Animation Shows Earnings of Biggest Movie Franchises of Last 20 Years

first_imgStay on target Bernie Sanders to Disney: Use ‘Avengers’ Profits to Pay Workers More’Avengers: Endgame’ Smashes Box Office Records As Disney/Marvel’s Avengers: Endgame passes Titanic to become the No. 2 movie ever worldwide, breaking opening weekend box office records, and earning almost $2.2 billion worldwide through its second weekend in theaters, the Marvel Cinematic Universe (MCU) has proven to be biggest movie franchise ever.There’s just something about those superheroes that wins overs moviegoers’ minds, hearts — and wallets.  And you can bet there will be more of these blockbusters from Marvel/Disney. But the MCU isn’t the only movie franchise that has reaped the rewards at the box office in the last 20 years.Reddit user /u/rebellious_scum captured North American box office sales for some of the biggest movie franchises over the last 20 years, starting from May 1999 (release of Star Wars: Episode 1) to April 2019, as reported by movie data website The Numbers, in a cool, mesmerizing animation.The animation also visualized daily ticket earnings for X-Men, The Fast and Furious, The Lord of the Rings and Harry Potter movies, which all started to rise up in the early 2000s.But according to the Visual Capitalist, the clear takeaway from the animation is “Marvel’s exponential earnings growth since it debuted with Iron Man in 2008.”As of April 4, the MCU franchise had earned (inflation-adjusted) revenue of $7.63 billion, which is almost double that of runner-up Star Wars. And that doesn’t yet take into account account data from the record-shattering April 26 release of Avengers: Endgame.Using the animation’s numbers, the Visual Capitalist further breaks down the average revenue per movie, with Star Wars and Middle-earth topping the list . Meanwhile, Marvel lands in third place, followed by Pirates of the Caribbean, the Wizarding World, and the DC Extended Universe (DCEU).Marvel’s dominance at the box office can be boiled down to Disney/Marvel’s ability to produce movies at breakneck speed, according to Visual Capitalist. For example, in 12 years, Marvel Studios has produced 22 movies including Avengers: Endgame, while the James Bond franchise has produced 24 movies since its inception 57 years ago in 1962.More on Geek.com:Bernie Sanders to Disney: Use ‘Avengers’ Profits to Pay Workers MoreRami Malek Is Your Next ‘James Bond’ VillainDon’t Expect New Star Wars Movies After ‘Episode IX’last_img read more

Its 2019 and John Romero Is Giving Away New Doom Levels

first_imgStay on target Sorry, You Can’t Date Keanu Reeves in ‘Cyberpunk 2077”Star Wars Pinball’ Has Your Favorite Brand in Ball Form Update: It’s 2019, and John Romero’s new Doom levels, “Sigil,” are available nowOne of the biggest gaming surprise of the last few years was that the reboot of Doom was not only good, not just great, but arguably the best game of that year. Somehow the new Bethesda-owned version of iD had managed to capture the spirit of the monumental demonic first-person shooter while also making it a game that felt acceptable in 2016, not 1993. So now the sequel Doom Eternal is by far one of our most anticipated upcoming games.However, that’s no longer the only upcoming Doom content we’re looking forward to. Doom co-creator John Romero, he of luscious hair and love for The Devil, has revealed that he is making and giving away bloody brand new levels for the original PC Doom next February.Set before Doom II and pitched as a “spiritual successor to the fourth episode of Doom,” Sigil contains nine chunky new single-player campaign missions as well as nine deathmatch arenas all for free. It’s pretty much an expansion pack. Remember those? Continuing the retro feel, Sigil will be distributed using the same classic WAD and MEGAWAD files Doom modders used to share custom content back in the day. And the physical version comes on USB drives designed to look like old-school floppy disks.How would you even get a physical copy of Sigil? Romero’s previous new Doom levels from a few years ago were just online. But considering the scope of Sigil, and its timing with Doom’s 25th anniversary, Romero is partnering with Limited Run Games to offer physical “fan boxes.” Along with the game the fan box includes a metal soundtrack from Buckethead and absolutely Satanic artwork from Christopher Lovell.Whether you get the fan box or not, Sigil will be available to everyone in February 2019. John Romero may not be with iD anymore, but he’ll always be a unholy part of Doom. For more on Doom, check out our thoughts on Doom Eternal as well as Doom’s leaps to platforms like VR and the Nintendo Switch.last_img read more

Heres 20 Off a Fully Playable Mini Tempest Arcade Machine

first_img Tempest is one of the most celebrated arcade games ever produced. It was revolutionary for its time, offering a gameplay experience like no other. And that’s what makes this 1:6 scale playable Tempest arcade machine so exciting, especially since it’s on sale for just $99.99.It was all the back in 1981 that Tempest first hit arcade floors. What helped make it an instant classic was the fact that it offered 3D vector graphics and it gave players the option to skip levels they’d already mastered. The unique triangular aesthetic of the game cabinet was also a draw and continues to be a source of nostalgic euphoria for those that remember playing it.And that’s why original Tempest arcade cabs continue to be in high demand. Unfortunately, finding an original in working condition is difficult and, if you do happen to locate one, you can expect a huge price tag to be attached to it. That puts the ownership of an original cab out of reach for most, which is what makes this scale replica so exciting.From the folks at RepliCade, this 1:6 scale Tempest arcade cab is a fully playable work of art. It matches every aspect of the original in stunning detail. The angles of the cabinet are accurate, the side artwork is perfect, and even the marquee and coin slots light up.And, though the cabinet is scaled down significantly, it still manages to offer a gameplay experience that’s just like the original. It features modern controls that are as responsive as can be and the high-resolution screen will let you see even the smallest objects in great detail. The cabinet itself is made with wood and metal for durability and the game ROM is officially licensed from Atari.Never played before? Then this is a fantastic opportunity to experience what it was like to play Tempest in an arcade. To win, players rotate a gun around the edge of a geometric playing field and shoot enemies as they approach. The geometric shape of the playing field changes from level to level, becoming progressively difficult. Which was really unique for the time, as most other games — like Pac-Man — maintained the same playing field throughout.Start collecting your quarters because this vintage styled arcade cabinet would look great in any games room, office, or bar. Get your game on and save 16 percent off the cost of the Tempest 1:6 scale playable arcade machine, available now at the Geek Shop for just $99.99. Stay on target This $500 SEO Tool Is Only $24 TodayThis Easy-to-Fly LED Drone Performs Acrobatic Moves center_img Tempest x Replicade 1:6 Scale Playable Arcade Machine – $99.99See Deallast_img read more

This Game of Thrones Star Predicted How the Series Would End in

first_img ‘Game of Thrones’ Targaryen Prequel Series Is Reportedly Coming to HBO‘Game of Thrones’ Star Kit Harington Joins Marvel’s &#… Stay on target Some fans are still puzzled over the Game of Thrones finale, however, Finn Jones, the actor who played Ser Loras Tyrell on the series, predicted the show’s mind-bending ending back in 2015.Jones reportedly discussed many ending plots four years ago, including the Iron Throne’s fate, People.com reported. The actor spoke about what he wished for in his last scenes and who he thought would help rebuild Westeros on Game of Thrones in a 2015 interview with Vulture.“You need to get rid of that Throne. That’s what I’d like to see at the end of the series, but that’s very utopian,” Jones told Vulture in the interview. “We’ll see.”Jones also hoped that Bran Stark would rebuild the seven kingdoms by the end of the series, and perhaps work with a small council that would include Tyrion Lannister, Brienne of Tarth, and some of the Tyrells.“My hope for Westeros is that Bran [Stark] dissolves the Iron Throne; he gives the power back to the individual realms. Him, his Small Council, which would be Brienne, Tyrion [Lannister], and maybe some of the Tyrells, because I’m biased,” Jones explained. “But they will try to keep the peace, after this devastating war has struck Westeros and killed a lot of people.”On what would happen to his own character, Jones said “Even if Loras [Tyrell] is imprisoned, I would like to see him get disfigured by the Sparrows, the same way he gets disfigured at Dragonstone with the boiling oil. I think that would be really interesting, because the only thing he has left are his looks and his ostentatiousness. And that’s been stripped from him.”Even though Jones’ character perished when the Great Sept of Baelor was destroyed, his predictions about the Game of Thrones finale were almost accurate: The Iron Throne is destroyed by one of Daenerys Targaryen’s dragons after she is killed by Jon Snow and Bran Stark becomes the new ruler of the “six” kingdoms, with the assistance of a helpful squad including Brienne of Tarth and Tyrion Lannister. So, not a bad way to conclude the series that ran for almost a decade.<span data-mce-type=”bookmark” style=”display: inline-block; width: 0px; overflow: hidden; line-height: 0;” class=”mce_SELRES_start”></span>More on Geek.com:‘Game of Thrones’ Fans Raise More Than $125K for Casts’ Charities Sophie Turner Shocked By ‘Game of Thrones’ Spoiler in Season 1 Poster ‘Game of Thrones’ Star Says Twist Ending Was George R.R. Martin’s Idealast_img read more

Watch Rude Alligator Crashes Couples Picnic Date in Florida

first_img Watch: Here’s How Florida’s Gatorland Is Preparing for Hurri…Alligators Spotted ‘Swimming’ in Road, Climbing Fences in Florida In Florida, a couple’s cute picnic date turned into a hair-raising situation when a hangry alligator decided to interrupt their intimate hangout and gobble up all their food, including some guacamole.On Thursday, Taylor Forte planned the date with her fiancé Trevor Walters near Lake Alice in Gainesville, Florida, CBS4 Gainesville News reported. When they were about to enjoy their feast, the pesky alligator swam up to the bank and sprinted to their picnic site.The couple immediately left the blanket and watched the alligator nosh on their picnic goodies.“He annihilated an entire block of cheese,” Walters said in an interview with Fox4 News. “Gobbled it down, lickity split. The salami didn’t stand a chance.”But, that wasn’t all: The alligator then ate half a watermelon, a pound of grapes, and a fresh batch of guacamole.A Florida couple, enjoying a nice picnic by the lake, got a surprise from an unwanted guest. #FOX35 https://t.co/GMppQE2aBS— Fox 35 News (@Fox35News) June 3, 2019Walters proceeded to make a lot of noise and distract the alligator, who eventually ran back into the water.“Unfortunately it sounds like that gator has been fed previously and has lost its weariness of people and is beginning to associate people with food,” Karen Parker with the Florida Fish and Wildlife Conservation Commission (FWC) told CBS4 Gainesville News.Parker warned people to not feed alligators, because they become a big issue for people and have to be removed by the FWC for safety reasons. If there is an annoying alligator, Parker urges a quick phone call to the FWC (866-392-4286) for assistance.More on Geek.com:8-Foot Alligator Spotted Hiding in Hallway of Florida Elementary SchoolMassive, 11-Foot Alligator ‘Breaks Into Home’ at 3 A.M. in Florida 10-Foot Alligator Takes Late-Night Stroll Across Florida Highway Stay on targetlast_img read more

Heres What Happened When Scientists Strapped Cameras to Cats

first_img Watch: Dolphin Leaps Feet Away From Unsuspecting SurferWatch: Deep-Sea Octopus ‘Billows Like a Circus Tent’ Since cameras have become smaller and more portable, scientists have been attaching them to animals — everything from sharks (to see how they hunt for prey) to penguins (to see how they communicate with each other in the icy waters off Antarctica).However, researchers haven’t much done with cats as they could be difficult to work with, according to Science magazine. One ecologist is trying to change that with a new study involving 16 cats and 16 small cameras.Maren Huck, behavioral ecologist at the University of Derby in the United Kingdom, attached small cameras on 16 cats and followed them for up to four years as they prowled their neighborhoods.Her findings, published in the journal Applied Animal Behavior Science, provided some interesting insights on the behavior of felines.For one, they’re not lazy as you think. “Cats are seen as relatively lazy, especially compared to dogs. But we saw that when they were outside, they became superalert,” Huck told Science magazine.  “They scanned their surroundings, sometimes for a half-hour or more on end.”They could also be quite sociable. “[Even] though cats are highly territorial, they didn’t always fight with other cats they encountered,” said Huck. “Often, they just sat a couple of meters away from each other for up to a half an hour. They may have been sizing each other up. Sometimes they would engage in a greeting, briefly touching noses.”The ecologist also told Science magazine cameras could also help provide more insight on how to improve their quality of life as pets. “There is also debate over whether cats should be kept indoors all the time. If we find that cats seem more bored or stressed out when kept indoors — for example, by pacing, like some animals do at the zoo —that means we need to think more about enriching their indoor lives, or giving them some outside time,” Huck said.More on Geek.com:Scientists Attach Cameras to White Sharks to Watch How They Hunt Their PreyHere’s What Happened When Scientists Left Camera Traps to Record Wild ApesEgyptian Fruit Bats Trade Food for Sex, Study Finds Stay on targetlast_img read more

Bethesda Has Doom Eternal and Some Other E3 2019 Games We Guess

first_imgStay on target Watch: Marvel and Square Enix’s ‘Avengers’ Gameplay Still Creeps Us OutPlay These E3 2019 Video Games Right Now It’s not that Bethesda doesn’t have cool new video games to show. It’s just when the publisher tries to fill an entire E3 press conference with its upcoming lineup, things start to feel a little bit like filler. And that’s before the constant cheering interruptions. Before you ask, no, we didn’t hear anything about Starfield or The Elder Scrolls 6 aside from Todd’s confirmation that they still exist.Instead, we got updates on already released games like new content for The Elder Scrolls Online and Elder Scrolls Legends. Rage 2 got a Too Many Cooks-style parody sitcom trailer to showcase new weapons, enemies, and cheat codes. On the mobile game front, deep cut Id Software throwback Commander Keen is returning as a cute but unfortunately free-to-play game. And Elder Scrolls Blades is coming to Nintendo Switch, which is cool but perhaps a little redundant considering you can already play Skyrim on that device.The Bethesda game most in need of an update though is Fallout 76 which launched last year in very rough shape. It’s weird to even say this, but the Wastelanders update brings back NPC quests and dialogue options and this was treated like a huge deal, not the game being brought up to the standard it should’ve been all along. At least it’s free. The game is also getting a battle royale mode, Nuclear Winter, because hey why not?When it comes to big console games though Bethesda’s future does look pretty bright. In just a few weeks we’ll get to slay Nazis in the 1980s as B.J.’s twin daughters, the stars of Wolfenstein Youngblood. Also on July 26 Wolfenstein Cyberpilot brings the series to VR. We didn’t see gameplay of GhostWire Tokyo from Tango Gameworks or Deathloop from Arkane. But both trailers impressed with their creepy Japanese ghost vanishing and stylish 1960s time repeats, respectively. For more on E3 check out what Microsoft said about the next Xbox and watch these trailers. But really the reason to stick around with this Bethesda show was to see new gameplay of Doom Eternal. This religious experiences sees the Doom Slayer fighting demons through Hell, Mars, Earth, and maybe even Heaven itself? It looks great. Even the multiplayer seems worthwhile this time. In this asymmetrical fight, two wily demons take on one powerful slayer. Doom Eternal launches November 22. And if you haven’t played the first one you’ll be able to stream it soon through Bethesda’s new Orion technology.last_img read more

DOC Reports Death Of Seward Inmate

first_imgFacebook0TwitterEmailPrintFriendly分享An inmate from Spring Creek Correctional Center in Seward died while in custody on Saturday, February 24, according to the Department of Corrections. At this time the cause of death is still be investigated by the state Medical Examiner’s Office and Alaska State Troopers.  This marks the first Alaska DOC death for 2018. According to courtview, Iyapana has been in custody since September 2007, serving time on the charges of first-degree sexual assault, as well as second-degree and fourth-degree assault. Romeo Iyapana, age 30, was pronounced deceased at Alaska Regional in Anchorage after he was taken to prison’s medical ward for evaluation before being transported to Seward Providence Medical Center. A short time later, Iyapana was flown to Anchorage for further medical treatment. According to reports, Iyapana began demonstrating concerning medical symptoms Saturday morning while housed in a cell alone at the correctional facility.last_img read more

Mercedes XClass pickup might be ready to kick the bucket report says

first_img 2018 Mercedes-Benz X-Class puts some fancy trim on your cowboy boots 2020 Volvo XC60 T8 Polestar Engineered first drive: Almost Super Trouper Enlarge ImageGood night, sweet prince, we hardly knew ye. Mercedes-Benz If you live in the US and don’t pay particularly close attention to car and truck models that aren’t sold here, you could easily be forgiven for not knowing that Mercedes-Benz makes a pickup truck. It’s called the X-Class, and it’s actually pretty cool.Unfortunately, it may not be long for this world if a report published Tuesday by Automotive News Europe is to be believed. The reason for the possible demise of the X-Class is the current worldwide sales slump for new vehicles. The X-Class, being kind of a niche product — and a badge-engineered one at that — is an easy target for cost savings. Yep, we said badge-engineered. The X-Class is based on a Nissan pickup (that we also don’t get in the US) called the Navara. Obviously, Mercedes being what it is, it changes a ton of stuff, so it’s not quite as bad as say, Volkswagen rebadging a Grand Caravan as the Routan.In any case, the X-Class (which has been around since 2017) hasn’t exactly been flying off of dealer lots. Automotive News Europe pegs the global sales for the model at just 16,700 units. By comparison, Mercedes shifted around 15,000 S-Class models in 2018 in the US alone.When you consider that the S-Class costs more than twice as much as an X-Class (based on German market prices) and sedan sales are in the proverbial terlet here, the model’s discontinuation starts to make some real sense.Now, we’ll shed no tears for the X-Class if and when it goes away, but we do like the idea of a Mercedes pickup. We just need to convince the folks back in Stuttgart to do some really wild stuff like make a Jeep Gladiatoresque version of the G-wagen and sell it in America. 0 Share your voice 48 Photos Mercedes-Benz Nissan 2019 Nissan Pathfinder Rock Creek Edition first drive: Its roots are showing Tags 2020 Kia Soul review: Well-rounded box 8:42 Now playing: Watch this: Trucks Car Industry Post a comment 2019 Mercedes-AMG GT53 4-door: A fancy-pants muscle car Mercedes-Benz More From Roadshowlast_img read more

Find Out Which Stations In your Area Have Gas With The Gas

first_imgPlease visit the GasBuddy website or consider downloading the GasBuddy app. Gasoline prices rose several cents overnight amid continuing fears of shortages in Texas and other states in the aftermath of Hurricane Harvey’s strike on the Gulf Coast. The national average for a gallon of regular gas rose in one day from $2.45 Thursday to $2.52 Friday, the American Automobile Association reported.If you are worried that gas stations in your area are running low, use the tool below to see which stations still have gas.  Sharelast_img read more

Netflix Hikes Price of US Streaming Service Standard Plan Jumps to 13

first_imgNetflix is flexing its pricing-power muscle to kick off 2019 — hiking fees for all streaming-video plans for customers in the U.S.Netflix’s most popular plan, the Standard tier that offers two HD streams, is increasing 18%, from $10.99 to $12.99 per month. The Premium plan, which provides up to four Ultra HD streams, is increasing from $13.99 to $15.99 per month (up 14.3%). In addition, the company for the first time is hiking its Basic plan, which offers a single non-HD stream, from $7.99 to $8.99 per month (+12.5%).The new prices, which are the biggest fee hikes in Netflix’s history, will apply to all new Netflix subscribers in the U.S. immediately. Existing subscribers will be moved to the new pricing plans “over the next few months,” according to the company. Netflix’s price increases also will extend to about 40 countries in Latin America where it bills in U.S. dollars, including Uruguay, Barbados, and Belize. However, the rate hikes will not take effect (for now) in the region’s biggest markets, Mexico and Brazil. The boost in revenue from the price increases could help “ease concerns” for investors about Netflix’s growing free-cash-flow deficit, CFRA Research analyst Tuna Amobi wrote in a research note reiterating a “buy” rating on the stock. “We anticipate a relatively seamless implementation of the latest price hike, given [Netflix’s] significantly expanded content offerings relative to its competitors’ pricing,” he wrote.At $12.99 per month, Netflix’s Standard plan will be more than Hulu’s ad-free option (currently $11.99) and Showtime’s streaming service ($10.99) but still less than HBO Now ($14.99). More competition is looming: Later this year, Disney plans to bow the “Disney+” service and WarnerMedia is plotting a movie-driven subscription streaming offering, but pricing for those hasn’t been announced. ×Actors Reveal Their Favorite Disney PrincessesSeveral actors, like Daisy Ridley, Awkwafina, Jeff Goldblum and Gina Rodriguez, reveal their favorite Disney princesses. Rapunzel, Mulan, Ariel,Tiana, Sleeping Beauty and Jasmine all got some love from the Disney stars.More VideosVolume 0%Press shift question mark to access a list of keyboard shortcutsKeyboard Shortcutsplay/pauseincrease volumedecrease volumeseek forwardsseek backwardstoggle captionstoggle fullscreenmute/unmuteseek to %SPACE↑↓→←cfm0-9Next UpJennifer Lopez Shares How She Became a Mogul04:350.5x1x1.25×1.5x2xLive00:0002:1502:15 “We change pricing from time to time as we continue investing in great entertainment and improving the overall Netflix experience,” a company spokeswoman said in a statement.Netflix shares rose up as much as 6.8% in morning trading Tuesday on news of the price increases, with investors bullish on the evidence of its growing market clout.The company is looking to boost top-line revenue to offset its ballooning content costs, which were projected to hit $13 billion on a gross basis in 2018. To fund its content-spending binge, Netflix has raised billions in new debt: It reported $8.34 billion in long-term debt as of Sept. 30, up from $6.50 billion at the end of 2017. It’s also continuing to burn cash, and most recently projected negative cash flow of more than $3 billion for 2018 (versus negative free cash flow of $2 billion a year prior).Netflix last raised rates in the fourth quarter of 2017 — two years after its previous hike — and faced minimal cancellations and no slowdown in net subscriber additions. It remains to be seen how the new price increases affect subscriber growth heading into 2019. Netflix is scheduled to report Q4 2018 results on Thursday, Jan. 17.According to Netflix, existing members will be notified by email and within the Netflix app 30 days before the new prices are applied to their accounts. The exact timing will depend on a specific member’s billing cycle.Netflix had 58.4 million U.S. customers as of the end the third quarter of 2018, with a worldwide total of 137.1 million streaming members.Wall Street analysts have believed Netflix has demonstrable leeway to safely raise fees without the risk of significant backlash. Greg Peters, the company’s chief product officer, said on Netflix’s quarterly investor interview last October that “we earn the right to increase price a bit” if the company keeps delivering on customer expectations.“[W]e earn the right to increase price a bit and then we take that new revenue, invested back into the model and that sort of continuous positive cycle we get to keep going, and we foresee that that will keep going for many years in the future,” Peters said. Popular on Variety last_img read more

Radioisotope studies show the continental crust formed 3 billion years ago

first_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. More information: “Emergence of modern continental crust about 3 billion years ago” Nature Geoscience, 2015. DOI: 10.1038/ngeo2466AbstractThe continental crust is the principal record of conditions on the Earth during the past 4.4 billion years. However, how the continental crust formed and evolved through time remains highly controversial. In particular, the composition and thickness of juvenile continental crust are unknown. Here we show that Rb/Sr ratios can be used as a proxy for both the silica content and the thickness of the continental crust. We calculate Rb/Sr ratios of the juvenile crust for over 13,000 samples, with Nd model ages ranging from the Hadean to Phanerozoic. The ratios were calculated based on the evolution of Sr isotopes in the period between the TDM Nd model age and the crystallization of the samples analysed. We find that the juvenile crust had a low silica content and was largely mafic in composition during the first 1.5 billion years of Earth’s evolution, consistent with magmatism on a pre-plate tectonics planet. About 3 billion years ago, the Rb/Sr ratios of the juvenile continental crust increased, indicating that the newly formed crust became more silica-rich and probably thicker. This transition is in turn linked to the onset of plate tectonics5 and an increase of continental detritus into the oceans. Earth’s crust slowly being destroyed © 2015 Phys.org One of the difficulties with determining the age of the Earth’s crust is that the crust itself is constantly undergoing melting and re-deposition due to subduction. This is a larger factor for the ocean floor than in continental crust because the continental crust is thick and buoyant, making it less susceptible to subduction. By combining information from various radioisotope pairs found in the continental crust, one can unearth clues as to how the crust was formed and when. In this paper, Dhuime, et al. studied the abundance of rubidium compared to strontium. Rubidium (87Rb) becomes strontium-87 (87Sr) through radioactive decay. Strontium-87 has a half-life of 48.8 billion years. Strontium-86, the most abundant isotope of Sr, is stable and does not undergo radioactive decay. Therefore, the abundance of 87Sr in the continental crust can be traced to the radioactive decay of 87Rb, and based on its half-life, one can determine the age of a rock sample.Whenever the Earth’s crust re-melts or is formed from magma deposition, the amount of 87Rb and silica increases in the residual melt, but the amount of 86Sr does not. Consequently, 87Rb/86Sr correlates with silica content. The silica content is important because the composition of the continental crust is predominantly silica, while the early Earth’s crust was likely mafic, or composed of predominantly iron and magnesium. To calculate 87Rb/86Sr, Dhuime, et al. first determined the 87Sr-to-86Sr ratio and then determined what the ratio was at the time when the crustal melt crystallized. From this they were able to calculate 87Rb/86Sr and therefore determine the amount of silica present at various time periods.This calculation was performed for over 13,000 volcanic and plutonic rock samples of varying ages, based on neodymium model ages. Results show that at about 3 billion years ago the Earth’s continental crust transitioned from a mafic crust to a silica-rich crust. Silica content increased from 3 billion years to 1 billion years ago. At 1 billion years, the amount of silica started to gradually decrease. This result coincides with previous studies using other radioisotope ratios. Furthermore, Dhuime, et al.’s data show that there is a positive correlation between the increase in 87Rb/86Sr and silica and crustal thickness. The authors point out that the gradual increase of 87Rb/86Sr from 3 billion years to 1 billion years may indicate that the Earth’s continental crust was thickening. They estimate that the average thickness of new continental crust increases from ~20 km at 3 billion years ago to ~40 km at 1 billion years ago, and then decreases to ~30 km to the present.Since subduction is a result of plate activity, the transition at 3 billion years may also indicate the onset of plate tectonics. The thickness of new continental crust reached a maximum and then began decreasing. The authors point out that this may coincide with the time of the Rodinia supercontinent and mountain formation.Overall, this study provides compelling evidence that the continental crust formed 3 billion years ago, coinciding with the onset of plate tectonics. Additionally, silica content could be used as a metric for determining crust thickness over time. Journal information: Nature Geosciencecenter_img (Phys.org)—New research sheds light on how and when the modern day continents began to form. Researchers from the University of Bristol analyzed radio isotope abundances in 13,000 samples of continental crust of varying age and found that the continents began to form around 3 billion years ago. This date may coincide with when plate tectonics began. Their research appears in Nature Geoscience. Citation: Radioisotope studies show the continental crust formed 3 billion years ago (2015, July 3) retrieved 18 August 2019 from https://phys.org/news/2015-07-radioisotope-continental-crust-billion-years.html Explore further Variation in the thickness of juvenile continental crust through time. Credit: (c) 2015 Nature Geoscience, 2015. doi:10.1038/ngeo2466last_img read more