Chi, G., Liu, Y. and Dube, B. 2009. Relationship between CO2
... The Red Lake greenstone belt is one of the foremost Au mining camps in Canada and hosts the world-class Campbell-Red Lake Au deposit. Belt-scale hydrothermal alteration is characterized by proximal ferroan dolomite zones associated with Au mineralization surrounded by distal calcite zones, both bein ...
... The Red Lake greenstone belt is one of the foremost Au mining camps in Canada and hosts the world-class Campbell-Red Lake Au deposit. Belt-scale hydrothermal alteration is characterized by proximal ferroan dolomite zones associated with Au mineralization surrounded by distal calcite zones, both bein ...
Economic geology research, volume 1 1999-2000
... during the county mapping by Gavelin (1955). During this period, some trenching was made and assays from trench samples indicated c. 3.1–3.6 % S and 0.8–1.4 % Cu which at the time was considered to be of no interest and consequently the exploration in the area ceased. Renewed interest in the area in ...
... during the county mapping by Gavelin (1955). During this period, some trenching was made and assays from trench samples indicated c. 3.1–3.6 % S and 0.8–1.4 % Cu which at the time was considered to be of no interest and consequently the exploration in the area ceased. Renewed interest in the area in ...
Mantle Influence, Rifting and Magmatism in the East African Rift
... west and south (Fig. 4). However, rifting was influenced by structures and rock fabrics in the Precambrian basement. The basement consists of Archean cratonic nuclei which were welded together by three successive Paleoproterozoic to early Paleozoic orogenic processes: ...
... west and south (Fig. 4). However, rifting was influenced by structures and rock fabrics in the Precambrian basement. The basement consists of Archean cratonic nuclei which were welded together by three successive Paleoproterozoic to early Paleozoic orogenic processes: ...
An Investigation of the carbonatites of the Kaapvaal Craton and their
... Carbonatites are exotic rocks which usually occur in discrete intrusions. Considering the association of carbonatites with rifting environments, this dissertation proposes that: carbonatites occur in extensional tectonic settings and therefore carbonatite occurrence can be used to constrain an exten ...
... Carbonatites are exotic rocks which usually occur in discrete intrusions. Considering the association of carbonatites with rifting environments, this dissertation proposes that: carbonatites occur in extensional tectonic settings and therefore carbonatite occurrence can be used to constrain an exten ...
Lecture 29: Stable Isotope Applications I
... All geothermometers are based on the apparently contradictory assumptions that complete equilibrium was achieved between phases during, or perhaps after, formation of the phases, but that the phases did not reequilibrate at any subsequent time. The reason these assumptions can be made and geothermom ...
... All geothermometers are based on the apparently contradictory assumptions that complete equilibrium was achieved between phases during, or perhaps after, formation of the phases, but that the phases did not reequilibrate at any subsequent time. The reason these assumptions can be made and geothermom ...
Thermal modelling of the Laramide orogeny: testing the £at
... whereby stress coupling of a subhorizontal oceanic slab to the upper plate transmitted stresses eastwards, producing basement-cored block uplifts and arc magmatism in the foreland. The thermal models presented here indicate that arc magma generation at significant distances inboard of the trench ( s ...
... whereby stress coupling of a subhorizontal oceanic slab to the upper plate transmitted stresses eastwards, producing basement-cored block uplifts and arc magmatism in the foreland. The thermal models presented here indicate that arc magma generation at significant distances inboard of the trench ( s ...
Geology of Sandia Park quadrangle, Bernalillo and Sandoval
... text, however, was written for stratigraphers and structural geologists. Engineers, laypersons, landowners, and those interested chiefly in the mechanical properties and general configuration of the rocks should read the structural multilayer section in the structural geology section. With the aid o ...
... text, however, was written for stratigraphers and structural geologists. Engineers, laypersons, landowners, and those interested chiefly in the mechanical properties and general configuration of the rocks should read the structural multilayer section in the structural geology section. With the aid o ...
as a PDF
... to that outlined by Christensen & Salisbury (1979). Oriented field samples of dunite and peridotite have been collected throughout each ultramafic massif. The density and distribution of samples depended on a variety of factors, including accessibility, structural information available from previous ...
... to that outlined by Christensen & Salisbury (1979). Oriented field samples of dunite and peridotite have been collected throughout each ultramafic massif. The density and distribution of samples depended on a variety of factors, including accessibility, structural information available from previous ...
SiphonPaper_Supplement_141124
... outcrop-to-outcrop hydrothermal siphons develop through a complex history of volcanism, lithospheric cooling, sedimentation, consolidation, lithification, alteration, and tectonic processes, all of which are highly variable and poorly known in detail at individual field sites. ...
... outcrop-to-outcrop hydrothermal siphons develop through a complex history of volcanism, lithospheric cooling, sedimentation, consolidation, lithification, alteration, and tectonic processes, all of which are highly variable and poorly known in detail at individual field sites. ...
imp prefaz.qxp - Istituto Nazionale di Oceanografia e di Geofisica
... tend to deepen where a process of active subduction is occurring. It is believed that the results described herewith could be used as additional elements for the study of seismogenesis. ...
... tend to deepen where a process of active subduction is occurring. It is believed that the results described herewith could be used as additional elements for the study of seismogenesis. ...
Physical volcanology of continental large igneous provinces: update
... Intrusive rocks are inferred to represent the solidified remnants of a plumbing system that fed eruptions at the surface, as well as themselves representing substantial accumulations of magma in the subsurface. The vast majority of intrusive rock within the upper crust is in widespread sills, the em ...
... Intrusive rocks are inferred to represent the solidified remnants of a plumbing system that fed eruptions at the surface, as well as themselves representing substantial accumulations of magma in the subsurface. The vast majority of intrusive rock within the upper crust is in widespread sills, the em ...
Fe isotopes: An emerging technique for understanding modern and
... very low solubility for Fe3+aq at neutral pH, which generally restricts Fe isotope variations to environments where redox boundaries exist. Fe-S interactions are also important (although incompletely understood), and such interactions are also closely tied to redox boundaries. Significant Fe isotope ...
... very low solubility for Fe3+aq at neutral pH, which generally restricts Fe isotope variations to environments where redox boundaries exist. Fe-S interactions are also important (although incompletely understood), and such interactions are also closely tied to redox boundaries. Significant Fe isotope ...
Chapter 21: Metamorphism
... Contact 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 roc ...
... Contact 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 roc ...
Introduction to Metamorphism
... Contact 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 roc ...
... Contact 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 roc ...
Pb composition of Mesozoic Pacific oceanic crust
... unmodified isotopic input into these subduction zones. The subducted ocean crust belongs to the oldest (130–167 Ma) in situ Pacific Ocean crust and thus has end-member character with respect to alteration and sediment load. The lithostratigraphic division of sedimentary units at Site 1149 into clays ...
... unmodified isotopic input into these subduction zones. The subducted ocean crust belongs to the oldest (130–167 Ma) in situ Pacific Ocean crust and thus has end-member character with respect to alteration and sediment load. The lithostratigraphic division of sedimentary units at Site 1149 into clays ...
The Basin and Range Province: Origin and Tectonic Significance
... Early students (e.g. King 1878, Dutton 1880) noted the presence of Mesozoic compressionalstructures in the region, and Nolan(1943) later madethe observation that Mesozoicand early Tertiary folding and thrusting, which ended in Eocenetime, had been followed rather closely by extensional faulting. He ...
... Early students (e.g. King 1878, Dutton 1880) noted the presence of Mesozoic compressionalstructures in the region, and Nolan(1943) later madethe observation that Mesozoicand early Tertiary folding and thrusting, which ended in Eocenetime, had been followed rather closely by extensional faulting. He ...
Arthur Holmes` paper of 1929 on convection currents within the
... passing downwards into granulite, both facies being subject to local transformation into eclogite under appropriate dynamic conditions. The thickness of the intermediate layer is found by Jeffreys to range from 20 to 25 km. Other observers confirm these figures or favour a slightly greater thickness ...
... passing downwards into granulite, both facies being subject to local transformation into eclogite under appropriate dynamic conditions. The thickness of the intermediate layer is found by Jeffreys to range from 20 to 25 km. Other observers confirm these figures or favour a slightly greater thickness ...
Characteristics and Petrogenesis of Alaskan-Type Ultramafic
... included in the Alaskan-type group. Exceptions are the basal ultramafic rocks of the tholeiitic, informally named La Perouse layered gabbro (Himmelberg and Loney, 1981; Loney and Himmelberg, 1983) in the Fairweather Range, the ultramafic rocks associated with the norite, diorite, granodiorite comple ...
... included in the Alaskan-type group. Exceptions are the basal ultramafic rocks of the tholeiitic, informally named La Perouse layered gabbro (Himmelberg and Loney, 1981; Loney and Himmelberg, 1983) in the Fairweather Range, the ultramafic rocks associated with the norite, diorite, granodiorite comple ...
Ascent of the ultrahigh-pressure Western Gneiss Region, Norway.
... and continental nappes of Baltican affinity; whether the continental nappes were microcontinents or outboard parts of Baltica is unknown. The Middle Allochthon, also of Baltican continental affinity, shares this ambiguity. The Lower Allochthon includes Baltican sedimentary and crystalline rocks. The ...
... and continental nappes of Baltican affinity; whether the continental nappes were microcontinents or outboard parts of Baltica is unknown. The Middle Allochthon, also of Baltican continental affinity, shares this ambiguity. The Lower Allochthon includes Baltican sedimentary and crystalline rocks. The ...
Edmond and Huh 2003 - Department of the Geophysical Sciences
... steady state closed system. Release of CO2 by mantle degassing and by biogenic precipitation of carbonates and their metamorphism in subduction zones balances the consumption by continental aluminosilicate weathering. Small perturbations in this balance bring about changes in PCO2 , but given the sm ...
... steady state closed system. Release of CO2 by mantle degassing and by biogenic precipitation of carbonates and their metamorphism in subduction zones balances the consumption by continental aluminosilicate weathering. Small perturbations in this balance bring about changes in PCO2 , but given the sm ...
the earth`s mantle elasticity and constitution
... Until some 50 years ago, the principal sources of information about the Earth's interior were geodesy and astronomy. The mean density and moment of inertia were known, and there were estimates of the effective rigidity based on the study of Earth tides. Since the mean density is about 5 .5, as compa ...
... Until some 50 years ago, the principal sources of information about the Earth's interior were geodesy and astronomy. The mean density and moment of inertia were known, and there were estimates of the effective rigidity based on the study of Earth tides. Since the mean density is about 5 .5, as compa ...
2.1.1 Introduction
... fault imparts only shearing motions in their directions; they are consequently known as nodal planes. Simplistically, then, a focal mechanism solution could be obtained by recording an earthquake at a number of seismographs distributed around its epicenter, determining the nature of the first motion ...
... fault imparts only shearing motions in their directions; they are consequently known as nodal planes. Simplistically, then, a focal mechanism solution could be obtained by recording an earthquake at a number of seismographs distributed around its epicenter, determining the nature of the first motion ...
The Architecture, Chemistry, and Evolution of - Cin
... Below we describe the major subduction-related arcs of the Americas, other significant arcs in the geologic record, and some of the tilted sections that expose deeper segments of arcs. 2.4.1. Extinct arcs. The western North American Cordillera comprises a continuous belt of arc products (mostly intru ...
... Below we describe the major subduction-related arcs of the Americas, other significant arcs in the geologic record, and some of the tilted sections that expose deeper segments of arcs. 2.4.1. Extinct arcs. The western North American Cordillera comprises a continuous belt of arc products (mostly intru ...
Crust and upper mantle discontinuity structure beneath eastern
... compensation of the heavily eroded topography [James et al., 1968; McNutt, 1980]. Data from the MOMA array allow us to systematically investigate crustal thickness and isostasy in the northern Appalachians. The MOMA array also provides new constraints on Moho topography into the Proterozoic craton, ...
... compensation of the heavily eroded topography [James et al., 1968; McNutt, 1980]. Data from the MOMA array allow us to systematically investigate crustal thickness and isostasy in the northern Appalachians. The MOMA array also provides new constraints on Moho topography into the Proterozoic craton, ...
ferrari answers
... intrinsically a 3D process and I proposed that the detachment propagated to the east and produced a migrating pulse of mafic volcanism. 3. What is the reason for the abrupt change for flat to steep subduction in the Cocos plate? Why is the Cocos plate more difficult to subduct than the Rivera plate? ...
... intrinsically a 3D process and I proposed that the detachment propagated to the east and produced a migrating pulse of mafic volcanism. 3. What is the reason for the abrupt change for flat to steep subduction in the Cocos plate? Why is the Cocos plate more difficult to subduct than the Rivera plate? ...
Baltic Shield
The Baltic Shield (sometimes referred to as the Fennoscandian Shield) is located in Fennoscandia (Norway, Sweden and Finland), northwest Russia and under the Baltic Sea. The Baltic Shield is defined as the exposed Precambrian northwest segment of the East European Craton. It is composed mostly of Archean and Proterozoic gneisses and greenstones which have undergone numerous deformations through tectonic activity (see Geology of Fennoscandia map [1]). The Baltic Shield contains the oldest rocks of the European continent. The lithospheric thickness is about 200-300 km. During the Pleistocene epoch, great continental ice sheets scoured and depressed the shield's surface, leaving a thin covering of glacial material and innumerable lakes and streams. The Baltic Shield is still rebounding today following the melting of the thick glaciers during the Quaternary Period.