New fault zone in Arkansas? Or geothermal activity?

[Roger]

Don't know how many caught this bit of news.



Yellow square marks the place and the place is near Magnet Cove.


http://earthquake.usgs.gov/eqcenter/rec ... 94.-92.php" onclick="window.open(this.href);return false;

Story link:

http://news.yahoo.com/s/ap/20081128/ap_ ... arthquakes" onclick="window.open(this.href);return false;

Be interesting to find out what caused it!

When I lived in Batesville, I was awakened at about 2:45 a.m. by the trembling of the house foundation. Thought: "Darn big truck on highway." Dozed back off, only to be awakended again. Thought: "WTH."

Didn't dawn on me until at school that morning, I slept though an earthquake. Sure enough, confirmed that evening on the news. Epicenter was west of Mammoth Spring near Moko in Fulton County. It was just a couple of miles from the Missouri border. 2.7 or so on the Richter as I recall.

[JTarver]

Well Roger, that's one possibility...earthquake....seizmowhatsits....geothermadoolies....sure.

Yet another possibility is the Super king sized ranchero gut-bomb you had the night before at the local tex mex.

Gotta keep your options open man, that's all I'm sayin.

Joe

[Richard]

I dunno. We don't do geology in Conway.

I have felt a few earthquakes or experienced aftermaths. Yellowstone (1959?), Alaska (1964 tidal wave in HI),
Sylmar(1971 left the bank a mess), Enola (yes Enola 1980's?).

Aint felt none of these current ones cuz I live in Conway. Donchaknow, earthquakes don't exist.

Channel 7 listed three topics of interest for viewers and asked which they thought was most important.
One was the earthquakes. It was the pick of the three. Obviously their viewers do not attend UCA.

[Fish]

Yeah, 2.7 is not exactly earth shaking... I'd bet those size quakes happen by the thousands all around the world. It's an order of magnitude scale, so a 4.0 would be about 90 times that powerful as a 2.7, and anywhere in the 4.0 range is considered a very light quake. Might feel a 2.7, but it would be very easy to sleep through it or attribute it to trucks or burrito backfiring.

So no worries of a some new nasty fault zone. Though it would be interesting if a 9.0 or so shook up the rocks in the Ouachitas and dumped a bunch more of them into the streams...

- Fish

[T Yamashita]

So no worries of a some new nasty fault zone. Though it would be interesting if a 9.0 or so shook up the rocks in the Ouachitas and dumped a bunch more of them into the streams...

I'd actually rather see a volcano somewhere in the vicinity of North Ouachita Mt or maybe over close to mena if we had a choice of natural geologic activity. At about 5K ft or so, it'd create an interesting rain shadow and gradient real quick. It'd also create mass chaos and death but maybe that'd let us huumans that we're not really the boss...

ty

[Trismegistus]

I'm leaning towards a little volcanoplastic intrusion -- Unlike most of Arkansas that is covered in sedimentary rock and allulvial deposits -- Magnet Cove and nearby Potash Sulfur Springs are Arkansas' best examples of an "igeneous intrusion" where the deep molten rock of the earth's upper mantle pushed up to -- but didn't quite make it to the surface, i.e. just short of a true volcano some zillion years ago. So maybe there be a little "grumbling" going on again -- maybe we will see a mountain rise.

TANGENT: Potash Sulfur (Wilson) Springs is now the home of Strategic Minerals Co. and I think it is the only place in the U.S. where vandium is mined. There are a bunch of other strategically important and rare minerals there as well. It was once renowned for its medicinal springs -- then known as Fairchild's Potash Sulfur Springs -- and was used both prior to and after the civil war -- often in combination with the waters of Hot Springs. After drinking and/or being wrapped in towels containing mercury (common way to treat syphyllis in late 1900s/early 1900s) patients would then bathe in the Hot Springs -- the hot baths would help the patients survive these near toxic doses of mercury they patients would then travel to nearby Potash Sulfur Springs, Fairchild's Chaybeate Springs, Grandma Chase's Springs, White Sulfur Springs, etc. for a couple of weeks of relaxation before pursuing another round of mercury treatment and Hot Spring baths.

As for Magnet Cove -- it's a mineral collector's paradise -- there are minerals there that are so rare that's the only place they have ever been found. Unfortunately some of the best places to go rock-hounding are closed to the public. I have a couple of pieces of rock se from Magnet Cove that are definitely unlike anything you'd find elsewhere in the state -- I refer to them as "lava iron".

Love Arkansas!!

[Roger]

Joe, response you gave was expected! Loved it. But, didn't eat Mexican that night!

Richard, you make me laugh! But, you're right!

Fish, it's simply the location not the SIZE. But yes, it gives hope! See above reply about fire food!

Tris, gonna go with the serious reply!

[Richard]

Wow! I'm right . . .
Roger said so . . . I'm right . . .
hard to believe . . . I'm right . . .
can you believe it? . . . I'm right.
Never thought it would happen . . . I'm right.
Someone else knows I'm right.

Wait a minute. :shock:

Roger! You accusing me of being Republican!

[Roger]

Richard, keep this on topic! Trust me, you've been right about a lot of things!

[Trismegistus]

My earthquake story --

First visit to Costa Rica November 2004 -- getting off the plane in San Jose Schuyler and I head to Manual Antonio stopping at Jaco for some beachside beverage on the way. We arrive at Quepos around 10 pm and stay at this place called Costa Verde where the slogan is: "more monkeys than people". And sure enough there were monkeys everywhere -- it's was dark so we couldn't see them but we could certainly hear them swinging in the trees and jumping from the rooftops. We settle into our lovely accomodations overlooking the Pacific Ocean and top the day's travel with some more beverage and fall asleep listening to the sounds of the surf and the monkeys.

At 2:04 am I awake to a loud commotion and in the dim light I try to make sense of my surroundings -- everything is going crazy -- I'm thinking tidal wave -- but there's no water. The entire place is shaking so my eyes go darting across the room and I'm looking to see how the monkeys got in our room. Just has to be those damn monkeys!! Pictures are falling from the walls, water lines are breaking and my bed and most of the furniture is bouncing across the room. But I can't see any monkeys. I look over at Schuyler and he's bloomin' sleeping -- it wasn't until his bed bumped into the heavy table that had made its way across the room and some beer bottles fell to the floor that he finally woke and sat up. I kid you not! By then I'm thinking clearly -- it's an earthquake!!! It's a bloomin' earthquake. I pull the sheet up to my neck screaming to Schuyler as the place continues to shake, rattle and roll.. After what seems like several minutes it subsides and I lay back in bed frozen in fear, catching my breath, giving thanks that it's all over. Ahh -- thank you Lord. But just as I regain my composure here it comes again -- oh no!! This time we made haste and run out of the place fearing that our lodging is about to collapse and slid into the ocean. Outside the other guests -- about 10-12 of us -- had already gathered in their underwear, pajamas and what NOT. As it was lightly raining we all huddled under a small light weight canopy and sat out the night with aftershocks occurring randomly all night long. Each one bringing renewed fear -- for the one thing in life you always assume is constant is that the ground stays put -- and it very, very unsettling when it doesn't.

By the time the sun came up the aftershocks were getting progressively weaker and by noon the earth again stood still. The earthquake registered at 6.4 leaving eight people dead, hundreds of homes destroyed or damaged, roadways, bridges and utility poles down and two boys from Arkansas needing to have their underwear changed. There have been very few instances in my life where I felt so helpless and filled with so much fear...made confronting those wall shots and big waves much easier once we got on the water a couple of days later.

[Richard]

This is John and Schuyler's quake.
http://earthquake.usgs.gov/eqcenter/eqi ... 04/usrban/" onclick="window.open(this.href);return false;

This was a damaging one that I experienced. I was probably farther away from the epicenter, living in Lancaster CA. Even at that things shook, rattled and rolled. As John said, suddenly the ground is not that firm base you are use to. Even when it didn't shake it seemed to. And significant unnerving aftershocks occurred several times that day. A friend was living in a mobile home and when the earthquake hit, he dove out of his mobile home. Laying on the ground he could see the ground move in waves like you would see on a lake. We both worked for a bank and when we got there, things were a mess. Boxes of files were dumped and scattered.
http://earthquake.usgs.gov/regional/sta ... _02_09.php" onclick="window.open(this.href);return false;

Then there were the Ouachitas. Two plates pushed together creating accordion like folds. Flat earth pushed from horizontal to perpendicular and in some cases falling back on itself burying younger rock under older. It is hard to believe but at one point the Ouachitas which stretch from Alabama to Mexico (most of it now buried) stood at a height comparable to today's Rockies.

The Ouachitas Rock!

[Jim Krueger]

Tris, from this and other posts where you mentioned the uniqueness of the Magnet Cove area, I have to agree. Recently, after a float at Rockport, I decided to drive Marlo through the area on our way back over to Hot Springs. I've always liked the rural scenery and topography of the area. I know this discussion is centered on earthquakes and not volcanoes but there is a valley just West of Magnet cove a couple of miles that I've always thought looks like an ancient caldera. Hwy 51 drops down a hill ,then as you're driving through the farmland at the bottom, the whole place seems to be perfectly ringed by hills. I figure it's just the way the place appears but is almost uncanny.

Richard, Marlo and I had the opportunity to spend a week last year in Anchorage, Ak. Since I have a collection of National Geographic magazines from the 1940s to date, I remember looking at the one in 64 detailing the earthquake there.
While we were in Anchorage, I had quite a bit of free time to explore the city and coastlines many bike trails. It was really amazing to stand there and contemplate how the terrain buckled and shifted, and subsided in many places. There are several places as you head South that one can see what appear to be whole glades of large dead trees that were living in 1964. In those places the ground sunk several feet, enough to cause them to be low enough for salt water to intrude, killing whole groves.


Best Regards
Jim Moose

[Richard]

WOW! igneous rock with ultramafic affinities is known in the Boston Mountains.
In the entire state of Arkansas total mapped exposure of igneous rock is less than 15 square miles.
http://www.geology.ar.gov/geology/igneous_rocks.htm" onclick="window.open(this.href);return false;

What is more amazing, 60,000 people, 12,000 students, and no geology at UCA . . . truly amazing

Lots of energy expended turning these rocks on edge.

http://good-times.webshots.com/video/30 ... good-times" onclick="window.open(this.href);return false;

http://good-times.webshots.com/video/30 ... good-times" onclick="window.open(this.href);return false;

[Richard]

This probably explains it all :shock:
Nd isotopic constraints on sediment sources of the Ouachita-Marathon fold belt
James D. Gleason, P. Jonathan Patchett, William R. Dickinson, and Joaquin Ruiz
University of Arizona, Department of Geosciences, Tucson, AZ, United States

Nd isotopes for the overthrust deep-marine Ouachita-Marathon sedimentary assemblage of Arkansas-Oklahoma and west Texas, and associated Paleozoic shelf and foreland deposits, resolve into three distinct populations: (1) Lower to Middle Ordovician, epsilon Nd = -13 to -16 (average T DM = 2.0 Ga); (2) Upper Ordovician to Pennsylvanian, epsilon Nd = -6 to -10 (average T DM = 1.6 Ga); and (3) Mississippian tuffs, epsilon Nd = -1 to -3 (average T DM = 1.1 Ga). A rapid shift in epsilon Nd from -15 (passive margin shales) to -7 (orogenic turbidites) in the Ouachita assemblage at ca. 450 Ma implies termination of craton-dominated sources and the emergence of the Appalachian orogen as the primary source of sediment for sea floor lying south of North America. This connection is reinforced by Nd isotopes in Ordovician-Silurian turbidites from both the Ouachita assemblage and the southern Appalachian Sevier-Martinsburg (Taconic) foredeep, which are identical (epsilon Nd = -7 to -). The post-450 Ma Ouachita assemblage falls along a single Nd isotopic trend that, significantly, is not deflected by onset of Carboniferous flysch (epsilon Nd = -7 to -10) sedimentation nor by associated regional volcanism. The less negative epsilon Nd (-2) of Mississippian ash-flow tuffs that erupted from arc(s) to the south probably resulted from isotopic mixing of old (Precambrian) crust with young, mantle-derived components within a continental margin arc. There is little isotopic, trace element, or petrographic evidence for any significant volcaniclastic detritus in the Carboniferous turbidites, indicating that volcanic arc sources were minimal. Nd isotopes in fluvio-deltaic strata of the Ouachita-Appalachian foreland and continental interior, that is, Arkoma, Illinois, and Black Warrior basins (epsilon Nd = -7 to -10), imply that continental margin pathways and interior basins received the same detritus as the Ouachita trough by Pennsylvanian time. These data are consistent with a composite Carboniferous Ouachita submarine fan complex built down the axis of a remnant ocean basin from varied mature/immature delivery systems tapping dominantly Appalachian fold-thrust belt sources to the east (Graham et al., 1975). Carboniferous turbidites from the Marathon fold belt (west Texas), which are isotopically similar (epsilon Nd = -8 to -11) to Ouachita turbidites, may have been ultimately derived from similar sources; however, they probably do not represent merely distal turbidites of a Ouachita fan complex. It is suggested that dominantly Appalachian-derived detritus, augmented by uplifted plutonic and fold-thrust belt sources south of the Marathon basin, was swept up into subduction complexes on the north side of the approaching arc and recycled along the collision zone.

This record provided courtesy of AGI/GeoRef.
:shock: :shock: :shock: :shock: :shock: :shock: :shock: :shock:

[Shark Attack]

Richard, you have probably just proved why there are no geology clases at UCA. WTF