Glauconite: Asteroid Impact Fallout or Horta Faeces

[Geomartian]

The Horta was the intelligent creature from the Star Trek episode “The Devil in the Dark”. As far as I know it is the only creature that can eat rock (ok, chitons but for the organic content of the coral).

The standard narrative about geological extinction boundaries is that there is a cessation of sedimentation so that the boundary is nearly always missing. According to the orthodoxy there is nearly always a hiatus at these boundaries. So, looking in your American backyard for the K/T boundary is futile (not). Their evidence for this hiatus is the appearance of Glauconite. This rock represents the faecal pellets of some kind of rock eating organism that lives in deep still water.

Interstellar asteroids are energetic enough to both liquefy huge amounts of rock but also to blast this molten rock across the planet. Getting vaporized and blown into space can change the chemistry of the rock a little bit. Still Glauconite sure looks a lot like molten mafic (mantle) material that froze in the shape of spheres before re-entering the atmosphere.

Why would the marker for a highly energetic interstellar asteroid impact be at an extinction boundary? Shucks, I guess I will believe their faeces.

 

[Catastrophe]

The Horta was the intelligent creature from the Star Trek episode “The Devil in the Dark”. As far as I know it is the only creature that can eat rock (ok, chitons but for the organic content of the coral).

The standard narrative about geological extinction boundaries is that there is a cessation of sedimentation so that the boundary is nearly always missing. According to the orthodoxy there is nearly always a hiatus at these boundaries. So, looking in your American backyard for the K/T boundary is futile (not). Their evidence for this hiatus is the appearance of Glauconite. This rock represents the faecal pellets of some kind of rock eating organism that lives in deep still water.

Interstellar asteroids are energetic enough to both liquefy huge amounts of rock but also to blast this molten rock across the planet. Getting vaporized and blown into space can change the chemistry of the rock a little bit. Still Glauconite sure looks a lot like molten mafic (mantle) material that froze in the shape of spheres before re-entering the atmosphere.

Why would the marker for a highly energetic interstellar asteroid impact be at an extinction boundary? Shucks, I guess I will believe their faeces.

Glauconite, greenish ferric-iron silicate mineral with micaceous structure [(K, Na)(Fe3+,Al, Mg)2(Si, Al)4O10(ΟH)2], characteristically formed on submarine elevations ranging in depth from 30 to 1,000 metres (100 to 3,300 feet) below sea level. Glauconite is abundant only in sea-floor areas that are isolated from large supplies of land-derived sediment.

 

[Geomartian]

After immersion in water Glauconite spheres are soft and fragile so it doesn’t transport well. So, part of the Wikipedia entry/description is correct. Once it falls out of the sky it can be fractured by movement or transport forming greensands. In eastern parts of the United States (New Jersey?) the greensands mark the K/T boundary. Greensands and glauconite are found at many K/T boundaries in Western North America.

There is another greensand marker on the western coast of Spain. This one is a marker for the asteroid impact which sealed off the Mediterranean ocean (Messinian salinity crisis) from the Atlantic. The impact was on the eastern side of Spain about 6 mya likely creating the Ronda Peridotite massif and other mantle material intrusions. Normal volcanic activity does not produce the glauconite found in ocean sediments off of the western coast of Spain.

The basalt/peridotite sheet blocking the Gibraltar Straight was laid over sand. The Atlantic eventually leaked through washing out the supporting sand and causing it to collapse.

 

[Catastrophe]

By the way, I Googled Horta Faeces, with the following result:

About 54,400 results (0.36 seconds)

Did you mean: Horse Faeces

 

[SpaceShuttleer]

That was a good episode.