Xenoliths of subducted crustal origin hosted by Miocene ultrapotassic igneous rocks in the southern Pamir provide important new information regarding the geological processes accompanying tectonism during the Indo-Eurasian collision. Four types have been studied: sanidine eclogites (omphacite, garnet, sanidine, quartz, biotite, kyanite), felsic granulites (garnet, quartz, sanidine and kyanite), basaltic eclogites (omphacite and garnet), and a glimmerite (biotite, clinopyroxene and sanidine). Apatite, rutile and carbonate are the most abundant minor phases. Hydrous phases (biotite and phengite in felsic granulites and basaltic eclogites, amphiboles in mafic and sanidine eclogites) and plagioclase form minor inclusions in garnet or kyanite. Solid-phase thermobarometry reveals recrystallization at mainly ultrahigh temperatures of 1000–1100°C and near-ultrahigh pressures of 2·5–2·8 GPa. Textures, parageneses and mineral compositions suggest derivation of the xenoliths from subducted basaltic, tonalitic and pelitic crust that experienced high-pressure dehydration melting, K-rich metasomatism, and solid-state re-equilibration. The timing of these processes is constrained by zircon ages from the xenoliths and 40Ar/39Ar ages of the host volcanic rocks to 57–11 Ma. These xenoliths reveal that deeply subducted crust may undergo extensive dehydration-driven partial melting, density-driven differentiation and disaggregation, and sequestration within the mantle. These processes may also contribute to the alkaline volcanism observed in continent-collision zones.

BRADLEY HACKER

PETER LUFFI

VALERY LUTKOV

VLADISLAV MINAEV

LOTHAR RATSCHBACHER

TERRY PLANK

MIHAI DUCEA

ALBERTO PATIÑO-DOUCE

MICHAEL McWILLIAMS

JIM METCALF

Journal of Petrology

《岩石学杂志》为在火成岩和变质岩石学和岩石发生的广泛领域发表高质量研究提供了一个国际论坛。发表的论文涵盖了主量元素、微量元素和同位素地球化学以及应用于岩石成因的年代学等领域的广泛主题；实验岩石学；岩浆生成、分化和就位过程；成岩矿物及其共生的定量研究；有助于解决基本岩石学问题的火成岩和变质岩的区域研究；岩石成因过程的理论模型。

The Journal of Petrology serves as an international forum for publishing high-quality research in the broad fields of igneous and metamorphic petrology and rock formation. The published papers cover a wide range of topics, including major and trace element geochemistry, isotopic studies, and geochronology applied to rock genesis; experimental petrology; processes of magma generation, differentiation, and emplacement; quantitative studies of diagenetic minerals and their associations; regional studies of igneous and metamorphic rocks that contribute to solving fundamental petrological issues; and theoretical models of rock formation processes.

《Journal of Petrology》是一个国际论坛，致力于发表关于火成岩和变质岩石学及其形成过程的高质量研究。该期刊涵盖了多个领域的主题，包括主量元素、微量元素和同位素地球化学，以及应用于岩石成因的年代学；实验岩石学；岩浆生成、分化和就位过程；成岩矿物及其共生的定量研究；以及有助于解决基本岩石学问题的火成岩和变质岩的区域研究。此外，期刊还探讨岩石成因过程的理论模型。

Category	Quartile
地球科学	2
地球科学, 地球化学与地球物理	2

Near-Ultrahigh Pressure Processing of Continental Crust: Miocene Crustal Xenoliths from the Pamir

ivySCI AI Smartly Parses PDF, Answers Researchers' Questions, and Helps You Understand Papers in Seconds

Journal Info

Category	Quartile
GEOCHEMISTRY & GEOPHYSICS	1