Qiang Ma

• PhD
• China University of Geosciences

The geochemical signatures of “adakites” are usually attributed to high-pressure ( ) partial melting of mafic rocks, and accordingly the occurrence of adakitic magmas in continental settings is frequently used as an indicator of a thickened or foundered lower crust at the time of magma emplacement. These premises are built on experiments and modeli...

High-Mg andesites (HMAs) and adakitic rocks are purported to occur exclusively in subduction zones in the modern Earth. In the North China Craton, early Cretaceous HMAs and adakitic dacites were erupted in a continental setting, apparently unrelated to subduction given their location distal (>1000 km) to the trench at that time. Here we report petr...

Granulite-facies xenoliths entrained within igneous rocks shed a light on poorly understood yet critical questions about age, origin and history of the lower continental crust. Here, we present the first coupled in-situ U-Pb, Lu-Hf and O isotope data for the Precambrian zircons from fourteen deep-crustal xenoliths from the North China craton. The g...

Eastern China provides a precious opportunity to explore how subduction drives evolution of the overlying continental lithosphere and to understand the fate of subducted plates. In this study, a synthesis of geochronological, whole-rock geochemical and zircon Hf isotopic data is used to examine temporal and spatial variations in distribution, compo...

Subduction of the paleo-Pacific plate during the late Mesozoic is thought to have been responsible for the destruction of the North China craton, manifested by intense volcanism, lithospheric deformation, and dramatic changes in surface morphology and terrestrial ecosystems. However, the timing and correlations of these consequential events remain...

The subducting Pacific slab stagnates in the mantle transition zone and creates a big mantle wedge (BMW) system in East Asia. A similar BMW structure may have already existed since the Early Cretaceous (>120 Ma), but how such a structure evolved from Early Cretaceous to the present day remains unclear. We address this issue by comparing composition...

The Yanliao Biota from northern China is one of the most famous Mesozoic terrestrial lagerstätten in the world, with well-preserved fossil records in the Jurassic volcanic-sedimentary Ningcheng and Jianchang basins. However, the temporal evolution of the Yanliao Biota remains controversial, mainly due to the confusing stratigraphic framework and th...

Continental intraplate basalts usually exhibit diverse compositions varying from silica-deficient alkaline basalts to silica-excess tholeiites. However, the mechanism of compositional diversity remains controversial. Here, we conducted comprehensive petrology, mineral chemistry, whole-rock geochemistry, and Sr–Nd–Hf isotopic compositions, as well a...

Continental intraplate basalts are widespread across Central-East Asia, and their melting mechanisms are poorly known. Herein, we present integrated studies of petrology, elemental-isotope systematics, and thermodynamic modeling of Cenozoic Liangcheng basalts, a representative volcanic field of the vast intracontinental basaltic magmatic province c...

The properties of subcontinental lithosphericmantle beneath the eastern North China Craton changed significantly in the Mesozoic Cenozoic,but details are sketchy.In this study,we report major element and oxygen isotopic compositions of olivine phenocrysts from early Cretaceous Xiaoling basalts and olivine xenocrysts from Quaternary Kuandian basalts...

The subducting Pacific slab stagnated in the mantle transition zone in eastern China and the overlying mantle forms a big mantle wedge (BMW). An analogical BMW structure seem to have been there in the early Cretaceous. However, it is still doubtful whether similar structures existed in the late Cretaceous to early Cenozoic, and if so, their detaile...

Most of Earth's volcanism occurs at tec-tonic plate boundaries associated with subduction or rifting processes. The mantle plume hypothesis is an important supplement to plate tectonics for explaining some high-volume intraplate volcanic fields. However , many intraplate magmatic provinces occur as low-volume, monogenetic basaltic-suite fields that...

The North China Craton (NCC) is widely regarded to have experienced considerable lithospheric thinning during the late Mesozoic. However, how the lower crust responded to the lithospheric thinning remains a topic of debate. Here we report zircon U-Pb-Hf isotopes, whole-rock geochemistry and Nd-Pb isotopic compositions for the Tianmushan pluton in X...

Newly discovered meta-troctolite enclaves in Early Paleozoic Huanggang diorite within dominantly meta-volcaniclastic greenschist to amphibolite facies Erlangping unit in central China extends the known extent of granulite-facies metamorphism in the Tongbai Orogen. Evidence for this granulite facies event is preserved in coronitic and symplectitic t...

The primary driver of magmatism, crustal deformation and metallogeny of the North China Craton in the Jurassic remains actively debated, either attributed to the subduction of the Paleo-Pacific (i.e., Izanagi) plate in the east or to the closure of the Mongol-Okhotsk Ocean in the north. This issue is addressed here by examining temporal and spatial...

The origin of enriched mantle 1 (EM1) component in the mantle has long been debated. EM1 source of basalts has been variously attributed to recycled sub-continental lithosphere, recycled lower continental crust, or recycled oceanic crust plus pelagic sediments. Molybdenum stable isotope systematics has the potential to resolve this debate, because...

Deep continental crust archives critical information on the bulk crustal composition as well as its formation. It is commonly the inherent zone for complex crust-mantle interaction. Unlike the shallow crust, the deep crust is generally inaccessible for direct geological sampling. Instead, knowledge of the deep crust can be obtained from a combinati...

Diverse origins have been proposed for continental adakites, with great emphasis on high-pressure melting of the lower crust. However, the source composition is usually ignored in interpreting the generation of the adakitic geochemical signature (e.g., high Sr/Yand La/Yb) and thusmay affect our understanding of the petrogenesis and tectonic setting...

High-precision U-Pb zircon ages of 125.755 ± 0.061 Ma and 124.122 ± 0.048 Ma, respectively, represent the onset and termination of Yixian Formation in the Jin-Yang basin, bracketing its duration to 1.633 ± 0.078 Myr.

As one of the oldest cratons on Earth, the North China Craton (NCC) is a frequent area for geological research due to its complex crustal evolution. Regarding the Paleoproterozoic crustal evolution of the craton, most studies have focused on continental amalgamation (i.e. horizontal crustal evolution), but few on the vertical crustal evolution. Her...

Late Mesozoic high-K calc-alkaline and high Sr/Y granitoids related to the skarn–porphyry–stratabound Cu–Au polymetallic deposits are widespread in the Middle–Lower Yangtze River Belt (MLYRB), Eastern China. However, the role of mantle-derived magmas in the petrogenesis of these granitoids remains controversial. In this study, we present new zircon...

Continental mafic igneous rocks and their xenocrysts provide information on the evolution of deep continent. Here we present new in situ U–Pb and Hf–O isotopes data for xenocrystic zircons discovered from the Late Mesozoic ultrapotassic to K-rich lamprophyres (150 ~ 140 Ma) in the eastern Yangtze Craton to address the poorly understood yet critical...

Determination of the physical and chemical structures of the inaccessible continental lithosphere by comprehensive geophysical and geochemical studies can provide valuable information on its formation and evolution. Extensive studies from various disciplines have revealed complex lithospheric modification of the North China Craton (NCC), but less a...

It remains unclear why some cratonic lithospheres like the North China Craton (NCC) have undergone significant thinning and catastrophic destruction. Here we provide evidence for a dense Phanerozoic cratonic keel beneath the NCC that provides a reason for the craton destruction during the late Mesozoic. We observed two long‐lasting (>100 Myr) episo...

The Bailongshan pegmatite district in south Xinjiang Province, NW China, is a newly discovered area of rare-element pegmatites. It is a superlarge Li–Rb reserve that includes an estimated 3.45 million tons of Li2O and 176,000 tons of Rb2O. On the basis of a detailed characterization of textures and minerals in the Bailongshan 2# and 5# pegmatites,...

Mesozoic granitoids are widely distributed in South China, but the mechanism for generating the felsic magmas is still in debate. To understand the possible origin of the granitoids, we use joint inversion methods and forward modelling of receiver functions to reveal the lithospheric structure in the Cathaysia block. The joint inversion of receiver...

The roles of subduction of the Pacific plate and the big mantle wedge (BMW) in the evolution of east Asian continental margin have attracted lots of attention in past years. This paper reviews recent progresses regarding the composition and chemical heterogeneity of the BMW beneath eastern Asia and geochemistry of Cenozoic basalts in the region, wi...

The continental lithosphere is not forever; some cratons have lost their original roots during the course of their evolution. Yet, it is not clear whether gravitational instability of dense lower crust is the primary driver of decratonization. This is addressed here with emphasis being placed on the North China Craton (NCC), because it represents o...

An increasing number of Hadean detrital and xenocrystic zircon crystals have been discovered in China, although its oldest crustal component remains enigmatic. Four xenoliths of garnet-free felsic granulites, entrained by the Mesozoic Xinyang volcanic rocks in the southern North China Craton (NCC), were selected for U-Pb dating and Lu-Hf isotopes o...

Metasomatism of the lithospheric mantle by subduction-related fluids/melts is recorded in the Early Cretaceous Xinkailing high magnesium andesites (HMAs) from Western Liaoning. Olivine-hosted melt inclusions within the Xinkailing HMAs are alkaline and record a much lower SiO2 content and higher Al2O3 and CaO contents than the sub-alkaline bulk rock...

Understanding how adakitic magmas form is important for understanding the formation of the continental crust. Generating such high-Sr/Y rocks by crystal fractionation of basalts/basaltic andesites in magma chambers has been proposed in a wide range of tectonic settings. However, the complementary cumulates predicted by this scenario have rarely bee...

The tectonic nature of the Chinese Tianshan Orogen during the Late Paleozoic has been long disputed. With aims of providing constraints on this issue, an integrated study of geochronology and geochemistry has been carried out on the Late Carboniferous pillow basaltic lava of the Qijiagou Group from the Bogda Mountains, Chinese North Tianshan. Zirco...

Deep-seated xenoliths in volcanic rocks offer direct glimpses into the nature and evolution of the lower continental crust. In this contribution, new data on the U-Pb ages and Hf isotopes of zircons in six felsic granulite xenoliths and one pyroxenite xenolith from the Hannuoba Cenozoic basalts, combined with published data from mafic to felsic xen...

U-Pb dating and Hf isotopic analyses were carried out on xenocrystic zircons from the Cenozoic alkali basalts in the Xilinhot region, NE China, to constrain the nature and evolution of the underlying Songliao terrane, and its role in the assembly of the Central Asian Orogenic Belt. Our data show a wide range of U-Pb age distributions, with Precambr...

Early Paleozoic amphibolite- to granulite-facies metamorphism, crustal anatexis and coeval magmatism are extensively developed in the Wuyi-Yunkai intraplate orogen in the South China block. However, the exact timing of granulite-facies partial melting and its link with orogenesis have not been well constrained. In this study, the charnockites, gnei...

The Huai' an Complex, an Archean to Proterozoic amphibolite to granulite facies high-grade terrane locates at the northcenter of the North China Craton, recording complicated crustal evolution. This paper is about the generation and implication for reworking of the lower crust according to the researching on the petrography, zircon U-Pb geochronolo...

Much of Eastern China underwent significant lithospheric thinning during Phanerozoic time. Compared to the wealth of detailed research on the destruction of the North China Craton since the Mesozoic, the lithospheric evolution of South China (including the Yangtze Craton and the Cathaysia block) is still unclear. In particular, studies of the weste...

The Carboniferous tectonic setting of the Junggar terrane, northern Xinjiang, NW China, has long been a matter of debate. Voluminous Carboniferous volcanic rocks are widely distributed in the Karamaili area, the southern part of the eastern Junggar terrane. Early Carboniferous rocks comprise basalts and basaltic andesites, with enrichment of LREE a...

How has the Earth's continental lithosphere evolved? Most of our knowledge is derived from surface exposures, but xenoliths carried in volcanic rocks can be an important source of information. The North China Craton (NCC) is one of the oldest in the world and Phanerozoic volcanic rocks with abundant xenoliths are widespread, making it an ideal area...

Adakite was originally defined as a specific type of magmatic rock derived from melting of subducted oceanic plates (Defant, M.J., Drummond, M.S., 1990. Derivation of some modern arc magmas by melting of young subducted lithosphere. Nature 347 (6294), 662–665), producing unique chemical signatures with high Sr/Y and La/Yb. However, widespread occur...

Large-scale volcanic rocks of the Lanqi Formation are developed in the Changheyingzi area, western. Liaoning Province. LA-ICPMS zircon U-Pb dating gives the Late Jurassic eruption age for andesitic breccia lava of the Lanqi. Formation as 159. 4 ±3. 4 Ma. In-situ zircon Hf analyses show that Lanqi Formation have 176Hf/177 Hf values of 0. 282098 to 0...