 34 million year old Florissant Formation along the bottom of what was once Lake Florissant. Scale is 2in (5cm). 2 Stop Two – Ice Age Gravels As the Geologic Trail ascends onto the low ridge, you will notice that the ground is made up of gravel. The gravel originates from decomposed granite that has been eroded by water from the slopes of surrounding hills into the Florissant valley. This overburden covers much of the Florissant Formation in the monument, but is only a few feet deep. A mammoth tooth (pictured right) and bones were discovered nearby in this layer and have been radiocarbon dated to more than 43,000 years ago (Late Pleistocene). At the time of the discovery in 1994, it was one of the highest elevations (8400ft or 2550m) at which an ice age mammoth had been found. A much larger fossil site was discovered in in 2010 at Snowmass, Colorado, 100 miles west of here. The Snowmastodon site provided over 5,000 fossils from mammoths and mastodons including a variety of smaller animals. The Snowmass site remains the highest altitude in the world, 8900ft (2700m), at which Pleistocene megafauna lived. 5cm 3 Stop Three – Grape Creek and Pikes Peak Granite As you cross the bridge, you will see that Grape Creek is the force that actively erodes and redeposits sediment, or alluvium, along the stream channel. While most of the sediment is relatively young, it underscores that geologic processes never cease and rock is constantly being reworked. From the bridge, you will see large boulders made of Pikes Peak Granite. This rock unit formed over 1.08 billion years ago deep beneath the surface, cooling over millions of years before being uplifted. In geology, igneous rocks that form underground with long cooling periods are plutonic. The Pike’s Peak Granite forms a structure called a batholith, which is a large intrusive igneous body that forms underground over time as the magma cools. It is about 25 miles (40km) wide and 80 miles (130km) long, extending from Castle Rock to just south past Colorado Springs. 4 Stop Four – Tuff Outcrop After crossing the bridge, you will begin to ascend the trail through a section of Wall Mountain Tuff. The Wall Mountain Tuff formed 37 million years ago as an ash flow that erupted from a caldera located near modern Mount Princeton, about 50 miles (80km) west of Florissant. This superheated ash cloud settled to the ground, welded together and cooled to form a rock called rhyolitic welded tuff. This is an example of a volcanic rock, which is any finely grained or glassy igneous rock that forms from the rapid cooling of surface eruptions or extruded lava. .25 mi Wall Mountain Tuff has a few small crystals visible to the naked eye, but it is mostly fine-grained beige material (groundmass). The visible crystals, or phenocrysts, formed in the magma long before the eruption. Meanwhile the microscopic crystals in the groundmass can only be seen under a microscope. The ash flow’s rapid cooling and explosiveness prevented large crystals from forming; geologists call this a pyroclastic texture. Rhyolitic Tuff vs Granite: Is there a difference? Qz Qz Qz 5 Rhyolitic welded tuff and granite may seem like two different rocks, but they are actually more similar than they appear. Rhyolitic tuff and granite share a similar chemistry, containing about the same parts of the minerals quartz, feldspar and amphibole. However, their crystal size and texture is what determines each type of rock. Granite (right) took thousands to millions of years to form phenocrysts whereas most of rhyolitic welded tuff (left) cooled instantaneously, thereby forming microscopic crystals. The photos to the left show the different sizes of crystals seen on each rock. Notice the size difference in the quartz (Qz) crystals on each rock. Scale is 1cm (.4 in). Stop Five – Geologic Trail Overlook Being the oldest rock in the monument, the Pikes Peak Granite is the foundation, or basement rock, of all overlying strata in the Florissant region. As you reach the overlook at the end of the trail, you will notice that you cross a contact
This publication was produced by a collaboration between the Bureau of Land Management (BLM) Royal Gorge Field Office, the National Park Service (NPS) at Florissant Fossil Beds National Monument, the Gold Belt Byway Association and the Geocorps America program of the Geological Society of America. The activities and content address Colorado Academic Standards (CAS) in Earth and Life Science. Written by Michael R. Johnson Illustrated by Paige A. Latendresse Updated by Andrew Smith Public Lands Belong to You! The BLM is a federal government agency that takes care of more than 245 million acres of land. Most of these lands are in the western part of the United States. These lands are America’s public lands, and they belong to all Americans. These public lands are almost equal in area to all the land in the states of Texas and California put together. The BLM manages public lands for many uses. The lands supply natural resources, such as coal, oil, natural gas and other minerals. The lands provide habitats for plants and animals. People enjoy the big open spaces on public lands. BLM lands also contain evidence of our country’s past, ranging from fossils to Indian artifacts to ghost towns. On BLM lands, fossil bones, teeth, turtle shells and other vertebrate fossils must be left where they are, but clams, snails and other invertebrates may be collected. When in doubt, leave it be! Junior Explorers The BLM’s Junior Explorer program helps introduce young explorers like you to the lands and resources the BLM manages. This guide to the Gold Belt Tour National Scenic Byway will help you to understand what rocks and fossils tell us about Earth’s past. You will also visit several spectacular locations, and learn where to find even more. Earning Your Junior Explorer Badge You can work through the activities with an older sibling, parent, or an adult you know. If you are 9-12 years old, you can try them on your own. Each explorer should complete the number of activities that match their age (for example, 10 year olds complete 10 activities). At least one activity should be a special Onsite Activity (at Florissant or Skyline Drive). When you complete the activities, check them against the Answer Key in the back of the booklet. Then say the Junior Explorer pledge on page 28 and sign the certificate. You can take the certificate to the Visitor Center at Florissant Fossil Beds National Monument, or bring it or mail it to: BLM Royal Gorge Field Office | 3028 E Main St., Cañon City, CO 81212 | phone: 719-269-8500. 2 Be a Scientist! Rocks and fossils are a record of the past. Geologists are scientists who know how to read rocks like a book to learn about the ancient surface of the Earth. Paleontologists are scientists who find fossils, and learn about life on Earth long ago. In this guide, you will learn how to read the rocks and study fossils just like those scientists, and then you can tell the story of how Colorado has changed through time! Maps can show not just where to go, but also what you’ll find there. Each site in this book has a certain color that matches the age of the rocks at that site. Color each site with its special color as you read about it. *Adults! Detailed directions to each location can be found in the back of this book. 3 7 Gold Belt Byway You will visit seven different places in this book that you can also see in person. These sites are part of the Gold Belt Tour National Scenic Byway, which is named for Colorado’s rich mining history. But these rocks have more than just gold to offer! Visiting BLM Lands Many of these locations are on public lands managed by the BLM. You are welcome to visit, but please remember that these lands belong to all of us! As you read this book, you will learn that there are rules for collecting fossils on public lands. Be sure to follow those rules so others can enjoy the land too! Fun Facts Each of the seven places in this book has its own story to tell. Florissant National Monument The Florissant Fossil Beds were discovered in the 1860s, but only became a National Monument in 1969 after a campaign led by scientists and environmentalists like Estella Leopold, Beatrice Willard, and Vim Wright. Shelf Road The narrow, winding, Shelf Road was the first road connecting Cripple Creek to the Arkansas River Valley. Imagine traveling that road with just a horse and wagon! Royal Gorge Royal Gorge was discovered in 1806 by Lt. Zebulon Pike, who thought the gorge was completely impassable. Today the gorge can be crossed by bridge, train, cable car, or zipline. Garden Park Area Cripple Creek and Victor When first mined in the late 19 to early 20th Centuries, the mines near Cripple Creek produced 22 million ounces of gold. That’s more than 100 elephants, and it would take 28 semi-trucks to move all that gold! Mining for gold continues in the area today! th The Marsh-Felch Quarry and the Cope Quarries were discovered in the late 19th Century as part of the “Bone

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