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

Aristotelian Physics: Change, Causes, and the Prime Mover

The study of Physics, in the Aristotelian sense, is the science of mobile entities. It explains change and evolution, detailing how they are produced by Potency [what is not but "can" become] and Act [what it is]. Change is the transition from what is potential to what is actual (to become something).

• Substantial Change: A transformation in the very nature of a thing (e.g., from a seed to a tree).
• Accidental Change: A transformation in a non-essential quality (e.g., from a student to a doctor). Accidental changes can be:
  • Quantitative (change in size or number)
  • Qualitative (change in quality or characteristic)
  • Locative (change in place or position)

Matter is defined as the potential to be shaped... Continue reading "Ancient Greek Physics: Aristotle's Causes & Pre-Socratic Thought" »

Properties of Minerals

Physical Properties

Exfoliation: The property of minerals to split along a preferred direction. These minerals have a weaker union between each crystalline unit. It depends on the internal structure of the crystal and is constant for each mineral. The following grades are usually distinguished: excellent, perfect, good, very flawed, and imperfect.

Fracture: When a mineral fractures, the chemical bonds are broken irregularly, unrelated to the symmetry of the structure.

Toughness: The resistance of a mineral to being scratched. It depends on the chemical bonds. Its value is calculated by comparing it with other minerals of known hardness (Mohs scale).

Specific Gravity: A number that expresses the relationship between the mineral'... Continue reading "Mineral Properties: Physical, Optical, and Chemical Characteristics" »

Geological Origin: Plate Movement

The relief units in the Iberian Peninsula are composed of layers of rock that have been folded or fractured. All these changes are caused by plate tectonics. The geological history of Spain is conditioned by the interaction of two plates: the Eurasian and African plates.

• Precambrian or Archaic Era

  (Started ~4 billion years ago) A set of lands emerged from the sea, with outcrops consisting of gneiss and slates in what are now the Central System and the Montes de Toledo. These were later eroded and covered by the sea. The Iberian Peninsula formed a vast geosyncline where materials were deposited.

• Primary or Paleozoic Era

  (Started ~600 million years ago) The first major orogeny occurred: the Hercynian orogeny. After

Population in Ecosystems: Self-regulation

People in ecosystems — autoregulación: A population is a set of individuals of the same species in a specific area. Growth is conditioned by the availability of environmental resources and by other stocks in the community. All biotic and abiotic factors that limit the growth of a population are called environmental resistance.

Growth Curves

Growth curves. Exponential growth occurs under special conditions and cannot be sustained for long in nature because it reaches a point where resources are exhausted and mass mortality of individuals occurs. In natural conditions a population begins to grow exponentially until, at a point, environmental resistance slows the growth.

The value around which the number... Continue reading "Population Dynamics, Pesticides and Biodiversity Risks" »

Biogeography: The branch of geography that studies the biological landscape, vegetation, and its spatial distribution.

Deciduous: Deciduous plants lose their leaves in autumn.

Cliserie: Staggering vegetation on the mountain slopes, appearing with different species according to height and orientation.

Ecosystem: A living set of organisms that share a common space, interacting with each other and dependent on variations or alterations from other influences.

Edaphology: The science that examines and studies the phenomena relating to soil.

Endemism: Species that inhabit exclusively a specific space, region, or mountain.

Gypsophila Species: Species that develop on plaster.

Halophilic Species: Species that grow in brackish sites.

Pirophytic Species: Species

Agglomerated Materials Defined

Stones, sand, and similar substances are materials that possess the property of adhering to other materials, forming what are known as mortar and concrete pastes. These materials are molded into their final form and subsequently harden.

Agglomerative Material Classification

Aerial Materials

These are materials that harden in the air and are not water-resistant (e.g., gypsum, aerial lime).

Hydraulic Materials

These harden both in air and in water (e.g., hydraulic lime, Portland cement).

Bituminous Materials

These are liquid or viscous hydrocarbons that harden by evaporation of their solvents or by cooling (e.g., asphalt cement).

Types of Gypsum

• Gypsum Dihydrate (CaSO₄·2H₂O): The most abundant form found in quarries.

Tassel House

Victor Horta, Brussels, 1892-1893

Key Features:

• Location: Brussels
• Architect: Victor Horta
• Style: Modernism (Art Nouveau)
• Period: 1892-1893
• Construction System: Industrial Materials

Historical Context

The 19th century was a time of profound political, economic, and cultural change. The Industrial Revolution and the French Revolution were particularly influential. Napoleon extended French influence throughout Europe. Following his defeat, the victorious European monarchies sought to restore the old order, a period known as the Restoration.

Cultural Movements

Three major artistic movements dominated this era: Neoclassicism, Realism, and Romanticism.

Modernism (Art Nouveau)

a) Emergence: Modernism, also known as Art Nouveau, emerged as a response... Continue reading "Victor Horta's Tassel House: A Modernist Masterpiece in Brussels" »

Stratigraphic Methods

Stratigraphic Discontinuities

Breaks in sedimentation are called diastems. A time lapse without sedimentation is called a hiatus. If erosion occurs during this time, it results in a stratigraphic unconformity. Types of unconformities include disconformity, angular unconformity, and nonconformity.

Principle of Superposition of Strata

This principle states that in an undisturbed sequence of strata (layers), the order from oldest to most recent ranges from bottom to top. Related principles include the Principle of Original Horizontality and the Principle of Lateral Continuity of strata.

Exceptions:

• The Principle of Original Horizontality may not be valid at the edges of sedimentary basins.
• The Principle of Lateral Continuity does

Demographics of the Spanish Fishing Population

The population engaged in maritime fishing is estimated at just over 68,000 people, joining the 14,500 dedicated to marine aquaculture. Less than 1% of the total national population comprises the active northwestern regions. Almost one-third of the total, 25,710 Galician fishermen, are aboard, along with almost all of the 30,000 dedicated to marisqueo (shellfish gathering).

Regional Trends and Shifts

Another significant change has happened in the South Mediterranean region with a decrease of 50%. The Levantine region remains stable in personnel. By contrast, the Tramontana and Canary regions have seen their rates rise because of an increased artisanal fleet. In the Canary region, the fishing population... Continue reading "Spanish Fishing Sector: Fleet Trends and EU Policy" »

Understanding Masonry Construction Techniques

Dry Stone Masonry

This type of masonry involves stacking rubble stones without using any mortar, or at most, using mud/clay. The stones are worked and carefully placed to fit closely together, ensuring that joints and gaps are minimal. These walls can be built with a slight incline or batter, typically between 1/7 and 1/5 of their height, for stability.

Mortared Masonry Walls

These walls are constructed using manufactured or natural stones laid without specific shaping, but employing mortar for bedding the stones and filling the joints. Key considerations include:

• Ensuring each rubble stone rests stably on the one below it.
• Trimming stones as needed to achieve a good fit.
• Using smaller stones, known as