A set square or triangle is an object used in engineering and technical drawing, with the aim of providing a straightedge at a right angle or other particular planar angle to a baseline. The simplest form of set square is a triangular piece of transparent plastic with the centre removed. More the set square bears the markings of a ruler and a half circle protractor; the outer edges are bevelled. These set squares come in two usual forms, both right triangles: one with 90-45-45 degree angles, the other with 30-60-90 degree angles. Combining the two forms by placing the hypotenuses together will yield 15° and 75° angles, they are purchased in packs with protractors and compasses. Less found is the adjustable set square. Here, the body of the object rejoined with a hinge marked with angles. Adjustment to the marked angle will produce any desired angle up to a maximum of 180°. In many European countries, the most common form of set square combines a 90-45-45 triangle with a protractor into a single tool made of clear plastic.
Named "Geodreieck", it was developed and trademarked by the German-Austrian manufacturer Aristo-Instrumente Dennert KG in 1964. Speed square Technical drawing tool
San Gabriel Mountains
The San Gabriel Mountains are a mountain range located in northern Los Angeles County and western San Bernardino County, United States. The mountain range is part of the Transverse Ranges and lies between the Los Angeles Basin and the Mojave Desert, with Interstate 5 to the west and Interstate 15 to the east; this range lies in, is surrounded by, the Angeles National Forest, with the San Andreas Fault as the northern border of the range. The highest peak in the range is Mount San Antonio referred to as Mt. Baldy. Mount Wilson is another famous peak, famed for the Mount Wilson Observatory and the antenna farm that houses many of the transmitters for local media; the observatory may be visited by the public. On October 10, 2014, President Obama designated the area the San Gabriel Mountains National Monument. To date, The Trust for Public Land has protected more than 3,800 acres of land in the San Gabriel Mountains, its foothills and the Angeles National Forest. Much of the range features rolling peaks.
The range lacks craggy features, but contains a large number of canyons and is very rugged and difficult to traverse. The San Gabriel Mountains are in effect a large fault block, uplifted and dissected by numerous rivers and washes; the highest elevation, Mount San Antonio at 10,064 feet, rises towards the eastern extremity of the range which extends from the Cajon Pass on the east, where the San Gabriel Mountain Range meets the San Bernardino Mountain Range, westward to meet the Santa Susanna range at Newhall Pass. North of San Fernando, the San Gabriel Mountains crest abruptly up to 4,000 feet. Pacoima and Big Tujunga Canyons cut through the range just east of San Fernando, carrying runoff into the San Fernando Valley. Little Tujunga Canyon Road bridges the range in this area, connecting the San Fernando Valley to the Santa Clara River valley in the north. Towering over Big Tujunga Canyon north of Big Tujunga Reservoir is Mount Gleason, which at 6,502 feet, is the highest in this region of the San Gabriels.
South of the gorge are the southern "foothills" of the mountains, which rise abruptly 4,000 feet above the Los Angeles Basin and give rise to the Arroyo Seco, a tributary of the Los Angeles River. Southeast of Big Tujunga Canyon, the southern front range of the San Gabriels grows in elevation, culminating in notable peaks such as Mount Wilson at 5,710 feet. On the north the range is abruptly dissected by the canyon of the West Fork San Gabriel River. Further north the range slopes up into the towering main crest of the San Gabriels, a sweeping arc-shaped massif 30 miles in length that includes most of the highest peaks in the range: Waterman Mountain, at 8,038 feet. On the north slopes of the San Gabriel crest, the northern ranks of mountains drop down incrementally to the floor of the Mojave Desert in a much more gradual manner than the sheer southern flank; the Angeles Crest Highway, one of the main routes across the San Gabriels, runs through this area from west to east. Little Rock, Big Rock and Sheep Creeks drain off the northern part of the mountains, forming large alluvial fans as they descend into the Mojave.
To the east, the San Andreas Fault cuts across the range, forming a series of long and narrow depressions, including Swarthout Valley and Lone Pine Canyon. South of Mount San Antonio, San Antonio Creek drains the mountains, cutting the deep San Antonio Canyon. East of San Antonio Canyon, the range loses elevation, the highest peaks in this section of the mountain range are in the south, rising above the Inland Empire cities of Claremont and Rancho Cucamonga. However, there are still several notable peaks in this region, including Telegraph Peak, at 8,985 feet, Cucamonga Peak, at 8,859 feet, Ontario Peak, rising 8,693 feet. Lytle Creek, flowing southeast, drains most of the extreme eastern San Gabriels; the range terminates at Cajon Pass, through which runs Interstate 15, beyond which rise the higher San Bernardino Mountains. The Range is bound on the north by the Antelope Valley and the Mojave Desert and to the south by the communities of greater Los Angeles area. In the western portion of the San Gabriel Mountain Range, the Sierra Pelona Ridge stretches from Soledad Canyon, formed by the Santa Clara River.
The Sierra Pelona Ridge includes Liebre Mountain, Sawmill Mountain, Grass Mountain, Redrock Peak, Burnt Peak, most of, part of the Angeles National Forest, but features several rural communities. Melting snow and rain runoff on the south side of the San Gabriels' highest mountains give rise to its largest river, the San Gabriel River. Just to the west of Mount Hawkins, a north-south divide separates water running down the two main forks of the river and their tributaries; the West Fork, beginning at Red Box Saddle, runs 14 miles eastward, the East Fork, starting north of Mount San Antonio, flows 18 miles south and west through a steep and precipitous gorge. The two meet at San Gabriel Reservoir, turn south, boring through the southern portion of the San Gabriels, emptying out of the mountains near Azusa into the urban San Gabriel Valley, to the Pacific Ocean near Seal Beach. San Gabriel Mountains peaks within the Angeles National Forest include: Mount San Antonio, 10,064 ft Pine Mountain, 9,648 ft Dawson Peak, 9,575 ft
Pomona was a goddess of fruitful abundance in ancient Roman religion and myth. Her name comes from the Latin word pomum, "fruit," orchard fruit. Pomona was said to be a wood nymph. In the myth narrated by Ovid, she scorned the love of the woodland gods Silvanus and Picus, but married Vertumnus after he tricked her, disguised as an old woman, she and Vertumnus shared a festival held on August 13. Her priest was called the flamen Pomonalis; the pruning knife was her attribute. There is a grove, sacred to her called the Pomonal, located not far from Ostia, the ancient port of Rome. Pomona was the goddess of fruit trees and orchards. Unlike many other Roman goddesses and gods, she does not have a Greek counterpart, though she is associated with Demeter, she cares for their cultivation. She was not associated with the harvest of fruits itself, but with the flourishing of the fruit trees. In artistic depictions she is shown with a platter of fruit or a cornucopia; the City of Pomona in Los Angeles County, California, is named after the goddess.
Pomona College was founded in the city and retained its name after relocating to its present-day location, Claremont. The Pomona Docks were built on the site of the Pomona Gardens. A former public house nearby was named the Pomona Palace. A bronze statue of Pomona sits atop the Pulitzer Fountain in Manhattan's Grand Army Plaza in New York; the fountain was funded by newspaper tycoon Joseph Pulitzer, designed by the architect Thomas Hastings, crowned by a statue conceived by the sculptor Karl Bitter. The fountain was dedicated in May 1916. Pomona is mentioned in C. S. Lewis's children's book Prince Caspian. Pomona is the title of a play by Alistair McDowell, commissioned in 2014 for the Royal Welsh College of Music and Drama. Karpo, one of the Horae; the ballet Pomona, with music by Constant Lambert, choreography by Frederick Ashton and scenery and costumes by Vanessa Bell, was first performed by the Vic-Wells Ballet at the Sadler's Wells Theatre on 17 January 1933. Chisholm, Hugh, ed.. "Pomona". Encyclopædia Britannica.
Cambridge University Press
Spain the Kingdom of Spain, is a country located in Europe. Its continental European territory is situated on the Iberian Peninsula, its territory includes two archipelagoes: the Canary Islands off the coast of Africa, the Balearic Islands in the Mediterranean Sea. The African enclaves of Ceuta, Peñón de Vélez de la Gomera make Spain the only European country to have a physical border with an African country. Several small islands in the Alboran Sea are part of Spanish territory; the country's mainland is bordered to the south and east by the Mediterranean Sea except for a small land boundary with Gibraltar. With an area of 505,990 km2, Spain is the largest country in Southern Europe, the second largest country in Western Europe and the European Union, the fourth largest country in the European continent. By population, Spain is the fifth in the European Union. Spain's capital and largest city is Madrid. Modern humans first arrived in the Iberian Peninsula around 35,000 years ago. Iberian cultures along with ancient Phoenician, Greek and Carthaginian settlements developed on the peninsula until it came under Roman rule around 200 BCE, after which the region was named Hispania, based on the earlier Phoenician name Spn or Spania.
At the end of the Western Roman Empire the Germanic tribal confederations migrated from Central Europe, invaded the Iberian peninsula and established independent realms in its western provinces, including the Suebi and Vandals. The Visigoths would forcibly integrate all remaining independent territories in the peninsula, including Byzantine provinces, into the Kingdom of Toledo, which more or less unified politically and all the former Roman provinces or successor kingdoms of what was documented as Hispania. In the early eighth century the Visigothic Kingdom fell to the Moors of the Umayyad Islamic Caliphate, who arrived to rule most of the peninsula in the year 726, leaving only a handful of small Christian realms in the north and lasting up to seven centuries in the Kingdom of Granada; this led to many wars during a long reconquering period across the Iberian Peninsula, which led to the creation of the Kingdom of Leon, Kingdom of Castile, Kingdom of Aragon and Kingdom of Navarre as the main Christian kingdoms to face the invasion.
Following the Moorish conquest, Europeans began a gradual process of retaking the region known as the Reconquista, which by the late 15th century culminated in the emergence of Spain as a unified country under the Catholic Monarchs. Until Aragon had been an independent kingdom, which had expanded toward the eastern Mediterranean, incorporating Sicily and Naples, had competed with Genoa and Venice. In the early modern period, Spain became the world's first global empire and the most powerful country in the world, leaving a large cultural and linguistic legacy that includes more than 570 million Hispanophones, making Spanish the world's second-most spoken native language, after Mandarin Chinese. During the Golden Age there were many advancements in the arts, with world-famous painters such as Diego Velázquez; the most famous Spanish literary work, Don Quixote, was published during the Golden Age. Spain hosts the world's third-largest number of UNESCO World Heritage Sites. Spain is a secular parliamentary democracy and a parliamentary monarchy, with King Felipe VI as head of state.
It is a major developed country and a high income country, with the world's fourteenth largest economy by nominal GDP and sixteenth largest by purchasing power parity. It is a member of the United Nations, the European Union, the Eurozone, the Council of Europe, the Organization of Ibero-American States, the Union for the Mediterranean, the North Atlantic Treaty Organization, the Organisation for Economic Co-operation and Development, Organization for Security and Co-operation in Europe, the Schengen Area, the World Trade Organization and many other international organisations. While not an official member, Spain has a "Permanent Invitation" to the G20 summits, participating in every summit, which makes Spain a de facto member of the group; the origins of the Roman name Hispania, from which the modern name España was derived, are uncertain due to inadequate evidence, although it is documented that the Phoenicians and Carthaginians referred to the region as Spania, therefore the most accepted etymology is a Semitic-Phoenician one.
Down the centuries there have been a number of accounts and hypotheses: The Renaissance scholar Antonio de Nebrija proposed that the word Hispania evolved from the Iberian word Hispalis, meaning "city of the western world". Jesús Luis Cunchillos argues that the root of the term span is the Phoenician word spy, meaning "to forge metals". Therefore, i-spn-ya would mean "the land where metals are forged", it may be a derivation of the Phoenician I-Shpania, meaning "island of rabbits", "land of rabbits" or "edge", a reference to Spain's location at the end of the Mediterranean. The word in question means "Hyrax" due to Phoenicians confusing the two animals. Hispania may derive from the poetic use of the term Hesperia, reflecting the Greek perception of Italy as a "western land" or "land of the setting sun" (Hesperia
April Fools' Day
April Fools' Day or April Fool's Day is an annual celebration commemorated on April 1st by playing practical jokes and spreading hoaxes. The jokes and their victims are called April fools. People playing April Fool jokes expose their prank by shouting "April fool" at the unfortunate victim; some newspapers and other published media report fake stories, which are explained the next day or below the news section in smaller letters. Although popular since the 19th century, the day is not a public holiday in any country. Aside from April Fools' Day, the custom of setting aside a day for the playing of harmless pranks upon one's neighbour has been common in the world. A disputed association between April 1 and foolishness is in Geoffrey Chaucer's The Canterbury Tales. In the "Nun's Priest's Tale", a vain cock Chauntecleer is tricked by a fox on Syn March bigan thritty dayes and two. Readers understood this line to mean "32 March", i.e. April 1. However, it is not clear that Chaucer was referencing April 1.
Modern scholars believe that there is a copying error in the extant manuscripts and that Chaucer wrote, Syn March was gon. If so, the passage would have meant 32 days after March, i.e. 2 May, the anniversary of the engagement of King Richard II of England to Anne of Bohemia, which took place in 1381. In 1508, French poet Eloy d'Amerval referred to a poisson d’avril the first reference to the celebration in France; some writers suggest that April Fools' originated because in the Middle Ages, New Year's Day was celebrated on March 25 in most European towns, through a holiday that in some areas of France ended on April 1, those who celebrated New Year's Eve on January 1 made fun of those who celebrated on other dates by the invention of April Fools' Day. The use of January 1 as New Year's Day became common in France only by the mid-16th century, the date was not adopted until 1564, thanks to the Edict of Roussillon. In 1539, Flemish poet Eduard de Dene wrote of a nobleman who sent his servants on foolish errands on April 1.
In the Netherlands, the origin of April Fools' Day is attributed to the Dutch victory at Brielle in 1572, where the Spanish Duke Álvarez de Toledo was defeated. "Op 1 april verloor Alva zijn bril" is a Dutch proverb, which can be translated to: "On the first of April, Alva lost his glasses." In this case, the glasses serve as a metaphor for Brielle. This theory, provides no explanation for the international celebration of April Fools' Day. In 1686, John Aubrey referred to the first British reference. On April 1, 1698, several people were tricked into going to the Tower of London to "see the Lions washed". Although no Biblical scholar or historian are known to have mentioned a relationship, some have expressed the belief that the origins of April Fool's Day may go back to the Genesis flood narrative. In a 1908 edition of the Harper's Weekly cartoonist Bertha R. McDonald wrote: Authorities gravely back with it to the time of Noah and the ark; the London Public Advertiser of March 13, 1769, printed: "The mistake of Noah sending the dove out of the ark before the water had abated, on the first day of April, to perpetuate the memory of this deliverance it was thought proper, whoever forgot so remarkable a circumstance, to punish them by sending them upon some sleeveless errand similar to that ineffectual message upon which the bird was sent by the patriarch".
In the UK, an April Fool joke is revealed by shouting "April fool!" at the recipient, who becomes the "April fool". A study in the 1950s, by folklorists Iona and Peter Opie, found that in the UK, in countries whose traditions derived from the UK, the joking ceased at midday; this continues to be the current practice with the holiday ceasing at noon, after which time it is no longer acceptable to play jokes. Ergo, a person playing a joke after midday is considered the "April fool" themselves. In Scotland, April Fools' Day was traditionally called'Huntigowk Day', although this name has fallen into disuse; the name is a corruption of ` Hunt the Gowk', "gowk" being Scots for a foolish person. The traditional prank is to ask someone to deliver a sealed message that requests help of some sort. In fact, the message reads "dinna smile. Hunt the gowk another mile." The recipient, upon reading it, will explain he can only help if he first contacts another person, sends the victim to this next person with an identical message, with the same result.
In England a "fool" is known by different names around the country, including a "noodle", "gob", "gobby" or "noddy". In Ireland, it was traditional to entrust the victim with an "important letter" to be given to a named person; that person would ask the victim to take it to someone else, so on. The letter when opened contained the words "send the fool further". In Poland, prima aprilis as a day of jokes is a centuries-long tradition, it is a day. Serious activities are avoided, every word said on April 1st can be a lie, or a joke; the conviction for this is so strong that the Polish anti-Turkish alliance with Leopold I signed on April 1, 1683, was backdated to March 31. However, for some in Poland prima aprilis ends at noon of April 1st, prima aprilis jokes after that hour are consid
The Pacific Ocean is the largest and deepest of Earth's oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean in the south and is bounded by Asia and Australia in the west and the Americas in the east. At 165,250,000 square kilometers in area, this largest division of the World Ocean—and, in turn, the hydrosphere—covers about 46% of Earth's water surface and about one-third of its total surface area, making it larger than all of Earth's land area combined; the centers of both the Water Hemisphere and the Western Hemisphere are in the Pacific Ocean. The equator subdivides it into the North Pacific Ocean and South Pacific Ocean, with two exceptions: the Galápagos and Gilbert Islands, while straddling the equator, are deemed wholly within the South Pacific, its mean depth is 4,000 meters. The Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 meters; the western Pacific has many peripheral seas. Though the peoples of Asia and Oceania have traveled the Pacific Ocean since prehistoric times, the eastern Pacific was first sighted by Europeans in the early 16th century when Spanish explorer Vasco Núñez de Balboa crossed the Isthmus of Panama in 1513 and discovered the great "southern sea" which he named Mar del Sur.
The ocean's current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish circumnavigation of the world in 1521, as he encountered favorable winds on reaching the ocean. He called it Mar Pacífico, which in both Portuguese and Spanish means "peaceful sea". Important human migrations occurred in the Pacific in prehistoric times. About 3000 BC, the Austronesian peoples on the island of Taiwan mastered the art of long-distance canoe travel and spread themselves and their languages south to the Philippines and maritime Southeast Asia. Long-distance trade developed all along the coast from Mozambique to Japan. Trade, therefore knowledge, extended to the Indonesian islands but not Australia. By at least 878 when there was a significant Islamic settlement in Canton much of this trade was controlled by Arabs or Muslims. In 219 BC Xu Fu sailed out into the Pacific searching for the elixir of immortality. From 1404 to 1433 Zheng He led expeditions into the Indian Ocean; the first contact of European navigators with the western edge of the Pacific Ocean was made by the Portuguese expeditions of António de Abreu and Francisco Serrão, via the Lesser Sunda Islands, to the Maluku Islands, in 1512, with Jorge Álvares's expedition to southern China in 1513, both ordered by Afonso de Albuquerque from Malacca.
The east side of the ocean was discovered by Spanish explorer Vasco Núñez de Balboa in 1513 after his expedition crossed the Isthmus of Panama and reached a new ocean. He named it Mar del Sur because the ocean was to the south of the coast of the isthmus where he first observed the Pacific. In 1519, Portuguese explorer Ferdinand Magellan sailed the Pacific East to West on a Spanish expedition to the Spice Islands that would result in the first world circumnavigation. Magellan called the ocean Pacífico because, after sailing through the stormy seas off Cape Horn, the expedition found calm waters; the ocean was called the Sea of Magellan in his honor until the eighteenth century. Although Magellan himself died in the Philippines in 1521, Spanish Basque navigator Juan Sebastián Elcano led the remains of the expedition back to Spain across the Indian Ocean and round the Cape of Good Hope, completing the first world circumnavigation in a single expedition in 1522. Sailing around and east of the Moluccas, between 1525 and 1527, Portuguese expeditions discovered the Caroline Islands, the Aru Islands, Papua New Guinea.
In 1542–43 the Portuguese reached Japan. In 1564, five Spanish ships carrying 379 explorers crossed the ocean from Mexico led by Miguel López de Legazpi, sailed to the Philippines and Mariana Islands. For the remainder of the 16th century, Spanish influence was paramount, with ships sailing from Mexico and Peru across the Pacific Ocean to the Philippines via Guam, establishing the Spanish East Indies; the Manila galleons operated for two and a half centuries, linking Manila and Acapulco, in one of the longest trade routes in history. Spanish expeditions discovered Tuvalu, the Marquesas, the Cook Islands, the Solomon Islands, the Admiralty Islands in the South Pacific. In the quest for Terra Australis, Spanish explorations in the 17th century, such as the expedition led by the Portuguese navigator Pedro Fernandes de Queirós, discovered the Pitcairn and Vanuatu archipelagos, sailed the Torres Strait between Australia and New Guinea, named after navigator Luís Vaz de Torres. Dutch explorers, sailing around southern Africa engaged in discovery and trade.
In the 16th and 17th centuries Spain considered the Pacific Ocean a mare clausum—a sea closed to other naval powers. As the only known entrance from the Atlantic, the Strait of Magellan was at times patrolled by fleets sent to prevent entrance of non-Spanish ships. On the western side of the Pacific Ocean the Dutch threatened the Spanish Philippines; the 18th cen
Los Angeles Basin
The Los Angeles Basin is a sedimentary basin located in southern California, in a region known as the Peninsular Ranges. The basin is connected to an anomalous group of east-west trending chains of mountains collectively known as the California Transverse Ranges; the present basin is a coastal lowland area, whose floor is marked by elongate low ridges and groups of hills, located on the edge of the Pacific plate. The Los Angeles Basin, along with the Santa Barbara Channel, the Ventura Basin, the San Fernando Valley, the San Gabriel Basin, lies within the greater southern California region. On the north and east, the lowland basin is bound by the Santa Monica Mountains and Puente, Repetto hills. To the southeast, the basin is bordered by the San Joaquin Hills; the western boundary of the basin is marked by the Continental Borderland and is part of the onshore portion. The California borderland is characterized by north-west trending offshore basins; the Los Angeles Basin is notable for its great structural relief and complexity in relation to its geologic youth and small size for its prolific oil production.
Yerkes et al. identify 5 major stages of the basin's evolution that begins in the Upper Cretaceous and ends in the Pleistocene. This basin can be classified as an irregular pull-apart basin accompanied by rotational tectonics during the post-early Miocene. Before the formation of the basin, the area that encompasses the Los Angeles basin began above ground. A rapid transgression and regression of the shoreline moved the area to a shallow marine environment. Tectonic instability coupled with volcanic activity in subsiding areas during the Middle Miocene set the stage for the modern basin; the basin formed in a submarine environment and was brought back above sea level when the rate of subsidence slowed. There is much discussion in the literature about the geologic time boundaries when each basin forming event took place. While exact ages may not be clear, Yerkes et al. provided a general timeline to categorize the sequence of depositional events in the LA Basin's evolution and they are as follows: During pre-Turonian, metamorphosed sedimentary and volcanic rocks are present that serve as the two major basement rock units for the LA Basin.
Large-scale movement along the Newport–Inglewood zone juxtaposed the two bedrock units along the east and west margins. During this phase, the basin was above sea level; the hallmarks of this phase were successive shoreline regression cycles. Deposition of older marine and non-marine sediments began to fill the basin. Towards the end of this phase, the shoreline began to retreat and deposition continued. After the deposition of the pre-Turonian units, there was a large emergence and erosion that can be observed as a major unconformity at the base of the middle Miocene units. Emergence did not occur in all sections of the basin. During this time, the basin was covered by a marine embayment. Rivers sourced in the highlands brought large amounts of detritus to the northeastern edge of the basin. During this period, the Topanga formation was being deposited; the present form and structural relief of the basin was established during this phase of accelerated subsidence and deposition which occurred during the late Miocene and continued through the early Pleistocene.
Clastic sedimentary rocks from the highland areas moved down the submarine slopes and infilled the basin floor. Subsidence and sedimentation most began in the southern portion basin. Subsidence and Deposition occurred without interruption, until the late Pliocene; until the rate of deposition overtook the rate of subsidence, the sea level began to fall. Towards the end of this phase, the margins of the basin began to rise above sea level. During the early Pleistocene, deposition began to outpace subsidence in the depressed parts of the basin and the shoreline began to move southward; this phase had movement along the Newport–Inglewood fault zone that resulted in the initiation of the modern basin. This movement caused the southwestern block to be uplifted relative to the central basin block; the central part of the basin continued to experience sediment deposition through the Pleistocene from flooding and erosional debris from the surrounding mountains and Puente Hills. This infill was responsible for the final retreat of the shoreline from the basin.
Deposition in the Holocene is characterized by non marine gravel and silt. This phase includes the late stage compressional deformation responsible for the formation of the hydrocarbon traps. Four major faults are present in the region and divide the basin in the central, northwest and northeast structural blocks; these blocks not only denote their geographic location, but they indicate the strata present and major structural features. The southwestern block was uplifted prior to the middle Miocene and is composed of marine strata and contains two major anticlines; this block contains the steeply-dipping Palos Verdes Hills fault zone. The middle Miocene volcanics can be seen locally within the southwest block; the northwestern block consists of clastic marine sediments of Late Cretaceous to Pleistocene age. Middle Miocene volcanics are present; this block has a broad anticline, truncated by the Santa Monica fault zone. The central block contains both marine and non-marine clastic rock units interbedded with volcanic rocks that are late Cretaceous to Pliocene in age.
Pliocene and Quaternary strata are most visible within the central block. Structurally, there is a synclinal trough; the northeastern block contains fine to coarse grained clastic marine rocks of Cenozoic age. Locally, middle Mi