September 29, 2014 | David F. Coppedge

Earth as a Habitable Planet

When viewed as a planet among planets, Earth is surprisingly surprising, considering how close it is to scientists’ investigating eyes.

No hell on EarthAstrobiology Magazine claims that the “Hadean Era” of the early Earth was not as “hellish” as previously thought.  Historical geologists at Vanderbilt have questioned the conventional wisdom, but the article admits there have been two schools of thought.  “Our conclusion is counterintuitive,” says Calvin Miller of Vanderbilt, defending his team’s new view. “Hadean zircons grew from magmas rather similar to those formed in modern subduction zones, but apparently even ‘cooler’ and ‘wetter’ than those being produced today.”

Natural fracking:  A “strange” sandstone formation in Colorado along the Rocky Mountain’s front range has baffled geologists.  Live Science calls it a case of “natural fracking” that injected fluid sand into bedrock (usually, intrusions occur the other way, igneous into sedimentary).  Science Magazine says the dates (based on zirons) of this Tava Formation make it older than the Rockies themselves.  It will change geologists’ perspective on the hypothetical supercontinent of Rodinia.

Gravity tectonics:  How did plate tectonics get started?  “How this gargantuan process got started on early Earth has been quite a mystery,” reporter Jesse Emspak wrote for Live Science.  The traditional theory has been that convection started spreading the continental plates around.  Now, a new computer model says that gravity was up to the job, the article says.  “There is still work to be done – it’s a computer model – but Rey thinks it goes some way to help explain the composition and structure of the current crust.”

Shaking up the uplift:  A geologist from Tulane is “shaking things up” about the formation of steep mountains, PhysOrg says.  “Nicole Gasparini was going upstream against a major trend in geologic research,” the article begins.  “Many geologists ascribe to the popular hypothesis about the formation of very steep mountain ranges: that a wet climate and heavy rainfall on one side of a mountain range are needed to drive erosion and uplift the mountain to high elevations.”  The classic case has been the Andes.  When Gasparini tested the idea with models, she didn’t see climate being a factor (even though, ironically, she never has visited the Andes).  Her ideas put “rain on the parade” of the leading theory, the article says

Going against the flow:  Models of river flow have been too simplistic, a group of geologists found on a 486-km raft trip down the Fraser River in Canada.  Nicole Gasparini described this paradigm-shifting work in Science Magazine about a paper by Venditti et al. in the same issue.  Rivers in steep-sided canyons don’t just cut straight down uniformly.  All kinds of turbulent effects, including swirling eddies, have significant effects on the walls of canyons and the shapes of riverbeds.  “The results call for a re-evaluation of how waterways carve through bedrock to form canyons,” Gasparini says.  See also PhysOrg and Science Daily.

Jesus had some words about geology.  He warned those who build their lives on the shifting sands of man’s opinions instead of the solid rock of His word (Matthew 7:24-29).

 

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