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Volcaniclastic
Volcaniclastics are geologic materials composed of broken fragments (clasts) of volcanic rock. These encompass all clastic volcanic materials, regardless of what process fragmented the rock, how it was subsequently transported, what environment it was deposited in, or whether nonvolcanic material is mingled with the volcanic clasts. The United States Geological Survey defines volcaniclastics somewhat more narrowly, to include only rock composed of volcanic rock fragments that have been transported some distance from their place of origin. In the broad sense of the term, volcaniclastics includes pyroclastic rocks such as the Bandelier Tuff; cinder cones and other tephra deposits; the basal and capping breccia that characterize ʻaʻā lava flows; and lahars and debris flows of volcanic origin.Vincent 2000, pp.27-28 Volcaniclastics make up more of the volume of many volcanoes than do lava flows. Volcaniclastics may have contributed as much as a third of all sedimentation in the geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Espinaso Formation
The Espinaso Formation is a Formation (geology), geologic formation in New Mexico. It has a radiometric dating, radiometric age of 34.6 to 26.9 million years, corresponding to the late Eocene through Oligocene Epoch (geology), epochs. Description The Espinaso Formation is principally debris flows and lahars from the Ortiz porphyry belt, with some interbedded lava flows and tuff beds. The upper part of the formation is dominated by upward-fining sequences, where sediments are coarser near the base of the sequence and finer towards the top. This suggests waning volcanic activity and decreasing topographic relief. The formation Interfingering, intertongues with the underlying Galisteo Formation but Unconformity, unconformably underlies the Tanos Formation of the Santa Fe Group (geology), Santa Fe Group. Radiometric dating gives an age range of 34.3 +/-0.8 million years (Million years, Ma) near the base of the formation, 34.6 +/-0.7 Ma near the middle, and 26.9 +/-0.6 my near the to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroclastic Rocks
Pyroclastic rocks are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroclasts. Pyroclastic rocks are a type of volcaniclastic deposit, which are deposits made predominantly of volcanic particles. 'Phreatic' pyroclastic deposits are a variety of pyroclastic rock that forms from volcanic steam explosions and they are entirely made of accidental clasts. 'Phreatomagmatic' pyroclastic deposits are formed from explosive interaction of magma with groundwater. The word ''pyroclastic'' is derived from the Greek , meaning fire; and , meaning broken. Unconsolidated accumulations of pyroclasts are described as tephra. Tephra may become lithified to a pyroclastic rock by cementation or chemical reactions as the result of the passage of hot gases ( fumarolic alteration) or groundwater (e.g. hydrothermal alteration and diagenesis) and burial, or, if it is emplaced at temperatures so hot that the soft gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peperite
A peperite is a type of volcaniclastic rock consisting of sedimentary rock that contains fragments of younger igneous material and is formed when magma comes into contact with wet sediments. The term was originally used to describe rocks from the Limagne region of France, from the similarity in appearance of the granules of dark basalt in the light-coloured limestone to black pepper. Typically the igneous fragments are glassy and show chilled-margins to the sedimentary matrix, distinguishing them from clasts with a sedimentary origin. Terminology The term has been used to describe a wide variety of rocks that are interpreted to have formed by the interaction between magma and sediments. This usage has led to overlap with other terms such as hyaloclastite. In the 2002 edition of ''"Igneous Rocks"'' by Le Maître et al., the definition is given as "A local term for a tuff or breccia, formed by the intrusion of magma into wet sediments. Usually consists of glassy fragments of igneou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroclastic Rock
Pyroclastic rocks are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroclasts. Pyroclastic rocks are a type of volcaniclastic deposit, which are deposits made predominantly of volcanic particles. 'Phreatic' pyroclastic deposits are a variety of pyroclastic rock that forms from volcanic steam explosions and they are entirely made of accidental clasts. 'Phreatomagmatic' pyroclastic deposits are formed from explosive interaction of magma with groundwater. The word ''pyroclastic'' is derived from the Greek , meaning fire; and , meaning broken. Unconsolidated accumulations of pyroclasts are described as tephra. Tephra may become lithified to a pyroclastic rock by cementation or chemical reactions as the result of the passage of hot gases (fumarolic alteration) or groundwater (e.g. hydrothermal alteration and diagenesis) and burial, or, if it is emplaced at temperatures so hot that the soft gla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanology
Volcanology (also spelled vulcanology) is the study of volcanoes, lava, magma and related geology, geological, geophysical and geochemistry, geochemical phenomena (volcanism). The term ''volcanology'' is derived from the Latin language, Latin word ''Vulcan (mythology), vulcan''. Vulcan was the ancient Roman mythology, Roman god of fire. A volcanologist is a geologist who studies the eruptive activity and formation of volcanoes and their current and historic eruptions. Volcanologists frequently visit volcanoes, especially active ones, to observe volcanic eruptions, collect eruptive products including tephra (such as Volcanic ash, ash or pumice), Rock (geology), rock and lava samples. One major focus of enquiry is the prediction of eruptions; there is currently no accurate way to do this, but predicting or forecasting eruptions, like predicting earthquakes, could save many lives. Modern volcanology image:Icelandic tephra.JPG, Volcanologist examining tephra horizons in south- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petrology
Petrology () is the branch of geology that studies rocks, their mineralogy, composition, texture, structure and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together because both make heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock. Modern sedimentary petrology is making increasing use of chemistry. Background Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale description of rocks while petrography is the speciality that deals with microscopic details. In the petroleum industry, lithology, or more specifically mud logging, is the graphic representation of geological formations being drilled through and drawn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuffite
Tuffite is a tuff containing both pyroclastic and detrital materials, but predominantly pyroclasts. According to the IUGS definition, tuffite contains 75% to 25% volcanic (epiclastic) material. There are several classifications that define tuffite. The classification in the IUGS recommendation is based on the definition established by Schmid (1981). Shvetsov defined tuffites as rocks containing 50% to 90% volcanic fragments. Tuffite should therefore contain more than half volcanic material. If rock contains more than 75% to 90% pyroclastic material, it is referred to as tuff. Some other, mostly older, sources state that tuffite may contain 10% to 50% volcanic material. (in Czech) The adjective ''tuffitic'' is used for sediments containing less than 25% volcanic fragments. A tuffite consists of angular and/or rounded fragments of effusive rocks and their minerals, and may also contain volcanic ash, pumice, and clay minerals. Nonvolcanic material may consist of terrigenous, chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellowstone National Park
Yellowstone National Park is a List of national parks of the United States, national park of the United States located in the northwest corner of Wyoming, with small portions extending into Montana and Idaho. It was established by the 42nd United States Congress, 42nd U.S. Congress through the Yellowstone National Park Protection Act and signed into law by President Ulysses S. Grant on March 1, 1872. Yellowstone was the first national park in the US, and is also widely understood to be the first national park in the world. The park is known for List of animals of Yellowstone, its wildlife and Geothermal areas of Yellowstone, its many geothermal features, especially the Old Faithful geyser, one of its most popular. While it represents many types of biomes, the subalpine forest is the most abundant. It is part of the South Central Rockies forests ecoregion. While Native Americans have lived in the Yellowstone region for at least 11,000 years, aside from visits by Mountain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washburn Group
Washburn (alternatively Wasseburne, Wasseborne, Wasshebourne, Wassheborne, Washbourne, Washburne, Washborne, Washborn, Wasborn, Washbon) is a toponymic surname, probably of Old English origin, with likely Anglo-Norman and Norman-French influences after the Conquest, as the name evolved. Origins Worcestershire and Gloucestershire This family, of Norman origin, can be traced through the lands in Worcestershire and Gloucestershire, namely the little hams of "Little Washbourne" and "Great Washbourne". Little Washbourne, historically in the parish of Overbury, and the manor thereon, eventually becoming known as "Wasseburne Militis" or "Knyghtes Wasshebourne", for the many from this line that bore that honour. In the ''Herald's College, London'', Vol. I., page 54, is given: Washbourne. "A name of ancient Norman descent; the founder was knighted on the field of battle by William the Conqueror and endowed with the lands of Little Washbourne and Great Washbourne, Counties of Glo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Mexico
New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also borders the state of Texas to the east and southeast, Oklahoma to the northeast, and shares Mexico-United States border, an international border with the Mexican states of Chihuahua (state), Chihuahua and Sonora to the south. New Mexico's largest city is Albuquerque, and its List of capitals in the United States, state capital is Santa Fe, New Mexico, Santa Fe, the oldest state capital in the U.S., founded in 1610 as the government seat of Santa Fe de Nuevo México, Nuevo México in New Spain. It also has the highest elevation of any state capital, at . New Mexico is the List of U.S. states and territories by area, fifth-largest of the fifty states by area, but with just over 2.1 million residents, ranks List of U.S. states and terri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuffaceous Lithic Sandstone - Flickr - Aspidoscelis (2)
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock containing 25% to 75% ash is described as ''tuffaceous'' (for example, ''tuffaceous sandstone''). A pyroclastic rock containing 25–75% volcanic bombs or volcanic blocks is called tuff breccia. Tuff composed of sandy volcanic material can be referred to as volcanic sandstone. Tuff is a relatively soft rock, so it has been used for construction since ancient times. Because it is common in Italy, the Romans used it often for construction. The Rapa Nui people used it to make most of the ''moai'' statues on Easter Island. Tuff can be classified as either igneous or sedimentary rock. It is usually studied in the context of igneous petrology, although it is sometimes described using sedimentological terms. Tuff is often erroneously called tufa i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
