Our local NSF geoscience education guru, Jill Karsten, is retiring. She and her husband, Rodey Batiza, are packing up their lives and moving back home, vacating the Beltway for good. This might be viewed as a shame as far as geoscience education funding is concerned: Jill has made her mark acting as an advocate of … Read more
Lockwood Dewitt is the purveyor of this week’s Friday fold ensemble: All these folds are primary (not tectonic) in nature: they are flow banding of the viscous lava that oozed out to make the Big Obsidian Flow at Newberry. And closer in: One more: Awesome stuff! Thanks for sharing, Lockwood! Happy Friday, everyone!
I was in Tucson this past weekend for a book project meeting, and my editor and coauthor and I took a hike on Sunday morning in the Tucson Mountains to Wasson Peak. Not far from the summit, we saw an epidotized tuff, where the fiamme and pumice blobs had undergone reactions to produce pods of … Read more
One last post from my September trip to Greece. Here’s a look north along the inside wall of the central caldera of Santorini, taken from the deck of the Santos Winery. It’s not hard to imagine the volcanic edifice that filled the space to the left (west) prior to The Big One.
Here is the view north across the central caldera of Santorini, Greece: Click to enlarge to 9000 pixels wide This caldera formed during the Bronze Age, maybe as early as 1628 BCE or so, maybe as late as 1500 BCE. There are new volcanic islands rising in the center.
Santorini is an island with nice exposures of the Tethyan subduction complex, yes. But did you know there’s also a volcano there? 🙂 Here’s a shot of some snorkelers, with a lovely stack of pyroclastics rising up behind them. Ash, lapilli, more ash — Santorini’s volcano has been very active over the years. This is … Read more
While in Santorini, Greece, your humble geoblogger braves a warm afternoon to search the hillsides for evidence of subduction.
A series of blog posts on the geology of Santorini and Athens, Greece begins with a look at a sea arch on the south shore of Thera.
On “Border to Beltway”‘s visit to Kilbourne Hole, after we whet our appetite with Hunt’s Hole, Michael finds a xenobomb. Ernie and Boris look on with envy: A “xenobomb” is a xenolith (in this case, of mantle peridotite), slathered in a coating of lava and tossed out of a volcano in the middle of a … Read more
Check out the immense climbing ripples preserved in surge deposits at Hunt’s Hole (a maar volcanic crater in southern New Mexico) and imagine the strong currents couples with an extraordinary amount of entrained pyroclastic material.