The Makran, Southeastern Iran: the anatomy of a convergent plate
... associated microcontinent of Southern Tethys; (i) and (ii) are section lines shown in Fig. 5. Palaeocene rocks indicates that some m61ange formation continued into the Palaeocene. This event ended by the late Palaeocene when there was an abrupt change in palaeography mainly involving uplift of geote ...
... associated microcontinent of Southern Tethys; (i) and (ii) are section lines shown in Fig. 5. Palaeocene rocks indicates that some m61ange formation continued into the Palaeocene. This event ended by the late Palaeocene when there was an abrupt change in palaeography mainly involving uplift of geote ...
how continents change and grow.
... rocks found in mountain belts. An &ccreti~tkslywedge develops where newly-formed layers of marine sediment u e folded and faulted as they are snawplowed off the subducring oceanic plate (see figure 4.32 and explanation in the previous chapter). Rock caught in and pulled down the subduction zone is s ...
... rocks found in mountain belts. An &ccreti~tkslywedge develops where newly-formed layers of marine sediment u e folded and faulted as they are snawplowed off the subducring oceanic plate (see figure 4.32 and explanation in the previous chapter). Rock caught in and pulled down the subduction zone is s ...
Density constraints on the formation of the continental Moho and crust
... Regardless of whether the mass of the continental crust has grown or has been conserved with time, the isotopic data indicate that large volumes of calcalkaline magmas could have originated from the mantle during certain episodes. For a detailed discussion of the relationship between isotopic "age p ...
... Regardless of whether the mass of the continental crust has grown or has been conserved with time, the isotopic data indicate that large volumes of calcalkaline magmas could have originated from the mantle during certain episodes. For a detailed discussion of the relationship between isotopic "age p ...
A Field, Petrographic, and Geochemical Study of Gabbros and
... pear to be layered locally, and possibly rhythmic layered but the latter is difficult to discern because of a well-developed vein network. The vein network consists of cross-cutting granitic veins {Figure 5). In places, the gabbros are metasomatized with complete replacement of primary mineralogy an ...
... pear to be layered locally, and possibly rhythmic layered but the latter is difficult to discern because of a well-developed vein network. The vein network consists of cross-cutting granitic veins {Figure 5). In places, the gabbros are metasomatized with complete replacement of primary mineralogy an ...
Bulk chemical analysis of rock samples: major elements
... are based on the observed sequence of crystallization of minerals from a melt, and take into account which minerals can and cannot coexist in equilibrium. However, these calculations are based on the following assumptions (which are rarely true): 1- No hydroxyl bearing minerals exist in the rock (i. ...
... are based on the observed sequence of crystallization of minerals from a melt, and take into account which minerals can and cannot coexist in equilibrium. However, these calculations are based on the following assumptions (which are rarely true): 1- No hydroxyl bearing minerals exist in the rock (i. ...
Petrologic and thermal constraints on the origin of leucogranites in
... (Winslow et al. 1995; Davidson et al. 1997; Whittington & Treloar 2002). In the three terranes, regional metamorphism and deformation of the host metapelitic sequences began several tens of millions of years prior to leucogranite magmatism during early stages of continental collisions, as shown by d ...
... (Winslow et al. 1995; Davidson et al. 1997; Whittington & Treloar 2002). In the three terranes, regional metamorphism and deformation of the host metapelitic sequences began several tens of millions of years prior to leucogranite magmatism during early stages of continental collisions, as shown by d ...
Petrology Lecture 9 Review
... 1. (T-F) It is possible for an index mineral to be present in a zone of higher grade than its own. 2. (T-F) Barrovian zones were developed in an area of rather narrow compositional range. In regions with different compositions, the use of additional or replacement index minerals may be appropriate. ...
... 1. (T-F) It is possible for an index mineral to be present in a zone of higher grade than its own. 2. (T-F) Barrovian zones were developed in an area of rather narrow compositional range. In regions with different compositions, the use of additional or replacement index minerals may be appropriate. ...
Metamorphic Petrology Review
... 1. (T-F) It is possible for an index mineral to be present in a zone of higher grade than its own. 2. (T-F) Barrovian zones were developed in an area of rather narrow compositional range. In regions with different compositions, the use of additional or replacement index minerals may be appropriate. ...
... 1. (T-F) It is possible for an index mineral to be present in a zone of higher grade than its own. 2. (T-F) Barrovian zones were developed in an area of rather narrow compositional range. In regions with different compositions, the use of additional or replacement index minerals may be appropriate. ...
1.6 General age and tectonic setting of the Arabian Shield
... as much as 5000 m. But at its greatest thickness the Phanerozoic cover is as much as 14 km (Fig. 1-5). On the west the shield is in fault and local deposition contact with rocks of the Red Sea basin. The basin developed during the opening of the Red Sea rift and is filled by late Mesozoic to Cenozoi ...
... as much as 5000 m. But at its greatest thickness the Phanerozoic cover is as much as 14 km (Fig. 1-5). On the west the shield is in fault and local deposition contact with rocks of the Red Sea basin. The basin developed during the opening of the Red Sea rift and is filled by late Mesozoic to Cenozoi ...
Exhuming Norwegian ultrahigh-pressure rocks
... responsible for the exhumation of Norwegian (ultra)high-pressure (UHP) rocks. Here we review data from the considerable volume of research describing this shear zone, and compile a strikeparallel cross section along the NSDZ from the Solund Basin in the south to the Sørøyane UHP domain in the north. ...
... responsible for the exhumation of Norwegian (ultra)high-pressure (UHP) rocks. Here we review data from the considerable volume of research describing this shear zone, and compile a strikeparallel cross section along the NSDZ from the Solund Basin in the south to the Sørøyane UHP domain in the north. ...
Geochronological constraint on the brittle-plastic deformation along the
... Mylonite samples on the western side of the cataclasite zone in the northern area show younger K-Ar ages of hornblende and biotite than those in other areas. This means that the western side of the northern area has a different cooling history. This different cooling history suggests that the granit ...
... Mylonite samples on the western side of the cataclasite zone in the northern area show younger K-Ar ages of hornblende and biotite than those in other areas. This means that the western side of the northern area has a different cooling history. This different cooling history suggests that the granit ...
structural zones transecting the southern rio grande rift
... Rozendal, 1975; Flawn, 1959; Wall and others, 1961) by this author supports gravity transport in response to basement block movement. The observed features here, as well as farther north, may have formed by right-lateral wrenching; I would propose that convergent wrenching produced the upthrusts alo ...
... Rozendal, 1975; Flawn, 1959; Wall and others, 1961) by this author supports gravity transport in response to basement block movement. The observed features here, as well as farther north, may have formed by right-lateral wrenching; I would propose that convergent wrenching produced the upthrusts alo ...
Opening of the North Atlantic and Norwegian
... of the North American Plate past the Eurasian Plate during the opening of the North Atlantic created an upthrust zone that formed due to space constraints associated with low-angle convergent strike slip or transform motion. The easiest direction for space relief for the squeezed sediments is vertic ...
... of the North American Plate past the Eurasian Plate during the opening of the North Atlantic created an upthrust zone that formed due to space constraints associated with low-angle convergent strike slip or transform motion. The easiest direction for space relief for the squeezed sediments is vertic ...
Rock Manual for Field Geology in Kumaun Region
... classified as extrusive (volcanic) vs. intrusive (plutonic) rocks, which are differentiated by the size of crystals present in the matrix (the finer-grained material that larger grains/crystals are embedded within). For sedimentary rocks, they are classified as clastic/fragmental vs. crystalline roc ...
... classified as extrusive (volcanic) vs. intrusive (plutonic) rocks, which are differentiated by the size of crystals present in the matrix (the finer-grained material that larger grains/crystals are embedded within). For sedimentary rocks, they are classified as clastic/fragmental vs. crystalline roc ...
Metamorphic Rocks Recall from the discussion of the rock cycle that
... another. Metamorphic rocks are produced from preexisting igneous, sedimentary, or even other metamorphic rocks. Thus, every metamorphic rock has a parent rock—the rock from which it was formed. Metamorphism, which means to “change form,” is a process that leads to changes in the mineral content, tex ...
... another. Metamorphic rocks are produced from preexisting igneous, sedimentary, or even other metamorphic rocks. Thus, every metamorphic rock has a parent rock—the rock from which it was formed. Metamorphism, which means to “change form,” is a process that leads to changes in the mineral content, tex ...
morphotectonic analysis of southern argolis peninsula
... Interchanging hills and valleys are observed. The terrain is rough. It is a new structure since is covered from Pleistocene volcanic formations. Methana Peninsula consists the northern part of the Hellenic Volcanic Arc. This region is a neotectonic active block with N-S direction. NW-SE faults of We ...
... Interchanging hills and valleys are observed. The terrain is rough. It is a new structure since is covered from Pleistocene volcanic formations. Methana Peninsula consists the northern part of the Hellenic Volcanic Arc. This region is a neotectonic active block with N-S direction. NW-SE faults of We ...
PowerPoint プレゼンテーション
... Plutons, stocks, and batholiths • The term pluton is used to denote a moderately large body of magma which is intruded essentially at one time and is contained within a single boundary. Plutons have various shapes but are commonly nearly circular in cross-section; an average area for many granitic p ...
... Plutons, stocks, and batholiths • The term pluton is used to denote a moderately large body of magma which is intruded essentially at one time and is contained within a single boundary. Plutons have various shapes but are commonly nearly circular in cross-section; an average area for many granitic p ...
Sequoia and Kings Canyon
... Although most of the rocks in the southern Sierra are granitic, there are many roof pendants of metamorphic rocks scattered through the granite. Most of the roof pendants are of irregular shape, but in general they are elongated to the northwest. Some are over ten miles long and several miles wide. ...
... Although most of the rocks in the southern Sierra are granitic, there are many roof pendants of metamorphic rocks scattered through the granite. Most of the roof pendants are of irregular shape, but in general they are elongated to the northwest. Some are over ten miles long and several miles wide. ...
Sample pages 2 PDF
... early Cretaceous there was in southern Africa through the Cretaceous and into the Miocene a period of comparative stability that led to the erosion of extensive low relief plains, called the African Surface. The surface was possibly eroded under tropical humid conditions, and remnants of kaolinised ...
... early Cretaceous there was in southern Africa through the Cretaceous and into the Miocene a period of comparative stability that led to the erosion of extensive low relief plains, called the African Surface. The surface was possibly eroded under tropical humid conditions, and remnants of kaolinised ...
Text - I2M Associates
... contaminated by crustal material introduced via plate subduction. We suggest two dynamic models that might be driving force for the volcanic activity, (1) intraplate lithospheric extension, resulted from long-term plate compression; (2) back-arc spreading at a plate margin. Such the mantle-lithosphe ...
... contaminated by crustal material introduced via plate subduction. We suggest two dynamic models that might be driving force for the volcanic activity, (1) intraplate lithospheric extension, resulted from long-term plate compression; (2) back-arc spreading at a plate margin. Such the mantle-lithosphe ...
CRUSTAL GROWTH IN SOUTHERN ARIZONA: U
... In the Pinal block, detrital zircons yield values from 1678 to 1731 Ma. ⑀Nd(t)values of metapelites and wackes range from ⴚ0.2 to 2.3. Values decrease from southeast to northwest, indicating progressive input of more evolved material toward the craton. Our data suggest that sedimentation within the ...
... In the Pinal block, detrital zircons yield values from 1678 to 1731 Ma. ⑀Nd(t)values of metapelites and wackes range from ⴚ0.2 to 2.3. Values decrease from southeast to northwest, indicating progressive input of more evolved material toward the craton. Our data suggest that sedimentation within the ...
Metamorphic Petrology Review
... • If water for hydration reactions were available in high-temperature mafic igneous rocks, would coarsegrained or fine-grained rocks react faster? Why? • (T-F) Hydration reactions may release large quantities of energy, significantly heating the rocks. • (T-F) If equilibrium is maintained, there is ...
... • If water for hydration reactions were available in high-temperature mafic igneous rocks, would coarsegrained or fine-grained rocks react faster? Why? • (T-F) Hydration reactions may release large quantities of energy, significantly heating the rocks. • (T-F) If equilibrium is maintained, there is ...
MANTLE- AND CRUST-DERIVED MAGMATISM IN THE
... lower εNd(t) compared with the TIB. The sources of the mafic magmatism can be interpreted in terms of a depleted mantle, variously overprinted by fluids and melts from subducted slabs. In the west (TIB), H2O-dominated fluids percolated and prepared shallower (lower Ce/Yb; spinel lherzolite field) ma ...
... lower εNd(t) compared with the TIB. The sources of the mafic magmatism can be interpreted in terms of a depleted mantle, variously overprinted by fluids and melts from subducted slabs. In the west (TIB), H2O-dominated fluids percolated and prepared shallower (lower Ce/Yb; spinel lherzolite field) ma ...
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.