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Roxbury Puddingstone
The Roxbury Conglomerate, also informally known as Roxbury puddingstone, is a name for a Formation (stratigraphy), rock formation that forms the bedrock underlying most of Roxbury, Massachusetts, now part of the city of Boston. The bedrock formation extends well beyond the limits of Roxbury, underlying part or all of Quincy, Massachusetts, Quincy, Canton, Massachusetts, Canton, Milton, Massachusetts, Milton, Dorchester, Massachusetts, Dorchester, Dedham, Massachusetts, Dedham, Jamaica Plain, Massachusetts, Jamaica Plain, Brighton, Massachusetts, Brighton, Brookline, Massachusetts, Brookline, Newton, Massachusetts, Newton, Needham, Massachusetts, Needham, and Dover, Massachusetts, Dover. It is named for exposures in Roxbury, in the Boston area. It is the Rock of the Commonwealth in Massachusetts. Zen, E., R. Goldsmith, Richard N. M. Ratcliffe, P. Robinson, R. S. Stanley, N. L. Hatch Jr., A. F. Shride, E. G. A. Weed, and D. R. Jones (1983"Bedrock geologic map of Massachusetts".Spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gettysburg Battlefield
The Gettysburg Battlefield is the area of the July 1–3, 1863, military engagements of the Battle of Gettysburg in and around Gettysburg, Pennsylvania. Locations of military engagements extend from the site of the first shot & at Knoxlyn Ridge on the west of the borough, to East Cavalry Field on the east. A military engagement prior to the battle was conducted at the Gettysburg Railroad trestle over Rock Creek (Monocacy River tributary), Rock Creek, which was burned on June 27. Geography Within of the Mason-Dixon line, Maryland/Pennsylvania state line, the Gettysburg battlefield is situated in the Geology of Pennsylvania#Gettysburg-Newark Lowlands, Gettysburg-Newark Basin of the Pennsylvania Regions#Pennsylvania Piedmont, Pennsylvania Piedmont entirely within the Potomac River Watershed near the Marsh and Rock creeks' triple point, with the Susquehanna River Watershed (near Oak Hill) occupying an area . Military engagements occurred within and around the borough of Gettysb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brighton, Massachusetts
Brighton is a former town and current neighborhood of Boston, Massachusetts, United States, located in the northwestern corner of the city. It is named after the English city of Brighton. Initially Brighton was part of Cambridge, and known as "Little Cambridge". Brighton separated from Cambridge in 1807 after a bridge dispute, and was annexed to Boston in 1874. For much of its early history, it was a rural town with a significant commercial center at its eastern end. The neighborhood of Allston was also formerly part of the town of Brighton, but is now often considered to be separate, leading to the name Allston–Brighton for the combined area. This historic center of Brighton is the Brighton Center Historic District. The Aberdeen section of Brighton was designated as a local architectural conservation district by the Boston Landmarks Commission in 2001. History In 1630, land comprising present-day Allston–Brighton and Newton was assigned to Watertown. In 1634, the Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility. Although its permeability and porosity is relatively low, siltstone is sometimes a tight gas reservoir rock, an unconventional reservoir for natural gas that requires hydraulic fracturing for economic gas production. Siltstone was prized in ancient Egypt for manufacturing statuary and cosmetic palettes. The siltstone quarried at Wadi Hammamat was a hard, fine-grained siltstone that resisted flaking and was almost ideal for such uses. Description There is not complete agreement on the definition of siltstone. One definition is that siltstone is mudrock (clastic sedimentary rock containing at least 50% clay and silt) in which at least 2/3 of the clay and silt fraction is composed of silt-sized particles. Silt is defined as grains 2–62 μm in diam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz Monzonite
Quartz monzonite is an intrusive, felsic, igneous rock that has an approximately equal proportion of orthoclase and plagioclase feldspars. It is typically a light colored phaneritic (coarse-grained) to porphyritic granitic rock. The plagioclase is typically intermediate to sodic in composition, andesine to oligoclase. Quartz is present in significant amounts. Biotite and/or hornblende constitute the dark minerals. Because of its coloring, it is often confused with granite, but whereas granite contains more than 20% quartz, quartz monzonite is only 5–20% quartz. Rock with less than five percent quartz is classified as monzonite. A rock with more alkali feldspar is a syenite whereas one with more plagioclase is a quartz diorite.Classification of Igneous Rocks The fine grained |
Granite
Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dike (geology), dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers. Granite is typical of a larger family of ''granitic rocks'', or ''granitoids'', that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF diagram, QAPF classification), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites) conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartzite
Quartzite is a hard, non- foliated metamorphic rock that was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts, and hence quartzite is a metasandstone. Pure quartzite is usually white to grey, though quartzites often occur in various shades of pink and red due to varying amounts of hematite. Other colors, such as yellow, green, blue and orange, are due to other minerals. The term ''quartzite'' is also sometimes used for very hard but unmetamorphosed sandstones that are composed of quartz grains thoroughly cemented with additional quartz. Such sedimentary rock has come to be described as orthoquartzite to distinguish it from metamorphic quartzite, which is sometimes called metaquartzite to emphasize its metamorphic origins. Quartzite is very resistant to chemical weathering and often forms ridges and resist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobble (geology)
A cobble (sometimes a cobblestone) is a clast of rock defined on the Udden–Wentworth scale as having a particle size of , larger than a pebble and smaller than a boulder. Other scales define a cobble's size differently. A rock made predominantly of cobbles is termed a conglomerate. Cobblestone is a building material based on cobbles. Etymology Cobbles, also called cobblestones, derive their name from the word cob, meaning a rounded lump. The term is further related to the German ', meaning ''head''. Chester Wentworth referred to cobbles as ''cobble bowlders'' in his 1922 paper that would become the basis for the Udden–Wentworth scale. Classifications Within the widely used Krumbein phi scale of grain sizes, cobbles are defined as clasts of rock ranging from −6 to −8 φ. This classification corresponds with the Udden–Wentworth size scale which defines cobbles as clasts with diameters from . On this scale, cobbles are larger than pebbles which measure in diame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pebble
A pebble is a clastic rocks, clast of rock (geology), rock with a grain size, particle size of based on the Particle size (grain size), Udden-Wentworth scale of sedimentology. Pebbles are generally considered larger than Granule (geology), granules ( in diameter) and smaller than Cobble (geology), cobbles ( in diameter). A rock made predominantly of pebbles is termed a conglomerate (geology), conglomerate. oldowan, Pebble tools are among the earliest known man-made artifacts, dating from the Palaeolithic period of human history. A beach composed chiefly of surface pebbles is commonly termed a shingle beach. This type of beach has armor (hydrology), armoring characteristics with respect to wave erosion, as well as ecological niches that provide habitat for animals and plants. Inshore banks of shingle (large quantities of pebbles) exist in some locations, such as the entrance to the River Ore, England, where the moving banks of shingle give notable navigational challenges. Pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puddingstone (rock)
Puddingstone, also known as either pudding stone or plum-pudding stone, is a popular name applied to a type of conglomerate that consists of distinctly rounded pebbles whose colours contrast sharply with the colour of the finer-grained, often sandy, matrix or cement surrounding them. The rounded pebbles and the sharp contrast in colour gives this type of conglomerate the appearance of a raisin or Christmas pudding.Neuendorf, K.E.K., J.P. Mehl, Jr., and J.A. Jackson (2005) ''Glossary of Geology.'' Springer-Verlag, New York, 779 pp., The McGraw-Hill Companies (2003) ''McGraw-Hill dictionary of geology and mineralogy'', 2nd ed. The McGraw-Hill Companies, Inc, New York, 420 pp., There are different types of puddingstone, with different composition, origin, and geographical distribution. Examples of different types of puddingstones include the Hertfordshire, Schunemunk, Roxbury, and St. Joseph Island (Drummond Island) puddingstones. Hertfordshire puddingstone Hertfordshire puddings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoproterozoic
The Neoproterozoic Era is the last of the three geologic eras of the Proterozoic geologic eon, eon, spanning from 1 billion to 538.8 million years ago, and is the last era of the Precambrian "supereon". It is preceded by the Mesoproterozoic era and succeeded by the Paleozoic era of the Phanerozoic eon, and is further subdivided into three geologic period, periods, the Tonian, Cryogenian and Ediacaran. One of the most severe glaciation events known in the geologic record occurred during the Cryogenian period of the Neoproterozoic, when global ice sheets may have reached the equator and created a "Snowball Earth" lasting about 100 million years. The earliest fossils of complex life are found in the Tonian period in the form of ''Otavia'', a primitive sponge, and the earliest fossil evidence of metazoan evolutionary radiation, radiation are found in the Ediacaran period, which included the namesaked Ediacaran biota as well as the oldest definitive cnidarians and bilaterians in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Massachusetts
Massachusetts ( ; ), officially the Commonwealth of Massachusetts, is a U.S. state, state in the New England region of the Northeastern United States. It borders the Atlantic Ocean and the Gulf of Maine to its east, Connecticut and Rhode Island to its south, New Hampshire and Vermont to its north, and New York (state), New York to its west. Massachusetts is the List of U.S. states and territories by area, sixth-smallest state by land area. With a 2024 U.S. Census Bureau-estimated population of 7,136,171, its highest estimated count ever, Massachusetts is the most populous state in New England, the List of U.S. states and territories by population, 16th-most-populous in the United States, and the List of states and territories of the United States by population density, third-most densely populated U.S. state, after New Jersey and Rhode Island. Massachusetts was a site of early British colonization of the Americas, English colonization. The Plymouth Colony was founded in 16 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dover, Massachusetts
Dover is a town in Norfolk County, Massachusetts, United States. The population was 5,923 at the time of the 2020 United States Census. With a median household income of more than $250,000, Dover is the wealthiest town in Massachusetts. Located about southwest of downtown Boston, Dover is a residential town nestled on the south banks of the Charles River. Almost all of the residential zoning requires or larger. As recently as the early 1960s, 75% of its annual town budget was allocated to snow removal, as only of the town's roads are state highway. Dover is bordered by Natick, Wellesley and Needham to the north, Westwood to the east, Walpole and Medfield to the south, and Sherborn to the west. For geographic and demographic information on the census-designated place Dover, please see the article Dover (CDP), Massachusetts. History The first recorded settlement of Dover was in 1640. It was later established as the Springfield Parish of Dedham in 1748, and incorpor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
