Geological history of Earth Geologic time represented in a diagram called a geological clock, showing the relative lengths of the eons of Earth's history and noting major events The geological history of Earth follows the major events in Earth's past based on the geologic time scale, a system of chronological measurement based on the study of the planet's rock layers (stratigraphy). Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left over from the formation of the Sun, which also created the rest of the Solar System. As the surface continually reshaped itself over hundreds of millions of years, continents formed and broke apart. They migrated across the surface, occasionally combining to form a supercontinent. Roughly 750 million years ago, the earliest-known supercontinent Rodinia, began to break apart. The present pattern of ice ages began about 40 million years ago, then intensified at the end of the Pliocene. Precambrian Hadean Eon
History of the Earth The history of the Earth concerns the development of the planet Earth from its formation to the present day. Nearly all branches of natural science have contributed to the understanding of the main events of the Earth's past. The age of Earth is approximately one-third of the age of the universe. An immense amount of biological and geological change has occurred in that time span. The first life forms appeared between 3.8 and 3.5 billion years ago. The earliest evidences for life on Earth are graphite found to be biogenic in 3.7 billion-year-old metasedimentary rocks discovered in Western Greenland and microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia. Photosynthetic life appeared around 2 billion years ago, enriching the atmosphere with oxygen. Geological change has been constantly occurring on our planet since the time of its formation and biological change since the first appearance of life. Geologic time scale
Geological history of Earth Geologic time represented in a diagram called a geological clock, showing the relative lengths of the eons of Earth's history and noting major events The geological history of Earth follows the major events in Earth's past based on the geologic time scale, a system of chronological measurement based on the study of the planet's rock layers (stratigraphy). Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left over from the formation of the Sun, which also created the rest of the Solar System. As the surface continually reshaped itself over hundreds of millions of years, continents formed and broke apart. The present pattern of ice ages began about 40 million years ago, then intensified at the end of the Pliocene. Precambrian The Precambrian includes approximately 90% of geologic time. Hadean Eon Archean Eon By 3.5 billion years ago, the Earth's magnetic field was established. Proterozoic Eon
Geologic time scale The geologic time scale (GTS) is a system of chronological measurement that relates stratigraphy to time, and is used by geologists, paleontologists, and other earth scientists to describe the timing and relationships between events that have occurred throughout Earth's history. The table of geologic time spans presented here agrees with the nomenclature, dates and standard color codes set forth by the International Commission on Stratigraphy. Evidence from radiometric dating indicates that the Earth is about 4.54 billion years old. Terminology Geologists qualify these units as Early, Mid, and Late when referring to time, and Lower, Middle, and Upper when referring to the corresponding rocks. History and nomenclature of the time scale Graphical representation of Earth's history as a spiral A comparative geological timescale The principles underlying geologic (geological) time scales were later laid down by Nicholas Steno in the late 17th century. Millions of Years
AMNH, NY: Permanent Exhibitions The Biodiversity and Environmental Halls offer a vivid and inspiring vision of the spectacular beauty and abundance of life on Earth. The Museum’s Birds Halls portray the wide variety of avian life on the planet, and the Hall of Reptiles and Amphibians reviews the anatomy, behavior, and various adaptations of these vertebrates. The Earth and Planetary Sciences halls showcase remarkable specimens, including meteorites, minerals, and rare gems, that offer clues about the origins of our solar system and the dynamic processes of our planet. One of the premier attractions in New York City is the Museum's series of fossil halls, including its two famed dinosaur halls in the David H. Koch Dinosaur Wing, as well as the Lila Acheson Wallace Wing of Mammals and Their Extinct Relatives. The Hall of Human Origins explores the evolutionary story of the human family, while the Cultural Halls examine the cultures of Asia, Africa, North and South America, and the Pacific.
Microbeads Microbeads are polyethylene microspheres that are widely used in cosmetics as exfoliating agents and personal care products such as toothpaste, as well as biomedical and health science research, microscopy techniques, fluid visualization and fluid flow analysis, and process troubleshooting. In the United States, microbeads are defined as less than five millimeters in its largest dimension. Microbeads are commercially available in particle sizes from 10 µm to 1000 µm (1mm). Low melting temperature and fast phase transitions make this material especially suitable for creating porous structures in ceramics and other materials. Types Fluorescent polyethylene microspheres are commonly used to run blind tests on laboratory and industrial processes, in order to develop proper methods and minimize cross-contamination of equipment and materials. Environmental effects Banning production and sale in cosmetics USA The Netherlands See also References
Timeline of plant evolution This article attempts to place key plant innovations in a geological context. It concerns itself only with novel adaptations and events that had a major ecological significance, not those that are of solely anthropological interest. The timeline displays a graphical representation of the adaptations; the text attempts to explain the nature and robustness of the evidence. Plant evolution is an aspect of the study of biological evolution, involving predominantly evolution of plants suited to live on land, greening of various land masses by the filling of their niches with land plants, and diversification of groups of land plants. Earliest classifiable plants In the strictly modern sense, the name plant refers to the biological classification kingdom Plantae. Scientists start the search for fossil evidence of plants with indirect evidence for their presence, the evidence of photosynthesis in the geological record. Key innovations in early plant evolution Paleozoic flora
History of the Earth - EvoWiki From EvoWiki Painting of a late Jurassic Scene on one of the large island in the Lower Saxony basin in northern Germany. It shows an adult and a juvenile specimen of the sauropod Europasaurus holgeri and Iguanodons passing by. There are two Compsognathus in the foreground and an Archaeopteryx at the right. According to mainstream science, the universe is approximately 13.7 billion years old. It is thought that our universe's existence can be traced back to an event in space-time known as the Big Bang. Artist's conception of a protoplanetary disk Artist's impression from 2005 of the asteroid belt and a hypothetical outer planet (now known to really exist as HD 69830 d) Our Earth formed quite some time after the universe did, scientists believe, based on current evidence, that it formed around 4.57 billion years ago. For the first 500 or 600 million years of the Earth's history, scientists believe that there was no life. Hadean The Hadean was the first period in Earth history. Archean