Mendenhall Glacier Sand Is Not Ground-up Bedrock.

This page is intended to share my 10,000 photos of more than 800 samples from Alaska, Tasmania, Maine and Oregon. I also have samples in my storage unit that I can send you. I need to find a place for all this material. Thanks. Email me.

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“Glacial” Sand and Gravel in the Juneau, Alaska vicinity is not “Ground Up Rock” but Petrified Organic Materials – $10

Near surface sand and gravel on the west shore of Mendenhall Lake and Eagle River Beach near Juneau, Alaska, are not individual particles of glacial sediment but delicate and interconnected networks of magnetite, and silicate materials that could not have moved far from where they formed and could not have been deposited by water and assembled by chance. Mineral grains have crisp, molded, not fractured or abraded, surfaces including pores, spines and ridges which continue onto adjacent grains. Organic structures are plainly visible on the surface and inside the sand, gravel and cobbles. All stages of a continuum between organic material and replacement by silicate minerals and magnetite are found. Magnetic particles in this sand are likely to be the product of bacterial respiration. The magnetite is not pure but is mixed with silica indicating that the silica and the magnetite were deposited together. This is a photo essay arranged by place and sample, for example, Place: Mendenhall Lake and Sample: mend west 1.12.13.

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Lanky Moss Experiments: sand forms under Rhytideadelphus loreus community – $7

Micro-photos show sand on the west shore of Mendenhall Lake is likely to be a deposit of mineralized peat. A C14 date of 1950 was obtained for organics trapped in magnetite grains as they formed. Silica silica grains form on the growing tips of “Commo Water Moss,” (Fontinalis antipyretica). Since the site was covered by a glacier until about 1940, it appears the sand in the top 100 mm was formed after the glacier retreated and the process is ongoing and current. The sandy beach has a thick cushion of “Lanky Moss,” Rhytideadelphus loreus, growing on the surface. So, if the sand is petrified organic material, and if the process is current and ongoing, then sand under moss must have formed recently and there should be a zone beneath the moss where newly and partially formed grains are common. To test this hypothesis a trowel was used to cut a cylindrical plug of moss and sand from the beach which was then examined from the top down to look for that zone of newly deposited silica and magnetite. This simple experiment confirmed the hypothesis. It revealed sand forming at all layers, growing moss, peat and mineral sand, most noticeably in the peat. Magnetic moss stems with no visible minerals attached were found just above the peaty layer. The community of moss, roots, fungus, blue green algae, bacteria and perhaps diatoms seems to be making the sand. Similar observations of a second patch of Lanky Moss growing on sand at Eagle Beach support this hypothesis.  

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Summary and Gallery

Below: The large grain is about 1mm and was collected with a magnet. The dark blue materials are presumed to be magnetite. 1950 is the C14 radiocarbon date of the organic material.

The silica surface is smooth and shiny, but uneven, showing many little opalescent patches that look like pores (A) notice how the organic material goes into, and out of, the grain. Inside it is silica, outside it is organic. B) This is a magnetic particle so this darker bluish material must be the magnetite. However, it doesn’t look like either massive or crystalline magnetite and it does have lots of stems and other organic structures running through it. C) This is a moss leaf. D) A small tubular structure projects from the surface, but it is organic at the tip. There is no way anything this fine survived a glacial rock tumbler.

The “ground up bedrock” theory would suggest this grain was broken from the bedrock in a fractured state. Travel under the glacier would have smoothed the surface… then some time later the moss and roots would have to invade the grain. In this case they would have done that since 1950. How they would grow through a sand grain in such diversity and abundance is a great mystery.

Then after somehow getting inside, the organic material would have to be replaced by minerals. It’s a really complicated story compared to the one where the organic material is there first and the minerals are deposited in them later.

Abstract

Sand at Mendenhall Lake is reported to be glacial moraine (Miller, 1957), bedrock ground-up by the glacier and dropped on the shore before the glacier melted back in the 1940’s. This “ground up rock” idea is a theory: there is no way to confirm it by direct observation.

Direct observation does not support the theory.

Photos of Mendenhall Lake sand and gravel document the formation of sand grains composed of silicates and magnetite in moss and peat along the shore. Radiocarbon dating indicates sand on the surface of the beach likely formed since 1950. The grains are all connected together and have molded, not fractured, surfaces. Adjacent grains conform to each other except where spaces between grains are filled with a dark silicate matrix. Organic fibers and the silicified remains of organic fibers also connect adjacent grains. Silica and magnetite sand appears to be forming at all levels in “lanky moss” and the peaty sand beneath it. Lanky moss at Eagle River Beach, about 40 kilometers away on the coast shows similar sand formation. It appears therefore that the glacial location is not as important as the community of organisms that live in the moss.

Gallery

image002

Sand appears to be forming in the moss along the shore ( A) a blue fiber sticks out of the grain B) this organic structure runs upward through all three of these grains C) moss leaves are trapped inside the grain).

Sand appears to be forming in the moss along the shore ( A) a blue fiber sticks out of the grain B) this organic structure runs upward through all three of these grains C) moss leaves are trapped inside the grain).
image003

This silica grain is forming near the growing tip of a moss plant:

This silica grain is forming near the growing tip of a moss plant:
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The grain has a molded surface as shown by the notch on the lower left. In Photoshop the image of the tip of the leaf just to the right of the grain was copied and pasted into the notch… it’s a perfect fit, a molded surface and the grain formed in moss. The arrows indicate where strands of fungus from either side of the moss leaf enter the grain of silica. The fungus “transits” the entire length of the grain and exits from the other end. Presence of the fungus inside the moss as well as inside the grain demonstrates the grain formed right where we see it. Further, since this is the growing tip of the moss plant, the grain could not have formed long ago.

The grain has a molded surface as shown by the notch on the lower left. In Photoshop the image of the tip of the leaf just to the right of the grain was copied and pasted into the notch… it’s a perfect fit, a molded surface and the grain formed in moss. The arrows indicate where strands of fungus from either side of the moss leaf enter the grain of silica. The fungus “transits” the entire length of the grain and exits from the other end. Presence of the fungus inside the moss as well as inside the grain demonstrates the grain formed right where we see it. Further, since this is the growing tip of the moss plant, the grain could not have formed long ago.
image022

Silica is replacing fungus: This root with attached moss, peat and sand was photographed in bright sunlight. Then to show the deposited silica, a digital photo processing program, Photoshop, was used to reduce the brightness and isolate the brightest parts of the image. These brightest spots also show a rainbow play of all colors suggesting the silica is likely opal.

Silica is replacing fungus: This root with attached moss, peat and sand was photographed in bright sunlight. Then to show the deposited silica, a digital photo processing program, Photoshop, was used to reduce the brightness and isolate the brightest parts of the image. These brightest spots also show a rainbow play of all colors suggesting the silica is likely opal.
image028

Fungus in “Interglacial wood” (2-3,000 year old wood covered by the most recent advance of Mendenhall Glacier) on he shore of Mendenhall Lake also is being replaced by silica. Below is a photo of this wood taken in bright sunlight with the brightness decreased to reveal the colorful silica, the brightest parts of the image. Similar sand and gravel deposits are found in Tasmania, Maine, and Oregon. The process is ongoing and widespread. Judging from the amount of sand out there this appears to be evidence of a huge biogeochemical system that has yet to be accounted for.

Fungus in “Interglacial wood” (2-3,000 year old wood covered by the most recent advance of Mendenhall Glacier) on he shore of Mendenhall Lake also is being replaced by silica. Below is a photo of this wood taken in bright sunlight with the brightness decreased to reveal the colorful silica, the brightest parts of the image. Similar sand and gravel deposits are found in Tasmania, Maine, and Oregon. The process is ongoing and widespread. Judging from the amount of sand out there this appears to be evidence of a huge biogeochemical system that has yet to be accounted for.
eagleriversand

This is sand from the mouth of Eagle River: The grains were supposedly formed as glaciers ground the bedrock into fragments of sand gravel and silt. They were then carried down the valley in a big glacial rock polisher where the sand was ground finer and gravel and cobbles were rounded. Finally, the sand and gravel were tumbled downstream by the river and deposited at the mouth where the river meets the ocean. these structures could not have been formed by abrasion or shaping from the outside and they could not have survived a long and violent journey in a rock crusher. These are molded, not abraded surfaces, and they look organic. B) Notice the way these adjacent grain surfaces, grains with different mineral compositions, fit together in such intricate ways. It is very unlikely that these grains were formed separately or that they travelled very far. C) these delicate structures appear to be made of silica and look like flattened organic materials.

This is sand from the mouth of Eagle River: The grains were supposedly formed as glaciers ground the bedrock into fragments of sand gravel and silt. They were then carried down the valley in a big glacial rock polisher where the sand was ground finer and gravel and cobbles were rounded. Finally, the sand and gravel were tumbled downstream by the river and deposited at the mouth where the river meets the ocean. these structures could not have been formed by abrasion or shaping from the outside and they could not have survived a long and violent journey in a rock crusher. These are molded, not abraded surfaces, and they look organic. B) Notice the way these adjacent grain surfaces, grains with different mineral compositions, fit together in such intricate ways. It is very unlikely that these grains were formed separately or that they travelled very far. C) these delicate structures appear to be made of silica and look like flattened organic materials.
lankymossimage

Lanky moss, Rhytideadelphus loreus, is a community of organisms, a moss forest with a vertical structure: Upper growing moss with green leaves Lower brown stem, attached sand grains with organic material, fungus, moss rhizomes, rhizomorphs, mychoryzae incorporated in the grains, all of which conform to each other in such a way they must have formed in place. Peat composed mostly of moss stems but with considerable sand (photo above…very easy to see the silica in this layer!). Roots, fungus, moss stem and rhizoids cyanobacteria, form a thick mat.. stems often cross at right angles.

Lanky moss, Rhytideadelphus loreus, is a community of organisms, a moss forest with a vertical structure: Upper growing moss with green leaves Lower brown stem, attached sand grains with organic material, fungus, moss rhizomes, rhizomorphs, mychoryzae incorporated in the grains, all of which conform to each other in such a way they must have formed in place. Peat composed mostly of moss stems but with considerable sand (photo above…very easy to see the silica in this layer!). Roots, fungus, moss stem and rhizoids cyanobacteria, form a thick mat.. stems often cross at right angles.
root

Mostly sand with the gauzy remains of moss, fungal and algal tissue and the grains that formed within them. It feels like the sand is held together with spider webs and it breaks down into egg shaped or conical clumps.

Mostly sand with the gauzy remains of moss, fungal and algal tissue and the grains that formed within them. It feels like the sand is held together with spider webs and it breaks down into egg shaped or conical clumps.
root2

Here is a magnetic particle from layer 2. lower moss stem

Here is a magnetic particle from layer 2. lower moss stem
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And from a little lower down … zone 3, more magnetic moss.

And from a little lower down … zone 3, more magnetic moss.
grains

The organic material either grew into these grains or the grains formed around the organic material. Adjacent grains fit together and overlap each other. So what would all that organic material want inside a grain of silica? Are roots or rhizomes known for growing luxuriantly and without any apparent difficulty into crystalline silica? The grain surface conforms to the organic material within.

The organic material either grew into these grains or the grains formed around the organic material. Adjacent grains fit together and overlap each other. So what would all that organic material want inside a grain of silica? Are roots or rhizomes known for growing luxuriantly and without any apparent difficulty into crystalline silica? The grain surface conforms to the organic material within.
silica

Silica is being deposited on the surface of small cobbles and on Common Water Moss, Fontinalis antipyretica.

Silica is being deposited on the surface of small cobbles and on Common Water Moss, Fontinalis antipyretica.