Lecture 6 - Mantle and Basalts
... cumulate products of crystallization within below-ridge mafic magma chambers ...
... cumulate products of crystallization within below-ridge mafic magma chambers ...
volcanogenic massive sulphide deposits
... also known as volcanic-associated, volcanic-hosted, and volcano-sedimentary-hosted massive sulphide deposits. They typically occur as lenses of polymetallic massive sulphide that form at or near the seafloor in submarine volcanic environments. They form from metal-enriched fluids associated with sea ...
... also known as volcanic-associated, volcanic-hosted, and volcano-sedimentary-hosted massive sulphide deposits. They typically occur as lenses of polymetallic massive sulphide that form at or near the seafloor in submarine volcanic environments. They form from metal-enriched fluids associated with sea ...
The potential for gold mineralisation in the British Permian and
... The examination of the mineral potential of the Permian and Triassic rocks of Britain follows on from the discovery of a close association between gold and the Permian red-bed sediments and volcanics in Devon (Leake et al., 1991; Leake et al., 1992; Cameron et al., 1994). As a result of this work, a ...
... The examination of the mineral potential of the Permian and Triassic rocks of Britain follows on from the discovery of a close association between gold and the Permian red-bed sediments and volcanics in Devon (Leake et al., 1991; Leake et al., 1992; Cameron et al., 1994). As a result of this work, a ...
Tourmaline Isotopes: No Element Left Behind
... these rocks does not significantly fractionate B isotopes, as demonstrated by Kasemann et al. (2000). These authors also showed that tourmaline from metamorphic rocks and granites in the same crustal section have overlapping B isotope compositions, consistent with their estimate for the average cont ...
... these rocks does not significantly fractionate B isotopes, as demonstrated by Kasemann et al. (2000). These authors also showed that tourmaline from metamorphic rocks and granites in the same crustal section have overlapping B isotope compositions, consistent with their estimate for the average cont ...
secondary planar structural elements
... cleavage can be envisioned as a dense population of joints or microfaults generally formed in low metamorphic grade, competent rocks such as sandstone and limestone, where fracture cleavage may coexist with and grade into slaty cleavage in interlayered pelites. Microscopic to metre scale sets of fol ...
... cleavage can be envisioned as a dense population of joints or microfaults generally formed in low metamorphic grade, competent rocks such as sandstone and limestone, where fracture cleavage may coexist with and grade into slaty cleavage in interlayered pelites. Microscopic to metre scale sets of fol ...
29. Sulfur Isotope Ratios of Leg 126 Igneous Rocks
... sites in the Sumisu Rift, the geological processes associated with renewed rifting before backarc spreading were investigated, whereas drilling at the forearc sites revealed that the forearc basin also was formed by rifting. The basement of backarc Sites 790 and 791 consists largely of basaltic rock ...
... sites in the Sumisu Rift, the geological processes associated with renewed rifting before backarc spreading were investigated, whereas drilling at the forearc sites revealed that the forearc basin also was formed by rifting. The basement of backarc Sites 790 and 791 consists largely of basaltic rock ...
Somma Vesuvius: the Volcano and the Observatory
... were completely filled. Furthermore, some buildings suffered damage, in particular to their more elevated parts. As palaeotemperature measurements have confirmed, a lull of several hours followed the massive fine-ash deposition and permitted its cooling down sufficiently to allow the passage of men ...
... were completely filled. Furthermore, some buildings suffered damage, in particular to their more elevated parts. As palaeotemperature measurements have confirmed, a lull of several hours followed the massive fine-ash deposition and permitted its cooling down sufficiently to allow the passage of men ...
Zircon dating ties NE Atlantic sill emplacement to initial Eocene global... Journal of the Geological Society
... method on plagioclase. The U–Pb system in zircon can be biased by the presence of xenocrystic components and by Pb loss. To avoid xenocrystic zircons the measurements were made on long, slender prisms, especially such crystals with longitudinal cavities or inclusions of melts and/or other minerals t ...
... method on plagioclase. The U–Pb system in zircon can be biased by the presence of xenocrystic components and by Pb loss. To avoid xenocrystic zircons the measurements were made on long, slender prisms, especially such crystals with longitudinal cavities or inclusions of melts and/or other minerals t ...
Flood basalts, continental breakup and the dispersal of
... Abstract. The present study used igneous provinces, mainly continental flood volcanics or oceanic plateaus, at times associated with regional updoming, major rifting and continental breakup, together with its precisely dated magmatic events, as indications for paths of plume activity. First-generati ...
... Abstract. The present study used igneous provinces, mainly continental flood volcanics or oceanic plateaus, at times associated with regional updoming, major rifting and continental breakup, together with its precisely dated magmatic events, as indications for paths of plume activity. First-generati ...
Geol.Soc Australia Spec Publ.22 2003
... 1996). The chemistry of most of the present-day volcanic rocks of the Halmahera islands, including Bacan, indicates a typical intra-oceanic arc character but at the southern end of the arc there is evidence of contamination by underlying continental basement (Morris et al. 1983). Geochemical work on ...
... 1996). The chemistry of most of the present-day volcanic rocks of the Halmahera islands, including Bacan, indicates a typical intra-oceanic arc character but at the southern end of the arc there is evidence of contamination by underlying continental basement (Morris et al. 1983). Geochemical work on ...
ZINCIAN SPINEL ASSOCIATED WITH METAMORPHOSED
... & Karlstrom 1999). The area covered by Figure 2 is shown as an inset. ...
... & Karlstrom 1999). The area covered by Figure 2 is shown as an inset. ...
borehole geology and alteration mineralogy of well he
... alternating sequences of lavas and hyaloclastites that belong to Plio-Pleistocene age (0.01-3.1 m.y.). The main difference between these two units is the volcanic environment. The lavas are erupted in interglacial periods whereas the hyaloclastites are formed during the glacial periods. The youngest ...
... alternating sequences of lavas and hyaloclastites that belong to Plio-Pleistocene age (0.01-3.1 m.y.). The main difference between these two units is the volcanic environment. The lavas are erupted in interglacial periods whereas the hyaloclastites are formed during the glacial periods. The youngest ...
Imaging igneous rocks on the North Atlantic rifted continental margin
... together with direct imaging of the extrusive basalts enables us to constrain the volumes of extrusive and intrusive igneous rocks produced near the Faroe Islands to be 340–420 and 560–780 km3 per kilometre along strike, respectively. The COT marked both by high-velocity intrusions and lower-crustal ...
... together with direct imaging of the extrusive basalts enables us to constrain the volumes of extrusive and intrusive igneous rocks produced near the Faroe Islands to be 340–420 and 560–780 km3 per kilometre along strike, respectively. The COT marked both by high-velocity intrusions and lower-crustal ...
Multi-Stage Origin of the Coast Range Ophiolite, Supra-Subduction Zone Ophiolites
... and depositional contacts with overlying Upper Jurassic sediments of the Great Valley Sequence. At other locales, plutonic rocks are scarce, the volcanic rocks are more like “oceanic” basalts (that is, basalts erupted at oceanic spreading centers or within oceanic plates), and contacts with sediment ...
... and depositional contacts with overlying Upper Jurassic sediments of the Great Valley Sequence. At other locales, plutonic rocks are scarce, the volcanic rocks are more like “oceanic” basalts (that is, basalts erupted at oceanic spreading centers or within oceanic plates), and contacts with sediment ...
Geothermal Development in Eritrea
... energy balance and statistics indicate that the total national energy consumption was 611 toe out of which 486 toe or 79.7% was consumed by the household sector, 60.5 toe or 9.9% by the public and commercial sectors, 51.1 toe or 8.4% by transport and 13.4 toe or just 2.2% by the manufacturing indust ...
... energy balance and statistics indicate that the total national energy consumption was 611 toe out of which 486 toe or 79.7% was consumed by the household sector, 60.5 toe or 9.9% by the public and commercial sectors, 51.1 toe or 8.4% by transport and 13.4 toe or just 2.2% by the manufacturing indust ...
Secondary_4
... Sc6.1.6. List down and rank the top 10 strongest volcano in the world; Sc6.1.7. Construct a model of volcano; Sc6.1.8. Show concern for the welfare of others in times of volcanic eruption. ...
... Sc6.1.6. List down and rank the top 10 strongest volcano in the world; Sc6.1.7. Construct a model of volcano; Sc6.1.8. Show concern for the welfare of others in times of volcanic eruption. ...
Gem Corundum in Alkali Basalt: Origin and Occurrence
... volcanic rocks, and particularly basalts because of the great depths from which they originate (at least 20 lzm in most areas), commonly carry to the surface xenoliths (rock fragments) and xenocrysts [crystals) of "foreign" origin. Thus, such fragments and crystals have no genetic relationship to th ...
... volcanic rocks, and particularly basalts because of the great depths from which they originate (at least 20 lzm in most areas), commonly carry to the surface xenoliths (rock fragments) and xenocrysts [crystals) of "foreign" origin. Thus, such fragments and crystals have no genetic relationship to th ...
2012 Americas School of Mines
... kilometer. This means that melting could begin at a depth of 30 km. This is quite deep. Magma is known to form at much shallower depths because water in minerals lowers the melting point of the rock. The rock does not melt all at once because the minerals in a rock mass have different melting points ...
... kilometer. This means that melting could begin at a depth of 30 km. This is quite deep. Magma is known to form at much shallower depths because water in minerals lowers the melting point of the rock. The rock does not melt all at once because the minerals in a rock mass have different melting points ...
Unblocking temperatures of viscous remanent magnetism in
... (LTD) cycles and measured after warming to room temperature, until no significant changes were observed in remanence. LTD cycling is designed to preferentially erase the remanence carried by multidomain (MD) magnetite grains and leave SD remanence unaffected [Dunlop et al., 1997; Housen et al., 2003] ...
... (LTD) cycles and measured after warming to room temperature, until no significant changes were observed in remanence. LTD cycling is designed to preferentially erase the remanence carried by multidomain (MD) magnetite grains and leave SD remanence unaffected [Dunlop et al., 1997; Housen et al., 2003] ...
A Guide for Identifying Common Rock and Fossil Specimens Found
... we often see laying out in pastures and farm fields throughout the province. They vary in size from a few centimetres up to some that are many meters in diameter and weigh hundreds of tonnes (Figure 1). Many of these fieldstones can contain fossils. ...
... we often see laying out in pastures and farm fields throughout the province. They vary in size from a few centimetres up to some that are many meters in diameter and weigh hundreds of tonnes (Figure 1). Many of these fieldstones can contain fossils. ...
Mechanics of active magmatic intraplating in the Rio Grande Rift
... pattern of surface uplift is consistent with an elastic inflation of a large sill‐like magma body, the SMB could not have formed via steady elastic inflation because the latter would be outpaced by magma solidification. We resolve this problem using coupled thermo‐ visco‐elastic models, and place co ...
... pattern of surface uplift is consistent with an elastic inflation of a large sill‐like magma body, the SMB could not have formed via steady elastic inflation because the latter would be outpaced by magma solidification. We resolve this problem using coupled thermo‐ visco‐elastic models, and place co ...
Thick-Structured Proterozoic Lithosphere of the Rocky Mountain
... represent ongoing asthenoMoho, directly under the spheric convection or old Cheyenne suture. We lithospheric compositional suggest this slab was bodies. This puzzle is trapped against the edge compounded by the of the thick, Archean-age observation that each is Wyoming lithosphere after aligned with ...
... represent ongoing asthenoMoho, directly under the spheric convection or old Cheyenne suture. We lithospheric compositional suggest this slab was bodies. This puzzle is trapped against the edge compounded by the of the thick, Archean-age observation that each is Wyoming lithosphere after aligned with ...
Perspectives on the origin of plagiogranite in ophiolites from oxygen
... crust altered by hydrothermal fluids with seawater-like isotopic compositions at high temperatures, possibly due to vertical migration of the boundary between an active magma chamber and a vigorous high-temperature hydrothermal system in the overlying crust. If the partial melt was assimilated into a ...
... crust altered by hydrothermal fluids with seawater-like isotopic compositions at high temperatures, possibly due to vertical migration of the boundary between an active magma chamber and a vigorous high-temperature hydrothermal system in the overlying crust. If the partial melt was assimilated into a ...
Western Greece and Ionian Sea petroleum systems
... western Greece. (1) Neogene and Quaternary post-Alpine sediments. (2) Meso-Hellenic molasses. (3) Pre-Apulian (Paxos) zone. (4) Ionian zone. (5) Gavrovo-Tripolis zone. (6) Pindos zone. (7) Sub-Pelagonian zone. (8) Ophiolites (modified from Karakitsios and Rigakis, 2007). ...
... western Greece. (1) Neogene and Quaternary post-Alpine sediments. (2) Meso-Hellenic molasses. (3) Pre-Apulian (Paxos) zone. (4) Ionian zone. (5) Gavrovo-Tripolis zone. (6) Pindos zone. (7) Sub-Pelagonian zone. (8) Ophiolites (modified from Karakitsios and Rigakis, 2007). ...
OVERVIEW Tectonics of the Himalaya and southern Tibet from two
... continental arc developed on stabilized crust of the Lhasa terrane that had accreted with Eurasia during the Late Jurassic (Dewey et al., 1988). The northern Lhasa block includes poorly characterized Precambrian–Cambrian metamorphic rocks unconformably overlain by Devonian–Upper Cretaceous shallow-w ...
... continental arc developed on stabilized crust of the Lhasa terrane that had accreted with Eurasia during the Late Jurassic (Dewey et al., 1988). The northern Lhasa block includes poorly characterized Precambrian–Cambrian metamorphic rocks unconformably overlain by Devonian–Upper Cretaceous shallow-w ...
Algoman orogeny
The Algoman orogeny, known as the Kenoran orogeny in Canada, was an episode of mountain-building (orogeny) during the Late Archean Eon that involved repeated episodes of continental collisions, compressions and subductions. The Superior province and the Minnesota River Valley terrane collided about 2,700 to 2,500 million years ago. The collision folded the Earth's crust and produced enough heat and pressure to metamorphose the rock. Blocks were added to the Superior province along a 1,200 km (750 mi) boundary that stretches from present-day eastern South Dakota into the Lake Huron area. The Algoman orogeny brought the Archaen Eon to a close, about 2,500 million years ago; it lasted less than 100 million years and marks a major change in the development of the earth’s crust.The Canadian shield contains belts of metavolcanic and metasedimentary rocks formed by the action of metamorphism on volcanic and sedimentary rock. The areas between individual belts consist of granites or granitic gneisses that form fault zones. These two types of belts can be seen in the Wabigoon, Quetico and Wawa subprovinces; the Wabigoon and Wawa are of volcanic origin and the Quetico is of sedimentary origin. These three subprovinces lie linearly in southwestern- to northeastern-oriented belts about 140 km (90 mi) wide on the southern portion of the Superior Province.The Slave province and portions of the Nain province were also affected. Between about 2,000 and 1,700 million years ago these combined with the Sask and Wyoming cratons to form the first supercontinent, the Kenorland supercontinent.