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

Biodiversity in Spain

Location: Southwest Europe. Spain has two large biogeographic regions: Atlantic and Mediterranean. The Canary Islands have a tropical climate. The Iberian Peninsula served as a refuge during glaciations. Many animal and plant species evolved, forming new species. The presence of mountain ranges allows species to reproduce at high altitudes, creating a gradation between northern and southern Europe.

Human Impact on Biodiversity

Biodiversity has been affected by human actions, which have transformed the natural landscape (forests replaced by arable fields, etc.). This has led to a loss of vegetation and an increase in urban and industrial sites.

Landscapes of Plants

Oceanic Plant Landscape

Found in the Galician and Biscay regions.... Continue reading "Spain's Biodiversity: Habitats and Threats" »

Weathering of Rocks by Atmospheric Agents

Clasts are fragments of rock torn from a larger rock mass. The fragmentation of rocks is caused by atmospheric agents such as rain and snow. These agents wet the rock, dissolving minerals and reacting with them. Temperature changes also contribute: the expansion of rocks as the sun heats them contrasts with the contraction caused by freezing. Water seeps into cracks in rocks, subjecting them to pressure during freezing (gelifraction).

Weathering is the set of processes due to atmospheric agents that produce the alteration and disintegration of rocks.

• Mechanical Weathering: The rock is fragmented due to expansion and contraction, the freezing of water, or the impact of falling rocks.
• Chemical Weathering:

Understanding Earth's Age and Geological Time

The Debate Over Earth's Age

• Biblical genealogies: Approximately 4,000 years.
• Mid-19th Century (Charles Darwin): Calculated erosion rates suggested 600 million years.
• Late 19th Century (Lord Kelvin): Based on Earth's cooling rate, concluded 100 million years.
• 20th Century (Radioactivity, Clair Patterson): Determined Earth's age to be 4.55 billion years.

Same Facts, Different Interpretations

• Catastrophism: Earth's features formed by sudden, short-lived, violent events (e.g., the Biblical Flood, championed by Georges Cuvier).
• Gradualism (Uniformitarianism): Earth's features formed by slow, continuous processes over vast periods (e.g., Charles Lyell, building on James Hutton's work).
• Neocatastrophism: A modern

1. Geological Processes: Origin and Types

1.1 External Geological Processes

• Source:
  • Solar energy
• Type:
  • Weathering: Action of the atmosphere
  • Erosion: Separation of fragments and soil disturbance
  • Transport: Movement of these fragments in favor of gravity

1.2 Internal Geological Processes

• Source:
  • Geothermal energy inside the Earth
• Type:
  • Orogenic Movements: Horizontal displacement
  • Epirogenic Movements: The rise and decline with increasing mass of the Earth's crust

2. Plate Tectonics

• Structure based on geochemical and dynamic models:

• Source of plate movement:
  • Two scenarios:

1. Convection currents or flaring rims creating constructive

Earth's Dynamic Processes and Landforms

The displacement of lithospheric plates is responsible for the construction of Earth's relief, through the formation of mountain ranges and mid-ocean ridges. This movement also causes significant deformation of rocks.

Lithospheric Plate Movement

Formation of Mountain Ranges

Areas of collision between two plates are subjected to immense pressure, which compresses sediments, causing them to fold and form towering mountains.

Mid-Ocean Ridges

Mid-ocean ridges are large submarine elevations located in the middle of oceans, where magma flows through a central groove called a rift.

Oceanic Trenches

Oceanic trenches are deep depressions found along the coasts of oceanic islands and continents, representing the deepest... Continue reading "Earth's Geological Dynamics: Landforms, Rocks, and Cycles" »

Wilson Cycle

1. Hot mantle materials rise, causing the crust to fracture due to its rigidity. The fractures allow magma to output, and blocks of the lithosphere move, initiating the formation of an intracontinental rift valley.
2. The expansion of the ocean floor creates a narrow sea.
3. The growth of the seafloor allows the development of a mature ocean basin. Stable continental margins are limited by the basin's floor, where an important place of sediment deposition occurs.
4. The stable continental margins become active when the oceanic lithosphere begins to sink in subduction.
5. The reduction of the ocean is very evident. Marginal ranges are formed on active continental margins.
6. The oceanic lithosphere continues to subduct and sink until the ocean is completely

Ties in Reinforced Concrete

Generic name given to a bar, individual wire, or continuous element, embracing and confining the longitudinal reinforcement bent in a circle, rectangle, or other polygonal shape, with no reentrant corners. View Boards.

Primary Reinforcement (Armour Home)

This is the reinforcement required to absorb external stresses induced in reinforced concrete.

Secondary Reinforcement (Armor Secondary)

This reinforcement is designed to properly confine the primary reinforcement within the concrete.

Distribution Bars

In general, these rods are designed to maintain the proper spacing and functioning of the main reinforcement bars in concrete slabs.

Retraction Bars (Shrinkage and Temperature Reinforcement)

These bars are installed in slabs... Continue reading "Essential Terminology for Concrete Reinforcement Elements" »

Classifying Energy Sources

Non-Renewable Energy

Energy sources available in limited quantities that are consumed much faster than they form.

Fossil Fuels

• Coal: A mineral fossil fuel originating from the decomposition of buried plant matter, accumulated over millions of years. Today, it's primarily used as fuel to produce thermal energy.
• Oil: A thick, dark, oily liquid formed from the decomposition of plant and animal remains buried for millions of years. It has a high calorific value, is relatively easy to extract and transport, and is used to generate electricity and produce materials like plastics and paints.
• Natural Gas: Has a similar origin and formation process to oil, often found together in deposits (jaciments). It's used as fuel or as a feedstock

Sustainable Basis: Insulation Layers

The first layer, which supports the ongoing support layer, consists of finishing materials such as maximbrado, ceramic, or phenolic boards. These are fireproof wood panels, often treated (high-density wood core reinforced with cellulose).

Thermal Insulation

In unventilated roofs, thermal insulation plates are typically placed above the first layer (often maximbrado), fixed to each other and to the base.

Protection and Finishing

This final layer prevents water entry, providing a waterproof interior. Common finishing materials include:

• Tiles
• Slate
• Metal sheets (chapas)
• Fiber cement
• Fiberglass
• Asphalted cardboard

Water Evacuation Systems

The roof's inclination facilitates water evacuation. Without proper drainage, water... Continue reading "Roof Construction Principles: Insulation, Drainage, and Structural Systems" »

Coastal Landforms

Coastal Dunes

Besides being in the desert, dunes can also form in coastal areas.

Coastal Dynamics

Coastal Erosion

Coastal relief is modeled by the action of waves, tides, and coastal currents. Waves constantly erode rocky shore areas. By hitting the weakest areas, they form caves, which can cause the gradual erosion of rocks. The resistance of rocks to erosion provokes the formation of arches. The remaining areas are gaps and islets. Rocks erode more easily when they are softer, which can lead to the formation of bays.

Coastal Sedimentation

Sand flats are made of material torn from the cliffs by the waves, materials transported by rivers, and shell fragments left by organisms. The larger sediments are deposited at the bottom of the... Continue reading "Coastal and Karst Landforms" »