John Day Fossil Beds National Monument
The John Day Fossil Beds National Monument is a protected area of the type of a National Monument in the U.S. state of Oregon. It consists of three non-contiguous parts called units, which are located along approximately 100 kilometers in the valley of the John Day River. Be managed sites with fossils of creatures from the Paleogene and Neogene geological periods with an age of about 44 to 6 million years. The disrupted layers themselves cover the period from about 54 to 6 million years.
Between 1931 and 1965, parts of today's National Monuments by the State of Oregon have been designated as state parks. In 1974 she was transferred to the protection program of the federal government and placed under the administration of the National Park Service.
All three parts of the John Day Fossil Beds National Monument located in north-eastern Oregon, east of the Cascade Range in the valley of the John Day River, a tributary of the Columbia River. The region is characterized by a semi- arid climate with hot, dry summers and cold winters. The rainfall occurs almost exclusively in spring and sway 230-400 mm per year.
The river itself is the only year-round water flow in the reserve. He is accompanied by a softwood forest, living in his environment wapiti and mule deer, minks and Canadian beaver. The exterminated by hunting North American river otter was reintroduced.
The Sheep Rock Unit of the territory is located in Grant County, between the villages of Kimberly and Dayville. Here the Thomas Condon Paleontology Center are consistent with the research laboratories and an exhibition on the paleontology and the adjacent Cant Ranch, the headquarters of the reserve management with an exhibition on the cultural history of the region. In this part of the recent rocks are the distinctive Sheep Rock and a Blue -called Basin area of badlands, and the Picture Gorge, a gorge of the John Day River, in the many petroglyphs of the Native Americans were found.
The Painted Hills Unit is located in Wheeler County 15 km west of Mitchell in the basin of the John Day River at Bridge Creek and is characterized by strikingly colored rock layers. In the shales of the rolling hills minerals are stored, which they color in yellow, gold, black and red tones, which seem to change with the light in the course of time of day and the weather. In soft rock composed largely fossilized plants were found in the 1920s and 1930s, which provide an insight into the climatic conditions, approximately 33 million years.
In the Clarno Unit, also in Wheeler County and 35 km west of the town of Fossil, the oldest and hardest rocks are open-minded. They originated about 44 million years ago during a volcanic eruption. The Clarno Palisades are steep cliffs with sharp erosion forms and a naturally formed stone arch.
Along the John Day River upstream you can rise through the earth and in increasingly younger geological layers. The large amount of time and the completeness of the layers as well as the wealth of plant and animal fossils in the reserve make it very important for the study of geology and paleontology. The following description of stratigraphic rock units follows the sequence of their emergence and advances from the older to the younger layers on.
The Clarno Formation contains the oldest rocks of the area, which in the Eocene ( Paleogene ) originated about 54 million years. Before about 44 million years ago a lahar mudflow called a volcanic eruption buried a long time largely stable, tropical rainforest. In the fossilized sediments of the mud flow over 175 different plant species of this forest have been found and documented so far. There are also a variety of insect fossils. The early mammals by various Urraubtiere ( Creodonta ) Hyrachyus (a relative of today's tapirs ) and Brontotheria represented ( relative of the rhinoceros ). In the swamps lived crocodiles and catfish -like fish bones. A well-known fossil locality, the outstanding mammal remains from this formation provided is the " Hancock Mammal Quarry ". There, a former Bayou with an age of about 40 million years ago is open, appear the fossilized bones of Haplohippus (a small original horse), Eubrontotherium, Achaenodon (a relative of today's pigs) and the large Assfresser Hemipsalodon in the sediments. Some of these species are found only here world. Also of importance are five complete rhino skull, originally called Clarno Rhinos and today represent the basal genus Rhinoceros Teletaceras.
John Day Formation
The John Day Formation consists mainly of clay and sandstone, which was deposited at the end of the Paleogene and early Neogene ( with an age from 39 to 18 million years ago). The John Day Formation is divided into several geological units called members.
- Bridge Creek Member: This unit contains 33 mya numerous animal and plant fossils. The plant fossils indicate that the region's climate became cooler and drier. For the first time attended seasons for a change in living conditions. The forests were dominated by the dawn redwood. Because the rocks of the area were formed from deposits of a river, are found almost exclusively aquatic organisms: fish, amphibians, insects and a few birds. In mammals, only a few bats are obtained.
- Turtle Cove Member: The rocks of this unit are predominantly blue - green volcanic ash. A fossil discovery site with an age of about 29 million years ago indicates that the climate had become dry again. Hardwood forests given the landscape. In these three-toed horse, mouse deer, beaver, and Oreodonta Nimravidae lived. The predators dominated the Amphicyonidae.
- Kimberly- Member: The rocks of this stratigraphic unit are gray to light pink. They arose out of clay ash deposits. The most important fossil sites location is about 24 million years old. The fossils suggest that the area was heavily forested. Found tree species birch, elm, maple and oak trees were present already quite similar. An animal fossils fall on rodents living in burrows. Among the predators the first dogs came and, next to continue living Amphicyonidae.
- Haystack Valley Members: About 20 million years old is a fossil deposit in the sand and ash deposits of alluvial cones of a continental basin, which hardened later into sandstone with intercalated tuffs. At the same time the layers were lifted and tilted with a slight dip from west to east by tectonic forces. Through the gap created rivers and streams, the deep dug in the relatively soft rock. The landscape was covered by the rivers mainly with softwood species such as poplars and alders, stood by large bushes zones on young alluvium. The fauna was dominated by large mammals such as rhinos and Chalicotherien, in more open areas lived horses and camels. This layer already belongs to the Neogene, after the border Paleogene / Neogene is currently geochronological dating to about 23 million years ago.
Picture Gorge Basalt
Before about 18 to 15 million years ago the whole area of the present sanctuary was covered by basaltic lavas: the Columbia Plateau basalt. The thin but continuous flood basalt layer is free of fossils.
To tufa benches and sandstones alternate About the Picture Gorge Basalt. They were deposited 15 to 12 million years ago. The tufa benches created from volcanic ash and sand - and siltstones are interpreted as floodplain sediments. Especially the tuff layers are rich in fossils. The landscape was flat, reminiscent of a present-day savanna with lakes that have been traversed by broad, slow-flowing streams and rivers. In the area lived horses, camels and peccaries, and Gomphotherium called, early relative of the elephant. In addition, the first cat from Asia migrated to the region. Oreodonta be found for the last time, they died as a result of.
The youngest rocks of the protected area are about 6-7 million years old. They are made of tuff and emerged from the ashes streams massive volcanic eruptions. How to show embedded fossils, the region was previously largely free of trees, a steppe with few bushes covered the landscape. In it lived horses, elephants, camels, rhinos and pronghorn on large grazers. Besides living peccaries, short-faced bears, cats, dogs, and two -toed sloths.
The basin of the John Day River was only sparsely inhabited by Indian tribes because of the harsh climate and low soil fertility. Northern Paiute, Umatilla, Wasco and Warm Springs Indians moved into small groups through the prairies east of the Cascade Range. From the 1840s, the first white men to Oregon, which was settled jointly by the United States and Britain came. After the Whitman Massacre of 1847 in nearby Walla Walla, at the Cayuse and Umatilla Miss Sion Station Marcus Whitman attacked, it came to continuing conflicts between Indians and settlers, the militia attacked several times, until 1855 all the Indians of the region in Reserves were forced and they had to abandon their traditional way of life largely.
The history of the fossil record in the bed of John Day Rivers begins with Thomas Condon ( 1822-1907 ). He had come as a pastor and missionary to The Dalles in Oregon and listened to in 1862 by prospectors that they had found fossilized bones. In 1865, he broke up the first time to search even after the sites. He found in various places individual fossils, he made the best finds on the John Day River.
Condon was formed as an autodidact. He ordered literature by mail, subscribed natural history magazines, built a collection, and met with all the scientists who came through the region. In his church and at school he gave public lectures on geology and paleontology. Late 1860s Condon came in contact with a group of field geologists of the U.S. Geological Survey, who recognized his collection as exceptional.
In 1869 he sent some findings on natural history museums on the east coast of the United States who were enthusiastic about the findings and ordered further material at Condon. 1871 took the Yale University the first excursion to the John Day River, led locally by Condon. The University of California, the Smithsonian Institute and other institutions recognized the importance of the sites.
1872, studied theology Condon was appointed professor of geology at the newly founded State University of Oregon in Eugene. Until 1900 published journals over 100 articles about the Fossils of the John Day River, and every natural history museum in the world exhibits had moved from the sites. 1902 appeared the first work that described the paleobotany of the region and in the following decades was the study of fossils continuously. 1956 Hancock Mammal Quarry is found, an archaeological site of 40 million year old fossils, with a large number of endemic species of mammals. He has researched in the 1980s.
From about 1925, the sites started to become a tourist destination. From 1931 to 1965, the state of Oregon bought specifically to surfaces to make them accessible to the countryside and the fossil fields of the public. Since 1951 find annually natural history and science courses for target groups of primary school classes instead of up to PhD students in the area. In 1974, the three parts of today's reserve were transferred from the protection program of the State of Oregon to the federal government and designated as a National Monument.
The National Monument today
Due to the decentralized structure with three units distributed over a larger area occupies only a small part of the visitors perceive the totality of the geological and paläologischen history of the monument. The transmission of content is done mainly by trails and individual information panels.
The new Thomas Condon Paleontology Center opened in 2004. Under one roof, visitor information, fossils exhibition and research center of the park are housed. The excavations in the area continue. Both Guest and scientists from different universities in the United States and from abroad, as well as to the permanent staff of the National Park Service excavations lead, prepare the findings for the collection of the National Monuments and explore the flora and fauna of the region. In recent years, the study of climate history has been added as a new task.
The old visitor center in the historic Cant Ranch near the Paleontology Center was rebuilt in the result and in addition to the management of the park is now an exhibit on the settlement and cultural history of the region. In the park itself there is no accommodation or camping sites, even restaurants.