Mihai N. Ducea

Mihai N. Ducea
The University of Arizona and University of Bucharest · Geosciences

Prof of Geology

About

369
Publications
98,670
Reads
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13,155
Citations
Citations since 2016
132 Research Items
8021 Citations
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Introduction
I am a tectonic petrologist - prof at the University of Arizona and a courtesy researcher at the University of Bucharest. I foucs on a variety of tectonics problems from subduction related (magmatism, subduction erosion, delamination) to extension and collision of the continents. I invetigate mineral evolution, ciclicity of orogens, sutures, transform faults, and metamorphism in collisional belts among others. At Univ. Arizona we run a trace elemental geochemical + radiogenic isotopic facility.
Additional affiliations
September 2000 - present
The University of Arizona
Position
  • Professor (Full)
January 1999 - January 2000
California Institute of Technology
Position
  • PostDoc Position

Publications

Publications (369)
Article
Full-text available
Convective removal of continental lithospheric roots has been postulated to be the primary mechanism of recycling lithospheric mass into the asthenosphere under large plateaux such as the Altiplano-Puna in the central Andes. Convective instabilities are especially likely to develop where there is extensive intermediate arc-like magmatism in the upp...
Article
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Continental magmatic arcs form above subduction zones where the upper plate is continental lithosphere and/or accreted transitional lithosphere. The best-studied examples are found along the western margin of the Americas. They are Earth's largest sites of intermediate magmatism. They are long lived (tens to hundreds of millions of years) and spati...
Article
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The world's biggest Phanerozoic magmatic arcs formed above subduction zones and comprise the products of continuous magma emplacement into the crust over periods of up to 500 My. However, the intensity of magmatic activity can vary significantly. Punctuated magmatic events lasting from 5 to 20 My can dwarf the volume of magmas generated through the...
Article
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13 The processes and fluxes that produce the distinct compositional structure of the 14 Earth's continental crust by subduction remain controversial. The rates of oceanic crust 15 production, in contrast, are well quantified and are generally believed to be faster than 16 those responsible for building magmatic systems in subduction settings. Here...
Article
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Garnet pyroxenites are the most common deep lithospheric xenolith assemblages found in Miocene volcanic rocks that erupted through the central part of the Sierra Nevada batholith. Elemental concentrations and isotope ratios are used to argue that the Sierra Nevada granitoids and the pyroxenite xenoliths are the melts and the residues/cumulates, res...
Article
We present new sedimentologic, petrographic, paleontological, and detrital zircon U‐Pb data on late Oligocene ‐ early Miocene sedimentary rocks of the thin‐skinned thrust belt of East Carpathians. These data were acquired to reconstruct the sedimentary routing system for two compositionally different turbidite fans made of the regionally extensive...
Article
The chemical composition of orogenic igneous rocks and their zircons is sensitive to crustal thickness and can be used to quantify the evolution of Moho depths beneath continents back in time.
Article
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Plain Language Summary How the Tibetan Plateau grows outward and deformed remains controversial. A large‐scale crustal flow model has been favored for the expansion of the southeast Tibetan Plateau, arguing that crustal materials could flow hundreds of km resulting in crustal thickening and uplift. Detailed geochemical and isotopic investigations o...
Article
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Convergent plate boundaries are key sites for continental crustal formation and recycling. Quantifying the evolution of crustal thickness and paleoelevation along ancient convergent margins represents a major goal in orogenic system analyses. Chemical and in some cases isotopic compositions of igneous rocks formed in modern supra‐subduction arcs an...
Article
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Subduction of lithospheric plates at convergent margins leads to transport of materials once close to or at the surface of Earth to great depths. Some of them later return to the surface by magmatism or degassing, whereas others end up being stored in the mantle for long periods of time. The fate of carbon-bearing minerals in subduction is of parti...
Article
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The Central Andes represent the archetypical Cordilleran orogenic system, with a well-developed continental volcanic arc and some of the thickest crust on Earth. Yet the relative contributions of shortening and magmatic additions to crustal thickening remain difficult to quantify, which hinders understanding processes of crustal evolution in contin...
Article
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Plain Language Summary Detailed relationships between crustal thickening, surface uplift, and climate remain unresolved. Although most mountains seem to be in isostatic equilibrium today, there is an imperfect correlation between elevation and crustal thickness in the modern continental lithosphere globally. We report trace element geochemical data...
Article
Continental-arc igneous rock compositions change in response to the transition from subduction to collision and these changes can reveal how the crust, lithosphere and magma sources evolved. Neotethys-related Late Cretaceous to Pleistocene subduction- and collision-related magmatic rocks from the ~350 km long southeast Urumieh-Dokhtar Magmatic Belt...
Article
Eastern Myanmar is located at the junction of the Changning-Menglian and Chiang Rai-Chiang Mai zone and is a crucial region for constraining the evolution of the eastern Paleo-Tethys. This study presents new zircon U-Pb geochronologic, mineral and whole-rock geochemical, and Sr-Nd-Hf-O isotopic data for magmatic rocks from the Sukhothai arc in east...
Article
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Granitic rocks, interpreted to be related to crustal melting, were emplaced into regions of thickened crust in southern Arizona during the Laramide orogeny (80-40 Ma). Laramide-age anatectic rocks are exposed as plutons, sills, and dike networks that are commonly found in the exhumed footwalls of metamorphic core complexes. This study investigates...
Article
Full-text available
Granitic rocks, interpreted to be related to crustal melting, were emplaced into regions of thickened crust in southern Arizona during the Laramide orogeny (80–40 Ma). Laramide-age anatectic rocks are exposed as plutons, sills, and dike networks that are commonly found in the exhumed footwalls of metamorphic core complexes. This study investigates...
Article
Full-text available
Thick-crusted (>45 km) Cordilleran arcs exhibit cyclic processes including periods of magmatic quiescence interspersed with pulses of high-flux magmatism. Most models assume that during high-flux events, fractional crystallization and partial melting within the deep crustal hot zone generate a dense (>3.4 g/cm 3) arclogitic subarc root that can rea...
Article
Full-text available
Thick-crusted (>45 km) Cordilleran arcs exhibit cyclic processes including periods of magmatic quiescence interspersed with pulses of high-flux magmatism. Most models assume that during high-flux events, fractional crystallization and partial melting within the deep crustal hot zone generate a dense (>3.4 g/cm3) arclogitic subarc root that can read...
Article
Full-text available
Recently, the basal beds of the lower section of the Lumbrera Formation have been referred to the early Eocene (Ypresian) based on the identification of a succession of hyperthermal events globally dated between 52 and 55 Ma. Nevertheless, this section have also been referred to the middle Eocene (Lutetian) based on the ‘evolutionary stage’ of its...
Article
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Marshallsussmanite (IMA2013-067) is a new pyroxenoid mineral from the Wessels mine, Kalahari Manganese Field, Northern Cape Province, South Africa. Marshallsussmanite has ideal formula NaCaMnSi 3 O 8 (OH) and triclinic P 1 symmetry. Marshallsussmanite forms vitreous pink bladed crystals to 2.1 cm. The mineral shows perfect cleavage on both {100} an...
Article
Full-text available
Despite decades of research, the mechanisms and processes of subduction initiation remain obscure, including the tectonic settings where subduction initiation begins and how magmatism responds. The Cretaceous Mawgyi Volcanics represent the earliest volcanic succession in the Wuntho-Popa arc of western Myanmar. This volcanic unit consists of an exce...
Data
A database containing previously published geochronologic, geochemical, and isotopic data on Mesozoic to Quaternary igneous rocks from the Carpathian-Pannonian region are presented. Georeferenced data making up this database belong mostly to five magmatic arcs: (1) the south Apuseni Jurassic island arc/backarc province, (2) a small volume mid Creta...
Article
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Recent empirical calibrations of Sr/Y and La/Yb from intermediate igneous rocks as proxies of crustal thickness yield discrepancies when applied to high ratios from thick crust. We recalibrated Sr/Y and La/Yb as proxies of crustal thickness and applied them to the Gangdese Mountains in southern Tibet. Crustal thickness at 180–170 Ma decreased from...
Article
Continental arcs in Cordilleran orogenic systems display episodic changes in magma production rate, alternating between flare ups (70–90 km³ km⁻¹ Myr⁻¹) and lulls (< 20 km³ km⁻¹ Myr⁻¹) on timescales of tens of millions of years. Arc segments or individual magmatic suites may have even higher rates, up several 100 s of km³ km⁻¹ Myr⁻¹, during flare u...
Preprint
Full-text available
Paper submitted to Revue Roumaine de Geologie with all data available freely at osf.io/rkv38.
Article
Full-text available
Marshallsussmanite (IMA2013-067) is a new pyroxenoid mineral from the Wessels mine, Kalahari Manganese Field, Northern Cape Province, South Africa. Marshallsussmanite has ideal formula NaCaMnSi3O8(OH) and triclinic P�1 symmetry. Marshallsussmanite forms vitreous pink bladed crystals to 2.1 cm. The mineral shows perfect cleavage on both {100} and {0...
Article
Full-text available
15 16 Recent analytical developments in the field of mass spectrometry have made possible accurate 17 measurements of "non-traditional" isotopic ratios of elements such as Fe, Cu, Ag, Sn, Sb and Hg. 18 The stable isotopes of these elements do not have any radioactive parents, but their ratios undergo 19 limited fractionation from various causes, mo...
Article
Double-dating using the apatite UPb and fission-track systems is becoming an increasingly popular method for resolving mid- to upper- crustal cooling. However, these thermochronometers constrain dates that are often difficult to link through geological time due to the large difference in temperature window between the two systems (typically >250 °C...
Conference Paper
Full-text available
During the Laramide orogeny (80–40 Ma) in southern Arizona, a series of weakly–strongly peraluminous granites (± muscovite ± garnet) were emplaced. These rocks have been interpreted to be crustal melts derived from local basement rocks, and we refer to them as the southern Arizona anatectic suite. This suite is distinct from dominantly metaluminous...
Conference Paper
Full-text available
Granitic rocks, interpreted to be related to crustal melting, were emplaced into regions of thickened crust in southern Arizona during the Laramide orogeny (80–40 Ma). Laramide-age anatectic rocks are exposed as plutons, sills, and dike networks that are commonly found in the exhumed footwalls of metamorphic core complexes. This study investigates...
Article
Arclogites are eclogite-like rocks formed magmatically as ultramafic residues and cumulates in the roots of thick arcs (Ducea et al., 2020a, Ducea et al., 2020b companion paper). They are inferred to be volumetrically important assemblages to complement subduction-related magmatic rocks at depth, in areas where the upper plate crust is thick. At th...
Article
Full-text available
Arclogites, or clinopyroxene-, garnet-, amphibole-, and Fe Ti oxide-bearing cumulates and restites (collectively representing residues) to andesitic continental arc magmas, are reviewed here and in a companion paper (Ducea et al., 2020). Experimental petrology and petrologic observations suggest that these eclogite facies rocks form magmatically in...
Article
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The Qinling Orogenic Belt in Central China is formed by an oblique continental collision between the North China and South China Blocks. In this review, we summarize the knowledge of the early Mesozoic magmatism, in combination with the coeval metamorphic characteristics, regional structural features and depositional history in the foreland and hin...
Article
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U-Th-Pb chemical dating is a suitable technique for determining ages of minerals (e.g., uraninite, 13 monazite) that have large amounts of U and/or Th such that the radiogenic Pb can be measured. 14 We investigate the chemical age of bitumen-supported uraninite from the vein-type Crucea 15 uranium deposit, which is located in the Tulghes Series bas...
Article
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Here we test for peridotite versus pyroxenite input in Mongolian Mesozoic and Cenozoic magmatism. A combination of new ⁴⁰Ar/³⁹Ar radiometric dating results, whole-rock major- and trace-element, Sr-Nd isotope, and mineral phenocryst geochemical data is used to decipher the petrogenesis of Cretaceous lavas (Tsagaan Nuur and Khukh Tolgoi) and dykes (S...
Article
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Significance Zircon, a common accessory mineral in crustal rocks, records plentiful and critical information on the Earth’s history. The isotopes of its major component, Zr, could be another powerful but unexplored tracer. We apply high-precision, high–spatial-resolution, in situ laser ablation Zr isotope measurements of magmatic zircons in contine...
Article
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Plain Language Summary Paleo‐elevation is an important factor in understanding the mountain building processes. Strong correlations are observed between crustal thickness, elevation, and Sr/Y and (La/Yb)N of magmatic rocks for both subduction‐related and collision‐related mountain belts. We established empirical equations derived from modern exampl...
Article
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Geochemical data on igneous rocks of the Urumieh-Dokhtar magmatic arc (UDMA) are used to reconstruct temporal variations in crustal thickness during the Tertiary. We use two approaches, (1) whole rock Sr/Y and La/Yb ratios, and (2) Nd isotopes and an assimilation model for magma genesis. Our results indicate that the crust was likely of normal thic...
Article
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The Santa Catalina‐Tortolita‐Rincon Mountains of Southeast Arizona are a classic metamorphic core complex (MCC) and represent footwall exposures of crustal rocks exhumed by a detachment system. This study presents new evidence for the formation of the majority of ductile deformation during the Eocene (~46 Ma), synchronous with the emplacement of th...
Article
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This study uses clinopyroxene (cpx) compositions and zircon Hf-O isotopes of the Eocene adakitic rocks (EARs) from the Qiangtang Block to resolve the mechanism(s) responsible for the formation of the central Tibetan Plateau. The two leading and opposing hypotheses for the origin of these rocks are (a) partially molten foundered lower crust and (b)...
Article
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Reconstructing orogenic systems made up dominantly by sediments accreted in trenches is challenging because of the incomplete lithological record of the subducted oceanic domain and its attached passive continental margin thrusted by collisional processes. In this respect, the remarkable ~600 km long continuity of sediments exposed in the Eastern C...
Article
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The Moroccan Anti-Atlas orogenic belt encloses several Precambrian inliers comprising two major Neoproterozoic ophiolitic complexes: the Sirwa and Bou Azzer ophiolites. These ophiolites expose crustal and mantle units, thrusting over fragments of a long-lived intra-oceanic arc system. We present a detailed geochronological and petro-geochemical stu...
Article
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Magmatic processes that occur during the transition from oceanic to continental subduction and collision in orogens are critical and still poorly resolved. Oceanic slab detachment in particular is hypothesized to mark a fundamental change in magmatism and deformation within an orogen. Here, we report on two Quaternary volcanic centers of Myanmar th...
Article
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Triassic rock units of northern Chile (28-29°S) record the transition, both in time and space, between two major orogenies that affected the southwestern margin of South America, the Gondwanian and Andean orogenies. The geodynamic configuration of the margin during this transition is still a matter of debate, particularly whether subduction was int...
Article
The Kalyus Beds of the late Ediacaran Nagoryany Formation occurring in the northeastern part of the Republic of Moldova are dominated by black argillites with phosphorites and calcareous concretions. Four lithological groups were examined with respect to their rare earth element (REE), major and trace element geochemistry: phosphorites, enriched ar...
Article
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Most arcs show systematic temporal and spatial variations in magmatism with clear shifts in igneous rock compositions between those of the magmatic front (MF) and those in the back-arc (BA). It is unclear if similar magmatic polarity is seen for extensional continental arcs. Herein, we use geochemical and isotopic characteristics coupled with zirco...