Fossil Pollen Reveals Florissant's Ice Age Environment

Out of the mists of prehistory—through fossil pollen and spores—comes an unprecedented glimpse into Florissant’s past. Experts used cutting-edge science to examine pollen and spores buried with a fossil mammoth to better understand the Ice Age world of Florissant.

Entrance to the Florissant Fossil Beds, Colorado

The Florissant mammoth lived and died more than 50,000 years ago, during the last Ice Age. Its bones were fossilized safely in the ground until a student intern found it in 1994. During careful excavation of the mammoth, all of the fossil material was collected and bagged—including soil, gravel, and sediment samples. A molar tooth and part of the mammoth’s jaw were the main fossils recovered. Scientists used these to identify the mammoth as a Columbian mammoth.

A lab recently analyzed a sample from the sediment layer just below the mammoth. The lab determined that the sedimentary layer is a limestone containing fine sandy and silty quartz grains.

New pollen evidence from the mammoth site at the Florissant Fossil Beds reveals environmental conditions during one of the warm, interglacial periods of Teller County's Ice Age.  Above is a fossil pine pollen. The abundance of pine pollen, along with the rock moss, indicates a dry climate at Florissant.  Photomicrogrpah is by D. Jarzen.

The lab first prepared the limestone for processing to recover pollen and spore grains. Solutions of corrosive chemicals such as potassium hydroxide, hydrochloric acid, and hydrogen fluoride removed the organic and mineral particles in the sample. The pollen, because it is composed of some of the most chemically resistant organic compounds in nature, survived this harsh chemical processing.

Next, lab workers made microscope slides from the residual pollen and carefully examined them. When viewed with a microscope, pollen grains from different plants have distinctive appearances that can identify the plant species they came from. The pollen and spores were identified and counted.

The lab work identified an amazing assemblage of Ice Age vegetation at Florissant, making it possible to reconstruct much of the local environment based on these tiny fossils. A major surprise was finding hickory (Carya) and oak (Quercus)—both hardwoods—in the Rocky Mountains from a lab sample that was at least 50,000 years old. From microscopic examination of the hardwood pollen it appears that they grew locally during the Ice Age. There is no reason to think they are reworked from sediments redeposited from earlier times.

Image of a hickory (Carya) pollen grain.  Pollen grains are incredibly resistant and are difficult to destroy by physical or chemical processes.  The plentiful and hardy nature of pollen makes it a source of data about past climates in specific places. Photomicrograph by D. Jarzen.

The pollen and spore assemblage is a tiny time capsule from Florissant’s Ice Age and reveals that Florissant had a dry climate during this interglacial period—indicated by the abundance of pine pollen and rock moss (Selaginella). The landscape was relatively open and covered with vegetation. Scattered stands of pine, along with some hardwoods growing near streams, dotted the landscape. Groundcover included asters, daisies, sunflowers (Compositae), and sagebrush. Most important was the rock moss, which grows on rocks and thrives on direct sunlight. Rock moss is a key indicator of a dry climate.

Image of an aster pollen grain.  Image of an aster pollen grain. Because most plant species have distinctive pollen shapes, botanists can identify from which plant the pollen came, allowing scientists to determine the plants found in a certain place at a given time. Photo by D. Jarzen.

Florissant’s fossil mammoth and associated material continues to yield scientific information. The current pollen study is important because in the continental United States there is little information on interglacial floras. The Florissant pollen adds significantly to our understanding of North American interglacial floras.

The Florissant mammoth and its associated pollen has not only unlocked some of the secrets of Florissant’s Ice Age, but has earned an enduring place in the paleontological record.

Note: Steven Veatch is the principal investigator working on the Florissant pollen project. His team incldes David Jazen of the University of Florida, Estella Leopold of the University of Washington, and Herbert Meyer, park paleontologist (Florissant Fossil Beds Natinal Monument).

The Mining Machines of the Greater Alma Mining District, Colorado

While staring into the campfire on a quiet summer night, I was thinking about the old mines I had explored during the day.  All of them were in rugged areas: canyons, gulches, or at the end of a two-track road that climbed above timberline. Underground mining used excavation, drilling, blasting, extracting, support, hoisting, ventilation, and drainage technologies to mine ore. Once the ore was mined, it was processed in mills for valuable metal deposits. A variety of machines were designed to use in these mining processes.

This tubular boiler was built by the Erie City Iron
Works in Erie Pennsylvania. Robert Kane photo.

The few surviving machines in the old mining camps are important artifacts that provide a way to understand mining and miners of the late 19th and early 20th century.

Tubular Boilers
Large, rusted boilers are among the physical remains of mining in the Greater Alma Mining District. There is a boiler in Buckskin Gulch and another one at the North London Mine, both have an interesting pattern of holes at the front—identifying each as a tubular boiler.

Side view of tubular boiler. Robert Kane photo.

Tubular boilers were popular in mining districts. Their name came from the long tubes running the horizontal length inside a cylindrical-shaped boiler. Inside the boiler the tubes were surrounded by water. Below the boiler a fire was kept burning. The heat and smoke from the fire was drawn through the long tubes—heating the water—and continued on, rising up through the smokestack. This process created steam very efficiently and powered mining and milling machines.

These boilers were built by the Erie City Iron Works in Erie Pennsylvania. The company started in 1851. After several mergers and acquisitions, the company is known today as Indeck Keystone Energy.

Air Compressors
The air compressors left behind in the Greater Alma District show that miners used machine drills rather than tempered hand drills. Machine drills were used as early as the last quarter of the 19th century. At first steam was used to power drills but there were problems. Steam drills were replaced by compressed air that powered pneumatic drills. Mines that used air compressors and other machinery were sufficiently capitalized to purchase expensive equipment and ship it to the remote goldfields of Colorado.

On its side is embossed “Ingersoll Rand Co., New York, Imperial Type 10.” Ingersall Rand was founded in 1871. The Ingersall Rand name came into existence in 1905 when Ingersoll-Sergeant Drill Company and Rand Drill Company merged. Robert Kane photo.

Snowstorm Dredge

The Snowstorm Dredge operated in the goldfields between Fairplay and Alma from 1941-1960s. It is the largest and last dragline dredge in Colorado and in the nation. The dredge processed about 600 tons of gravel an hour.

Side view of the Snowstorm dredge. Photo by Robert Kane.

Snowstorm dredge. Photo by Robert Kane.

The Ice Age at the Florissant Fossil Beds: The Discovery of a Columbian Mammoth

The Florissant Fossil Beds National Monument is one of the most important plant and insect fossil sites in the world. The late Eocene age, 34 million-year-old fossils range from plant and insect impressions in paper-thin lake shale to massive petrified tree stumps. A more recent time period is represented at the fossil beds in gravels that accumulated during the last Ice Age at several sites at the fossil beds. At one of these locations gravels buried the remains of a mammoth, the first and only mammoth scientifically documented in Teller County, Colorado.

The Florissant mammoth was discovered in 1994 in a road cut near the visitor center when a student noticed small fragments of bone material scattered around the entrance of a rodent burrow. The student made a significant fossil discovery. While many fossil discoveries are the result of organized scientific work, this discovery was by sheer chance.

Paleontology does not move fast. Two years later (1996), the area surrounding the rodent burrow was systematically excavated and a mammoth jaw and molar tooth were found. The tooth was sent to a laboratory for radiocarbon dating. The laboratory dated the tooth at 50,000 years old—the limit of radiocarbon dating: This age would be the minimum age for the Florissant mammoth.

Florissant Fossil Beds Specimen No. 2392

In 2004, studies of the fossil material continued. Measurements were made on the tooth fragment, making it possible to identify the fossil material as a Columbian mammoth rather than a woolly mammoth. These findings were presented at a scientific conference in Denver the same year, making the Florissant mammoth part of the permanent scientific record.

The mammoth fossil material is important for several reasons. It documents the presence of mammoths at Florissant and shows these animals lived at an elevation of 8,400 feet--a relatively high elevation for mammoths.

The Florissant mammoth is still being studied. In 2010, sediments found with the mammoth were sent to a laboratory in Canada to see if there were any Ice Age pollen and spores. The lab returned microscope slides that, under a microscope, revealed an assemblage of pollen and spores--opening up yet another avenue for exploration, this time studying microfossils. The Florissant fossil beds continue to yield intriguing and exciting information about the distant past.

Bear Dens of Pinnacle Park, Cripple Creek and Victor Mining District

Historic bear cage in foreground, mining activity in the

background.

The Woods family founded Victor during the Cripple Creek and Victor gold rush.  The family had many interests in the mining district. They owned the Gold Coin Mine, the First National Bank of Victor, the Pikes Peak Power Company which supplied hydroelectric power from a dam at Skaguay Reservoir, and many other enterprises.

Bricks were carefully placed to form an arch over the entrance

to the bear caves.

The Woods were concerned with the social life of miners and invested some of their money back into the mining district for this cause. They built the fabulous Gold Coin Club that was designed for the recreation of the miners who worked in the Gold Coin Mine.  Another Woods family project was building Pinnacle Park–an 1890s theme park at the town of Cameron. Pinnacle Park was a vast amusement park with a picnic ground, a zoo, and merry-go-rounds. This was an exciting place where all of the people of the mining district could go for a variety of amusements and relaxation—and place away from the hard work of the mines.

Families brought picnics and came for the day to play ballgames, horseshoes, listen to concerts, dance, and engage in other entertainments. Pinnacle Park's zoo was a big draw. The bear dens were popular.  The dens had cement pads in front and were enclosed with heavy-gauge wire.  Higher up, behind the bear dens, was a row of smaller dens that housed smaller zoo animals such as bobcats and foxes.

Pinnacle Park was an extremely popular place in the gold camp and drew large crowds on the Fourth of July and Labor Day.   A trolley and train brought people to the entrance.

Today nothing remains of Pinnacle Park other than a few rows of animal cages from the zoo.  The gold mine operating in the district is mining right to the edge of these historical structures. Soon they will be gone.  These dens are an interesting part of the gold camp's history and represents a part of the story of how people lived and played in the district in the late 19th century.  These dens need to be saved, and there is discussion that the City of Cripple Creek will attempt to move these structures.