Notes, summaries, assignments, exams, and problems for Geology

Rigging (Brick Arrangement)

Rigging is the arrangement of bricks in walls. It considers the dimensions of the wall and corner connections to ensure the wall rises uniformly at all heights.

Soga (Stretcher)

Soga (Stretcher) refers to the sides of the wall formed by the longest face of the brick. This face is typically 1/2 foot (approx. 12 cm) thick and is often used on the visible facades of walls.

Tizón (Header)

Tizón (Header) refers to the end face of the brick. In brickwork, headers are often used to tie walls together and support structural loads. The visible face of a header is typically the width of the brick (e.g., 12.5 cm).

English Bond

English Bond is a brickwork pattern that alternates courses of stretchers (soga) and headers (tizón).... Continue reading "Key Construction Terms and Material Tests" »

Major Invertebrate Phyla

Mollusks

Mollusks are soft-bodied animals whose anatomical plan typically includes a head, a foot, a visceral mass, and a mantle, often secreting an external shell. Notable examples include gastropods, bivalves (characterized by two flexible shells united by a hinge), and cephalopods, marine predators whose foot has evolved into tentacles.

Arthropods

Arthropods are the most abundant animals on the planet. Their body is typically divided into segments, forming a head with sensory and feeding structures, a thorax, and an abdomen. They periodically need to shed their chitinous exoskeleton, which is rigid and does not expand as the animal grows. The main classes are:

• Insects: Possess three pairs of legs and one or two pairs

The Galaico-Leonese Massif

The northwest corner of the Meseta Central, the Galaico-Leonese Massif, fractured and rejuvenated during the Alpine orogeny. It consists of Paleozoic materials and features rounded, low-lying mountains cut by faults. Its most prominent mountains are Segundera, Cabrera, and Ancares.

The Cantabrian Mountains

The Cantabrian Mountains have two sectors:

• The Asturian Massif: Composed of Paleozoic materials that were part of the Meseta Central and rejuvenated in the Alpine orogeny. Its western end features varying hardness of materials (slates and quartzites), while its eastern end consists of limestone.
• The eastern Cantabrian Mountains: Composed of Mesozoic limestone materials deposited by the sea and folded during the Alpine

Factors Influencing Spain's Climate

Tropical Anticyclones: The Azores High

The Azores High is the main center of atmospheric action over Spain. The air mass originating from this anticyclone comes into contact with the sea, becoming a tropical marine air mass. In summer, the Azores High, warm and dry, dominates much of the Iberian Peninsula and the Balearic Islands. Tropical anticyclones are also responsible for the warm and dry tropical continental air mass. Air from the Sahara Desert drags dust particles, leading to 'mud rain' when precipitation occurs.

Atlantic Storms

Westerly depressions crossing Europe are pushed by the wind. These bring variable cloudiness, rains, winds, and fluctuating temperatures across Europe. They primarily affect the... Continue reading "Understanding Spain's Climate: Key Influences and Regional Variations" »

Origin of Life on Earth

The early ocean contained organic molecules: lipids, amino acids, carbohydrates, forming an organic soup. Coacervates formed, which were (proto) lipid droplets surrounded by RNA. These coacervates acquired the ability to nurture and make copies of themselves, therefore forming the first simple cells: prokaryotes and heterotrophic cells that were already anaerobic. These cells contained RNA.

Many cells died from lack of food, and others, through mutation, were able to make their own food with H₂O + CO₂ and energy from the sun. These were autotrophic prokaryotic cells. They produced oxygen, which combined with other elements over the course of nature. The ozone layer formed, protecting living things from ultraviolet radiation.... Continue reading "Earth's Formation and Dynamic Processes" »

Water Contaminants

Water pollution can have natural or human origins. Contaminants can be physical (suspended solids), chemical (organic matter, nitrogen compounds, heavy metals), or biological (bacteria, viruses, protozoa, parasitic worms). Effects: Birds cannot fly due to oil ingress, fish stocks decrease, and coastal ecosystems are affected. Consequences:

• Eutrophication: Proliferation of photosynthetic organisms in water bodies.
• Water Temperature Increase: Hot water mixes with cold water and contaminates it.
• Salinization of Aquifers: Salty ocean water mixes with fresh groundwater.

Water Purification

Drinking water should be odorless, colorless, and tasteless, and it should contain no toxic substances. Water undergoes chemical processes to remove... Continue reading "Water Contamination, Purification, and Biodiversity Conservation" »

Steel Heat Treatments

Standardizing (Normalizing)

Steels often exhibit plastic deformation; for example, they might have a pearlitic structure with relatively irregular grain sizes. A standard thermal treatment, known as normalizing, is applied to refine the steel and achieve a uniform grain distribution. Normalizing involves heating the material to a temperature between 55°C and 85°C above the upper critical temperature, followed by relatively fast cooling in air.

Annealing

This procedure is applied to low and medium-carbon steels that have been machined or significantly deformed through cold forming. The alloy is heated to austenitize it, typically 15°C to 40°C above the critical temperature. It is then allowed to cool slowly inside the furnace,... Continue reading "Steel Heat Treatments and Corrosion Mechanisms" »

Metamorphism: Rock Transformations

Metamorphism refers to the set of transformations that a rock undergoes when subjected to pressure and temperature conditions different from those that prevailed during its genesis.

Factors Influencing Metamorphism

Changes in temperature, pressure, and fluid flow alter the stability of minerals.

• Temperature Increase: This can be due to the confinement of rocks within the Earth's crust and the movement of fault blocks, which release heat.
• Pressure Increase: Pressure increases can result from:
  • Confinement: The accumulation of sediments exerts a uniform pressure inside, known as lithostatic pressure (Pl).
  • Folding: This introduces a horizontal pressure component called tectonic pressure (Pt).
  • Presence of a Fluid Phase:

Analysis of Precipitation

Total Precipitation

• Very abundant: +1000 mm (mountain climate)
• Abundant: +800 mm (oceanic climate)
• Short: 800-300 mm (continentalized coastal Mediterranean climate)
• Very low: <300 mm (sub-desert steppe climate)
• Extremely low: <150 mm (desert climate)

Distribution of Rainfall

• Regular: No dry month with rainfall < 30 mm (oceanic climate)
• Fairly regular: Maximum of 2 dry months (oceanic climate transitioning towards continental Mediterranean)
• Irregular: More than 2 dry months (Mediterranean climate), +7 dry months (dry sub-desert or steppe Mediterranean climate)

Noteworthy points:

• Seasons with more abundant precipitation
• Months with less or no rainfall (dry months)

Analysis of Temperature

Average Annual Temperature and Thermal

Composition of the Atmosphere: The atmosphere is the envelope of the land held around our planet by gravity. It is composed of a set of gases and other gaseous elements in suspension. The atmosphere's presence avoids large oscillations of temperature on the Earth's surface, as solar radiation decreases during the day and prevents excessive heat loss at night. In the absence of the atmosphere, temperatures could reach over 95°C during the day and drop to -180°C overnight. The atmosphere contains the necessary components for organisms to perform their vital processes.

Origin and Balance of the Atmosphere: Gases in the atmosphere originated from the rocks of the Earth approximately 4.6 billion years ago, when the Earth's materials were in a semi-... Continue reading "Understanding the Composition and Structure of the Atmosphere" »