Talk about catastrophism: imagine a geological process creating a dyke 150 miles deep in a few minutes. This is a new model for how diatremes formed, as described in Nature last week.1 The surprise end of the abstract by Lionel Wilson and James W. Head III states, “No precursor to the eruption is felt at the surface and the processes are complete in about an hour.” Diatremes are deep, funnel-shaped dykes made of kimberlite rock. They extend down 200 to 250 meters into the earth and are famous as sources of diamonds. The origin of diatremes has long been a puzzle. Diverse and unusual, they have seemingly contradictory characteristics:Relative to normal magmatic eruptions, the most unusual of these characteristics raise the questions of how is it possible to: (1) transport diamonds from the mantle (where they are stable) to the surface (where they are metastable) fast enough to avoid significant alteration over the intervening range of depths at which they are unstable; (2) transport significant quantities of mantle xenoliths to near-surface levels; (3) produce intrusive pyroclastic kimberlitic material at depths where pressures would normally preclude magma fragmentation by volatile expansion, and then separate most of the volatiles from the pyroclastic materials; (4) generate extensive fracturing and brecciation of host rocks in many parts of the system, with minimal contact metamorphic effects; and (5) produce complex shallow structures (diatremes and root zones) in which an unusual widening of the conduit system occurs, sometimes with extensions that do not connect to the surface, and where complex mixtures of fragmented material and coherent dyke segments are present.In light of the difficulties previous models have had, the authors propose a catastrophic eruption: “We propose that essentially all of the rise of kimberlitic magma to the surface takes place via rapid propagation of a dyke from unusually great depths (Fig. 2) rather than the much slower propagation of a diapir to shallower depths before transitioning to a dyke,” they explained. “This very deep dyke initiation and propagation minimizes thermodynamic problems associated with transporting diamonds from mantle depths to the surface.” In their model, which describes six stages of the eruption, carbon dioxide creates a sort of magma foam that propagates upward explosively. Here is the brief description:Dyke initiation in a deep CO2-rich source region in the mantle leads to rapid propagation of the dyke tip, below which CO2 fluid collects, with a zone of magmatic foam beneath. When the tip breaks the surface of the ground, gas release causes a depressurization wave to travel into the magma. This wave implodes the dyke walls, fragments the magma, and creates a ‘ringing’ fluidization wave. Together, these processes form the diatreme. Catastrophic magma chilling seals the dyke.The walls open up, fill with the kimberlite, and close in rapid succession. How quickly? No millions of years required: “The termination of the eruption immediately after diatreme formation, probably within at most a few tens of minutes of the onset of eruption, is a direct consequence of the extreme cooling of magma during the large pressure reductions that occur on venting to the atmosphere.” Long ages are not needed to explain the rocks found inside, either: “The subsequent very rapid pressure and temperature fluctuations lead to the formation of a diverse suite of rock types in the intrusive deposits that characterize these eruptions.” In cases where water substitutes for carbon dioxide, the process could be more protracted, they said, similar to “traditional basaltic pyroclastic eruptions.” Those may take a few more hours.1Lionel Wilson and James W. Head III, “An integrated model of kimberlite ascent and eruption,” Nature 447, 53-57 (3 May 2007) | doi:10.1038/nature05692.If this model is correct, who needs millions of years? Of all the catastrophic geological processes described in the literature, this one seems among the fastest. Imagine a funnel-shaped crater filled with rocks and minerals forming in less than an hour. Undoubtedly, a passing uniformitarian-trained geologist would look at the deposits an hour later and deduce that they took millions of years of slow, gradual processes to form. It is clear from this example that the presumption of long ages is a mindset drilled into geologists’ heads, not a requirement of the evidence. This would be a good subject for a Biblical geologist to investigate in more detail. See also last year’s surprise announcement that rich gold deposits could form in a human lifetime (10/15/2006). Better hope you are not in the wrong spot when one of these eruptions is about to blow. Come by shortly afterwards, though; you might just find acres of diamonds. How’s that for fast delivery? From mantle to surface, your diamond delivered in just one hour. Lucy, meanwhile, is somewhere in the sky without any. She is mourning her demotion as a human ancestor (04/10/2007). The party at Charlie & Charlie’s really rocked for awhile. Now that morning has come, she realizes her fling didn’t result in any lasting commitments.(Visited 29 times, 1 visits today)FacebookTwitterPinterestSave分享0
Diverse, unique, and thought-provoking and with myriad themes such as the National Register of Citizens, fake news, and Balakot air strike, the Durga Puja marquees (pandals) have come alive in Kolkata this autumn.Almost 3,000 community Durga Pujas are organised in the State capital and another 25,000 in the districts and every Puja organiser is trying to do something different through themes, lightings and decorations all aimed at wooing the people to their pandal.While a Durga Puja pandal at Vivekananda Sarbojanin Durgotsav has tried to tackle the subject of evolution of news and of how fake news reaches the public, the organisers at Young Boys Club Sarbojanin Durga Puja have created scenes from the Balakot air strike, where along with models of IAF jets, there is a life-size model of IAF pilot Wing Commander Abhinandan Varthaman.The Rajdanga Naba Uday Sangha has tried to bring to the fore what is emerging as the most politically sensitive issue in the State, the NRC exercise in Assam. Refugees have been described and badminton rackets — representing two countries — have been slotted in front of the pandal.The community Puja organisers have also tried to bring alive various monuments such as the golden temple of Amritsar revered by Sikhs at the Bhowanipore Baish Palli Northern Park. At Kharagpur’s Netaji Byamagar of West Midnapore, an attempt has been made to replicate the model of ancient Egypt, whereas at the Kumartuli Park Sarbojanin Durgotsav Committee, in north Kolkata the theme is related to space and the extra-terrestrial intergalactic connections.When it comes to spectacle and grandeur only a few can match the Santosh Mitra Square Durga Puja that has installed a 13 feet tall idol of the Goddess at an estimated cost of ₹20 crore.Organisers have not shunned themes of social inclusion and highlighted the marginalisation of the third gender. At Dum Dum Tarun Dal, a song “tumi dekho nari pusush, ami dekhi sudhui manush” (you see only man and woman, but I see only the human) floated with reference to Chaitanya Mahaprabhu’s love for Lord Krishna, and the various taboos associated with the third gender.
The following volunteer positions on the National Indigenous Advisory Committee are still available: · Committee Chairperson · Athlete Development· Official/Technical Development· Community Awareness· Cultural Education Please see attached the memorandum with details of the positions and process for application, as well as the positions descriptions for all positions on the National Indigenous Advisory Committee. Applications close on Wednesday 30th June 2010. If you have any questions, please contact the national office on (02) 6212 2800.Related Filesnational_indigenous_advisory_committee_memo-pdfindigenous_committee_-_job_descriptions_01-pdf
Trippier insists Spurs remain title challengersby Paul Vegas10 months agoSend to a friendShare the loveTottenham defender Kieran Trippier insists they remain title challengers.Spurs meet Everton on Sunday.”Every single game we want to win, our mentality is to get the three points,” said Trippier.”Things are looking good and the last set of results have been perfect for us and we are in every competition at the moment.”It’s another long season ahead, we’re not even at Christmas yet. So I think it’s too early to tell if we are in the title race or if we are going to win the league.” About the authorPaul VegasShare the loveHave your say
Agent: Southampton will regret losing Gabbiadiniby Paul Vegas10 months agoSend to a friendShare the loveManolo Gabbadini’s agent says Southampton will regret losing the Italy striker.Samp have agreed to re-sign Gabbiadini on loan with a €12m obligation to buy from Southampton.“He felt good at Sampdoria and wanted to go back home,” Silvio Pagliari told Sky Sport Italia from Milan Linate airport, where he was waiting for the 27-year-old.“We wouldn’t have gone anywhere on loan. It was his will to cut the cord with Southampton, although he had a great time there.“He also discussed tactics with Sampdoria and I’m sure he’ll carve out a place in the team.“He’s a good player and, in my opinion, one of the best strikers in Italy.” TagsTransfersAbout the authorPaul VegasShare the loveHave your say
Marouane Fellaini insists no Man Utd regretsby Paul Vegas14 days agoSend to a friendShare the loveFormer Manchester United midfielder Marouane Fellaini has no regrets over his time at Old Trafford.United’s cup double and second placed finish in 2016 the undisputed highlight of his five-and-half years at the club.Fellaini, now with Shandong Luneng, told the Daily Mail: “I played five and half years for Manchester. My first season was a transition, so I was in transition, I know I didn’t have a great season. But after that I played my games, played well and I won things.”Okay, I didn’t win the Premier League but that’s part of football. Manchester City was a strong team and was difficult to battle against them.”But I did some great games, scored some important goals, so for me I was very happy with my time in Manchester.’ Unfortunately, Old Trafford isn’t quite so cheery right now.” About the authorPaul VegasShare the loveHave your say
ESPN.Which team deserves to be No. 1 in college football’s preseason polls? According to ESPN, it’s the defending national champions – Alabama. ESPN released its updated preseason top 25 for the 2016 college football season earlier this month, and they’ve got the Crimson Tide at the top. Trailing Nick Saban’s team in the polls are Clemson, Michigan, Florida State and Oklahoma. Here’s the full top 25. Will Alabama win another one this year?1. Alabama 2. Clemson 3. Michigan 4. Florida State 5. Oklahoma 6. LSU 7. Stanford 8. Notre Dame 9. Ohio State 10. Tennessee 11. USC 12. Georgia 13. Ole Miss 14. Oklahoma State 15. Michigan State 16. Washington 17. Houston 18. North Carolina 19. Oregon 20. TCU 21. Texas A&M 22. UCLA 23. Iowa 24. Miami 25. Louisville[ESPN]
Mr. Montague also said that the AAJ intends to invest and upgrade the aerodromes that are currently operational in Negril; Ken Jones (Port Antonio); Tinson Pen; Lionel Densham (Treasure Beach) and Ian Fleming, St. Mary. “If all goes to plan we should have divested this asset by the end of the calendar year. The invitation for the bid is now open and the eight pre-qualified bidders have been invited,” he told the House, during his contribution to the 2018/19 Sectoral Debate in the House of Representatives on May 30. Minister of Transport and Mining, Hon. Robert Montague, says the Airports Authority of Jamaica (AAJ) is far advanced with the divestment of the Norman Manley International Airport.“If all goes to plan we should have divested this asset by the end of the calendar year. The invitation for the bid is now open and the eight pre-qualified bidders have been invited,” he told the House, during his contribution to the 2018/19 Sectoral Debate in the House of Representatives on May 30.The Minister informed that assessment and evaluation will be in June and that by September/October, the signing should take place with the preferred bidder.Mr. Montague also said that the AAJ intends to invest and upgrade the aerodromes that are currently operational in Negril; Ken Jones (Port Antonio); Tinson Pen; Lionel Densham (Treasure Beach) and Ian Fleming, St. Mary.He said the scope of works will include fencing, runway rehabilitation, repairs to terminals and establishment of pilot lounges.In addition, Mr. Montague said the AAJ is seeking a partner to assist with the setting up of an internal airline to assist with domestic movement of people and goods.“In today’s Jamaica we need scheduled internal flights, so the call is for persons in the private sector to come forward and let the negotiations begin,” the Minister said.Meanwhile, Mr. Montague said the Government is again moving to market and open up the country’s aviation industry.He informed that discussions have begun with private pilot associations in North America.“One association has 180,000 members. If we could get five per cent of the owners to come to Jamaica, that’s 9,000 flights per year or 25 flights per day. Can you imagine what that would mean for fuel sales, villa and car rental, aircraft maintenance, catering and additional jobs to bring more prosperity,” the Minister said. Minister of Transport and Mining, Hon. Robert Montague, says the Airports Authority of Jamaica (AAJ) is far advanced with the divestment of the Norman Manley International Airport. Story Highlights
zoom Greek shipping companies Oceanic Illsabe Limited and Oceanfleet Shipping Limited, and two of their employees, were convicted of violating the Act to Prevent Pollution from Ships (APPS), obstruction of justice, false statements, witness tampering and conspiracy, according to the US Department of Justice.Convicted by a federal jury in Greenville, North Carolina, Oceanic Illsabe Limited is the owner of the M/V Ocean Hope, a large cargo vessel that was responsible for dumping tons of oily waste into the Pacific Ocean last year, while Oceanfleet Shipping Limited was the managing operator of the vessel.Also convicted at trial were two senior engineering officers who worked aboard the vessel, Rustico Ignacio and Cassius Samson. The jury convicted on each of the nine counts in the indictment.The US Department of Justice said that in June 2015 the vessel discharged around ten metric tons of sludge into the ocean. The vessel was also regularly pumping contaminated water directly overboard. None of these discharges were disclosed as required.The evidence presented during the nine-day trial demonstrated that the companies were aware that the ship had not offloaded any oil sludge from the vessel since September 2014 and that the ship rarely used its oil-water separator.Instead, the vessel’s second engineer, Samson, ordered crewmembers to connect what is known in the industry as a “magic pipe” to bypass the vessel’s oil-water separator and pump oil sludge overboard. In addition, crewmembers were ordered to pump oily water from the vessel’s bilges directly into the ocean up to several times per week. The dumping occurred with the knowledge and approval of the ship’s chief engineer, Ignacio.Finally, the engineers used a tank designated for oily wastes to store diesel fuel for sale on the black market.Upon arriving at the Port of Wilmington, Oceanic, Oceanfleet, Ignacio and Samson attempted to hide these discharges by presenting a false and fictitious oil record book to US Coast Guard inspectors. When inspectors uncovered evidence of dumping, the defendants ordered lower-level crewmembers to lie to Coast Guard personnel. Samson also made several false statements to a Coast Guard inspector regarding the bypass of the oil-water separator.At the conclusion of trial, defendants Oceanic and Oceanfleet were convicted of one count of conspiracy, one count of violating APPS, two counts of obstruction of justice, one count of false statements and four counts of witness tampering.Ignacio was convicted of one count of conspiracy, one count of violating APPS, one count of obstruction of justice and two counts of witness tampering, while Samson was convicted of one count of conspiracy, one count of violating APPS, two counts of obstruction of justice, one count of false statements and three counts of witness tampering.The companies could be fined up to USD 500,000 per count, in addition to other possible penalties.Ignacio and Samson face a maximum penalty of 20 years in prison for the obstruction of justice charges.
CIUDAD VICTORIA, Mexico – At least 200 demonstrators blocked a major commercial bridge between Mexico and Texas on Monday to protest the disappearance of dozens of people in the border city of Nuevo Laredo, snarling traffic in both directions into the night.The protest began around 9:30 a.m. at the bridge, which is used exclusively by cargo trucks travelling between Tamaulipas state and Laredo, Texas, and was still going late Monday.Thousands of trucks make the crossing each day, and long lines of tractor-trailers backed up along the highway.Demonstrators were protesting what they consider a weak response by authorities to 43 complaints filed with prosecutors over disappearances in Nuevo Laredo.“We are demanding justice,” said Estela Gonzalez, who lodged a complaint about a missing nephew-in-law. “Alive or dead or however they may be, we want to know what happened to them.”Nuevo Laredo’s acting mayor, Rafael Pedraza Dominguez, went to the bridge in the afternoon to try to persuade the protesters to leave, promising to engage in talks with them.But they ignored his pleas and vowed to maintain the roadblock.“What we want is a solution, and if (the missing) have already been harmed, well, what happened to their bodies?” Gonzalez said.Nuevo Laredo is a key smuggling corridor for rival drug gangs, and the city has been experiencing a wave of violence.In March, four members of a family were killed in the crossfire between Mexican marines and gang members. The following month federal prosecutors issued a report faulting officers for the deaths.