A short geologic history of the northeast United States
... deformation, metamorphism, and intrusion. The major Grenville orogenic period, ending about 950 million years ago, concluded the Precambrian. The eastern limit of the Grenville rocks is not known; it may have lain well to the east of what is now North America. The next major event seems to have been ...
... deformation, metamorphism, and intrusion. The major Grenville orogenic period, ending about 950 million years ago, concluded the Precambrian. The eastern limit of the Grenville rocks is not known; it may have lain well to the east of what is now North America. The next major event seems to have been ...
Plate Boundaries - Learn Earth Science
... How do oceanic and continental crust compare with regard to thickness and density? continental Density (ESRTs pg 10) thickness ...
... How do oceanic and continental crust compare with regard to thickness and density? continental Density (ESRTs pg 10) thickness ...
Plate Boundaries
... How do oceanic and continental crust compare with regard to thickness and density? continental Density (ESRTs pg 10) thickness ...
... How do oceanic and continental crust compare with regard to thickness and density? continental Density (ESRTs pg 10) thickness ...
7.4 Forces that move plates.
... Write a description of each example and suggest how each might have formed. ...
... Write a description of each example and suggest how each might have formed. ...
1.6 Drifting apart
... Draw what you imagine Iceland will look like in the future after rifting has completed. Provide new names for each of the smaller islands. In which direction, and towards which continent, will each island drift? ...
... Draw what you imagine Iceland will look like in the future after rifting has completed. Provide new names for each of the smaller islands. In which direction, and towards which continent, will each island drift? ...
A. Identifying Tectonic Plate Boundaries B. Tectonic Plate Movement
... 2. Trace where tectonic plates are moving APART with BLUE pen or marker & add small BLUE ARROWS to show their movement. 3. Trace the San Andreas fault in GREEN (or another color) pen or marker and add small GREEN ARROWS to show how the plates are sliding past one ...
... 2. Trace where tectonic plates are moving APART with BLUE pen or marker & add small BLUE ARROWS to show their movement. 3. Trace the San Andreas fault in GREEN (or another color) pen or marker and add small GREEN ARROWS to show how the plates are sliding past one ...
A. Identifying Tectonic Plate Boundaries B. Tectonic Plate Movement
... 2. Trace where tectonic plates are moving APART with BLUE pen or marker & add small BLUE ARROWS to show their movement. 3. Trace the San ...
... 2. Trace where tectonic plates are moving APART with BLUE pen or marker & add small BLUE ARROWS to show their movement. 3. Trace the San ...
Magma Genesis in Orogenic Belts
... Late stages of ocean closure:ANDESITIC magmas rise and join to form DIAPIRS which rise into upper crust As more and more diapirs rise, over-riding plate heats up Heating leads to partial melting of early formed diorites, producing GRANITIC magmas Low density (2.4-2.6) viscous granitic magmas rise sl ...
... Late stages of ocean closure:ANDESITIC magmas rise and join to form DIAPIRS which rise into upper crust As more and more diapirs rise, over-riding plate heats up Heating leads to partial melting of early formed diorites, producing GRANITIC magmas Low density (2.4-2.6) viscous granitic magmas rise sl ...
ocks in the lithosphere
... Lithosphere: The lithosphere of the Earth, is not homogeneous. Crust under the oceans is only about 5 km thick while continental crust can be up to 65 km thick. Also, ocean crust is made of denser minerals than continental crust. The tectonic plates are made up of Earth’s crust and the upper part o ...
... Lithosphere: The lithosphere of the Earth, is not homogeneous. Crust under the oceans is only about 5 km thick while continental crust can be up to 65 km thick. Also, ocean crust is made of denser minerals than continental crust. The tectonic plates are made up of Earth’s crust and the upper part o ...
Geología Norteamerica
... Some belts seem to be continuous along the strike and extremely short on strike. Some of them consist of a single terrane but in some others several discrete segments have been identified along the strike. These terranes have undergone synattachment and postattachment deformations. Moreover, the str ...
... Some belts seem to be continuous along the strike and extremely short on strike. Some of them consist of a single terrane but in some others several discrete segments have been identified along the strike. These terranes have undergone synattachment and postattachment deformations. Moreover, the str ...
File
... What is… – Lava from volcanoes = igneous rock – Subduction zones = pressure and heat (metamorphic or igneous. – Divergent boundaries = new crust (rock) ...
... What is… – Lava from volcanoes = igneous rock – Subduction zones = pressure and heat (metamorphic or igneous. – Divergent boundaries = new crust (rock) ...
Lecture 6 Structural Geology, Gettysburg NMP, Chickamauga and Chattanooga NMP
... plastic (or ductile) means that it does not ...
... plastic (or ductile) means that it does not ...
Chapter 3. Archean Crustal Provinces
... would subduct slower. Consequently, we expect that the length of midocean ridge, but not the rate of spreading, had played the more important role in the dissipation of terrestrial heat. According to Hargraves (1986), heat loss from the ridges ∞ cubic root of ridge length, => for a 2-3x higher of he ...
... would subduct slower. Consequently, we expect that the length of midocean ridge, but not the rate of spreading, had played the more important role in the dissipation of terrestrial heat. According to Hargraves (1986), heat loss from the ridges ∞ cubic root of ridge length, => for a 2-3x higher of he ...
Geology of British Columbia and Vancouver Island
... The Westcoast Crystalline complex (WCC) includes granitic rocks that are the intrusive equivalents of the Bonanza Fm. ...
... The Westcoast Crystalline complex (WCC) includes granitic rocks that are the intrusive equivalents of the Bonanza Fm. ...
geo-4840 tectonics-s04
... Introduction and course content; Anatomy and tectonic processes in mountain belts. Main themes: 1) Material balance and properties Uplift and subsidence. Topography, crustal and lithospheric thicknesses/structure ...
... Introduction and course content; Anatomy and tectonic processes in mountain belts. Main themes: 1) Material balance and properties Uplift and subsidence. Topography, crustal and lithospheric thicknesses/structure ...
presentation
... Shows the juxtaposition of rocks from a variety of geologic settings 2. 51 new age dates – Mesoproterozoic (1.4 billion years) to Miocene (20 million years). Oldest dated rocks are in S Londonderry, VT; youngest unit is the Brandon lignite, a deposit of brown coal and clay, dated as 20 mya based on ...
... Shows the juxtaposition of rocks from a variety of geologic settings 2. 51 new age dates – Mesoproterozoic (1.4 billion years) to Miocene (20 million years). Oldest dated rocks are in S Londonderry, VT; youngest unit is the Brandon lignite, a deposit of brown coal and clay, dated as 20 mya based on ...
Overview of Information about the Broad River watershed
... Hayesville Fault initially formed in different geological environments that were geographically separated from North America by significant expanses of ocean (Fig. 2). These “exotic” sequences are termed tectonic “terranes”. They collided with North America sometime prior to 325 million years ago an ...
... Hayesville Fault initially formed in different geological environments that were geographically separated from North America by significant expanses of ocean (Fig. 2). These “exotic” sequences are termed tectonic “terranes”. They collided with North America sometime prior to 325 million years ago an ...
Continental Crust
... • The Earth’s crust is divided into 12 major plates which are moved in various directions. • This plate motion causes them to collide, pull apart, or scrape against each other. • Each type of interaction causes a characteristic set of Earth structures or “tectonic” features. • The word, tectonic, re ...
... • The Earth’s crust is divided into 12 major plates which are moved in various directions. • This plate motion causes them to collide, pull apart, or scrape against each other. • Each type of interaction causes a characteristic set of Earth structures or “tectonic” features. • The word, tectonic, re ...
Field Mapping of the Redrock Area, Burro Mountains, southwest
... Paleoproterozoic sedimentary rocks in the Burro Mountains, southern Mazatzal province, have an unknown depositional age, depositional setting, and source region, and they were subsequently metamorphosed by one or all of the magmatic events that occurred at 1.63 Ga, 1.46 Ga, and 1.25 Ga. The main goa ...
... Paleoproterozoic sedimentary rocks in the Burro Mountains, southern Mazatzal province, have an unknown depositional age, depositional setting, and source region, and they were subsequently metamorphosed by one or all of the magmatic events that occurred at 1.63 Ga, 1.46 Ga, and 1.25 Ga. The main goa ...
Great Lakes tectonic zone
The Great Lakes tectonic zone is bounded by South Dakota at its tip and heads northeast to south of Duluth, Minnesota, then heads east through northern Wisconsin, Marquette, Michigan, and then trends more northeasterly to skim the northern-most shores of lakes Michigan and Huron before ending in the Sudbury, Ontario, Canada, area.During the Late Archean Era the Algoman orogeny added landmass to the Superior province by volcanic activity and continental collision along a boundary that stretches from present-day South Dakota, U.S., into the Lake Huron region near Sudbury, Ontario, Canada.This crustal boundary is the Great Lakes tectonic zone. It is 1,400 km (870 mi) long, and separates the older Archean gneissic terrane to the south from younger Late Archean greenstone-granite terrane to the north.The zone is characterized by active compression during the Algoman orogeny (about 2,700 million years ago), a pulling-apart (extensional) tectonics (2,450 to 2,100 million years ago), a second compression during the Penokean orogeny (1,900 to 1,850 million years ago), a second extension during Middle Proterozoic time (1,600 million years ago) and minor reactivation during Phanerozoic time (the past 500 million years).Collision began along the Great Lakes tectonic zone (GLTZ) with the Algoman mountain-building event and continued for tens of millions of years. During the formation of the GLTZ, the gneissic Minnesota River Valley subprovince was thrust up onto the Superior province's edge as it consumed the Superior province's oceanic crust. Fragmentation of the Kenorland supercontinent began 2,450 million years ago and was completed by 2,100 million years ago. The Wyoming province is the continental landmass that is hypothesized to have rifted away from the southern Superior province portion of Kenorland, before moving rapidly west and docking with the Laurentia supercontinent 1,850 to 1,715 million years ago. Sedimentation from the GLTZ-rifting environment continued into the Penokean orogeny, which is the next major tectonic event in the Great Lakes region. Several earthquakes have been documented in Minnesota, Michigan's Upper Peninsula and Sudbury in the last 120 years along the GLTZ.