Soil Textural Triangle and Earth Science Guided Notes

Flashcards covering soil texture classification, soil profile horizons, rock formation and textures, weathering processes, mass movement, and intrusive geological features.

What three separates are used on the Soil Textural Triangle to classify soil texture?

Sand Separate, Silt Separate, and Clay Separate.

What question is posed in prompt number $7$ of the guided notes on soil texture?

Which soil textural class do you believe is best for growing plants? Why?

In Guided Practice problem $1$, what are the specified percentages of sand, silt, and clay?

$40\%$ Sand, $50\%$ Silt, and $10\%$ Clay.

In Guided Practice problem $2$, what are the given percentages of sand, silt, and clay?

$70\%$ Sand, $15\%$ Silt, and $15\%$ Clay.

In Guided Practice problem $3$, what are the given percentages of sand, silt, and clay?

$35\%$ Sand, $15\%$ Silt, and $50\%$ Clay.

In Guided Practice problem $4$, what are the given percentages of sand, silt, and clay?

$20\%$ Sand, $60\%$ Silt, and $20\%$ Clay.

In Guided Practice problem $5$, what are the given percentages of sand, silt, and clay?

$30\%$ Sand, $40\%$ Silt, and $30\%$ Clay.

What are the five soil horizons shown from top to bottom in the soil profile diagram?

$O$, $A$ (Topsoil), $B$ (subsoil), $C$ (Parent material), and $R$ (Bedrock).

How do igneous rocks form, and what are their common textures?

They form by magma cooling down and hardening, and their common textures are glassy and bubbly.

How do sedimentary rocks form, and what are their common textures?

They form from pieces of rocks and minerals getting pressed and glued together over time, and their common textures are clastic and non-clastic.

How do metamorphic rocks form, and what are their common textures?

They form by rocks getting changed underground with heat and pressure, and their common textures are foliated and non-foliated.

What defines a foliated rock texture according to the notes?

It has squiggly parallel stripes formed by rocks getting squished by pressure.

What defines a strata texture?

Flat straight lines formed by layers of mud and sand stacking up.

What describes a conglomerate texture?

A chunky mix of rounded gravel-sized rocks glued together.

What characterizes a porphyritic texture?

A smooth rock background with big chunky crystals scattered inside it.

What causes a rock to have a glassy texture?

It forms when rock cools instantly, making it smooth.

What is mass movement, and what fast and slow examples are noted?

Mass movement occurs when gravity pulls dirt, mud, or rocks downhill; it can happen fast as a landslide, mudflow, or rockslide, or slowly as a slump or creep.

What is talus?

A pile of broken, loose rocks beneath a mountain wall at the bottom of a cliff.

How is deposition described in the notes?

When wind, waves, or water move sediment and drop it in a new spot, such as dropping sand to form beaches.

What is humus?

Rich, dark forest dirt made of rotted leaves that makes soil good for growing.

What is regolith?

Loose dirt and crushed rocks sitting on top of hard bedrock, covering it like sand.

What is the difference between soil and dirt according to the notes?

Soil is an ecosystem of minerals, water, and organic material; dirt is dead, displaced minerals that lacks structure and nutrients.

What is an igneous intrusion, and what are the three forms identified?

Hot magma that cools into rock underground; a batholith is the huge blob at the bottom, a dike shoots straight up, and a sill spreads out flat sideways.

What is regional metamorphism, and what geographic example is given?

Metamorphism covering huge areas using heat and pressure, such as in the Appalachians.

What is contact metamorphism, and what geographic example is given?

A smaller-scale metamorphism that bakes the rocks touching hot magma, such as in the Henry Mountains.

How does mechanical weathering differ from chemical weathering?

Mechanical weathering physically breaks rocks into smaller pieces (such as water freezing in cracks or roots pushing them apart), whereas chemical weathering changes rock minerals through chemical reactions (such as acidic rain dissolving limestone into caves or iron in rocks rusting).

What is the difference between porosity and permeability in soil?

Porosity is how much water soil can hold, while permeability is how fast water moves through it.

How is a mineral defined in the notes, and what examples are provided?

A naturally occurring, non-living unit with a set crystal structure, such as quartz or salt.