On Mud Lumps on the Miss. Delta

We have had sent in some papers about mud lumps.

Mudlumps: Diapiric Structures in Mississippi Delta Sediments

“Mudlump islands are surface manifestations of intrusive clay masses that result from depositional processes at the mouths of major Mississippi River distributaries. The stratigraphy and structure of mudlumps at the South Pass mouth have been studied by means of a drilling and coring program which included drilling holes to a depth of 700 ft. Subsurface information obtained establishes the relationship between older shelf and prodeltaic river deposits and younger, progradational delta-front and river-mouth bar sediments.”

Mudlumps at the Mouths of the Mississippi – from LSU

‘Mud Lump’ Leads To Damage At Nola Walf – 2008 article from Waterways Journal Weekly

This National Geographic article on the big 2011 earthquake that hit Japan has a lot about clay sediments on the seafloor –

The 2011 Japan Tsunami Was Caused By Largest Fault Slip Ever Recorded
Clay lubricated the fault zone in the Japan trench, producing the devastating tsunami, researchers say.

 

 

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4 thoughts on “On Mud Lumps on the Miss. Delta

  1. On the Japan EQ: I watched a television program some time ago about silent quakes discovered in the lowest portion of the Marianas Trench. They were saying that a special type of sediment formed from the friction of the type of rock involved caused the fault to slide “silently”. I saw another program on the Weather Channel that discussed how scientists were using information acquired about the ability of some faults to slide “silently” because of certain types of sediments, gasses and fluids present in some faults. I took from the show that they were trying to learn more about the process in order to develop methods to possibly prevent infrastructure damage and loss of life caused by the shaking that occurs in the sudden release of tension in more usual earthquakes. While I believe it to be an admirable goal, it frightened me a little to know that scientists were playing around with such things. What would happen without tension slowing the motion of these faults? That easy slippage didn’t work out so well for the poor people of Japan!! This uncontrolled motion is one of the things that frighten me about the modern hydraulic fracturing method of oil/gas recovery, injection well disposal of drilling waste and even of carbon storage.

    Louisiana is one of the locations where faults slip silently. When the measured slippage is average out over long periods of time the movement rates appear to be in minimal increments but, in many instances the total amount of movement actually occurred in one or two instances. I’ve read that movement rates may be by as much as 3 feet at one time. When you consider the fact that our faults move in a downward motion toward the Gulf of Mexico; that water, oil and gas withdrawal increases the rate of slippage that would naturally occur; that fracking and injection operations cause seismic activity and that fracking, injection and carbon storage processes place fluid, sediment and gasses into faults…well, it sure does bring home the importance of responsible governance of what/when/where/how much of these operations we choose to allow in our state. Just how fast do we want to slide “silently” into the Gulf of Mexico?

    • Yes!
      All of that info was sent in by a reader. I had never heard of mud lumps before and if it didn’t involve clay I wouldn’t have connected it to Japan story. I hope they aren’t related but . . .

      • Never heard of “mud lumps” either. Seems they are mini mud volcanoes. They spew liquid mud and gas from a conical vent. I think their average size is between 2 and 20 acres. They can appear in a very short period of time and change considerably in only a few hours. They are even faulted. Apparently, because they are of clay, they don’t wash away easily as a sandbar might. Louisiana is so interesting!! As for a connection between mud lumps and Japan…I don’t know but, the connection between the science involved in the Japan EQ, special sediments to keep fractures open during fracking operations and geological engineering…scares me!!

  2. Also, everybody, this post was added to the Methane Page to make it easier to find. The geology stuff gets put there as well as methane items.

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