51 votes

How did forests end up covering pyramids?

I am an archaeologist and I specialize in the ancient Maya. Here's how it happens: 1: The vast majority of ancient Maya buildings are built using a "core and veneer" technique. The bulk of the ...
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  • 631
16 votes
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How did forests end up covering pyramids?

The accumulation of soil in such situations takes a long time. The main way soil would have been naturally transported there would be by the wind. The wind blown soil would get caught and accumulate. ...
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9 votes
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Is silicon dioxide (silica) found in all types of soil on the planet?

tl;dr Silica is everywhere, in everything. The amounts can be close to 100% in quartz sand, or less than 1% in things like peat or limestones (and derived soils). Finding completely pure soils (let's ...
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6 votes

How can poor tropical soils be enriched by biological means?

There are two main problems that "wear out" soil, and people working on this deal with both of them. A soil might be low in organic matter and nitrogen, perhaps because all the crops were sold away ...
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  • 531
5 votes

How can poor tropical soils be enriched by biological means?

The greatest asset of soils in tropical regions is the organic matter rich 'O-horizon'. Check any reference on soil profiles, they will tell you a lot. Yes, the tropical climate is conducive to ...
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  • 183
5 votes

Can Some not all mountains actually be Giant petrified Tree Stumps?

...the process that had occurred with the flood... I'm assuming that you are talking about the biblical flood. There is no evidence that the flood had ever occurred. Can...mountains actually be ...
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4 votes

How did forests end up covering pyramids?

Most of the Mexican pyramids are less steep than their Egyptian counterparts, and have niches and terraces which their Egyptian counterparts don't. An important difference is the climate, which is ...
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4 votes
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How to obtain the saturation point of a soil layer from the volumetric soil water content data?

I assume you mean sensors that measure volumetric soil water content. The answer will depend on the amount of precipitation and the permeability of the soil. Soils don't reach full saturation in some ...
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3 votes
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What is the connection (if any) between jarosite and subsoil biological activity near Spain's Río Tinto?

From what I've read so far, it appears jarosite may not be a prerequisite for the formation of certain life forms, instead that it is produced by certain organisms. Río Tinto (Huelva, southwestern ...
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3 votes

How to make Martian soil

Just as there are many different rocks and soils on Earth, so there are many different rocks and soils on Mars. To reproduce a Martian soil, you need to bear two things in mind. Firstly it should have ...
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2 votes

Effect of organic matter on salinity

Organic matter affects the pH and makes the soil more acidic. The best example of this is in peat bogs, where only acid tolerant plants can live and the peat is so acidic that micro-organisms don't ...
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2 votes

How did forests end up covering pyramids?

Disclaimer: this answer is based on what I remember from school and TV. When a volcano erupts with lava flows, the magma cools and forms an inhospitable, sterile surface. The first life to colonise ...
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  • 213
2 votes

Soil Science and the carbon cycle - is carbon released from soil into the atmosphere?

There are two ways carbon is released from soil. The first is cellular respiration of plants that uses previously stored energy (visualized in this chart). The second is when heterotrophs consume ...
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2 votes
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Can we define "drainage density" for a soil column (point-scale)?

Fundamentally it doesn't make sense to describe the point scale model with hillslope length and drainage density. If you are looking to model a soil column, you could use Darcy's law or Richard's ...
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2 votes

How deep is soil?

"Soil" is a loose amalgam of various earthen materials and organic detritus, thus conditions that create soil in various regions; soil "Thickness" depends on where soil ends and ...
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2 votes
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"Down wash" as a source for mineral particles in the soil

Downwash can be part of some erosion environments where minerals are moved down from their host rock environment to another location. Black Snake Range - Granite Slopes, Victoria, Australia The crest ...
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1 vote

Signs of hydrocarbon contamination in soil?

Being devoid of plant life can be due to a number of reasons: purposely sprayed with herbicides, sub soil salt rising to or near the surface or possibly a mass leak of hydrocarbons. Are there any salt ...
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1 vote
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How does manure & other organic matter improve soil structure?

Surface area Organic material in soil is finely divided and provides a large surface area to mass ratio. Clay particles have a similarly large surface area, but most clays stick to each other because ...
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1 vote

Generalized Soil Unit Information on Soil Characteristics of FAO/UNESCO Soil Map

From the readme.doc file, it looks that 1, 2 and 3 following AF and the other soil symbols in the excel files you mention are about this: Texture classes reflect the relative proportions of clay (...
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  • 347
1 vote

sub soil data finding

The United States Geological survey might have some data on soil As should the US Dept of Agriculture. More to it, Universities with Agriculture departments
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1 vote
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Is a hotter climate making trees grow faster and have lighter wood?

Many tree species do grow faster in climates that are warmer than their native range, especially where the added heat is combined with moist conditions, and faster growth is generally associated with ...
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1 vote

Is a hotter climate making trees grow faster and have lighter wood?

Nothing to do with climate change . Faster growth produces somewhat lower density and strength. There are strength tables for wood written more than 50 years ago that have separate listings for "...
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1 vote

What is the "pressure gradient" within the richards equation

The pressure as measured at a point z+dz (dz infinitesimally small) and z. At the surface, pressure is the atmospheric pressure. Just below the surface, let's say at 1 cm depth, pressure is ...
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  • 292
1 vote

How did forests end up covering pyramids?

The Accumulation of organic detritus begins when a structure is abandoned or poorly maintained. Plants that thrive without soil (epiphytes, lithophytes) are often the first generation of plants. As ...
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1 vote
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The state of Nitrogen, Phosphorous and Potassium during Anaerobic Digession

You're the man who grows coconuts and had a small problem with mimosa plants which you now intend to compost. Don't forget that coconut fronds blown down by the wind and any other waste products from ...
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1 vote

Leaching Requirement

Here is some supplemental material for the good answer above. It won’t let me comment, http://www.fao.org/docrep/x5871e/x5871e04.htm
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  • 159
1 vote

How can poor tropical soils be enriched by biological means?

Soil enrichment by biological means involves getting biological/organic material into the soil. The organic fraction of a soil profile is called humus. This is a natural process but it can be ...
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