Ridgecrest is a city in Kern County, United States. It is located along U. S. Route 395 in the Indian Wells Valley in northeastern Kern County, the population was 27,616 at the 2010 census, up from 24,927 at the 2000 census. It was incorporated as a city in 1963, Ridgecrest is surrounded by four mountain ranges, the Sierra Nevada on the west, the Cosos on the north, the Argus Range on the east, and the El Paso Mountains on the south. It is approximately 82 miles from the Lancaster/Palmdale area and approximately 145 miles from both Bakersfield and San Bernardino, the three nearest major urban centers, private air travel in and out of the city is provided through the Inyokern Airport. There are currently no scheduled flights in or out of Ridgecrest. Ridgecrest is within two hours of the highest and the lowest points in the conterminous U. S, the settlement began as a farming community called Crumville in 1912, honoring James and Robert Crum, local dairymen. The first post office opened in 1941, by 1943, Ridgecrest had grown to 115 homes and 196 residents.
NOTS was established in November 1943, providing a strong job base for the years to come, during this era the growth of Ridgecrest was governed by the continuing needs of the high tech industries coupled to the Naval Stations programs for testing arms and guidance systems. According to the United States Census Bureau, the city has an area of 21.4 square miles. Ridgecrest is located in Indian Wells Valley, which is a extension of Owens Valley. The area, associated with the Eastern California Shear Zone, has experienced numerous earthquake swarms in the past often with no obvious mainshock, the weather in the Indian Wells Valley is predominantly influenced by its high desert location. The climate is characterized by hot days and cool nights with extremely arid conditions prevailing throughout the summer months, the mean annual maximum temperature for the Ridgecrest area is 75 °F while the mean annual minimum temperature is 48 °F. There are wide annual temperature fluctuations that occur from a high of 119 °F to a low of 1 °F, the area is known to have wind as high as 75 mph on a sunny day.
Whenever winds exceed 30 mph dust devils and dust clouds form in the area, December is the coolest month with an average maximum temperature of 60 °F and an average minimum temperature of 30 °F. The all-time minimum temperature of 1 °F was recorded on December 23,1963, Ridgecrest is a desert, with an average of less than 5 inches equivalent rainfall per year, which includes less than 2 inches of snow. July is the hottest month with an maximum temperature of 103 °F. The all-time maximum temperature of 119 °F was recorded on July 31,1971, the 2010 United States Census reported that Ridgecrest had a population of 27,616. The population density was 1,289.5 people per square mile
Santa Monica Mountains National Recreation Area
Overall administration is by the National Park Service, coordinating with state, county and university agencies. The Santa Monica Mountains Recreation Area preserves one of the best examples of a Mediterranean climate ecosystem in the world and it protects one of the highest densities of archaeological resources in any mountain range in the world. The Santa Monica Mountains NRA contains 156,671 acres in the Santa Monica Mountains of the Transverse Ranges between the Pacific Ocean and inland valleys and its southeastern slopes are part of the headwaters of the Los Angeles River. In size the Santa Monica Mountains National Recreation Area is the largest urban park in the United States. Besides geologic forces, people who inhabited the area in the past have been ones to affect the land, there were different reasons for people to come into the area. Some came to live and others to work the land, the first groups to live in the mountains were the Native American tribes called the Chumash and the Tongva who lived here for thousands of years.
Then came the Spanish Explorers and Homesteaders from other areas of the country, the Homesteaders brought new ideas and cultures that shaped the landscape and mindset of the area, and California overall. Up to this day, people continue to live, places such as Paramount Ranch, Solstice Canyon, and Rancho Sierra Vista/ Satwiwa still have that history that has been left behind by people in the past. The past stories from people are discovered through photographs, letters. Santa Monica Mountains National Recreation Area strives to make sure the collections, the first area in the Santa Monica Mountains set aside for public use was Griffith Park which was donated to the city of Los Angeles by Griffith J. Griffith in 1896. During the first decade of the century, Frederick H. Rindge made several attempts to create a forest reserve in the Santa Monica Mountains. These reserves were precursors to national forests, in 1902 California’s State Mining Bureau examined the area being considered for the establishment of a forest reserve.
The resulting report was sent to Washington where the proposal for a reserve was denied, in 1907 an application was submitted to the Secretary of the Interior requesting that at least 70,000 acres in the mountains be designated a forest reserve. This time state mineralogist Lewis E. Aubury opposed the venture and he wrote the L. A. C. and endeavor to ascertain his views on the subject, and further protest against the creation of this proposed reserve”. Days the U. S. Limestone deposits were discovered in the mountains behind Pacific Palisades in 1925 which led to a battle between wealthy home owners of the area and land developers. The quarry site was in Traylor Canyon, three miles inland from the sea, between Santa Ynez and Temescal Canyons. Alphonzo Bell, Sr. was the real estate developer behind the scheme while local opposition was led by Sylvia Morrison. After much criticism of his plan, Bell offered a new proposal
Bureau of Land Management
President Harry S. Truman created the BLM in 1946 by combining two existing agencies, the General Land Office and the Grazing Service. Most BLM public lands are located in these 12 western states, Arizona, Colorado, Montana, New Mexico, Utah and Wyoming. The mission of the BLM is to sustain the health, originally BLM holdings were described as land nobody wanted because homesteaders had passed them by. All the same, ranchers hold nearly 18,000 permits, the agency manages 221 wilderness areas,23 national monuments and some 636 other protected areas as part of the National Landscape Conservation System totaling about 30 million acres. There are more than 63,000 oil and gas wells on BLM public lands, total energy leases generated approximately $5.4 billion in 2013, an amount divided among the Treasury, the states, and Native American groups. The BLMs roots go back to the Land Ordinance of 1785 and these laws provided for the survey and settlement of the lands that the original 13 colonies ceded to the federal government after the American Revolution.
As additional lands were acquired by the United States from Spain and other countries, the United States Congress directed that they be explored, during the Revolutionary War, military bounty land was promised to soldiers who fought for the colonies. After the war, the Treaty of Paris of 1783, signed by the United States, France, in the 1780s, other states relinquished their own claims to land in modern-day Ohio. By this time, the United States needed revenue to function, Land was sold so that the government would have money to survive. In order to sell the land, surveys needed to be conducted, the Land Ordinance of 1785 instructed a geographer to oversee this work as undertaken by a group of surveyors. The first years of surveying were completed by trial and error, once the territory of Ohio had been surveyed, in 1812, Congress established the General Land Office as part of the Department of the Treasury to oversee the disposition of these federal lands. By the early 1800s, promised bounty land claims were finally fulfilled, over the years, other bounty land and homestead laws were enacted to dispose of federal land.
Several different types of patents existed and these include cash entry, homestead, military warrants, mineral certificates, private land claims, state selections, town sites, and town lots. A system of land offices spread throughout the territories, patenting land that was surveyed via the corresponding Office of the Surveyor General of a particular territory. This pattern gradually spread across the entire United States, the laws that spurred this system with the exception of the General Mining Law of 1872 and the Desert Land Act of 1877 have since been repealed or superseded. The Mineral Leasing Act of 1920 allowed leasing and production of selected commodities, such as coal, gas, the Taylor Grazing Act of 1934 established the United States Grazing Service to manage the public rangelands by establishment of advisory boards that set grazing fees. The Oregon and California Revested Lands Sustained Yield Management Act of 1937, commonly referred as the O&C Act, in 1946, the Grazing Service was merged with the General Land Office to form the Bureau of Land Management within the Department of the Interior.
It took several years for new agency to integrate and reorganize
Lava Beds National Monument
Lava Beds National Monument is located in northeastern California, in Siskiyou and Modoc counties. The Monument lies on the flank of the Medicine Lake Volcano. The region in and around Lava Beds Monument lies at the junction of the Sierra-Klamath, the Monument was established as a United States National Monument on November 21,1925, and includes more than 46,000 acres. Lava Beds National Monument has numerous lava tube caves, with twenty-five having marked entrances and developed trails for public access, the monument offers trails through the high Great Basin xeric shrubland desert landscape and the volcanic field. 1872–1873, this area was the site of the Modoc War, the area of Captain Jacks Stronghold was named in his honor. Volcanic eruptions on the Medicine Lake shield volcano have created a rugged landscape punctuated by these many landforms of volcanism. Cinder cones are formed when magma is under great pressure and it is released in a fountain of lava, blown into the air from a central vent.
The lava cools as it falls, forming cinders that pile up around the vent, when the pressure has been relieved, the rest of the lava flows from the base of the cone. Cinder cones typically only erupt once, the cinder cones of Hippo Butte, Three Sisters, Juniper Butte, and Crescent Butte are all older than the Mammoth and Modoc Crater flows, more than 30, 000–40,000 years old. Eagle Nest Butte and Bearpaw Butte are 114,000 years old, Schonchin Butte cinder cone and the andesitic flow from its base were formed around 62,000 years ago. The flow that formed Valentine Cave erupted 10,850 years ago, an eruption that formed The Castles is younger than the Mammoth Crater flows. Even younger were eruptions from Fleener Chimneys, such as the Devils Homestead flow,10,500 years ago, about 1,110 years ago, plus or minus 60 years, the Callahan flow was produced by an eruption from Cinder Butte. Though Cinder Butte is just outside the boundary of the monument, spatter cones are built out of thicker lava. The lava is thrown out of the vent and builds, layer by layer, Fleener Chimneys and Black Crater are examples of spatter cones.
Roughly ninety percent of the lava in the Lava Beds Monument is basaltic, there are primarily two kinds of basaltic lava flows, pahoehoe and aa. Pahoehoe is smooth, often ropy and is the most common type of lava in Lava Beds, aa is formed when pahoehoe cools and loses some of its gases. Aa is rough and jagged, an excellent example is the Devils Homestead lava flow, most of the rest of the lava in the monument is andesitic. Pumice, a type of lava, is found covering the monument
Located at the foot of the Sierra Nevada in Californias Owens Valley between the towns of Lone Pine to the south and Independence to the north, it is approximately 230 miles north of Los Angeles. Long before the first incarcerees arrived in March 1942, Manzanar was home to Native Americans and miners formally established the town of Manzanar in 1910, but abandoned the town by 1929 after the City of Los Angeles purchased the water rights to virtually the entire area. As different as these groups were, their histories displayed a common thread of forced relocation, the primary focus is the Japanese American incarceration era, as specified in the legislation that created the Manzanar National Historic Site. The site interprets the former town of Manzanar, the days, the settlement by the Owens Valley Paiute. Let us review the main points of the debate, over 120,000 residents of the U. S. A. two thirds of whom were American citizens, were incarcerated under armed guard. There were no crimes committed, no trials, and no convictions, to detain American citizens in a site under armed guard surely constitutes a concentration camp.
But what were the used by the government officials who were involved in the process. Raymond Okamura provides us with a detailed list of terms, lets consider three such euphemisms, evacuation and non-aliens. Earthquake and flood victims are evacuated and relocated, the words refer to moving people in order to rescue and protect them from danger. The official government policy makers consistently used evacuation to refer to the removal of the Japanese Americans. These are euphemisms as the terms do not imply forced removal nor incarceration in enclosures patrolled by armed guards. Hirabayashi went on to describe the harm done by the use of such euphemisms, the harm in continuing to use the governments euphemisms is that it disguises or softens the reality which subsequently has been legally recognized as a grave error. The actions abrogated some fundamental principles underlying the Constitution, the document under which we govern ourselves. This erosion of fundamental rights has consequences for all citizens of our society, some have argued that the Nazi Germany camps during the Holocaust were concentration camps and to refer to the Japanese American camps likewise would be an affront to the Jews.
It is certainly true that the Japanese Americans did not suffer the fate of the Jews in the terrible concentration camps or death camps where Nazi Germany practiced a policy of genocide. Although the loss of life was minimal in Americas concentration camps and Walter Weglyns research concerning Nazi Germanys euphemisms for their concentration camps revealed such phrases as protective custody camps, reception centers, and transit camps. Ironically, two Nazi euphemisms were identical to our governments usage, assembly centers and relocation centers and it might be well to point out, that the Nazis were not operating under the U. S. Constitution. Comparisons usually neglect to point out that Hitler was operating under the rules of the Third Reich
Badlands are a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded by wind and water. They are characterized by steep slopes, minimal vegetation, lack of a substantial regolith and they can resemble malpaís, a terrain of volcanic rock. Canyons, gullies, mesas and they are often difficult to navigate by foot. Badlands often have a color display that alternates from dark black/blue coal stria to be bright clays to red scoria. Badlands are partially characterized by their thin to nonexistent regolith layers, the regolith profiles of badlands in arid climates are likely to resemble one another. In these regions, the layer is typically composed of silt, shale. This layer can form either a compact crust or a looser, Badlands such as those found in the Mancos Shale, the Brule Formation, the Chadron Formation, and the Dinosaur Provincial Park can be generally said to fit this profile. In less arid regions, the regolith profile can vary considerably, some badlands have no regolith layer whatsoever, capping instead in bare rock such as sandstone.
Others have a regolith with a clay veneer, and still others have a biological crust of algae or lichens, in addition to lacking significant regolith, they lack much vegetation. The lack of vegetation could very well be a result of the lack of a substantial regolith, the formation of badlands is a result of two processes and erosion. The process of deposition describes the accumulation, over time, of layers of mineral material, different environments such as seas, rivers, or tropical zones, deposit different sorts of clays and sand. Once the deposited sediments have solidified, the material becomes subject to erosion. It is sometimes taught that badlands erode at a steady rate of about 1 inch per year. In actuality, the processes by which the erosion responses take place vary depending on the precise interbedding of the sedimentary material. In 2010, researchers at Badlands National Park initiated a 3-year project to learn more about the erosion rate of the specific badlands found in that park.
Some of the best-known badland formations can be found in Canada, in the U. S. Makoshika State Park in Montana and Badlands National Park in South Dakota together form a series of extensive badland formations. Among the Henry Mountains area, about 1500m above sea level, another popular area of badland formations is Toadstool Geologic Park in the Oglala National Grassland of northwestern Nebraska. Dinosaur National Monument in Colorado and Utah are badlands settings, a small badland called Hells Half-Acre is present in Natrona County, Wyoming
Pinnacles National Park
Pinnacles is managed by the National Park Service and the majority of the park is protected as wilderness. The national park is divided by the formations into East and West Divisions, connected by foot trails. The east side has shade and water, the west has high walls, the rock formations provide for spectacular pinnacles that attract rock climbers. The park features unusual talus caves that house at least thirteen species of bat, Pinnacles is most often visited in spring or fall because of the intense heat during the summer months. Park lands are prime habitat for prairie falcons, and are a site for California condors that have been hatched in captivity. Pinnacles National Monument was established in 1908 by U. S. President Theodore Roosevelt, Pinnacles National Park was created from the former Pinnacles National Monument by legislation passed by Congress in late 2012 and signed into law by President Barack Obama on January 10,2013. Native Americans in the Pinnacles region comprised the Chalon and Mutsun groups of the Ohlone people and these native people declined with the arrival of the Spanish in the 18th century, who brought novel diseases and changes to the natives way of life.
The last Chalon had died or departed from the area by 1810, from 1810 to 1865, when the first Anglo-American settlers arrived, the Pinnacles region was a wilderness without human use or habitation. The establishment of a Spanish mission at Soledad hastened the areas native depopulation through disease, archaeological surveys have found thirteen sites inhabited by Native Americans, twelve of which post-date the establishment of the missions. One site is believed to be about 2000 years old, by the 1880s the Pinnacles, known as the Palisades, were visited by picnickers from the surrounding communities who would explore the caves and camp. The first account of the Pinnacles region appeared in print in 1881, between 1889 and 1891, newspaper articles shifted from describing excursions to the Palisades to calling them the Pinnacles. Interest in the rose to the point that the Hollister Free Lance sent a reporter to the Pinnacles. Investors came from San Francisco to consider placing a hotel there. In 1894 a post office was established in Bear Valley, since there was at least one other Bear Valley in California, the post office was named Cook after Mrs.
Hains maiden name. In 1924 the post office was renamed Pinnacles, Schuyler Hain was a homesteader who arrived in the Pinnacles area in 1891 from Michigan, following his parents and eight siblings to Bear Valley. White, was a student at Stanford University, and White brought one of his professors to see the Pinnacles in 1893, dr. Gilbert was impressed by the scenery, and his comments inspired Hain to publicize the region. Hain led tours to Bear Valley and through the caves, advocating the preservation of the Pinnacles, Hains efforts resulted in a 1904 visit by Stanford president David Starr Jordan, who contacted Fresno Congressman James C. Jordan and Needham in turn influenced Gifford Pinchot to advocate the establishment of the Pinnacles Forest Reserve to President Theodore Roosevelt, Roosevelt proclaimed the establishment on July 8,1906
Golden Gate National Recreation Area
The Golden Gate National Recreation Area is a U. S. National Recreation Area protecting 80,002 acres of ecologically and historically significant landscapes surrounding the San Francisco Bay Area. Much of the park is land used by the United States Army. GGNRA is managed by the National Park Service and is one of the most visited units of the National Park system in the United States, with more than 15 million visitors a year. It is one of the largest urban parks in the world, the park is not one continuous locale, but rather a collection of areas that stretch from southern San Mateo County to northern Marin County, and includes several areas of San Francisco. The park is as diverse as it is expansive, it contains famous tourist attractions such as Muir Woods National Monument, the park was created thanks to the cooperative legislative efforts of cosponsors Congressman William S. Mailliard and Congressman Phillip Burton. In 1972, President Richard Nixon signed into law An Act to Establish the Golden Gate National Recreation Area, the bill allocated $120 million for land acquisition and development.
The National Park Service first purchased Alcatraz and Fort Mason from the U. S. Army, the Nature Conservancy transferred the land to the GGNRA. These properties formed the basis for the park. Throughout the next 30 years, the National Park service acquired land and historic sites from the U. S. Army, private landowners and corporations, incorporating them into the GGNRA. Many decommissioned Army bases and fortifications were incorporated into the park, including Fort Funston, four Nike missile sites, The Presidio, the latest acquisition by the National Park Service is Mori Point, a small parcel of land on the Pacifica coast. In 1988, UNESCO designated the GGNRA and 12 adjacent protected areas the Golden Gate Biosphere Reserve, the property, located south of Pacifica and surrounding the communities of Moss Beach and Montara, is home to many diverse plant and animal species. The bill passed in the Senate, but did not pass the House of Representatives, Fort Baker - former Army post located on the northern side of the Golden Gate Headlands Center for the Arts - an artist residency program set in renovated military buildings in the Marin Headlands.
Nike Missile Site SF-88 - a decommissioned Army surface-to-air missile site located near Fort Barry, located at the southwestern corner of the Presidio Battery Chamberlin - one of the last remaining coastal defense disappearing guns on the U. S. Trails lead across the ridge and to Sharp Park beach, the site includes recently restored wetlands and a pond, protecting endangered San Francisco garter snake and red-legged frog habitat. Rancho Corral de Tierra - the GGNRAs newest park, Golden Gate National Recreation Area Scenery Video, a video showing the scenery observed from the GGNRA, including footage from Lands End
Cabrillo National Monument
Cabrillo National Monument is at the southern tip of the Point Loma Peninsula in San Diego, California. It commemorates the landing of Juan Rodríguez Cabrillo at San Diego Bay on September 28,1542 and this event marked the first time a European expedition had set foot on what became the West Coast of the United States. The site was designated as California Historical Landmark #56 in 1932, as with all historical units of the National Park Service, Cabrillo was listed on the National Register of Historic Places on October 15,1966. The annual Cabrillo Festival Open House is held on a Sunday each October and it commemorates Cabrillo with a reenactment of his landing at Ballast Point, in San Diego Bay. The park offers a view of San Diegos harbor and skyline, as well as Coronado, on clear days, a wide expanse of the Pacific Ocean and Mexicos Coronado Islands are visible. A visitor center screens a film about Cabrillos voyage and has exhibits about the expedition, the Old Point Loma Lighthouse is the highest point in the park and has been a San Diego icon since 1855.
The lighthouse was closed in 1891, and a new one opened at an elevation, because fog. The old lighthouse is now a museum, and visitors may enter it, the area encompassed by the national monument includes various former military installations, such as coastal artillery batteries, built to protect the harbor of San Diego from enemy warships. Many of these installations can be seen walking around the area. A former army building hosts an exhibit that tells the story of history at Point Loma. The area near the monument entrance was used for gliding activities in 1929-1935. Even Charles Lindbergh soared in a Bowlus sailplane along the cliffs of Point Loma in 1930, markers for these accomplishments can be found near the entrance, and the site is recognized as a National Soaring Landmark by the National Soaring Museum. On October 14,1913, by proclamation, Woodrow Wilson reserved 0.5 acres of Fort Rosecrans for The Order of Panama. To construct a statue of Juan Rodriguez Cabrillo. In 1939 the Portuguese government commissioned a statue of Cabrillo.
The sandstone statue, executed by sculptor Alvaro de Bree, is 14 feet tall, the statue was intended for the Golden Gate International Exposition in San Francisco but arrived too late and was stored in an Oakland, California garage. Then-State Senator Ed Fletcher managed to obtain the statue in 1940 over the objections of Bay Area officials and it was stored for several years on the grounds of the Naval Training Center San Diego, out of public view, and was finally installed at Cabrillo Monument in 1949. The sandstone statue suffered severe weathering because of its position and was replaced in 1988 by a replica made of limestone
Bird of prey
Bird of prey or predatory bird, known as raptors, refers to several species of birds that hunt and feed on rodents and other small animals. The term raptor is derived from the Latin word rapere, meaning to seize or take by force and these birds are characterized by keen vision that allows them to detect their prey during flight and powerful talons and beaks. Taken literally, the bird of prey has a wide meaning that includes many birds that hunt and feed on animals. In ornithology, the definition for bird of prey has a meaning, birds that have very good eyesight for finding food, strong feet for holding food. Most birds of prey have strong curved talons for catching or killing prey, Birds of prey generally prey on vertebrates, which are usually quite large relative to the size of the bird. Most eat carrion, at least occasionally, and vultures, the order Accipitriformes is believed to have originated 44 million years ago when it split from the common ancestor of the secretarybird and the accipitrid species.
The phylogeny of Accipitriformes is complex and difficult to unravel, widespread paraphylies were observed in many phylogenetic studies. More recent and detailed studies show similar results, according to the findings of a 2014 study, the sister relationship between larger clades of Accipitriformes was well supported. The diurnal birds of prey are formally classified into five families of two orders, the Cathartidae are sometimes placed separately in an enlarged stork family and may be raised to an order of their own, Cathartiiformes. The secretary bird and/or osprey are sometimes listed as subfamilies of Acciptridae and Pandioninae, australias letter-winged kite is a member of the family Accipitridae, although it is a nocturnal bird. He placed all birds of prey into an order, subdividing this into four genera, Falco, Strix. This approach was followed by subsequent authors such as Gmelin, louis Pierre Veillot used additional ranks, tribe, genus, species. Birds of prey were divided into diurnal and nocturnal tribes, the owls remained monogeneric, thus Veillots families were similar to the Linnaean genera, with the difference that shrikes were no longer included amongst the birds of prey.
In addition to the original Vultur and Falco, Veillot adopted four genera from Savigny, Haliæetus, Pandion and he introduced five new genera of vultures and eleven new genera of accipitrines. The common names for birds of prey are based on structure. Eagles tend to be large birds with long, broad wings, booted eagles have legs and feet feathered to the toes and build very large stick nests. Ospreys, a species found worldwide that specializes in catching fish. Kites have long wings and relatively weak legs and they spend much of their time soaring
Mesa is the American English term for tableland, an elevated area of land with a flat top and sides that are usually steep cliffs. It takes its name from its characteristic table-top shape and it may be called a table hill, table-topped hill or table mountain. It is larger than a butte, which it resembles closely. Examples are found in other nations including Spain, Sardinia and South Africa, India. Grand Mesa is a mesa located in western Colorado in the Southwest United States. Cerro Negro is a mesa in Argentina, the term mesa is used throughout the United States to describe a flat-topped mountain or hill. Mesas form by weathering and erosion of layered rocks that have been uplifted by tectonic activity. This process is called differential erosion, the most resistant rock types include sandstone, quartzite, chert, lava flows and sills. Lava flows and sills, in particular, are resistant to weathering and erosion. The less resistant rock layers are made up of shale. The differences in strength of rock layers is what gives mesas their distinctive shape.
Less resistant rocks are eroded away on the surface into valleys, a large area of very resistant rock, such as a sill may shield the layers below it from erosion while the softer rock surrounding it is eroded into valleys, thus forming a caprock. Differences in rock type reflect on the sides of a mesa, as instead of smooth slopes, the more resistant layers form the cliffs, or stairsteps, while the less resistant layers form gentle slopes, or benches, between the cliffs. Cliffs retreat and are cut off from the main cliff, or plateau. When the cliff edge does not retreat uniformly, but instead is indented by headward eroding streams, as the underlying shale erodes away, it can no longer support the overlying cliff layers, which collapse and retreat. When the caprock has caved away to the point where only a little remains, a transitional zone on Mars, known as the fretted terrain, lies between highly cratered highlands and less cratered lowlands. The younger lowland exhibits steep walled mesas and knobs, the mesa and knobs are separated by flat lying lowlands.
They are thought to form from ice-facilitated mass wasting processes from ground or atmospheric sources, the mesas and knobs decrease in size with increasing distance from the highland escarpment