Petromagnetism of the continental lithosphere and the origin of regional magnetic anomalies: A review

Pechersky, D. M.; Genshaft, Yu. S.

doi:10.2205/2001es000059

Cited by 10 publications

(6 citation statements)

References 42 publications

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“…These pyroxenite xenoliths show a considerable range of magnetization but low average values of χ (< 40 × 10 À8 m 3 kg À1 ) ( Table 6), J i (< 0.15 Am À1 ), and NRM (< 0.1 Am À1 ), close to the values of the Hannuoba mafic granulite xenoliths [Q. S. and worldwide upper mantle xenoliths [Wasilewski and Mayhew, 1992]. These results indicate that the mafic granulites, pyroxenites and lherzolites are too weakly magnetic to match the requirement of the long-wavelength anomalies (> 1 Am À1 ) [Pechersky and Genshaft, 2001]. Therefore, the limiting depth of magnetization in the crust does not extend to the top of the present crust-mantle transition zone (~32 km).…”

Section: Implications Forsupporting

confidence: 54%

“…Liu et al ., ] and worldwide upper mantle xenoliths [ Wasilewski and Mayhew , ]. These results indicate that the mafic granulites, pyroxenites and lherzolites are too weakly magnetic to match the requirement of the long‐wavelength anomalies (> 1 Am −1 ) [ Pechersky and Genshaft , ]. Therefore, the limiting depth of magnetization in the crust does not extend to the top of the present crust‐mantle transition zone (~ 32 km).…”

Section: Discussionmentioning

confidence: 99%

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Magnetic mineralogy of pyroxenite xenoliths from Hannuoba basalts, northern North China Craton: Implications for magnetism in the continental lower crust

Zheng

Zeng

et al. 2014

J. Geophys. Res. Solid Earth

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Studies of the petrology, mineral chemistry, and rock magnetic properties of nine pyroxenite xenoliths from Hannuoba basalts, northern North China Craton, have been made to determine the magnetization signature of the continental lower crust. These pyroxenites are weakly magnetic with low average susceptibility (χ) and saturation isothermal remanent magnetization (M rs ) of 39.59 × 10 À8 m 3 kg À1and 12.05 × 10 À3 Am 2 kg À1 , respectively. The magnetic minerals are mainly magnetite, pyrrhotite, and Fe-rich spinel, which significantly contribute to χ and natural remanent magnetization. Magnetite occurs as interstitial microcrystals together with zeolite aggregates, indicating a secondary origin in a supergene environment. In contrast, pyrrhotite and Fe-rich spinel were formed prior to the xenoliths' ascent to the surface, as evidenced by their dominant occurrence as tiny inclusions and thin exsolution lamellae in pyroxene. The Fe-rich spinel has~50% mole fraction of Fe 3 O 4 and corresponds to the strongest magnetization, and its coexistence with Mg-rich spinel implies a reheating event due to the underplating of basaltic magma. Besides, armalcolite and ilmenite were found in the reaction rims between xenoliths and the basalt, but they contribute little to the whole rock magnetization. However, these pyroxenite xenoliths would be nonmagnetic at in situ depths, as well as peridotite and mafic granulite xenoliths derived from the crust-mantle transition zone (~32-42 km). Therefore, we suggest the limiting depth of magnetization at the boundary between weakly magnetic deep-seated (lower crust and upper mantle) xenoliths and strongly magnetic Archean granulite facies rocks (~32 km) in Hannuoba, northern North China Craton.

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Section: Implications Forsupporting

confidence: 54%

Section: Discussionmentioning

confidence: 99%

Magnetic mineralogy of pyroxenite xenoliths from Hannuoba basalts, northern North China Craton: Implications for magnetism in the continental lower crust

Zheng

Zeng

et al. 2014

J. Geophys. Res. Solid Earth

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“…По результатам совместной интерпретации плотностных и магнитных разрезов с данными магнитотеллурических зондирований было установлено, что проводящие слои в диапазоне глубин от 20 км до 45 км на плотностном разрезе соответствуют реологически ослабленным зонам повышенной пористости в условиях разогрева до температуры более, чем 600°С. На геомагнитном разрезе эта зона разогрева приурочена к областям слабомагнитных пород, находящихся при температурах выше точки Кюри (560°С) (Бердичевский и др., 1999;Киссин, 2009;Копытенко и др., 2011;Pechersky, Genshaft, 2001).…”

Section: исследование известных термальных источников юга восточной сunclassified

Geothermal Zones of the South of East Siberia

Petrova¹,

Kopytenko²

2019

Bulletin of KRAESC. Earth Sciences

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“…Composition of this mineral is very sensitive to temperature, pressure, and the existing water content in molten material [6] [7]. Plagioclase is present as one of the major minerals in composition of volcanic rocks in Sarcheshmeh zone.…”

Section: Chemistry Of Plagioclasementioning

confidence: 99%

The Petrography, Mineralography and Microprobe Analysis on New Exploratory Excavation Phase in Sarcheshmeh Copper Mine Pit and Comparing Them with Existing Data from the Other Area in South West Sarcheshmeh

Riseh¹,

Abedini²,

Emami³

et al. 2017

OJG

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Kerman region where Sarcheshmeh zone is located includes the end part of Uremia-Dokhtar Zone. Extrusive igneous group in Sarcheshmeh is as follows: 1) andesite and 2) rhyodacite. The group of intrusive igneous rocks includes 1) porphyry granite, 2) porphyry granodiorite, and 3) porphyry diorite. Nochoon mine is located at 4 km of southwest of Sarcheshmeh copper mine and it comprises of a group of extrusive igneous rocks as follows: 1) andesite, and 2) dacite. Based on results of microprobe analysis, pyroxene mineral's composition in these rocks of diopside and augite indicates amphiboles of composite zone of magnesium hosting type and existing plagioclases in regional rock for labradorite and bitonit composition. The most common compounds are chlorite with formula among antigorite and amosite. Comparison of magnetite mineralization in Sarcheshmeh and Nochoon indicates vein mineralization in Nochoon and disseminated granulation in Sarcheshmeh and particularly concerning to chalcopyrite, Nochoon includes more veins than Sarcheshmeh.

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Petromagnetism of the continental lithosphere and the origin of regional magnetic anomalies: A review

Cited by 10 publications

References 42 publications

Magnetic mineralogy of pyroxenite xenoliths from Hannuoba basalts, northern North China Craton: Implications for magnetism in the continental lower crust

Magnetic mineralogy of pyroxenite xenoliths from Hannuoba basalts, northern North China Craton: Implications for magnetism in the continental lower crust

Geothermal Zones of the South of East Siberia

The Petrography, Mineralography and Microprobe Analysis on New Exploratory Excavation Phase in Sarcheshmeh Copper Mine Pit and Comparing Them with Existing Data from the Other Area in South West Sarcheshmeh

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