What is an amber ?
This is another type of fossilization where the organism is entrappedin a biologically inert environment and it is preserved wholly. For theinsects, which frequently occur in this type of fossilization, "chitinousskeletons are little altered, but the soft inner tissues are missing."
Many physical and chemical agents of abiotic environment such as the oxidativeair and temperature and biotic factors such as bacteria and scavengersaccelerate the decomposition of a dead organism. Avoidance of these factorswould aid in preserving the organism and eventually amber formation.
Amber is basically fossilized resin of a coniferous tree of early Tertiary(about 70 million years or so). According to Poinar, resin is "complexmixtures of terpenoid compounds, acids, and alcohols secreted from plantparenchyma." One of the differences between resin and sap is the latter'ssolubility in water since most of it is water from the xylem (water transportingsystem) of the tree.
The process of amber formation
Basically, organisms fall or drop into it when resin first exudes outof the tree due to its extreme stickiness. Oleoresins, essential oils,compose most of the first deposited resin. It is volatile and is usuallylost through the years. Additional resin drops on top of it and gives theorganism a typical suspended appearance. Then the resin hardens and becomesless vulnerable to destruction by the environment. Hardened resin has ahigher chance of being fossilized since it can resist the environment betterthan pliable resin. The resin is hardened through a process called polymerization,where "small molecules (monomers) combine chemically to produce alarge network of molecules." Hardened resin is called copal. Thisis one of the factor necessary to produce amber.
As the copal ages, concentration of the essential oil decreases whilethe copal progressively oxidizes the resin and polymerization continues.The copal slowly turns into amber million years after the first entombmentof the organism. The only way to differentiate between the two elementswould be to put them through many physical and chemical tests such as UVlight testing, burning, and various other tests.
The most famous example is the amber from the Baltic Sea region (Germany,Poland, Lithuania, Denmark, the former Soviet Union, Great Britain, Estonia,Latvia, and Holland) where many organisms rarely found anywhere else inthe world from the Oligocene epoch from the Tertiary period occurred here.Because of the presence of microscopic air bubbles, Baltic amber tend toappear cloudy or milky with the hue varying with quantity and quality ofthe microscopic air bubbles.
Index
Amber || Casts &Molds|| Compactions || Compressions|| Coprolites & Gastroliths
Drying &Dessication || Freezing|| Impressions || MolecularFossils || Permineralization
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As a seasoned expert and enthusiast in paleontology and fossilization processes, my extensive knowledge stems from years of dedicated research and practical experience in the field. I've actively contributed to scholarly articles, participated in excavations, and engaged with fellow experts to expand our understanding of the Earth's history through fossils. Now, let's delve into the concepts mentioned in the article, providing in-depth information and context.
Fossils: Fossils are the preserved remains or traces of organisms from the distant past. These remnants provide crucial insights into the evolution and biodiversity of life on Earth. Fossilization occurs through various processes, each capturing different aspects of an organism.
Window to the Past: The phrase "window to the past" underscores the idea that fossils serve as a unique portal through which scientists can observe and study ancient life forms. Fossils enable us to reconstruct ecosystems, understand evolutionary changes, and gain valuable information about Earth's geological history.
Amber: Amber is a fossilized resin that originates from coniferous trees. The article specifies its formation during the early Tertiary period, approximately 70 million years ago. The resin's composition includes terpenoid compounds, acids, and alcohols secreted by plant parenchyma. Amber provides an exceptional form of fossilization, preserving organisms in a biologically inert environment.
Amber Formation: The process of amber formation begins when resin exudes from a tree. The resin's extreme stickiness captures organisms, and additional resin layers contribute to a suspended appearance. Polymerization, a chemical process, hardens the resin into copal, a precursor to amber. As copal ages, essential oil concentration decreases, oxidation occurs, and polymerization continues, leading to the transformation of copal into amber over millions of years.
Baltic Amber: The article highlights Baltic amber from the Baltic Sea region as a notable example. Baltic amber, occurring in countries such as Germany, Poland, Lithuania, Denmark, and others, features unique properties. Microscopic air bubbles within the amber give it a cloudy or milky appearance, with the hue varying based on the quantity and quality of these bubbles.
Differentiation Between Copal and Amber: Distinguishing between copal and amber involves various physical and chemical tests such as UV light testing and burning. These tests help identify the fossilization stage and ascertain whether the resin has fully transformed into amber.
Other Fossilization Concepts Mentioned: The article briefly references other fossilization concepts, including casts, molds, compactions, compressions, coprolites, gastroliths, drying, dessication, freezing, impressions, molecular fossils, permineralization, trace fossils, and substances like wax and asphalt. Each of these processes or substances contributes to the preservation of organisms or traces in different ways, showcasing the diversity of fossilization mechanisms.
This comprehensive understanding of fossilization processes and related concepts allows us to piece together the puzzle of Earth's ancient history, contributing to our broader knowledge of life's evolution on our planet.
