Biologic Processes
Geological Processes:
They are processes that take place on the earth's surface
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Types of rocks: igneous, sedimentary and metamorphic: The elements that form magma are different and crystallize at different temperatures
The origin of the rocks is very diverse. According to it, rocks are classified into sedimentary, igneous and metamorphic
Massive Extinctions on Earth:
The history of the earth is determined through investigations based on geological record that remains inscribed on the rocks
CARBON DATING AND ITS APPLICATIONS: Carbon-14, 14C or radiocarbon, is a radioactive isotope of carbon, discovered on February 27, 1940 by Martin Kamen and Sam Rubén. Its nucleus contains 6 protons and 8 neutrons. Willard Libby determined a value for the half-life of this isotope of 5568 years. Later determinations at Cambridge produced a value of 5,730 years. Due to its presence in all organic materials, carbon-14 is used in the dating of organic specimens
Fossil Record: Fossils are the remains or signs of the activity of past organisms. Said remains, preserved in sedimentary rocks, may have undergone changes in their composition or more or less intense deformations. The science that deals with the study of fossils is paleontology.
Effects of the volcanic eruptions on the terrestrial crust: Volcanoes are geologic structures where melted and fragmented rocks that comes from the inside of the Earth emeges to the surface through an opening or crater, which generally has a conic shape
Formation and the cycle of rocks : The lithological cycle or rock cycle is a geological concept that describes the transitions of material in geological time that allow all rock to transform. The geologic processes that happen in the Earth are the formation cycle of the rocks and the geologic cycle.
Tectonic Plates
A tectonic plate or lithospheric plate is a relatively rigid fragment of the lithosphere that moves over the asthenosphere, a relatively plastic area of the upper mantle.
Geologic cycle : The Earth's geological cycle is a continuous process of transformation that began billions of years ago. The internal geological cycle usually destroys the relief of the earth's crust through various processes: weathering, erosion, transport or sedimentation.
Which layers form the Earth?
Layers of the Earth ,from the external to the internal are: crust,mantle,core.
External Geological Agents:
They are caused by solar radiation and the force of gravity. can be passive or active
WHAT ARE FOSSILS FORMED: Scientific studies reveal that in prehistoric times, when organisms died, they could remain submerged under water, marine bottoms or ground sediments .Organisms buried begin a decomposition process and their soft and fleshy tissues disappear , while internal or external skeletons are preserved.
Part of the organic matter can be replaced by minerals, which contributes to its conservation keeping the definition of its structures. The replacement of minerals in organic matter explains the definition of rings in fossils of petrified trees.
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Mantle: It extends from the base of the crust to the core.In the mantle,we can distinguish.The mesosphere ,or inferior mantle,which extends from the limit of the mantle- core until a depth of 660 km.
Nucleus: It is the layer located in the center of the Earth and corresponds to the deepest zone. The external nucleus is solid and the internal,given the existing temperatures,is formed by liquid and gaseous materials.
Crust: It is in contact with the atmosphere and the hydrosphere .It corresponds to a thin layer that is divided in two types:continental crust,formed by continents and sectors of the low depth sea,which together are between 35 to 40 km thick; and the ocean crust .which corresponds to the oceanic sectors of the depths,which thickness is estimated in 5 km.
Passive: Atmospheric agents capable of disintegrating rocks but not to mobilize the fragments produced.
Active: Atmospheric agents capable of achieving fragmentation and mobilizing fragments of rock.
The geologic cycle integrates two types of processes
Types of fossilization: .
The internal geologic processes are responsible for creating the relief.
The external geological processes are responsible for modelling the relief (glyptogenesis) through the action of biological agents such as the atmosphere, the biosphere, aside from the action of the solar energy and gravity
MUMMIFICATION: It is the process by which a corpse is prevented from reaching its natural putrefaction.
The cycle of rocks : This cycle indicates the geological time it takes for the rocks to transform, and this is because the rocks are forced to change because they are linked to other cycles, such as the water cycle or the movements of tectonic plates. The cycle of rocks starts with the consolidation of magma and the formation of magmatic rocks until the formation of sedimentary rocks.
CONSERVATION USING TAR: Tar deposits are characterized for having substances that from an antiseptic environment and prevent decomposition of the organism.
FREEZING: The decrease in temperature prevents microorganisms from decomposing the remains. :
PRESERVATION OF HARD PARTS: It is characterized for preserving hard parts (bones), due to a quick burial that isolates them from oxidation and decomposition.
INSECTS IN AMBER: Insects in amber are preserved by carbonaceous compression, which is characterized for keeping the external shape of the trapped remains.
Ordovician: It happened approximately 440 to 450 years ago.
These ones can be expelled to the surface in volcanic eruptions our turn into metamorphic rocks due to the exposition to high temperature and pressure
Rocks on the surface decompose, degrade or erode and form loose materials called debris
Due to the action of water (rain or rivers), debris is dragged and sediments
These sediments are subject to physical and chemical changes, which is characteristic of a process called diagenesis, which forms sedimentary rocks.
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Devonian: It is known as the era of fish. It started approximately 416 million years ago.
Permian: It is characterized for being the period in which Pangea was formed. It lasted from 299 million years ago until 215 million years ago.
Triassic: It is a period, the fragmentation of the pangea was produced. It started 251 million years ago and ended 199 million years ago .
These sediments are subject to physical and chemical changes, which is characteristic of a process called diagenesis, which forms sedimentary rocks.
Sedimentary rocks can go through processes that turn them into metamorphic rocks
Finally, metamorphic rocks can give place to igneous rocks or emerge to the surface to turn into debris, then into sedimentary rocks and so on until they complete or repeat the cycle.
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Endogenous rocks: Those that do not originate from the Earth's surface and, therefore, the internal heat of the Earth and pressure intervene in their formation.
They are formed by the solidification of magma, This means, the rocky material which is hot, liquid and is located in the deepest layers of the Earth and comes out to the exterior in a volcanic eruption. This process is known as crystallization.
Exogenous rocks: Sedimentary rocks are rocks that are formed by the accumulation of sediments, formed from particles of various sizes transported by water, ice or wind, and are subjected to physical and chemical processes, which give rise to consolidated materials.
Metamorphic:
Metamorphic rocks are rocks formed by modifying other pre-existing rocks inside the Earth through a process called metamorphism. Through heat and / or pressure
Continental drift
If magma is solidified under the surface of the Earth, it is called plutonic or intrusive. This type of rocks is dense, not porous as granites. In their formation process there is a slow cooling of the magma, reason why big crystals
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If the cooling happens over the lithosphere, the rock is called volcanic or extrusive
Radiocarbon dating is the most reliable isotope-based technique for determining the age of organic samples less than 50,000 years old.2 It is based on the law of exponential decay of radioactive isotopes
Metamorphic rocks can be differentiated in two groups
Layered rocks: They have parallel lines formed by a differential heat and pressure during their creation .
Non-layered rocks: Mineral grains do not show a regular orientation but a mosaic, like in the case of marble
Sedimentary rocks are classified according to the way in which they are formation: .
Detritic or clastic: They originate by the mechanic accumulation of preexisting rock sediments known as clasts. These last are formed by erosion, transportation and accumulation of other materials of the terrestrial surface .
Chemical or non-clastic:Their formation is produced by the deposition of chemical compounds or by the accumulation of organic substances. The material dissolved is transported to a region where lithification takes place (compression and cementation of sediments), which forms rocks. This process is produced almost every time in water solutions. The rocks formed by the accumulation of fragments of organisms such as corals are known as biochemical sedimentary rocks
Impacts of volcanic activity
Volcanic eruptions can cause irreparable damage, such as loss of human life. Some victims die from injuries or burns caused by the debris of structures collapsed by the seismic waves of the volcano, or by the emanated lava.
Volcanic activity deposits many gases and huge amounts of energy in the atmosphere and on the terrestrial surface. It expels materials such as ashes and pyroclasts. It is calculated that there are around 1300 continental active volcanoes (those which have presented eruptive activity in the last 10000 years)
Active volcanoes in Ecuador
The Geophysics Institute of the Polytechnic National School has quantified 27 volcanoes which are potentially active in Ecuador. These include the ones in the Galapagos Islands, Marchena, Cerro Azul, Fernandina, Santo Tomas, Alcedo, Darwin and Wolf. In the continent, there are seven volcanoes: Cayambe, Guagua Pichincha, Cotopaxi, Reventador, Sangay, Tungurahua and Potrerillos-Chacana.
Cotopaxi is a snowed stratovolcano which is 5897 meters over the sea leve, which when it reactivated, became one of the most active high volcanoes in the world. Historical data and geological register prove that it has presented very big rhyolitic eruptions, where lava has ran like a river. Because of its background, there is a need for the central governments to prepare and for decentralized autonomous governments to form committees in charge of managing risks
Volcanic eruptions and their impact on the terrestrial crust
These have the ability to break the earth's crust and make mountains and mountain ranges rise. Sometimes these forces cause volcanic eruptions. Other changes occur in the earth's crust, where wind, tides, and water wear down the surface and modify the landscape.
Volcanic eruptions can be devastating. An event that exemplifies the destructive power of a volcano is the eruption of the “Nevado del Ruiz” on November 13, 1985 in Colombia. The eruption caused a big glacial detachment and the glide of lahars (volcanic sediment fluids with a great amount of water can be hot or cold), which provoked the death of approximately 23000 inhabitants and the destruction of entire ecosystems.
The Continental Drift refers to the hypothesis, credited to the German meteorologist Alfred Wegener, and published in 1915 in his work "The Origin of Continents and Oceans", where it states that during the end of the Paleozoic period and at the beginning of the Mesozoic period
the land masses were originally united in a single supercontinent which he called Pangea (from the Greek pan [all] + gh or gaia [Earth] “all the earth”); Panthalassa ("all seas") was the huge global ocean that surrounded the Pangea.
In 1620, the English philosopher Francis Bacon noted the similarity of the shapes of the west coast of Africa and the east of South America, although he did not suggest that the two continents had been united earlier.
Radioactive dating: achievements and challenges for scientist
The proposal that the continents could move was made for the first time in 1858 by Antonio Snider, an American living in Paris.Wegener theory
Alfred Wegener
There are isotopes with disintegration times which are more prolonged. This makes them useful to date longer periods of time. The radioactive series of uranium, 238U, is used to determine the age of rocks on Earth. The method consists in finding the ratio between 238U(Uranium) and its final product ²⁰⁶Pb(Lead)
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