Experimental Studies of Igneous Rock Series: A Zoned Pluton in the Wallowa Batholith, Oregon

Piwinskii, A.J.; Wyllie, Peter J.

doi:10.1086/627323

Cited by 155 publications

(47 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This formulation was selected to fit the variation of crystallinity with temperature observed for magma of granodioritic composition (Piwinskii and Wyllie, 1968). Most calculations were performed assuming outward inflating spherical magma chambers, though we tested sensitivity to the intrusion geometry by comparing these results with horizontally expanding cylinders and vertically accreting cylinders.…”

Section: Thermal Modeling and Calculation Of Synthetic Populations Ofmentioning

confidence: 99%

Estimates of Volume and Magma Input in Crustal Magmatic Systems from Zircon Geochronology: The Effect of Modeling Assumptions and System Variables

2016

View full text Add to dashboard Cite

Magma fluxes in the Earth's crust play an important role in regulating the relationship between the frequency and magnitude of volcanic eruptions, the chemical evolution of magmatic systems, and the distribution of geothermal energy and mineral resources on our planet. Therefore, quantifying magma productivity and the rate of magma transfer within the crust can provide valuable insights to characterize the long-term behavior of volcanic systems and to unveil the link between the physical and chemical evolution of magmatic systems and their potential to generate resources. We performed thermal modeling to compute the temperature evolution of crustal magmatic intrusions with different final volumes assembled over a variety of timescales (i.e., at different magma fluxes). Using these results, we calculated synthetic populations of zircon ages assuming the number of zircons crystallizing in a given time period is directly proportional to the volume of magma at temperature within the zircon crystallization range. The statistical analysis of the calculated populations of zircon ages shows that the mode, median, and standard deviation of the populations varies coherently as function of the rate of magma injection and final volume of the crustal intrusions. Therefore, the statistical properties of the population of zircon ages can add useful constraints to quantify the rate of magma injection and the final volume of magmatic intrusions. Here, we explore the effect of different ranges of zircon saturation temperature, intrusion geometry, and wall rock temperature on the calculated distributions of zircon ages. Additionally, we determine the effect of undersampling on the variability of mode, median, and standards deviation of calculated populations of zircon ages to estimate the minimum number of zircon analyses necessary to obtain meaningful estimates of magma flux and final intrusion volume.

show abstract

Section: Thermal Modeling and Calculation Of Synthetic Populations Ofmentioning

confidence: 99%

Estimates of Volume and Magma Input in Crustal Magmatic Systems from Zircon Geochronology: The Effect of Modeling Assumptions and System Variables

2016

View full text Add to dashboard Cite

show abstract

“…The dashed line separates data for granodiorites, monzonites, and tonalites from those for acid igneous rocks and sediments. Sources of data (other than this paper) are Piwinskii (1968), Piwinskii and Wyllie (1968) and Thompson (1981). (Weertman, 1971).…”

Section: Solidi Of Acid and Intermediate Silica-saturatedmentioning

confidence: 99%

Thermal aspects of the origin of Hebridean Tertiary acid magmas. II. Experimental melting behaviour of the granites at 1 kbar P_H₂0

Thompson

1983

Mineral. mag.

View full text Add to dashboard Cite

ABSTRACT. Experimental melting equilibria at 1 kbar PH2O are reported for three early Tertiary granites from Skye and one from Rhum, together with a quartz rnonzonite from Ardnamurchan. The Hebridean Province leucogranites show cotectic melting behaviour, whilst associated 'primitive' (mostly adamellitic) acid plutons have silicate liquidi N 925 ~ and plagiodase liquidi ~ 875 ~ At such high temperatures the morefusible crustal rock types of the region would be almost completely molten. If the Tertiary 'primitive' acid magmas were simple crustal melts, they would inherit the incompatible element ratios of their sialic progenitors. This is demonstrably not so. Minor element ratios in these plutons are consistent with extensive fractional crystallization during the evolution of their magmas. But it is, in most individual instances, extremely difficult to specify, either by thermal or geochemical arguments, whether (1) fractional crystallization followed sialic contamination of basic magmas or (2) mixing occurred between fractionation residua and sialic melts. Both the minor element ratios and cotectic melting behaviour of the Hebridean Province leucogranites are consistent with the view that they are products of extreme fractional crystallization of (sial contaminated) more-basic magmas. Nevertheless, it is clear--when the sequence and timing of emplacement of acid magmas within individual intrusive centres is considered--that very complex polycyclic combinations of fusion, fractionation, and re-fusion were involved in the evolution of these granites.The solidi of the samples studied experimentally, together with published data, show a progressive rise in temperature as the compositions of the rocks diverge from the minimum melting composition in NaA1Si30 sKA1Si3Os SiO2 at 1 kbarH2 o. This relationship is important when considering the likely nature of sialic contamination of basic to intermediate continental magmatic suites fed through reservoir systems which are swarms of dykes and, or, sills. Because salic low-solidus crustal rock types also show near-cotectic melting behaviour, (~ Copyright the Mineralogical Society

show abstract

“…Melting experiments of natural granitic rocks under watersaturated conditions produce eutectic melts (quartzalbite-orthoclase) with hornblende, calcic plagioclase and biotite in the residuum (e.g. Piwinskii, 1968;Piwinskii & Wyllie, 1968;Gibbon & Wyllie, 1969).…”

Section: Discussionmentioning

confidence: 99%

Ductile shearing and migmatization at mid‐crustal levels in an Archaean high‐grade gneiss belt, northern Gallatin Range, Montana, USA

Mogk

1992

Journal Metamorphic Geology

View full text Add to dashboard Cite

A high-grade Archaean gneiss terrane in the northern Gallatin Range, south-western Montana, USA, contains a trondhjemite-tonalite gneiss (TTG) sequence that was migmatized during pervasive ductile shearing. Metamorphism of these rocks is in the upper amphibolite to granulite facies at temperatures of 680-735 "C, pressures in excess of 8 kbar, and a 'clockwise' P-T-t path is inferred. Ductile shearing occurred in metre-scale anastomosing bands of high strain throughout the area. The TTGs have been extensively migmatized via vapour-present melt reactions involving the incongruent melting of biotitebearing TTG to produce hornblende and granitic melt. The granitic melt is produced in narrow envelopes adjacent to ductile shear zones in response to infiltration of water-rich solutions. Melt migration occurred on a local scale, and extraction of melt from the system left behind a plagioclase-hornblende residuum with minor interstitial microcline. Ductile shearing and migmatization in the TTG operated in a positive feedback mechanism; the entire volume of gneiss was chemically and mechanically reworked through the cyclical infiltration of aqueous solutions, vapour-present melting and melt-enhanced deformation. The proposed melt reaction may be an important crustal differentiation process considering that (1) many collisional orogens d o not attain temperatures high enough to permit vapour-absent melting, (2) pervasive networks of ductile shear zones at mid-crustal levels may serve as channels for fluid ingress and melt extraction, and (3) the large volumes of TTGs in Archaean and Phanerozoic orogens may constitute a significant source reservoir for certain types of high-level granites.

show abstract

Experimental Studies of Igneous Rock Series: A Zoned Pluton in the Wallowa Batholith, Oregon

Cited by 155 publications

References 46 publications

Estimates of Volume and Magma Input in Crustal Magmatic Systems from Zircon Geochronology: The Effect of Modeling Assumptions and System Variables

Estimates of Volume and Magma Input in Crustal Magmatic Systems from Zircon Geochronology: The Effect of Modeling Assumptions and System Variables

Thermal aspects of the origin of Hebridean Tertiary acid magmas. II. Experimental melting behaviour of the granites at 1 kbar P_H₂0

Ductile shearing and migmatization at mid‐crustal levels in an Archaean high‐grade gneiss belt, northern Gallatin Range, Montana, USA

Contact Info

Product

Resources

About

Experimental Studies of Igneous Rock Series: A Zoned Pluton in the Wallowa Batholith, Oregon

Cited by 155 publications

References 46 publications

Estimates of Volume and Magma Input in Crustal Magmatic Systems from Zircon Geochronology: The Effect of Modeling Assumptions and System Variables

Estimates of Volume and Magma Input in Crustal Magmatic Systems from Zircon Geochronology: The Effect of Modeling Assumptions and System Variables

Thermal aspects of the origin of Hebridean Tertiary acid magmas. II. Experimental melting behaviour of the granites at 1 kbar PH20

Ductile shearing and migmatization at mid‐crustal levels in an Archaean high‐grade gneiss belt, northern Gallatin Range, Montana, USA

Contact Info

Product

Resources

About

Thermal aspects of the origin of Hebridean Tertiary acid magmas. II. Experimental melting behaviour of the granites at 1 kbar P_H₂0