Especialidades JA/Arena/Respuestas

Arena

Nivel de destreza

1

Año

1956

Version

17.05.2024

Autoridad de aprobación

Asociación General

1

Hacer una colección de 30 arenas de diferentes colores. Correctamente etiquetadas con el nombre y cada localidad donde fueron encontradas.

2

¿Qué significa el término «arena»? Nombrar dos tipos de arena.

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. As the term is used by geologists, sand particles range in diameter from 0.0625 (or 1⁄16 mm) to 2 millimeters. An individual particle in this range size is termed a sand grain.

3

Dar el origen de la arena y qué minerales contiene.

Sand is formed through two primary processes - Physical and Chemical.

4

¿Cuál es la diferencia entre la arena y el suelo?

Sand is composed of inorganic material, even if it had biogenic origins (shells, coral, diatoms, foraminfera). Soil, however, is made up of sand, silt, clay, and organic humus (broken down plant and animal matter).

5

¿Qué se entiende por forma, superficie, fractura de grano y tamaño de grano?

Shape

The shape of a grain of sand can tell us about its history. Rounded grains are those which are relatively old, the rounding being caused by the grain getting blown around by wind or pushed around by water. Grains with more angular surface are relatively young, not having had time to get rounded by the forces of nature.

6

Definir los siguientes y dar el uso de cada uno:

6a

Glacial

6b

Calcáreos

6c

Arenas movedizas

6d

Arenas de vidrio

6e

Arenas de moldeo

6f

Arenas de pulir

6g

Arenas para construir

6h

Arenas de filtro

6i

Arenas de horno

6j

Arenas de la orilla del lago

7

Examinar cinco clases de especímenes de arena bajo magnificación y observar sus diferentes características.

Using a hand lens or a microscope, examine the sand grains, looking for the features described in requirement 5 (shape, surface, grain fracture, and grain size). You can also note its color and its variability are all the grains the same size? Are they all the same shape, or are there big differences from one grain to the next?

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4. Mona Island, Puerto Rico. A biogenic sand.

5. Soesogakk, Jeju, South Korea. Volcanic origin.

6. Mustang Island, Texas. An example of very fine sand.

7. Lake Champlain, Vermont. An example of a very coarse sand.

8. Columbia River, Oregon. An example of riverine sand.

8

Memorizar y discutir Génesis 22:17, Proverbios 27:3, y Salmo 139:17 y 18.

I will surely bless you and make your descendants as numerous as the stars in the sky and as the sand on the seashore. Your descendants will take possession of the cities of their enemies
-- Genesis 22:17 (NIV)

Stone is heavy and sand a burden,

but provocation by a fool is heavier than both.
-- Proverbs 27:3 (NIV)

How precious to me are your thoughts, O God!

How vast is the sum of them!

Were I to count them,

they would outnumber the grains of sand.

When I awake,

I am still with you.
-- Psalm 139:17, 18 (NIV)

References

• Rock microstructure