#californiageology

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I love the San Onofre Breccia! Thought to be an ancient landslide, it contains so much variety. Jagged fragments of black schist, greenstone, white quartz, and the beautiful glaucophane schist displaying lavender and purplish tones, all spliced up by dikes of calcite while the tenacious Pacific sculpts interesting formations within it. #geology #geologizing #lagunabeach #breccia #sanonofrebreccia #beach #hiking #optoutside #pacific #california #californiageology #earth #nature #schist #naturephotography #erosion
I’ve got more cool Franciscan rocks coming but for some more background info of what’s going on, here’s a look at a computer modeled subduction trench showing the down-going ocean slab in green, accretionary wedge in orange at top, high pressure areas in bright pinks (not the grayish pink mantle at bottom) are in the swirled mixture of obducted rocks (those rocks returning to the surface) that are wedged between the down-going green slab and the continental slab above (light green and sitting on top of dark green basalt). These obducted rocks are the rocks I’ve been collecting and they consist of blocks of variously fresh, retrograded, altered and weathered high-pressure low-temperature rocks as well as less-metamorphosed oceanic crustal rocks (metabasalts) all swirled and mixed into matrix rocks the blocks are found in (serpentinite, phyllite, greywacke) ...and I’ve also found a few high grade metamorphics that were scraped off the bottom of the continental crust. These rocks form in a high-temperature high-pressure environment commonly found beneath continents. It’s a great combination of lithologies that can only be seen at the tops of subduction zones. There’s also a map showing major locations for this rock assemblage which include active subduction zones like the Ring of Fire and much older sutured areas where extinct subduction zones are found on continents (e.g. Brazil, Ural Mtns in Russia, the Himalaya arch) and the Caledonide Orogeny (an ancient suture now split apart by the opening of the Atlantic Ocean). Last map is a simplified map of California showing where the Franciscan rocks are located. #geologistonboard #californiageology #ophiolite #serpentine #basalt #blueschist #eclogite #platetectonics #geology #geologia #earth #map #franciscansubductioncomplex #rocksrock #geogyrocks #roadtrip
Sometimes we tend to see dikes as veins through the rock because we can’t see the third-dimension on a rock surface, but here’s a great example of a dike edge-on appearing more like a sheet. The latter is how we should remember to see them. This is a calcite dike through San Onofre Breccia. The sheets create perfect erosional fracture points and when fragments fall like this one, the dike sheet is nicely exposed. #geology #geologyrocks #lagunabeach #dike #geologizing #breccia #sanonofrebreccia #beach #erosion #nature #earth #california #californiageology #naturephotography #hiking #optoutside
Another wet FSC Franciscan Subduction Complex creek cobble ...I’ve got lots of them! This one appears to be blueschist fragments swirled thru ductile deformation at depth with something hard n white ..silica or massive grossular garnet or maybe a semi-jadeite??? 🤷‍♀️ ...and I think there’s also some retrograding peridotite clasts which are now fully altered to black serpentinite full of white veins. There is minor aragonite filling some fractures. I’ll show why I think the black used to be peridotite in the next post. #geologistonboard #franciscansubductioncomplex #californiageology #platetectonics #petrology #blueschist #serpentinite #subductionzone #structuralgeology #geoscience #geology #geologia #creekwalking #wandering #geologyrocks #highpressuremetamorphism #franciscanassemblage
...another of my recent FSC Franciscan Subduction Complex cobble finds. This rock is so sparkly full of mica (probably phengite) which doesn’t show at all in the pics and it’s a dreamy ductile swirl of blues n greens with some red garnets. The surface protolith (rock before metamorphism) was most likely oceanic seamount or spreading-ridge basalt. It’s been prograde metamorphosed on its way down the subduction channel probably to high pressure eclogite facies then retrograded back down to blueschist w garnets and some yellow-green greenschist minerals like epidote n chlorite. Some high pressure higher temperature amphibolite could have also formed then retrograded back down to the deep true-green swirls of greenschist facies as well (actinolite). The retrograding occurred deep enough for the two rocks to co-mingle into these swirls. Then it was rapidly exhumed to the surface with no brittle deformation and entrained into a sedimentary mélange (olistostrome) where it sat until erosion thru the softer unmetamorphosed mélange exposed it ..then it rapidly tumbled down a steep creek into this beauty. That’s my best preliminary explanation for the story of this rock using only this hand sample ...to add details or other possibilities I would need to make thin sections and look under the optical microscope and run other diagnostic tests #geologistonboard #franciscansubductioncomplex #californiageology #franciscanassemblage #platetectonics #blueschist #greenschist #metamorphic #ductiledeformation #structuralgeology #petrology #creekwalking #hiking #geology #subductionzone #explore #instacool #geologia #geoscience #geologyrocks
Imprints in siltstone always grab my eye, but I’m not sure if my brain is turning these imprints into trace fossils or if they are, in fact, trace fossils. What do you think? Do you see hoof tracks? #geology #geologizing #siltstone #california #californiageology #sedimentary #tracefossils #optoutside #hiking #earth #nature #naturephotography
Can’t believe I’m a native second generation PG and never saw California’s Old Faithful before. Yeah it’s technically not a real geyser in that it was drilled years ago, but it’s been operating in its own for forever now. And yeah it’s $15 but even Yellowstone has an entrance fee. It’s awesome and it goes every 5-15 min!! Take that Wyoming and New Zealand!! It’s a must see!! Calistoga rules!!! #oldfaithfulgeyser #californiageyser #californiaoldfaithfulgeyser #californiageology #geologyrules #calistogageyser #californiaprofessionalgeologist
Metabasalt (metabasite) and aragonite cobble I recently found ...brecciated basalt in white aragonite (pressure conversion from carbonates) ...from a sedimentary mélange in the central belt of the Franciscan Subduction Complex. This formed (I think) in low temp and low-moderate pressure conditions in the shallow brittle zone of the subduction channel where rocks shatter (no ductile deformation). Then in the non-shattered basalt you can see parallel tension cracks! ...so although compression clearly dominates, this shows tension occurring also (probably in between waves/pulses of compression) #geologistonboard #californiageology #fieldgeology #structuralgeology #basalt #metabasalt #breccia #
Here’s the first of my wild cobbles (wet) from a mélange zone in the Central Franciscan Subduction Complex. This rock blows me away!! They are mostly garnet-free blueschist (I think) with all kinds of alteration and ductile deformation and retrograde metamorphism going on. The matrix for the mélanges in this area is either a phyllite or greywacke (both of which are relatively undeformed!!) and nothing like the matrix here ...so I think this cobble is a representation of what is going on tectonically deep in the subduction channel 😲 and as these exotic high-pressure blocks of rock travel back up the channel to become entrained in the sediments of the accretionary wedge at the top of the subduction zone. What do y’all think?!?! 🤔...lots more of these coming! #geologistonboard #californiageology #franciscansubductioncomplex #franciscanassemblage #platetectonics #metamorphicrock #blueschist #greenschist #wild #wildrocks #structuralgeology #highpressuremetamorphism #earth #bluerocks
Lawsonite eclogite named after the Scottish geologist who named both the San Andreas Fault and the Franciscan Formation (now renamed). He also built the first earthquake proof in The SF Bay Area! I collected it in Tiburon, Marin County, California -I got 3 small HEAVY boulders from a fresh rip rap pile before it was all sadly buried during a construction project 💪🏼 ⚒ ...continuing the Franciscan Subduction Complex Chronicles: For about 70 million years (170-100 mya) basalt of the Pacific Ocean floor was traveling down several successive (now extinct and stacked up against one another) subduction zones along the west coast of North America, staying relatively cool and metamorphosing to blueschist as the pressure increased with depth. As the blueschist continued the travel and reached depths near the mantle where pressure and temperature are both high (but not quite high enough to melt the rock) it metamorphosed to eclogite -an ultra-high pressure UHP rock. The ratio and size of minerals here varies within the crude layering ..green omphacite pyroxene, red garnets, shiny flat white phengite mica, tiny blue lawsonite and a few other trace minerals. Most of the eclogite in a case like this continues to travel deeper into the mantle where it will melt and mix with mantle peridotites to create hot magma mixtures that will rise to form all combinations of plutonic (granitic +) and volcanic rocks. ...but small amounts of peridotite, eclogite and blueschist rise back up the subduction channel and get mixed in with surface sediments and end up accreted to continents where subduction is occurring. Erosion eventually exposes them and they provide proof of an existing or extinct subduction zone. The map shows where to look for these rocks 🗺 👀 ..................coming next are more of my recent finds showing how these rocks dramatically deform and alter as they rise to the surface .....get excited!! 😜 🤗😲 #geologistonboard #eclogite #californiageology #marincounty #metamorphicpetrology #petrology #mineralogy #platetectonics #geology #geologia #earth #science #franciscansubductioncomplex #mesozoic
Muchas gracias a estas geologas de SJSU, por crear este evento tan especial. ¤ ¤ A special shout out to these three wonderful SJSU geologists for leading this #amazing Geo-Hike. • • (Laura Mosqueda, Elizabeth Gutberlet, Ana Jaime). * * #henrycoe #henrywcoestatepark #goodvibes #geology #geologyinthefield #henrythegnome #findyourpark #encuentratuparque #geología #aprendemas #goodvibes #nature #naturaleza #geohikes #HuntingHollow #HH2018 #californiageology #geologists
So here’s the first of my Franciscan Subduction Complex blue schist posts. This is a basic high pressure but low temperature blueschist with normal foliation as seen by the aligned garnets. The blue minerals are small and don’t show the more visible schistosity of most other schists. When basalt starts it’s way down a subduction zone it shatters n brecciates (posts coming) where pressures are low. As it goes deeper and the pressure increases it goes thru complete metamorphism to beautiful blue glaucophane n lawsonite, sometimes with perfectly formed euhedral garnets like here and a few other minerals. It also undergoes ductile deformation ...posts coming about that. The green is probably greenschist facies minerals like actinolite, chlorite and epidote. Notice the green rims around the garnets! The white is high pressure aragonite. I’m not sure if they are prograde (original metamorphism as the basalt traveled down to increasing pressure) or retrograde (when pressure decreases as the rock travels back up to the surface) ..either way it’s a lovely rock. The facies diagram shows the pressures and temperatures of different metamorphic facies. Any rock type can theoretically find itself metamorphosed within these categories and the new rocks they become will all be different. For example, rocks other than basalt that undergo blueschist facies metamorphism become something other than blueschist. #geologistonboard #californiageology #franciscansubductioncomplex #california #rockhound #metamorphicpetrology #blueschist #highpressuremetamorphism #subductionzone #platetectonics #basalt #bluerocks #garnet #fieldgeology #rockcollection #travel #earth #mineralogy #instarocks #insta #
Today was a special (and a very successful!) day for 3 of our geology undergrads as they led their first Geo-hike at Henry Coe State Park. These ladies spent their summer waking up before the sun to chart paths and locate good rock outcrops to use to teach the general public more about geology. Today, they got to see all their hard work pay off! #feelsgood #hardwork #hardworkpaysoff #geohike #geologyhike #henrycoe #henrycoestatepark #californiageology #sjsugeology #sjsu #geology #geologyrocks
In honor of the Big Sur, California JADE FESTIVAL that begins today! Wish I were there! This fine vintage piece from Big Sur is a true California collectible and is available at my Etsy shop for just $49, as well as many others! #bigsur #bigsurjadefestival #bigsurjade #plaskettcreek #jadecove #californiajade #nephrite #bigsurnephritejade #nephritejade #bigsurcalifornia #californiacollectibles #gemstones #gem #gems #mineralsforsale #geology #californiageology #californiadreamin #greenjade #greennephrite #californiaminerals #jade #greenjade #crystals #hippies #retro #peace #love
1/? • Glass Mountain, this eerie mound of obsidian and pumice sits quietly in the thin air of the Medicine Lake Highlands. Be careful if you decide to go, weather tends to be erratic and I drew blood picking up the obsidian pieces. #californiageology #visitcalifornia #geology #medicinelakehighlands
The first picture features the ever looming Mount Shasta, the tallest volcano in the Cascade Range. With a volume of 108 cubic miles, it is quite possibly the largest composite stratovolcano on Earth. It last erupted in 1786, and is currently on watch. —————————————————————————————— The second picture features the tail end of the Cascade Range, with Castle Crags jutting out in the right. Castle Crags is actually the core of a long dead volcano, and is what geologists call a stock intrusion, as it covers less than 40 square miles and is distinct from the surrounding rocks. #visitcalifornia #californiageology #geology #volcanology
Here’s most of my latest haul of high-pressure metamorphics from the Franciscan Subduction Complex. The top basket is mostly fine-grained blueschists, altered blueschists , brecciated blueschists, blueschist with garnets, macro-foliated blueschists w mica and just about anything else that can happen to a blueschist ...I’ll be posting closeups soon. Bottom basket has more Franciscan goodies of all sorts ...not sure what it all is but I’ll post with my observations and thoughts on identification. These are some of the coolest rocks I’ve ever collected!! The last 3 pics are agate/jasper from the bottom basket. First one appears to have some red basalt slivers. Second one has red n green altered basalt slivers with white high-pressure aragonite ..all encased in yellow jasper and last pic is a solid jasper #geologistonboard #franciscansubductioncomplex #franciscancomplex #californiageology #metamorphic #basalt #platetectonics #jasper #lapidary #blueschist #rockcollection #highpressuremetamorphism #geologist #geology #geologia #agate
Here’s another Franciscan Subduction Complex mélange cobble I found many years ago. After making my last post I just happened to walk past it in my backyard and did a big double take!! 😲 When I found it I had no idea what the heck it was ..but after my recent finds in the heart of the most studied Franciscan mélange zones, I immediately recognized this rock as a long forgotten sister to the first rock of my last post!!! (...the bunless petrified 🍔) I’d love to make a thin section of this rock or at least take some better magnified pics. It’s really cool under the hand lens. The main difference between the two rocks is this one has yellowish alteration rims around the larger basalt clasts and many smaller brecciated and finely elongated slivers of completely altered basalt creating a 🕷 spider-veined pattern thru-out the matrix of high-pressure white aragonite. Subduction-zone plate-tectonic energy is strong in this one!! 😎⚒ 🌏 ⚒😎 .. #geologistonboard #californiageology #franciscanformation #franciscansubductioncomplex #geologicmelange #highpressuremetamorphism #metamorphicpetrology #cobble #basalt #aragonite #sonomacounty #mendocinocounty #geology #geologia #geological #subductionzone #igmetpet #igneouspetrology #
What happens when basalt (as oceanic crust) travels several miles down a subduction zone deep under a continent?? I’ve collected dozens of interesting cobbles and in-situ rock samples from California’s Franciscan Subduction Complex (mostly from Marin,Sonoma and Mendocino counties) that tell their story... ...part 1 The basalt goes thru many metamorphic changes as it travels down about to the crust-mantle boundary but not all of it stays down there. The varying pressures of the subduction process end up rotating and raising or somehow pushing/squeezing back up to the surface many large blocks of the varying stages of metamorphosed basalt. Most of these blocks get mixed into sediments and no longer look like (or are) basalt (next few posts) but here are some cobbles from raised blocks that are still recognizable as basalt or broken slivers of basalt. They contain white high-pressure low-temperature aragonite veins (altered carbonates) which is one of the defining features of these rocks. ..and they contain green altered phenocrysts (altered crystals) and lots of amygdaloidal cavities from gas bubbles that are filled prob with zeolites or maybe the aragonite. They show the lowest grade of high P low T metamorphism (zeolite facies) and I think they’re cool!!! 😎 ⚒ 😎 ...more coming #geologistonboard #geology #platetectonics #subductionzone #californiageology #californiacoastrange #mendocinocounty #sonomacounty #marincounty #structuralgeology #petrology #travel #nature #earth #rocks #minerals #hiking #roadtrip #geologicmap #geological #geologist #zeolitefacies #basalt #aragonite #zeolite #metamorphicrock
A wonderful felsic dike specimen I stumbled upon. Second image is a close-up of the contact zone between the dike and country rock. #geology #geologizing #californiageology #california #dike #dyke #california #felsic #earth #nature #naturephotography #borrego #igneous #hiking #optoutside
A geology minor who really likes rocks? What a shock!!💥
For all you stoned n stony hearts ...here’s a mafic 🖤 xenolith in a random block of Penryn pluton granodiorite and some pics of the old Griffith quarry 😍 It was a small quarry open in the 1800s and provided stone for buildings at Stanford University, Alcatraz, the State Capitol, and several buildings in San Francisco including the SF Mint. This pluton is one of the westernmost plutons of the Sierra Nevada batholith. ...nice lil hike, no ticks or rattlers or poison oak ☠️ #geologistonboard #penrynpluton #california #californiageology #foothills #highway49 #gold #goldfever #motherlode #sierranevadabatholith #granitequarry #penryn #newcastle #ophir #roadtrip #travel #insta #heart #stoneheart #granite #igneous #geology #geologia #duckweed #fireecosystem #subductionzone #mesozoic #mining
Over many centuries the stone has been sculpted by a #weathering process that creates these honeycomb formations called Tafoni. It is formed by the combination of salt and wind, and can be observed up close at Pebble Beach- Bean Hollow State Beach 📷by halfmoonbaystatebeach ~~~~~~~~~~~ ~~~~~~~~~~~ #beanhollowstatebeach #pebblebeach #tafoni #sanmateocoast #geology #geologyrocks #californiageology
Over many centuries the stone has been sculpted by a weathering process that creates these honeycomb formations called Tafoni. It is formed by the combination of salt and wind, and can be observed up close at Pebble Beach- Bean Hollow State Beach 🌊 #beanhollowstatebeach #pebblebeach #tafoni #sanmateocoast #geology #geologyrocks #californiageology
Can’t you sense the extreme pressure this rock underwent? This type of rock is classified as a mylonite, which means it formed below earths surface at least 4 miles, typically near a fault zone, and experienced such pressure and shear that it slightly melted and was kneaded like dough to stretch the original minerals into semi-parallel lines. The light-colored rock is called a porphyroclast and also suffered the extreme pressures, slightly melting and stretching. Notice the stress lines emanating from the porphyroclast? Fascinating! #geology #geologizing #mylonite #california #californiageology #science #hiking #getoutside #optoutside #earth #nature #naturephotography #porphyroclast #metamorphic
Wallace Creek of the Carrizo Plain is largely known by geologists for its gullies and channels that record evidence of the movement along the San Andreas Fault. Channels that run from northeast to southwest have been offset by the dextral (right lateral) movement of the fault. The offset channels and gullies are significant to geologists because they can be used to measure the amount of offset that has occurred in this section of the fault. The last earthquake to have occurred here was in 1857 and the earthquake is responsible for displacing the land along the fault by about 30 feet. Research published in 1984 proposes that the San Andreas fault is unlikely to generate another great earthquake for another ~100 years (Sieh and Jahns, 1984) which is adjusted to ~66 years at the present. Images taken: April, 2017 Sources: Lecture notes from a graduate course at California State University Northridge taught by Dr. Doug Yule; an informative website on Wallace Creek, partly sponsored by Southern California Earthquake Center and the U.S. Geologic Survey and designed by CalTech professors; Sieh, K. E., Jahns, R. H., Holocene activity of the San Andreas fault at Wallace Creek, California, 1984. Geological Society of America Bulletin, v. 95, p. 883-896. #CaliforniaGeology #Geology #Nature #Travel
(1) The handsome San Onofre Breccia on surf patrol. (2 & 3) Sheets of calcite dikes eroding away slower than the surrounding breccia causing them to protrude. #geology #california #californiageology #geologizing #breccia #sanonofrebreccia #beach #earth #geologizing #nature #naturephotography #erosion #dike #dyke #calcite
#Repost from @geologyeverywhere with @regram.app ... Salah satu contoh kasus dari proses rezim tektonik ekstensional di Death Valley, California yang menghasilkan fault detachments dan cekungan-cekungan kecil diantaranya. Secara morfologi permukaannya yang membentuk jajaran pegunungan dan rendahan-rendahan #earthscience #geology #geoscience #deathvalley #faulting #faultline #basinandrange #normalfault #sedimentaryrocks #tiltedrocks #geologyrocks #geologyeverywhere #structuralgeology #tectonics #aerialgeology #californiageology #geopedia #geoenthusiast
A really great way to remember you're afraid of heights is to drive solo to a canyon where you can only climb to the next "level" by scaling a freestanding ladder shoved up against a 90° rock wall! LOL. I had to have a panic attack and watch several small groups and a family of 6 including small children and their grandparents climb a ladder without hesitation before I could muster the strength to do the same... but I did!! It was my first time driving theu the southernmost part of Joshua Tree Nat'l Park and resemebled the landscape/ geology of Death Valley! Some of my absolute favie phone snaps of this place in my stories ;) . . Ladder canyon, April 2018. . . . . . . . . . . . #slotcanyon #mojavedeset #saltonsea #erosion #geology #laddercanyon #120mm #hikingwithmamiya #portra #desertdays #mediumformat #ishootfilm #shootfilmstaybroke #californiageology
This is the closest plunging syncline to my house and I love it!!! A syncline is a u-shaped rock formation, but this one plunges underground and pops back up about 1/2 mile away. #geology #geologizing #syncline #plungingsyncline #california #californiageology #devilspunchbowl #whythedevilgotallthecoolrockformations #askingforafriend #sandstone #sanandreas #sanandreasfault #hiking #camping #optoutside #nature #naturephotography #earth #pearblossum #drone #dronevideo #karmadrone #gopro #goprovideo #goprophotography . 🎵 @ramesesb 🎵
Discussing with my boys whether the rock formation behind them is as a result of a landslide, river deposit or other. 🤔What do you think and why?🤔 #geology #geologizing #borrego #borregosprings #palmcanyon #palmcanyontrail #hiking #camping #optoutside #camelbak #california #californiageology #earth #nature #naturephotography
Anyone home? A cool web in a hole in the rock. I wasn't sticking my fingers in to find out! #gazoscreekstatebeachcalifornia #gazoscreekstatebeach #añonuevostatepark #highway1 #beach #californiageology
Gazos Creek State Beach Pescadero California Año Nuevo State Park These rock formations are really interesting to me. The layers and veins are pretty and thought provoking. #gazoscreekstatebeachcalifornia . #californiageology #rockformations #geologyrocks #nature #añonuevostatepark #pescadero #highway1
Gazos Creek State Park, Pescadero California Año Nuevo State Park From what I have researched, the area of Gazos Creek and Pigeon Point is part of an area geologically known as the Pigeon Point Rock Formation, a 70 million year old formation that was once part of the Sierra Nevada range. #californiageology #gazoscreekstatebeachcalifornia #añonuevo #añonuevostatepark #geologyrocks #highway1 #coastalviews #rockformations #gazoscreekbeach
It's a bird... it's a plane... it's a volcanic bomb? What do volcanoes have to do with bombs?? . When a volcano is actively spewing lava, it can come out in effusive flows, or if there is more gas in the lava, as spurts of airborne molten material. As this material flies through the air, it cools and hardens into rock, forming volcanic bombs... which is what you're looking at. . Depending on how gooey (hot and viscous) the lava was at eruption, the bomb can take a variety of shapes, from tiny droplets to large blobs that are round, lentil-shaped, or elongate and twisted. This one is a bit elongate, and has a nice twist to it. . . #pisgahcrater #mojavedesert #cindercone #volcano #california #californianative #geology #education #earthscience #outdoorculture #volcanicbomb #pahoehoe #aa #scicomm #womeninscience #californiageology #inspiration #nature #adventure #landscapephotography
Gorgeous wind-blown ripples in black volcanic sand at Pisgah Crater. This cinder cone is the result of basaltic magmatism, although the date of most recent activity is poorly constrained and estimated between 2,000 to 20,000 to 50,000 years ago. The site has the cinder cone, as well as lava tubes and surrounding lava flows that range from pahoehoe to a'a (smooth and ropy to very sharp and jagged). The rock shown here has pahoehoe texture. . . . #pisgahcrater #mojavedesert #cindercone #volcano #california #californianative #geology #education #earthscience #outdoorculture #volcanicbomb #pahoehoe #aa #scicomm #womeninscience #californiageology #inspiration #nature #adventure #landscapephotography
When you see them layers tilted more than 45, you know that the San Andreas still alive. #mormonrocks #geology #geologizing #california #i15 #californiageology #cajonpass #sandstone #sedimentary #sanandreas #drone #karmadrone #goprophotography #goprovideo #gopro #hiking #camping #nature #naturephotography #naturevideography #optoutside •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••🎵🔥@ramesesb 🔥 🎵He got new music out, check it.
Swimming hole geology. Beautiful boulders to enjoy the river on ❤️ . . #californiageology #americanrivertrail #auburnstaterecreationarea #iloverocks #geologylover
🇧🇷Falhas normais cortando uma brecha ao longo da "Black Mountains" - Death Valley, Califórnia. . . 🇺🇸Conjugate normal faults cutting breccia along the Black Mountains frontal fault, Death Valley, California. . ▶@geologyeverywhere ▶http://geologypics.com/geological-item/brittle-structures-photos/ . #geology #geologia #falhas #faults #gelogie #igeology #ilovegeology #geologiaéfodapracaralho #lovegeology #geologyrocks #rocks #fieldtrip #fieldwork #trabalhodecampo #deathvalley #californiageology #california
🇧🇷Essas incríveis formações em forma de colunas helicoidais foram encontradas nas margens do lago Crowley, Califórnia, EUA. As colunas de pedra de até 20 metros de altura são conectadas por arcos altos, como se fossem parte de um antigo templo. Pesquisadores determinaram que as colunas foram criadas pela infiltração de água gelada - e vapor subindo - de cinzas vulcânicas expelidas por uma explosão cataclísmica há 760 mil anos "Essas colunas são produtos espetaculares de um experimento natural na física da convecção hidrotérmica", disse Noah Randolph-Flagg, 25 anos, candidato a PhD e principal autor do estudo, em uma entrevista. As colunas começaram a se formar enquanto o degelo se infiltrava no tufo ainda quente. A água ferveu, criando "células de convecção uniformemente espaçadas, semelhantes às de tubos de calor" . . 🇺🇸These amazing formations in the shape of helical columns were found on the shores of Crowley Lake, California, USA. The stone columns up to 20 feet tall connected by high arches, as if part of an ancient Moorish temple. Researchers have determined that the columns were created by cold water percolating down into — and steam rising up out of — hot volcanic ash spewed by a cataclysmic explosion 760,000 years ago. "These columns are spectacular products of a natural experiment in the physics of hydrothermal convection," Noah Randolph-Flagg, 25, a PhD candidate and lead author of the study, said in an interview. The columns began forming as snowmelt seeped into the still hot tuff. The water boiled, creating "evenly spaced convection cells similar to heat pipes". . . ▶http://www.geologyin.com/2017/01/mystery-of-crowley-lake-columns-solved.html . #geologia #geologyin #californiageology #vulcanismo #geology #geologyrocks #rocks #geologywonders #ilovelogeology #geolove #geologiaéfodapracaralho #igeology #igeologico #vulcão
A quick traverse of the rocks across the central Sierra Nevada from the western foothills to the east side ..part 2 1-2 volcanics at the top of Sonora Pass, an old toll road that used to take several weeks to #travel from Sonora to Bridgeport during the gold rush days. 3 euhedral (perfectly formed) orthoclase crystal in Sierra granite ..shows inclusions of black hornblende/biotite crystals aligned parallel to the growing crystal faces 4 Sierra granite pegmatite vein, grey is quartz, off-white is feldspars. The left side shows graphic granite, a texture derived from large single crystals of quartz and feldspar slow-cooling but remaining interwoven thus creating an illusion of lettering when sliced. 5 Bishop Tuff ..rhyolitic volcanic ash on eastern side of the Sierra ..part of the Long Valley Caldera suite of volcanics, the 3rd largest supervolcano site in the USA (after Yellowstone and Valles in New Mexico) #californiageology #geologistonboard #sierranevada #mountains #volcanic #granite #andesite #bishoptuff #goldrush #highway108 #sonorapass #basalt #roadtrip #ontheroadagain #science #nature
A quick traverse of the rocks across the central Sierra Nevada from the western foothills to the east side ..part 1 1 eroded tops of Mariposa Slate, called tombstones 💀 vertically dipping, one of ~15 exotic terranes of the FMB Foothill Melange Belt (and other related rocks) ...all terranes are in tectonic (fault) contact with each other, they rafted west during the Jurassic and piled up chaotically at the top of the subduction zone. Many shear zones ❤️ and hydrothermal activity along this ~250 mile belt of stacked accreted material. 2-3 fluvial(river) gravels 4 Mehrten Formation ...brecciated and auto-brecciated andesite from the island arc volcanoes 🌋 active during subduction ..similar to those active today all along the western Pacific rim from the Aleutians to Russia, Japan, Southeast Asia to the Philippines and New Zealand. 5-6 mountains of columnar basalt on the way up to Sonora Pass #californiageology #geologistonboard #sierranevada #mountains #volcanic #granite #andesite #bishoptuff #goldrush #highway108 #sonorapass #basalt #roadtrip #ontheroadagain #travel #science #nature
The Salton Sea sits within the Salton Trough at 236 feet below sea level. This is an active tectonic pull-apart basin; my boys are standing on basaltic rock that oozed up during a spreading event in the past. This area is also home to the only active volcanoes in Southern California. Don’t worry, the eruptions would be more similar to Hawaii than say, Mount St. Helens. How cool if a fissure opened up here!! #geology #californiageology #getoutside #geologizing #igneous #saltonsea #saltonseabeach #obsidian #volcano #roadtrip #nature #earth #naturephotography #hiking #camping #saltontrough #sanandreas #sanandreasfault
Drilled potholes Here are a few pics from the hundreds of pothole pics I’ve collected (I guess I’m a little weird 🤷‍♀️) sorry for lack of scale but these are all big! 1 eroded but originally deep pothole in 🇨🇭Switzerland 2 Wilcox Hollow, Deerfield River, Massachusetts shows the drill/vortex pattern 3 New York ..fractured, eroded partial pothole 4 Fossil Falls, CA looking up w dramatic drill/vortex pattern! 😍 5 partial with a guy for scale, not sure of location 6 Utah ..ice climber in a big eroded pothole! I’ll post some even larger, more dramatic potholes after I finish posting the pics from my most recent road trip (over central Sierra, boonies of Nevada, megaflood potholes n plunge pools in Idaho and Washington and all my 💎💎loot 💎💎 from Madras, Oregon rock show!!) #geologistonboard #potholes #drilledpotholes #watervortex #megaflood #fossilfalls #californiageology #newyorkgeology #switzerlandgeology #massachusettsgeology #watererosion #vortex #powerofwater #geology #geologia #hydrology #fluiddynamics #flood #flooderosion #ilovepotholes #giantpotholes #pleistocenefloods
Shadow selfie 👋🏼 and decent sized potholes along the middle fork of the Stanislaus River. High gradient (steep) rivers with a high volume of snow melt do a good job of polishing the bedrock along the river (here granodiorite) but the constant pounding and turbulence also makes the water act like a drill that can form large rounded and in this case irregular potholes. More perfect potholes I’ve seen in the Alps and New York State are much longer and perfectly round, straight and deep and definitely look like a gigantic drill was used to carve them out ...in other words water (plus sediment) that is moving fast enough and turbulent enough can do an amazing job of drilling into solid rock! #ontheroadagain #geologistonboard #californiageology #sonorapass #stanislausriver #highway108 #sierranevada #granite #goldcountry #sierrafoothills #geology #geologia #hydrology #river #water #snowmelt #waterfall #potholes #geologicwork #erosion #california #mountains #bridge #underthebridge #roadtrip #batholith
Apakah ini Breksi Autoklastik atau Breksi Pyroclastik atau Breksi Kataklastik atau Breksi Epiklastik? Regrann from @geologistonboard - Titus Canyon part 4: the ‘megabreccia’ (also called jigsaw breccia or crackle breccia) and the narrows of the lower part of the canyon. Pic 3 is looking back up the canyon Overturned Paleozoic limestones now marblized and infilled with calcite/travertine. The breccia varies a lot, some portions have bright red hematitic veins (pics 5-6), even the infilled calcite is brecciated in places and various modes of formation are proposed including tectonic, phreatic and hydrothermal or some combination to form a multi-stage breccia #tituscanyon #deathvalley #geologistonboard #californiageology #geoscience #geology #geologia #paleozoic #roadtrip #4x4 #megabreccia #basinandrange #marble #travertine #paleozoic #sportsmobile #travel - #regrann
Had a crock-pot lunch in the Alabama Hills (that cooked in our new mini crockpot while we were driving!) then headed home. Pic 1 is clouded Mt Whitney from the Alabama Hills, pic 3 shows the peak of Mt Whitney. The Alabama Hills are a granite ~15-20my older than the Sierra batholith and they were covered with thick vegetation which caused the deep weathering before the present arid conditions developed. The map shows how the Alabama Hills (they run north-south just west of Lone Pine) are sandwiched between the steep fault scarp of the Independent Fault (normal fault along which this portion of the Sierra rose) and the Inyo and Owens Valley (right-lateral) Fault Zones which are some of the faults thought to be absorbing the dextral shear between the Pacific and North American tectonic plates. Tectonics make for great beauty!! 😎 #geologistonboard #mtwhitney #alabamahills #geologicmap #geology #geologia #earthscience #sunset #californiageology #sportsmobile #metcedessprinter #granite #normalfault #basinandrange #dextralshear #roadtrip #easternsierra #sierranevada #lonepine #travel
Titus Canyon, Death Valley part 5 ..at the bottom is the most dramatic part of the canyon with high steep walls and the mega-breccia and so many beautiful travertine veins with mini-breccias. Scale on first 2 pics is about 12” across the pic. Last 2 pics are of exiting the canyon onto an alluvial fan on the main floor of Death Valley and airing back up ...then the hose of our air compressor failed after airing back up the two front tires ..ugh 😑 ..so we had to poke along all the way to Stovepipe Wells to find out their air hose was completely shot ..so a guy in a Jeep with onboard air helped us fill the back tires!!! After a nice cool morning trip down the canyon we finally left Death Valley at 107 degrees 🔥 #tituscanyon #deathvalley #geologistonboard #geology #geologia #travertine #paleozoic #4x4 #offroad #sportsmobile #mercedessprinter #californiageology #sedimentary #petrology #earthscience #adventure #basinandrange #desert #travel
Beat up, wrinkled and stained this book is hands down our favorite for local California road trips. It’s like having a geologist in your back seat. As we drive area highways and main arteries Michelle will read about what we are seeing outside the windows; how it got there and what it means on a geologic scale. We got ours whin a ranger at Lava Beds NP recommended it. We are so glad she did! @californiathroughmylens @californiacamping #californiaroadtrip #geology #sundaysuggestions #outthewindow #californiaadventure #californiathroughmylens #roadtrip #bookrecommendations #travel #travelcouple #travelbooks #californiageology #earthquake
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