Unveil the enigmatic stories of ancient landscapes dating back to the early Triassic and Jurassic.
GEOLOGY, PALEONTOLOGY, ARCHAEOLOGY FIELD STUDY OPPORTUNITIES
INDEX BENEFITS 1 GEOLOGY 2 PALEONTOLOGY 5 ARCHAEOLOGY 8 TRAVEL 10
BENEFITS Ghost Ranch has a unique and phenomenal depth of natural resources, both historic and prehistoric, which span almost 250 million years of geology; one of the best paleontological records in the world of the beginning of the Age of Dinosaurs; pre-colonial archaeology going back some 8000 years; and a succession of post-Colombian settlements by several nations and cultures, as well as the establishment of the Ranch itself. This last period encompasses an early phase of cattle ranching and rustling, abandonment of the property, its eventual acquisition for conservation purposes and as a resort and “dude ranch,” including its occupation by famous visitors (Hollywood actors, political figures, and Manhattan Project scientists) and as the artist Georgia O’Keeffe’s summer residence, and finally its transition to a conference center, a place for spiritual renewal, and an educational center for geology, paleontology, natural history, and art, among many other offerings. Benefits of Field School at Ghost Ranch • Local experts available to enhance learning • Library open 24/7 • Wi-Fi • Meals including boxed lunches • Camping, Dorm Lodging, Casitas • Classroom with A/V Equipment
GEOLOGY
Photo by Katharine Kimball
Ghost Ranch is located on the far eastern end of the Colorado Plateau. Colorful rock formations are a result of it escaping the uplift of the Laramide Orogeny and subsequent erosion events. A place of magnificent natural beauty, Ghost Ranch is comprised of deep, multicolored canyons and cliffs, plains, grasslands and streams. 200 million years ago Ghost Ranch and the American Southwest were located close to the equator in a monsoon-like climate with heavy seasonal precipitation. Its rocks date back to 130 million years of ancient geological history, representing lakes, floodplains, and deserts. Its fossils illuminate the beginning of the Age of Dinosaurs in North America and provide the a new paradigm of how they took over terrestrial ecosystems for the next 150 years.
GEOLOGY
GEOLOGY Your Field School Experience The geologic composition of Ghost Ranch provides a clear understanding of sedimentology and stratigraphy of Ghost Ranch. These two important subdivisions of geology demonstrate the geologic processes that took place in this area that missed the treacherous repercussions of the Rio Grande Rift. A general concentration on sedimentology, the study of the processes of formation, transport and deposition of material that accumulates as sediment in the various environments that existed at Ghost Ranch going back to the early Triassic period. Also, the eventual formation of sedimentary rock. Understanding sedimentary processes and products to allow the interpretation of the dynamics of depositional environments, and where a record of these processes is preserved in sedimentary rocks, it allows us to interpret the rock formations in terms of these environments. However, no study of sedimentary rocks would be complete without stratigraphy, which attempts to determine the order and timing of geological events preserved within these rocks. An accurate chronological framework allows us to establish the spatial and temporal changes in former sedimentary and tectonic environments, which in turn, allows us to interpret the rocks in terms of those environments. Students may be instructed to identify and accurately describe sedimentary depostis, recognize spatial and temporal variations within the rocks and interpret sedimentary rocks in terms of the evolving environmental conditions under which they formed.
Your Outdoor Classroom窶認ormations Found at Ghost Ranch 1) Upper Triassic Chinle Group The oldest exposed rock formation at the Ranch is from the Upper Triassic Chinle group, which can be traced back to the Chama Basin. These rocks, which are brick red to grayish green in color, consist of sediments from six different rock units. The sediments from this layer were deposited by rivers around 205 to 228 million years ago, when the tectonic plates under the Ghost Ranch area were situated at about 10 degrees north of the equator. The Shinarump Formation is the white to yellow to green coarse grained sediment that is mainly quartz sandstone. This formation also contains well-rounded quartzite cobbles and is topped by the Salitral Formation. The Salitral Formation is exposed on the south side of the Ranch, which is along the Rio Chama tributary. The Upper Triassic Chinle formation can be seen on all the hiking trails that begin at the Ranch. The mudstone Painted Desert that can be accessed through our trail rides, is Petrified Desert Member of the Petrified Forest Formation. The uppermost unit of the Chinle layer is a thinly bedded red-brown to gray brown siltstone to sandstone. This interval holds the skeletons of the renowned New Mexico state fossil Coelophysis bauri. A great opportunity for geology students interested in paleontological studies to dive into this promising field of constant discovery.
The Entrada sandstone is estimated to be approximately 161 to 165 million years old. This implies that there is a gap in time of some 45 million years between the Triassic floor deposits and the base of the cliffs. Paleocurrent research shows that the Entrada sediments were transported by wind which blew from the south to the southwest. The Entrada sandstone formation dates back to approximately 161 to 165 million years ago (mya). The Todilto Formation, which consists of a basal limestone and shale unit (Luciano Mesa member) and, in places, 25 to 100 feet of gypsum (Tonque Arroyo member), was deposited atop the Entrada Sandstone. The contact between the Entrada and the Luciano Mesa, the Todilto, reflects the incursion of shallow seas into the area (limestone and shale), and their later retreat (represented by the gypsum evaporites). The sea, an extension of the Pacific Ocean, is not thought to have quite reached New Mexico, but salt waters seeping through the desert formed a large saline lake that later dried out. The Todilto Formation caps the Shining Cliffs; its greyish color forms a sharp contrast to the yellow green rocks of the underlying Entrada Sandstone. The Todilto Formation grades up into the Summerville Formation, another Middle Jurassic deposit of various sandstones, siltstones and mudstones representing ancient rivers and lakes. The base of 25 to 40 feet of the Summerville Formation is tabular white to tan sandstone interbedded with green to red mudstone and traces of shale. These and higher deposits sit atop the Shining Cliffs and are recessed from them, retreating with slopes that are less vertical but still very steep. The Brushy Basin member of the Late Jurassic Morrison Formation, the only member of the Morrison Formation present at Ghost Ranch, is made of pistachio green to salmon pink mudstone with a few interbedded tan and green sandstone beds. 3) Cretaceous Rocks The mesas around Ghost Ranch are capped by Cretaceous coastal plain, shoreline and marine units that were deposited along the western margin of the Western Interior Seaway 93 to 125 million years ago. Approximately 25 million years of Earth’s history is missing across the contact between the Late Jurassic Morrison Formation and the Early Cretaceous Burro Canyon Formation. These rocks are pinkish green and were also formed by rivers and lakes at the beginning of the Cretaceous Period. Rocks from the later Cretaceous, such as the Dakota Formation and the Mancos Shale, as well as rocks from the Early Tertiary (after the Age of Dinosaurs), are known from the vicinity of Ghost Ranch but do not outcrop on the Ranch itself. 4) Quaternary Sediments The youngest units exposed around Ghost Ranch are Quaternary terrace and pediment gravels along the drainages, and extensive landslide and colluvial deposits along the escarpment. These represent the erosion of more ancient rocks, the incorporation of organic and other particles and the re-deposition of these materials as the remains of yearly floods and rains, or the flood deposits of local streams.
GEOLOGY
2) Jurassic Rocks Above the badlands that comprise the floors of the canyons and washes at Ghost Ranch tower the “Shining Cliffs.� These spectacular cliffs are made of Jurassic age rocks. The oldest of the Middle Jurassic rocks, the Entrada Sandstone, forms the prominent red, yellow, and white cliffs just above Ghost Ranch. These deposits are part of a vast dune field that covered much of northern New Mexico and the Colorado Plateau for tens of millions of years after the end of the Triassic Period.
PALEONTOLOGY
Ghost Ranch is a world-renowned site for Triassic paleontology. Its low, red-grey mounded hills and washes boast three fossil quarries that are famous among scholars and amateur paleontologists, and a number of other sites where isolated skulls, bones, or skeletons have been found.
PALEONTOLOGY The three major quarries are the Canjilon Quarry (now situated on U.S. Forest Service land), the Coelophysis Quarry, and the Hayden Quarry. Dozens of different kinds of fossil reptiles, amphibians, and other vertebrates have been discovered, as well as fossil plants and invertebrates. Its quarries have, in recent years, given a whole new perspective to our understanding of how the dinosaurs began to take dominance of the terrestrial realm in the Late Triassic, over 200 million years ago.
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The type specimen of Vancleavia campi, a small aquatic carnivorous reptile with a large head and fangs The type specimen of Whitakersaurus, a relative of today’s Sphenodon, the sole member of an ancient group of widespread reptiles, now confined to a few islands off New Zealand Remains of an unusual Triassic reptile named Drepanosaurus, alleged to have had both aquatic and arboreal habits Bones of the very early crocodile Hesperosuchus, which Colbert originally described based on material from the same (Chinle) formation in northern Arizona Various bones of what appear to be new species of a postosuchid (crocodile relative), another small crocodylomorph, and other unpublished small reptiles
PALEONTOLOGY
The complete fauna known so far from the Canjilon Quarry is as follows: • Some fragmentary material of fishes and large amphibians • A bony scute of the aquatic reptile Vancleavea, known better from the Coelophysis Quarry • A femur from an unidentified relative of crocodiles • At least four partially articulated skeletons of the armored aetosaurian reptile Typothorax • 11 skulls and postcranial remains of the crocodile-like phytosaur Machaeroprosopus • Various archosaur remains and some limb bones of a small theropod dinosaur • The fauna known so far from the Coelophysis Quarry includes: • Blocks with thousands of complete and partial skeletons of the small carnivorous dinosaur Coelophysis bauri • The skull and skeletal remains of a new species of small carnivorous dinosaur, Daemonosaurus • The type specimen of a phytosaur named Redondasaurus bermani,which is related to Machaeroprosopus from the Canjilon Quarry • Redfieldid rayfin fishes • Remains of coelacanths, an ancient type of lobefin related to tetrapods, which now occur only in deep waters in the Indian Ocean but in Triassic times were globally widespread and included many freshwater forms such as this one • The type specimen of Effigia okeeffeae, a small reptile that superficially looks like a beaked carnivorous dinosaur but is actually a relative of crocodiles
THE HAYDEN QUARRY
PALEONTOLOGY
In the Hayden Quarry, several early dinosaurs are represented, including one partial and two nearly complete skeletons (so far) of a new theropod dinosaur, Tawa hallae. This is only one of a series of discoveries that have come directly or partly from new finds in the Hayden Quarry: • In 2007 , description of Dromomeron romeri, a close relative of dinosaurs living contemporaneously with them, was published in Science •
In 2007 , description of the odd, beaked crocodile relative Effigia okeeffae (the genus name means “ghost,” in honor of the Ranch, and the species name honors Georgia O’Keeffe) was published in the Bulletin of the American Museum of Natural History. The type specimen came from one of the first blocks that Ned Colbert’s crew excavated from the Coelophysis Quarry (though unrecognized for what it was), and a related form has been identified from the Hayden Quarry.
that some features of the hindlimb that scientists had previously used to recognize different kinds of ancient reptiles could simply be features of different growth stages of the same animal. • In 2011 , radioisotopic date based on uranium/lead isotopes from zircon crystals obtained an approximate date of 212 million years for the Hayden Quarry. The taxa identified so far from the Hayden Quarry include: • • • •
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In 2009 , description of Tawa hallae was published in Science.
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In 2009 , description of Vancleavea campi, a small, carnivorous, aquatic or semi-aquatic reptile, was published in the Zoological Journal of the Linnean Society. The original specimens were found in the Coelophysis Quarry, and additional specimens on which the analysis was based came from the Hayden and Canjilon quarries, as well as others in the southwest.
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In 2009 , new species of Dromomeron, D. gregorii, was published in the Journal of Vertebrate Paleontology. This study also documented how the hindlimbs and postures of the first dinosaurs evolved from those of their close relatives, and it showed
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The type specimen of the very early carnivorous dinosaur Tawa hallae, as well as other specimens A small dinosaur related to Coelophysis The type specimen and other material of two species of the small dinosaur relative Dromomeron Bones of a four-legged, beaked, plant-eating relative of dinosaurs called a silesaur Partial skeletons of the crocodile-like phytosaur Machaeroprosopus and the armored aetosaur Typothorax Remains of two shuvosaurids, small beaked crocodile relatives related to Effigia, from the Coelophysis Quarry Bones of a large, carnivorous relative of crocodiles, informally called a rauisuchid Some bones from a small, ancient relative of mammals Remains of two unusual Triassic reptiles related to Drepanosaurus, alleged to have had both aquatic and arboreal habits Fragmentary remains of a small reptile, a large metoposaurid amphibian, and some redfieldid fishes.
ARCHAEOLOGY
Cover and this photo by Nate Zivin
The Ghost Ranch area preserves the remains of a series of pre-Columbian cultures, some dating as far back as 8,000 BP. (Some of the oldest North American sites are about 12,000 years old, and they are found near Clovis in east-central New Mexico.) The earliest known inhabitants of Ghost Ranch were hunters and gatherers who migrated seasonally to collect plants and hunt game, following the course of the Chama River. These populations left behind spear and dart points, stone-lined fire hearths, campsites with debris from making meat-cutting tools, and broken and burned animal bones. But this civilization predated pottery and the bow and arrow. It also predated the construction of pit houses, surface houses, pueblos, and other well-known kinds of structures. More recent deposits tell of seasonal settlements of a pottery-making people, the Ancestral Puebloan, likely related to the modern Tewa-language speakers of Santa Clara and other Northern Rio Grande Pueblos. Even more recent campsites of Ute, Apache, Navajo and other peoples have been found in the region immediately adjacent to Ghost Ranch.
ARCHAEOLOGY The Ruth Hawley Ellis Museum of Anthropology at Ghost Ranch preserves for study over 150,000 artifacts from excavations on the Ranch as well as from private and Forest Service land. Many of these items were collected by crews from Ghost Ranch’s archaeology seminar over the last 40 years. The Ghost Ranch property originally stretched from the Cliffs of Shining Stone to the middle of the Chama River, and covered a large portion of the Piedra Lumbre Valley. The construction of the Abiquiu Dam by the Army Corps of Engineers for flood and sediment control in 1963 created a lake at the 6173-foot elevation contour line; its water level was raised in 1983 to the 6220-foot contour line to increase the storage capacity of the lake. The lake also flooded several hundred acres of Ghost Ranch land. Archaeological sites in the flood pool had been previously identified in 1958 and 1974 -75 by crews of archaeologists from the School for American Research (SAR) in Santa Fe who surveyed the landscape beginning at the dam axis and extending for 9 miles along the Rio Chama. Later, a portion of these sites was partially excavated by SAR, including the Palisade Ruin, a small 50-room pueblo constructed of adobe with a palisade composed of 250 piñon and juniper posts dated to AD 1314 by tree-ring dating.
ARCHAEOLOGY
Across the Chama River is the Riana Ruin, built in AD 1335. It has about 25 rooms, and was constructed of basalt boulder masonry. Aside from these two small pueblos adjacent to Ghost Ranch, there are hundreds of other open-air sites – clusters of waste flakes from a variety of stones, especially Pedernal chert and Polvadera obsidian, that indicate tool manufacturing, eroded areas of burnt rock and ash indicating fire hearths, and several rock shelters on the property. But there are no prehistoric pueblos, that is, multiroom and multi-story structures, on Ghost Ranch. The styles of the dart and spear points made of the local Pedernal chert and Polvadera obsidian help archaeologists date these open air artifact scatters back several thousand years. In the late 1960’s, Dr. Florence Hawley Ellis of the University of New Mexico was recruited by Ghost Ranch Director Rev. Jim Hall to give seminars on cultural anthropology at the Ranch during the summers. Dr. Ellis and her UNM archaeology field school had stayed at Ghost Ranch in the 1960’s while they excavated the prehistoric village of Sapawe on New Mexico State and U.S. Forest Service land near El Rito, New Mexico. In 1971, after she retired from UNM, Dr. Ellis taught her first class for Ghost Ranch: a sojourn to many of the ancestral Puebloan sites in the Southwest. So began the tradition of the archaeology field school and seminars that have continued for over 40 years, during which time a great number of artifacts has been collected and many new sites have been discovered and recorded. At the end of the summer of 1971, John Hayden, a forester with the Carson National Forest, took the archaeology field class to one of the basalt flows on Canjilon Mountain, about 20 miles to the north of Ghost Ranch on Carson National Forest land. He had found some unusual “stacked stone circular structures” while checking timber sales for the Forest Service, and he thought that there might be more to discover. Dr. Ellis’ archaeology group found 28 complete pottery vessels, canteens, and cooking pots in the nooks and crannies of the basalt flow. The vessels were laboriously mapped and collected in the next few days. The “bird nests” (Ellis’ term for the stacked-stone circular structures) were excavated beginning in 1972, and several garden plots defined by low stone walls were tested for pollen grains of domesticated plants. Dr. Ellis dubbed these structures and accompanying artifact and pottery scatters a part of the “Gallina” civilization, a sub-group of the Anasazi, dating to AD 1050-1300.
Photo by Jesse Fisher
TRAVELING TO GHOST RANCH
Ghost Ranch is located 14 miles north of Abiquiu, and 65 miles northwest of Santa Fe (forty miles beyond Espanola) on U.S. Highway 84 between mileposts 224 and 225. The drive is two and a half hours from Albuquerque Sunport, the nearest full service commercial airport. TO LEARN MORE ABOUT A FIELD STUDY PROGRAM FOR YOUR STUDENTS Contac t: Mar tha Yates Mar thaY@GhostR anch.org TO LEARN MORE ABOUT BRINGING YOUR GROUP TO GHOST RANCH Contac t: Charlene Carroll CharleneC@GhostR anch.org