scholarly journals Trace element abundances of Mauna Kea basalt from phase 2 of the Hawaii Scientific Drilling Project: Petrogenetic implications of correlations with major element content and isotopic ratios

2003 ◽  
Vol 4 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
S. Huang ◽  
F. A. Frey
Keyword(s):  
Trace Element ◽  
Major Element ◽  
Element Content ◽  
Isotopic Ratios ◽  
Phase 2 ◽  
Scientific Drilling ◽  
Element Abundances ◽  
Drilling Project

Geochemical constraints on the differentiation processes that were active in the Sept Iles complex

1986 ◽  
Vol 23 (5) ◽  
pp. 670-681 ◽  
Author(s):  
Michael D. Higgins ◽  
R. Doig
Keyword(s):  
Mass Balance ◽  
Trace Element ◽  
Fractional Crystallization ◽  
Major Element ◽  
Alkali Feldspar ◽  
Granitic Magma ◽  
Trace Element Distribution ◽  
Accessory Mineral ◽  
Quartz Syenite ◽  
Element Abundances

Major- and trace-element abundances in the major units (gabbro, anorthosite, monzonite, syenite, and granite) of the unmetamorphosed Sept Iles complex have been evaluated to determine if these rocks can be related by simple magmatic processes or if it is necessary to invoke separately derived magmas. Major-element mass-balance and trace-element distribution calculations indicate that the diorite and quartz syenite were produced by fractional crystallization of plagioclase and augite, together with minor hypersthene and ilmenite, from a parental gabbroic magma. The Sr depletion of the granite, as compared with the quartz syenite, cannot be developed readily by partial melting and is better explained by fractional crystallization models. Major-element mass-balance solutions indicate that the granite was formed by removal of alkali feldspar, plagioclase, amphibole, and ilmenite from a quartz syenitic magma. Depletion of REE in the granite was probably the result of amphibole or REE-rich accessory mineral fractionation. It is unlikely that an unrelated, independently generated granitic magma could have a composition so related to the remainder of the complex. Therefore, fractional crystallization of a parental gabbroic magma is the dominant process that controlled the diversity of magma in the complex.

An evaluation of major element heterogeneity in the mantle sources of basalts

1980 ◽  
Vol 297 (1431) ◽  
pp. 383-407 ◽  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Major Element ◽  
Major Elements ◽  
Element Abundances ◽  
Ocean Island ◽  
Basaltic Rocks ◽  
The North ◽  
Mantle Sources ◽  
Incompatible Trace Elements

Understanding the evolution of the mantle requires a knowledge of the relative variations of the major elements, trace elements and isotopes in the mantle. Most of the evidence for mantle heterogeneity is based on variations in the trace element and isotopic ratios of basaltic rocks. These ratios are presumed to reflect variations in the mantle sources. To compare major element heterogeneities with trace element and isotopic heterogeneities, it is necessary that the major element abundances in basalts also reflect variations in the mantle sources. Probably the only major element for which this is so is iron. If a basalt has only undergone fractional crystallization of olivine, then the abundance of FeO in the basalt reflects the FeO/MgO ratio of the mantle source, the degree of melting, and the pressure at which melting occurs. Relative pressures and degrees of melting can often be constrained, so that variations in the abundances of FeO can be used to obtain information about variations in the FeO/MgO ratio of the mantle sources of basalts. Comparison of FeO contents with trace element and isotopic contents of basalts shows some striking correlations and leads to the following conclusions. 1. Parental magmas for Kilauean basalts from Hawaii may be related by different degrees of melting of a homogeneous, garnet-bearing source. 2. Mid-ocean ridge basalts from the North Atlantic show a negative correlation of La/Sm with FeO, suggesting that the sources that are most enriched in incompatible trace elements are most depleted in FeO relative to MgO, and are probably also depleted in the other components of basalt. This correlation does not apply to the entire suboceanic mantle. 3. A comparison of tholeiites from near the Azores and from Hawaii shows that sources with similar Nd and Sr isotope ratios may have undergone distinctly different histories in the development of their major and trace element abundances. 4. Ocean island tholeiites tend to be more enriched in FeO than ocean floor tholeiites. Either the ocean island sources have greater FeO/MgO ratios, or melting begins at significantly greater pressures beneath ocean islands than beneath ocean ridges. 5. Major element variations in the mantle are controlled mainly by tectonics and the addition or removal of silicate melts. Trace element variations, however, may be controlled by the addition or removal of fluids as well. Thus major elements, trace elements and isotopes may each give a different perspective important to the understanding of the evolution of the mantle.

Petrology of syenites from center III of the Coldwell alkaline complex, northwestern Ontario, Canada

1993 ◽  
Vol 30 (1) ◽  
pp. 145-158 ◽  
Author(s):  
Roger H. Mitchell ◽  
R. Garth Platt ◽  
Jurate Lukosius-Sanders ◽  
Maureen Artist-Downey ◽  
Shelley Moogk-Pickard
Keyword(s):  
Rare Earth ◽  
Trace Element ◽  
Major Element ◽  
Volcanic Rocks ◽  
Basalt Magma ◽  
Alkaline Complex ◽  
Quartz Syenite ◽  
Element Abundances ◽  
Northwestern Ontario ◽  
Single Batch

Center III of the Coldwell alkaline complex consists of metaluminous hypersolvus syenites, which in order of intrusion are magnesiohornblende syenite, contaminated ferro-edenite syenite, ferroedenite syenite, and quartz syenite. Contaminated syenites were formed by the assimilation of coeval basaltic volcanic rocks. The suite as a whole is characterized by the presence of a wide variety of amphiboles ranging in composition from magnesiohornblende through ferroedenite and ferrorichterite to arfvedsonite. Pyroxenes are rare and hedenbergite is present in significant amounts only in quartz syenite. Whole-rock major element data indicate that the majority of the syenites do not represent liquid compositions. The syenites have high contents of Nb, Zr, Th, U, Y, and Ga and have the geochemical character of A-type granitoids. Rare earth and other trace element abundances suggest that the quartz syenites cannot be differentiates of the magma that formed the ferroedenite syenites. All syenites are considered to have originated by the extensive fractional crystallization of mantle-derived basalt magma within the plutonic infrastructure of the complex. The syenite suite does not represent the differentiation products of a single batch of magma. Multiple intrusion, contamination, and brecciation of preexisting syenite plutons have resulted in the complex geological relationships characteristic of center III.

Major- and trace-element characterization, expanded distribution, and a new chronology for the latest Pleistocene Glacier Peak tephras in western North America

2009 ◽  
Vol 71 (2) ◽  
pp. 201-216 ◽  
Author(s):  
Stephen C. Kuehn ◽  
Duane G. Froese ◽  
Paul E. Carrara ◽  
Franklin F. Foit ◽  
Nicholas J.G. Pearce ◽  
...  
Keyword(s):  
North America ◽  
Trace Element ◽  
Late Pleistocene ◽  
Major Element ◽  
Element Composition ◽  
Western North America ◽  
Major Element Composition ◽  
Element Abundances ◽  
Southern Alberta ◽  
Tephra Beds

AbstractThe Glacier Peak tephra beds are among the most widespread and arguably some of the most important late Pleistocene chronostratigraphic markers in western North America. These beds represent a series of closely-spaced Plinian and sub-Plinian eruptions from Glacier Peak, Washington. The two most widespread beds, Glacier Peak ‘G’ and ‘B’, are reliably distinguished by their glass major and trace element abundances. These beds are also more broadly distributed than previously considered, covering at least 550,000 and 260,000 km2, respectively. A third bed, the Irvine bed, known only from southern Alberta, is similar in its major-element composition to the Glacier Peak G bed, but it shows considerable differences in trace element concentrations. The Irvine bed is likely considerably older than the G and B tephras and probably records an additional Plinian eruption, perhaps also from Glacier Peak but from a different magma than G through B. A review of the published radiocarbon ages, new ages in this study, and consideration in a Bayesian framework suggest that the widespread G and B beds are several hundred years older than widely assumed. Our revised age is about 11,600 14C yr BP or a calibrated age (at 2 sigma) of 13,710–13,410 cal yr BP.

Salton Sea Scientific Drilling Project; on-site science management; California

1986 ◽  
Author(s):  
J.H. Sass ◽  
S.S. Priest ◽  
L.C. Robison ◽  
J.D. Hendricks
Keyword(s):  
Salton Sea ◽  
Scientific Drilling ◽  
Science Management ◽  
Drilling Project
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