29. Sulfur Isotope Ratios of Leg 126 Igneous Rocks
... from Satsuma-Iwojima contain pyrrhotite and are saturated with respect to sulfur in spite of the low sulfur concentration (Ueda and Itaya, 1981), and similar observations have been made at other Japanese volcanic systems (Sakurajima and Okiura; Ueda and Sakai, 1984). Fe3+/total Fe ratios in the Sumi ...
... from Satsuma-Iwojima contain pyrrhotite and are saturated with respect to sulfur in spite of the low sulfur concentration (Ueda and Itaya, 1981), and similar observations have been made at other Japanese volcanic systems (Sakurajima and Okiura; Ueda and Sakai, 1984). Fe3+/total Fe ratios in the Sumi ...
geology of the virginia city quadrangle
... mean of 11 of 15 steps comprising 91.7% of 39Ar gave an age of ...
... mean of 11 of 15 steps comprising 91.7% of 39Ar gave an age of ...
Chapter 21: Metamorphism
... – Most easily recognized where a pluton is introduced into shallow rocks in a static environment – The rocks near the pluton are often high-grade rocks with an isotropic fabric: hornfelses (or granofelses) in which relict textures and structures are common – Polymetamorphic rocks are common, usually ...
... – Most easily recognized where a pluton is introduced into shallow rocks in a static environment – The rocks near the pluton are often high-grade rocks with an isotropic fabric: hornfelses (or granofelses) in which relict textures and structures are common – Polymetamorphic rocks are common, usually ...
Introduction to Metamorphism
... – Most easily recognized where a pluton is introduced into shallow rocks in a static environment – The rocks near the pluton are often high-grade rocks with an isotropic fabric: hornfelses (or granofelses) in which relict textures and structures are common – Polymetamorphic rocks are common, usually ...
... – Most easily recognized where a pluton is introduced into shallow rocks in a static environment – The rocks near the pluton are often high-grade rocks with an isotropic fabric: hornfelses (or granofelses) in which relict textures and structures are common – Polymetamorphic rocks are common, usually ...
Polygenetic Soils of the North-Central Part of the Gangetic Plains: A
... for these varies from 80/20 to 60/40. Floodplains show gefuric, chitonic and monic related distribution patterns (rdp) and, in the piedmonts, the rdp varies from enaulic to close porphyric. The nature and distribution of sand and silt indicate sedimentary layering and very weak pedogenic alteration. ...
... for these varies from 80/20 to 60/40. Floodplains show gefuric, chitonic and monic related distribution patterns (rdp) and, in the piedmonts, the rdp varies from enaulic to close porphyric. The nature and distribution of sand and silt indicate sedimentary layering and very weak pedogenic alteration. ...
Petrology and structure of syenite intrusions of the Okenyenya
... samples representative of the full range of intermediate and acid intrusive rock types from Okenyenya are given in Table 1. All of these rocks consist dominantly of microperthitic orthoclase showing various degrees of exsolution. Plagioclase, generally oligoclase, occurs in subordinate amounts as di ...
... samples representative of the full range of intermediate and acid intrusive rock types from Okenyenya are given in Table 1. All of these rocks consist dominantly of microperthitic orthoclase showing various degrees of exsolution. Plagioclase, generally oligoclase, occurs in subordinate amounts as di ...
Bedrock Geology along the Northern Margin of the Athabasca Basin
... garnetiferous leucogranite to garnet-biotite ± orthopyroxene ± graphite gneiss with colour indices of 2 to 20. Pods of garnetite up to 1 m in size are common. Garnet is generally altered and quartz is typically blue in colour. The presence of graphite is consistent with their non-magnetic character ...
... garnetiferous leucogranite to garnet-biotite ± orthopyroxene ± graphite gneiss with colour indices of 2 to 20. Pods of garnetite up to 1 m in size are common. Garnet is generally altered and quartz is typically blue in colour. The presence of graphite is consistent with their non-magnetic character ...
geologic field guide to the phoenix mountains, central arizona
... beds and gray phyllite. The sandy beds are not micaceous and do not have a strongly developed cleavage. The gray phyllite is mostly fine grained with well-developed cleavage. It locally contains large red jasper clasts derived from ferruginous quartzite, quartz clasts, and fine-grained white clasts, ...
... beds and gray phyllite. The sandy beds are not micaceous and do not have a strongly developed cleavage. The gray phyllite is mostly fine grained with well-developed cleavage. It locally contains large red jasper clasts derived from ferruginous quartzite, quartz clasts, and fine-grained white clasts, ...
Extensional origin of ductile fabrics in the Schist Belt, Central Brooks
... Abstract--Blueschist-faciesrocks are locally preserved in the internal zone of the Brooks Range orogen, where a high-strain foliation ($2) and down-dip stretching lineation occur for hundreds of kilometers along strike of the normal fault-bounded, southern edge of the orogen. This locally mylonitic ...
... Abstract--Blueschist-faciesrocks are locally preserved in the internal zone of the Brooks Range orogen, where a high-strain foliation ($2) and down-dip stretching lineation occur for hundreds of kilometers along strike of the normal fault-bounded, southern edge of the orogen. This locally mylonitic ...
投影片 1
... type of metal sulfide ore deposits, mainly Cu-Zn which are associated with and created by volcanic-associated hydrothermal events. They are predominantly stratiform accumulations of sulfide minerals that precipitate from hydrothermal fluids at or below the seafloor, in a wide range of ancient and mo ...
... type of metal sulfide ore deposits, mainly Cu-Zn which are associated with and created by volcanic-associated hydrothermal events. They are predominantly stratiform accumulations of sulfide minerals that precipitate from hydrothermal fluids at or below the seafloor, in a wide range of ancient and mo ...
7. Skagit River
... The North Cascades is the most rugged mountain range in the coterminous United States, a wilderness province so formidable that it deterred most explorers into the middle of the twentieth century. From its deep, glacially-carved valleys to its steep ice-mantled summit crests, it is the most heavily ...
... The North Cascades is the most rugged mountain range in the coterminous United States, a wilderness province so formidable that it deterred most explorers into the middle of the twentieth century. From its deep, glacially-carved valleys to its steep ice-mantled summit crests, it is the most heavily ...
Recycling of the continental crust | SpringerLink
... sedimentary rocks. The favoured explanation is that during the Archean, the sedimentary mass was growing and preserved sedimentary rocks a,e mainly first-cycle whereas during the post-Archean, the mass of sediments was near constant and preserved sedimentary rocks were strongly influenced by sedimen ...
... sedimentary rocks. The favoured explanation is that during the Archean, the sedimentary mass was growing and preserved sedimentary rocks a,e mainly first-cycle whereas during the post-Archean, the mass of sediments was near constant and preserved sedimentary rocks were strongly influenced by sedimen ...
North America`s Midcontinent Rift: When Rift Met LIP
... does not explain that the copper deposits result from the MCR’s volcanic rocks. ...
... does not explain that the copper deposits result from the MCR’s volcanic rocks. ...
The Penokean orogeny in the Lake Superior region
... extension and subsidence of the Superior craton resulted in a broad shallow sea characterized by volcanic grabens (Menominee Group in northern Michigan). The classic Lake Superior banded iron-formations, including those in the Marquette, Gogebic, Mesabi and Gunflint Iron Ranges, formed in that sea. ...
... extension and subsidence of the Superior craton resulted in a broad shallow sea characterized by volcanic grabens (Menominee Group in northern Michigan). The classic Lake Superior banded iron-formations, including those in the Marquette, Gogebic, Mesabi and Gunflint Iron Ranges, formed in that sea. ...
Geologic Map of the Leonia Quadrangle, Bonner and Boundary
... Prichard Formation, member e (Mesoproterozoic)—Light gray- to whiteweathering siltite and quartzite, and darker argillite. Siltite dominates over very feldspathic quartzite. Beds of both are 1-10 dm thick; some are parallel laminated, but many exhibit features of current traction such as rippled top ...
... Prichard Formation, member e (Mesoproterozoic)—Light gray- to whiteweathering siltite and quartzite, and darker argillite. Siltite dominates over very feldspathic quartzite. Beds of both are 1-10 dm thick; some are parallel laminated, but many exhibit features of current traction such as rippled top ...
A Geochemical Study of Crustal Plutonic Rocks from the Southern
... and RD64 (R/V KK81-06-26) from the northern wall of the Mariana trench near Guam, which is located in the southern part of the Izu-Bonin-Mariana (IBM) island arc system. The locations of the dredges are significant as the area contains volcanic rocks (forearc basalts and boninites) that have been pi ...
... and RD64 (R/V KK81-06-26) from the northern wall of the Mariana trench near Guam, which is located in the southern part of the Izu-Bonin-Mariana (IBM) island arc system. The locations of the dredges are significant as the area contains volcanic rocks (forearc basalts and boninites) that have been pi ...
Sublayer and Offset Dikes of the Sudbury Igneous
... North Range of the Sudbury structure. It extends up to a further 10 m into these rocks as thin apophyses. It is also present along the South Range but is much less common (Grant and Bite 1984) (3) Onaping Formation; this is a breccia composed of fragments of country rocks and recrystallized glassy m ...
... North Range of the Sudbury structure. It extends up to a further 10 m into these rocks as thin apophyses. It is also present along the South Range but is much less common (Grant and Bite 1984) (3) Onaping Formation; this is a breccia composed of fragments of country rocks and recrystallized glassy m ...
The geological singularities of a world
... The recent declaration of the Almaden Mine as Patrimony of the Humanity has been a recognition to an exceptional ore deposit. In the Almaden town surroundings special geological events occurred that gave rise to some deposits of a scarce metal that are surely unique at crustal levels. The Hg deposit ...
... The recent declaration of the Almaden Mine as Patrimony of the Humanity has been a recognition to an exceptional ore deposit. In the Almaden town surroundings special geological events occurred that gave rise to some deposits of a scarce metal that are surely unique at crustal levels. The Hg deposit ...
The Southern Mountains Zone, Isle of Rum, Scotland
... Although often massive in appearance, the mesobreccia is well organized in places and displays marked clast alignment and/or grading (Fig. 6a). Locally, abrupt variations in matrix/clast support, grain-size, grading and clast-type proportions delimit discrete bodies within what otherwise might seem ...
... Although often massive in appearance, the mesobreccia is well organized in places and displays marked clast alignment and/or grading (Fig. 6a). Locally, abrupt variations in matrix/clast support, grain-size, grading and clast-type proportions delimit discrete bodies within what otherwise might seem ...
STRATEGIC STONE STUDY - British Geological Survey
... also have been affected by thrusting and faulting, and partial melting as well as serpentinization. Many of these varied rock types have provided vernacular building materials. All these events have contributed to creating the wide diversity of rock types and minerals that have shaped the Cornish an ...
... also have been affected by thrusting and faulting, and partial melting as well as serpentinization. Many of these varied rock types have provided vernacular building materials. All these events have contributed to creating the wide diversity of rock types and minerals that have shaped the Cornish an ...
Excursion Guidebook
... Middle Ordovician age (455 Ma), buried under sediments; it is 540 m deep and 4 km in diameter. The crater’s features are vaguely reflected in surface topography. As a result of the impact, Ordovician limestone layers dip at about 20 degrees in the abandoned Paluküla limestone quarry. It is the secon ...
... Middle Ordovician age (455 Ma), buried under sediments; it is 540 m deep and 4 km in diameter. The crater’s features are vaguely reflected in surface topography. As a result of the impact, Ordovician limestone layers dip at about 20 degrees in the abandoned Paluküla limestone quarry. It is the secon ...
Wolverine Deposit Stratigraphy and Shale Relationships
... consists of either carbonaceous shale or carbonate-exhalite and these are conformably overlain, in turn, by carbonaceous shale interlayered with rhyolitic siltstone and iron formation, rhyolite siltstone breccias, and upper carbonaceous shale, all being capped by basalt, mafic volcaniclastic rocks, ...
... consists of either carbonaceous shale or carbonate-exhalite and these are conformably overlain, in turn, by carbonaceous shale interlayered with rhyolitic siltstone and iron formation, rhyolite siltstone breccias, and upper carbonaceous shale, all being capped by basalt, mafic volcaniclastic rocks, ...
appendix 2 - Rockmass.net
... 2.2 Composition and structure of faults Faults and fracture zones can vary in composition from mostly brecciated or crushed material with relatively small amounts of clay to highly weathered or hydrothermally altered, highly plastic, swelling clay gouge. The composition of these pieces can be simila ...
... 2.2 Composition and structure of faults Faults and fracture zones can vary in composition from mostly brecciated or crushed material with relatively small amounts of clay to highly weathered or hydrothermally altered, highly plastic, swelling clay gouge. The composition of these pieces can be simila ...
Late Miocene to Pliocene stratigraphic evolution of northeast
... faults on the east and west margins of the island. The bedrock geology of Carmen Island consists primarily of dipping Miocene volcanic rocks (Comondu Formation of Hausback, 1984; Sawlan, 1991) overlain by less steeply dipping Pliocene sedimentary rocks and smaller patches of raised Quaternary limes ...
... faults on the east and west margins of the island. The bedrock geology of Carmen Island consists primarily of dipping Miocene volcanic rocks (Comondu Formation of Hausback, 1984; Sawlan, 1991) overlain by less steeply dipping Pliocene sedimentary rocks and smaller patches of raised Quaternary limes ...
Elevated 87Sr/86Sr Ratios From Mafic Intrusions in the Atlanta Lobe
... plutons show deeper levels of exposure than do plutons from the better studied Sierran Nevada batholith. Additional work on the border zone rocks of the Atlanta lobe includes regional summaries and reconnaissance studies by Anderson (1952), Larsen and Schmidt (1958), Schmidt (1964), Taubeneck (1971) ...
... plutons show deeper levels of exposure than do plutons from the better studied Sierran Nevada batholith. Additional work on the border zone rocks of the Atlanta lobe includes regional summaries and reconnaissance studies by Anderson (1952), Larsen and Schmidt (1958), Schmidt (1964), Taubeneck (1971) ...
Clastic rock
Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus, chunks and smaller grains of rock broken off other rocks by physical weathering. Geologists use the term clastic with reference to sedimentary rocks as well as to particles in sediment transport whether in suspension or as bed load, and in sediment deposits.