Geochemistry and zircon U-Pb ages of granulite xenolith from Tuoyun basalts, Xinjiang: Implications for the petrogenesis and the lower crustal nature beneath the southwestern Tianshan

2005 ◽  
Vol 50 (12) ◽  
pp. 1242-1251 ◽  
Author(s):  
Jianping Zheng ◽  
Zhaohua Luo ◽  
Chunmei Yu ◽  
Xiaolu Yu ◽  
Ruisheng Zhang ◽  
...  
Keyword(s):  
Granulite Xenolith ◽  
Southwestern Tianshan ◽  
Lower Crustal

scholarly journals A U‐Pb Study of Zircons from a Lower Crustal Granulite Xenolith of the Spanish Central System: A Record of Iberian Lithospheric Evolution from the Neoproterozoic to the Triassic

2006 ◽  
Vol 114 (4) ◽  
pp. 471-483 ◽  
Author(s):  
Javier Fernández‐Suárez ◽  
Ricardo Arenas ◽  
Teresa E. Jeffries ◽  
Martin J. Whitehouse ◽  
Carlos Villaseca
Keyword(s):  
Central System ◽  
Granulite Xenolith ◽  
System A ◽  
Spanish Central System ◽  
Lower Crustal ◽  
Lithospheric Evolution

ID-TIMS U-PB GEOCHRONOLOGY OF LOWER CRUSTAL CUMULATE COMPLEXES IN THE KOHISTAN TERRANE, NORTH-EAST PAKISTAN: IMPLICATIONS FOR ISLAND ARC FORMATION

2016 ◽  
Author(s):  
Jack Edward Stirling ◽  
◽  
Steven W. Denyszyn ◽  
Marco L. Fiorentini ◽  
Robert R. Loucks
Keyword(s):  
Island Arc ◽  
North East ◽  
Lower Crustal

PRESERVATION OF FOUNDERED LOWER CRUSTAL CUMULATES IN THE HIGASHI-AKAISHI ULTRAMAFIC BODY, JAPAN

2019 ◽  
Author(s):  
Meghan Guild ◽  
◽  
Christy B. Till ◽  
Tomoyuki Mizukami ◽  
Simon Wallis
Keyword(s):  
Lower Crustal

Magmatic and tectonic emplacement of the Pukaskwa batholith, Superior Province, Ontario, CanadaThis article is one of a series of papers published in this Special Issue on the theme of Geochronology in honour of Tom Krogh.

2011 ◽  
Vol 48 (2) ◽  
pp. 187-204 ◽  
Author(s):  
Gary P. Beakhouse ◽  
Shoufa Lin ◽  
Sandra L. Kamo
Keyword(s):  
Partial Melting ◽  
Abrupt Change ◽  
Superior Province ◽  
Density Inversion ◽  
Tectonic Processes ◽  
Slab Breakoff ◽  
Greenstone Belts ◽  
Lower Crustal ◽  
Basaltic Crust ◽  
Structural Dome

The Neoarchean Pukaskwa batholith consists of pre-, syn-, and post-tectonic phases emplaced over an interval of 50 million years. Pre-tectonic phases are broadly synvolcanic and have a high-Al tonalite–trondhjemite–granodiorite (TTG) affinity interpreted to reflect derivation by partial melting of basaltic crust at lower crustal or upper mantle depths. Minor syn-tectonic phases slightly post-date volcanism and have geochemical characteristics suggesting some involvement or interaction with an ultramafic (mantle) source component. Magmatic emplacement of pre- and syn-tectonic phases occurred in the midcrust at paleopressures of 550–600 MPa and these components of the batholith are thought to be representative of the midcrust underlying greenstone belts during their development. Subsequent to emplacement of the syntectonic phases, and likely at approximately 2680 Ma, the Pukaskwa batholith was uplifted as a structural dome relative to flanking greenstone belts synchronously with ongoing regional sinistral transpressive deformation. The driving force for vertical tectonism is interpreted to be density inversion (Rayleigh–Taylor-type instabilities) involving denser greenstone belts and underlying felsic plutonic crust. The trigger for initiation of this process is interpreted to be an abrupt change in the rheology of the midcrust attributed to introduction of heat from the mantle attendant with slab breakoff or lithospheric delamination following the cessation of subduction. This process also led to partial melting of the intermediate to felsic midcrust generating post-tectonic granitic phases at approximately 2667 Ma. We propose that late density inversion-driven vertical tectonics is an inevitable consequence of horizontal (plate) tectonic processes associated with greenstone belt development within the Superior Province.

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