The Chicxulub crater is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is located near the town of Chicxulub, it was formed by a large asteroid or comet about 11 to 81 kilometers in diameter, the Chicxulub impactor, striking the Earth. The date of the impact coincides with the Cretaceous–Paleogene boundary less than 66 million years ago, a accepted theory is that worldwide climate disruption from the event was the cause of the Cretaceous–Paleogene extinction event, a mass extinction in which 75% of plant and animal species on Earth became extinct, including all non-avian dinosaurs; the crater is estimated to be 150 kilometers in diameter and 20 kilometers in depth, well into the continental crust of the region of about 10–30 kilometers depth. It is the second largest confirmed impact structure on Earth, the only one whose peak ring is intact and directly accessible for scientific research; the crater was discovered by Antonio Camargo and Glen Penfield, geophysicists, looking for petroleum in the Yucatán Peninsula during the late 1970s.
Penfield was unable to obtain evidence that the geological feature was a crater and gave up his search. Through contact with Alan Hildebrand in 1990, Penfield obtained samples that suggested it was an impact feature. Evidence for the impact origin of the crater includes shocked quartz, a gravity anomaly, tektites in surrounding areas. In 2016, a scientific drilling project drilled deep into the peak ring of the impact crater, hundreds of meters below the current sea floor, to obtain rock core samples from the impact itself; the discoveries were seen as confirming current theories related to both the crater impact and its effects. In 1978, geophysicists Glen Penfield and Antonio Camargo were working for the Mexican state-owned oil company Petróleos Mexicanos, or Pemex, as part of an airborne magnetic survey of the Gulf of Mexico north of the Yucatán Peninsula. Penfield's job was to use geophysical data to scout possible locations for oil drilling. In the offshore magnetic data, Penfield noted anomalies whose depth he estimated, mapped.
He obtained onshore gravity data from the 1940s. According to Penfield, "The old data showed a large concentric set of onshore gravity anomalies; when I laid it next to my No. 2 pencil mapping of the offshore magnetic anomalies, the fit was perfect: a shallow, 180-kilometer diameter gravity-magnetic bullseye on the non-magnetic, uniform carbonate background of the Yucatan platform! We recognized the crater as the Cretaceous-Paleogene boundary event." A decade earlier, the same map suggested an impact feature to contractor Robert Baltosser, but he was forbidden to publicize his conclusion by Pemex corporate policy of the time. Pemex disallowed release of specific data but let Penfield and company official Antonio Camargo present their results at the 1981 Society of Exploration Geophysicists conference; that year's conference was underattended and their report attracted scant attention. Coincidentally, many experts in impact craters and the K–Pg boundary were attending a separate conference on Earth impacts.
Although Penfield had plenty of geophysical data sets, he had no rock cores or other physical evidence of an impact. He knew. In 1951, one bored into what was described as a thick layer of andesite about 1.3 kilometers down. This layer could have resulted from the intense heat and pressure of an Earth impact, but at the time of the borings it was dismissed as a lava dome—a feature uncharacteristic of the region's geology. Penfield was told such samples had been lost or destroyed; when attempts at returning to the drill sites and looking for rocks proved fruitless, Penfield abandoned his search, published his findings and returned to his Pemex work. At the same time, in 1980, geologist Walter Alvarez and his father, Nobel Prize-winning scientist Luis Walter Alvarez, put forth their hypothesis that a large extraterrestrial body had struck Earth at the time of the Cretaceous–Paleogene boundary. In 1981, unaware of Penfield's discovery, University of Arizona graduate student Alan R. Hildebrand and faculty adviser William V. Boynton published a draft Earth-impact theory and sought a candidate crater.
Their evidence included greenish-brown clay with surplus iridium containing shocked quartz grains and small weathered glass beads that looked to be tektites. Thick, jumbled deposits of coarse rock fragments were present, thought to have been scoured from one place and deposited elsewhere by a megatsunami resulting from an Earth impact; such deposits occur in many locations but seem concentrated in the Caribbean basin at the K–Pg boundary. So when Haitian professor Florentine Morás discovered what he thought to be evidence of an ancient volcano on Haiti, Hildebrand suggested it could be a telltale feature of a nearby impact. Tests on samples retrieved from the K–Pg boundary revealed more tektite glass, formed only in the heat of asteroid impacts and high-yield nuclear detonations. In 1990, Houston Chronicle reporter Carlos Byars told Hildebrand of Penfield's earlier discovery of a possible impact crater. Hildebrand contacted Penfield in April 1990 and the pair soon secured two drill samples from the Pemex wells, stored in New Orleans.
Hildebrand's team tested the samples, which showed shock-metamorphic materials. A team of California researchers including Kevin Pope, Adriana Ocampo, Charles Duller, surveying regional satellite images in 1996, found a cenote ring centered on Chicxulub that matched the one Penfi
Queluz is a city within the Sintra Municipality, on the Portuguese Riviera, in the Lisbon metropolitan area of Portugal. It is famed as the home of Queluz National Palace, the 18th century pleasure palace of the Portuguese Royal Family, as well as notable institutions like the Portuguese School of Equestrian Art. Queluz had a population 78,273 inhabitants in 2001; the origin of the name Queluz has been disputed over time. The prevailing thesis, by David Lim and José Pedro Machado, suggests that the name had its origin in the Arabic terms câ and Llûs, affirming the suggestion that it was in The Valley of the Almond Tree. However, another suggestion, has it as forming from the Mountain of Light, Monte Abraão, where worship of the sun was common. Human occupation of theis area dates back to the Late Neolithic or early Chalcolithic, owing to the number of Neolithic monuments and vestiges from abandoned settlements unearthed by archeologists; these earliest date established to this settlement was 4200 B.
C. followed by comparable settlements in 2000 B. C.. In the year 1147, when Afonso I of Portugal forces conquered the city of Lisbon, a similar campaign within the Sintra mountains captures the heath of Queluz, bringing the lands under Christian control. From the first century until the 18th century, the region was agrarian, occupied by homes and few estates established by the clergy and/or nobility. In the 18th century, Infante Pedro of Braganza, in his capacity as Lord of the House of the Infantado, acquired an estate in Queluz belonging to the Marquis of Castelo Rodrigo, subsequently built a humble hunting lodge. Following his marriage to Queen Maria I of Portugal, the estate was radically expanded into the Rococo pleasure palace, today known as the Queluz National Palace. Following the transfer of the Portuguese Royal Court to Queluz, during the reign of Queen Maria I and King Pedro III, numerous members of the Portuguese nobility established estates and palaces in the area, Sintra being the longtime retreat of the Portuguese aristocracy.
Between July and August is a free fair outside the D. Maria Pousada that recreates the golden age of the Queluz National Palace; the Seventeenth Fair recreates the reign of Queen Mary I of Portugal, transports visitors back into a period where artisans and merchants produced arts and crafts. Choral concerts are common to Sunday afternoons at Queluz National Palace, owing to the three choirs in the city; the Monte Abraão Fair is the biggest in Queluz, allowing the sale of clothes, handicrafts and vegetables, flowers and implements. The biggest and most known teams in Queluz are Real Sport Clube, CA Queluz and JOMA. Real Sport Clube is Queluz local football team, CA Queluz the basketball one and JOMA main sport is athletics. Real Sport Clube plays on the Segunda Liga. CA Queluz has been Portuguese basketball champions in 1984 and 2005, they won the Portuguese Cup in 1983 and 2005, completing the double. JOMA as been Portuguese champions on both individual and collective athletics competitions. Crossed by Jamor river, the city is interspersed by various parks, with three in the district: two in the civil parish of Queluz and the other in Massamá: Forest of Queluz, a small enclosed, isolated wooded area, it covers 21 hectares, sustained due to its public use, ecological wealth and as a relic of vegetation climate.
Felício Loureiro Park, another emblematic park wooded and equipped for recreation and exercise. It is divided into two zones: the first extends along the river Jamor and includes the a sculpture of José Pedro Croft. Queluz has a micro-climate, classified as an Upper Thermo-Mediterranean sub-humid type, with average annual precipitation of 825 millimetres. With three train stations, Queluz falls within the Sintra-Lisbon corridor, with connections to Amadora and Sintra. Vimeca buslines connect Queluz to Oeiras, Lisbon and Carcavelos. Taxi services within Queluz, handled from the centralized "taxi squares" and services achieved from telephone services. Peter IV of Portugal, son of John VI of Portugal and Carlota Joaquina of Spain, he became King Peter IV of Portugal, before abdicating in favour of his daughter Maria da Gloria.