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The kinematics and deformation pattern along the Altyn Tagh fault (ATF), one of the largest strike‐slip faults on Earth is of great significance for understanding the growth of the Tibetan Plateau. However, the initial rupture along the ATF remains debated given the limited constraints on the depositional age of associated Cenozoic syntectonic strata. Here we investigated the syntectonic Cenozoic strata in the Xorkol Basin, associated with the strike‐slip faulting along the ATF. New uranium‐lead analyses of the carbonate deposits in the Paleogene strata yield dates of 58.9 ± 1.29 Ma, representing the initial rupture of the ATF. This first documented radioisotopic age coincides with the ca. 60 Ma onset timing of India‐Asia collision, highlighting its far‐field effect at the northern edge of the Tibetan Plateau. We infer that the deformation of the entire Tibetan Plateau started synchronously with the India‐Asia collision. Plain Language Summary: Carbonate U‐Pb dating techniques applied to rocks associated with the Altyn Tagh fault, a major fault in North Tibet, reveal that the fault started slipping about 58.9 million years ago, coinciding with the time when India collided with Asia. This finding provides new constraints on when and where this fault formed and suggests that the northern Tibetan Plateau started deformation earlier than previously thought. This result emphasizes that the entire Tibetan Plateau deformed simultaneously in the early Cenozoic. Key Points: Calcite U‐Pb dating yields ca. 59 Ma age for carbonate strata in the East Xorkol BasinXorkol Basin was a pull‐apart basin during the Paleocene due to the left‐lateral strike‐slip faulting along the Altyn Tagh faultWidespread Paleocene‐Eocene tectonism in Northern Tibet highlights the far‐field effect of the India‐Asia collision [ABSTRACT FROM AUTHOR]

Palaeomagnetic studies in the Malani Igneous Suite (ca. 770-750 Ma) of the Marwar Crustal Block, NW India, provide essential constraints on palaeogeographic reconstructions of the Rodinia Supercontinent. The Malani Igneous Suite is intrusive into megacrystic granite and granite-gneissic enclaves of the Marwar Crustal Block. A crustal-scale NE-SW ductile transpressional shear zone with a southeasterly dip known as the Phulad Shear Zone (820-810 Ma) separates this Marwar Crustal Block from the rocks farther east. The pre-shearing tectonic evolution of the Marwar Crustal Block is poorly understood. Three phases of ductile deformations (D1, D2, and D3, with associated fabrics S1, S2, and S3) were identified in the Marwar Crustal Block. The D1 deformation is restricted to enclave gneisses. The megacrystic granite was emplaced syn-tectonically during D2 deformation. The S2 magmatic foliation (NNW-SSE) in the megacrystic granite is oblique to the Phulad Shear Zone. The D3 deformation in the megacrystic granite is synchronous with the Phulad Shear Zone mylonites. Another porphyritic granite (Phulad granite, ca. 820 Ma) emplaced syn-tectonically during D3 deformation along and across the Phulad Shear Zone. U-Pb zircon dates in the Marwar Crustal Block document ca. 890 Ma and ca. 860 Ma magmatic dates. U-Pb-Th monazite dates in the Marwar Crustal Block show a strong peak at ca. 820 Ma. By integrating critical field relations, deformational patterns, and geochronology, we argue that the Marwar Crustal Block shows distinct geological evolution prior to its accretion with the remaining parts of India. We propose that the accretion of the Marwar Crustal Block must be younger than ca. 860 Ma and culminated during ca. 820-810 Ma to form the Greater India landmass along the Phulad Shear Zone. [ABSTRACT FROM AUTHOR]

The Sung Valley ultramafic–alkaline–carbonatite complex (UACC) of Meghalaya, NE, India, is a result of magmatic activity related to the Kerguelen mantle plume spanning from 101 to 115 Ma. In the present study, an integrated crystal size distribution (CSD), mineral chemistry, and melt inclusion analysis are carried out on the ijolites present within this UACC. The CSD analysis shows that these ijolites were formed in multiple stages through changes in the crystallization environment, such as cooling and nucleation rates. Raman spectroscopy of mineral inclusions of rutile, aphthitalite, apatite, carbonate–silicate melt inclusions, and disordered graphite within clinopyroxene and titanite, respectively, indicates a heterogeneous composition of the parental magma. These mineral and melt inclusion phases further suggest localized changes in oxygen fugacity (fO2) due to redox reactions in the lower crust. SEM–EDX analysis of the exposed melt inclusions reveals the presence of alkali-bearing diopside, phlogopite, and andradite, along with an unidentified carbonated silicate daughter phase. The studied melt inclusions are dominated by carbonate, whereas silicates are subordinate. The presence of this fully crystallized carbonate–silicate melt as calcite, diopside, phlogopite, magnetite, apatite, and andradite suggests the presence of "nano-calciocarbonatites" in these ijolites. Our study provides insights into different mechanisms of the loss of alkalies from initially entrapped alkaline carbonate melt in clinopyroxenes. The predominant occurrence of calcite as the only carbonate phase in the studied melt inclusions is a result of silicate–carbonate melt immiscibility, calcite-normative system in these inclusions, dealkalization of the alkaline carbonates in the presence of external fluid, and/or redistribution of the alkalies to the daughter alkali-bearing silicates. [ABSTRACT FROM AUTHOR]

The South China Craton comprises the Yangtze and Cathaysia blocks and is one of the largest Precambrian continental blocks in East Asia. However, the early geological and geographical evolution of the Cathaysia block is relatively poorly understood, due to the sparse exposure of pre-Neoproterozoic rocks and reworking during Phanerozoic polyphase magmatism and metamorphism. In this contribution, we carried out detrital zircon U-Pb geochronology and sedimentary analyses on five Proterozoic meta-sedimentary rocks collected from the northeastern Cathaysia block, which belong to the previously defined Chencai, Mayuan, and Mamianshan Groups (strata). LA-ICP-MS U-Pb dating results of the detrital zircons show various ~1.85–1.35 Ga maximum depositional ages. They are significantly older than the previously constrained Neoproterozoic formation ages of these Proterozoic strata of northeastern Cathaysia, suggesting that their deposition and formation were probably initiated as early as the late Paleoproterozoic. Provenance analyses reveal that the late Paleoproterozoic to early Mesoproterozoic detrital zircons with igneous-origin were derived from in situ contemporary crystalline basements in eastern Cathaysia. In addition, by implication, the easternmost part of Cathaysia was probably an emerged area (i.e., the "proto-Cathaysia Land") under active erosion. It had a ~NWW orientation and provided detrital sediments to the neighboring marine basin (i.e., the Cathaysia Sea) during the late Paleoproterozoic to early Mesoproterozoic. Finally, the Paleoproterozoic evolution of Cathaysia was involved in the assembly of the Nuna supercontinent. Our results, together with the published data, reveal a distinct late Paleoproterozoic (~1.8 Ga) detrital zircon age peak, which seems to support the view that eastern Cathaysia had close tectonic affinities with terranes such as the Precambrian terranes of current northern India, in the framework of the Nuna supercontinent reconstruction. [ABSTRACT FROM AUTHOR]

Long‐distance lateral magma propagation may reflect the complex interaction between regional tectonics and crustal uplift. Here, we report observations on the Taxkorgan intrusive complex (TIC) of the Central Pamir. TIC is a 70 km long, 10–18 km wide, north‐northwest–elongated body intruded into mid‐upper crust in parallel with, and close to, the Kongur Shan Extensional System. New zircon U‐Pb dating shows that syenite samples exhibit a clear younging pattern from south to north along the pluton axis within an interval between 11.5 and 10.3 Ma, which is interpreted as lateral magma propagation from a single feeder zone at its northwestern margin. The lateral magma propagation was caused by a combination of crustal rigidity differences, and a topography‐induced pressure gradient that is nearly orthogonal to the least compressive stress. We propose that long‐distance lateral magma propagation plays an important role in plateau expansion, restraining the thickness and elevation of the Pamir Plateau. Plain Language Summary: Long‐distance lateral magma propagation within the crust has been documented for diverse magmatic systems. The Miocene Taxkorgan intrusive complex was formed during India‐Asia collision in the Central Pamir Plateau, and it consists of a syenite pluton and several discrete lobes of monzogranites. New SIMS zircon U‐Pb dating results shows that monzogranites across TIC have overlapping ages between 12.4 and 12.2 Ma, indicating they were emplaced from a series of synchronous and independent magma feeder zones. In contrast, syenite samples exhibit a clear younging pattern from south to north within an interval between 11.5 and 10.3 Ma. The pattern of decreasing ages along the pluton axis is interpreted as lateral magma propagation from a single feeder zone at its northwestern margin. It is inferred that long‐distance lateral magma propagation, such as documented for the Taxkorgan intrusive complex, played a key role in plateau expansion, restraining the thickness and elevation of the Pamir Plateau. Key Points: Taxkorgan intrusive complex (TIC) syenite pluton shows a clear younging pattern from south to north within an interval between 11.5 and 10.3 MaTIC syenite pluton formed by lateral magma propagation from a single feeder zone at its northwestern marginLong‐distance lateral magma propagation plays an important role in plateau expansion, restraining the thickness and elevation of Plateau [ABSTRACT FROM AUTHOR]

The soda granite (~Paleoproterozoic) of the Singhbhum Craton (SC) of eastern India occurs along the entire stretch of the Singhbhum Shear Zone (SSZ; or Copper Belt Thrust Zone). The SSZ (marking a thrust contact between the adjacent North Singhbhum mobile belt and SC) serves as the important locale to host apatite‐magnetite, copper sulphide, and uraniferous mineralization. Typical field occurrence of soda granite is either as tongues (or patches) within a shear zone or as lit‐per‐lit style injections into surrounding country rocks which are generally highly sheared and mylonitized. Experimental studies on granite bodies can potentially throw light on their mineralogical and petrogenetic aspects; however, these studies are hitherto unreported in case of soda granites for almost the last 60 years. In this view, during the present research, experimental studies on soda granites have been carried out and these decipher the nature of the stability relationship of K‐feldspar (and transgression to more disordered anorthoclase), amphibole (both Ca‐amphibole and Fe–Mg–Mn amphibole and breaking down of Ca‐amphibole to Fe–Mg–Mn amphibole + non‐quad pyroxene + quartz at an appropriate temperature), biotite, muscovite, and albite (high albite‐ low albite displacive transformation). Whole‐rock chemistry (deduced from homogenized glass compositions) indicates its peraluminous, S‐type nature with an affinity towards Caledonian post‐collisional plutons. Characteristic geochemical plots suggest a pelitic source material for melting (and subsequent internal differentiation of the melt) and this has given rise to both migmatite as well as patchy soda granite exposures in the field. It is suggested that partial melting of mainly metapelitic (and minor mafic magmatic rocks) source (belonging to Singhbhum Series) gave rise to soda granites in this region. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Duolong ore district experienced two periods of exhumation and two periods of burial. • The periods of burial are attributed to northeast-southwest striking fault and thrust nappe structure related to the Lhasa-Qiangtang collision. • The India-Asia collision is the main reason for the exhumation and uplift of the Duolong ore district since Paleocene. The Early Cretaceous Duolong porphyry-epithermal copper ore district is one of the largest copper ore districts in the central Tibetan Plateau. In order to investigate the preservation mechanism of Early Cretaceous porphyry-epithermal mineralization, new apatite and zircon fission track dating and (U-Th)/He dating of pre-ore sandstone, ore-related and barren intrusive rocks, and post-ore igneous rock, thermal modeling together with previous thermochronological data of the Duolong ore district were combined to study the burial and exhumation processes. Apatite fission track ages range from 68 ± 4 to 40 ± 4 Ma, with mean track lengths varying from 12.1 ± 2.0 to 12.8 ± 2.4 μm. Zircon fission track ages range from 106 ± 4 to 86 ± 4 Ma. In addition, apatite (U-Th)/He yields average age ranging from 62.7 ± 4.2 to 22.6 ± 1.2 Ma, and zircon (U-Th)/He yields average age of 112.3 ± 5.1 Ma. The thermal modeling shows that the Duolong ore district experienced two periods of exhumation and two stages of burial. The first period of exhumation with rate of 0.14 km/m.y. took place immediately after the ore formation which caused the erosion of orebody. Two periods of burial are thought to be related to northeast-southwest striking fault and thrust nappe structure induced by Lhasa-Qiangtang collision between 110 and 65 Ma when the overlying rocks of orebodies were thickened to 4 km. The last period of exhumation with rate of 0.062 km/m.y. (since 65 Ma) is attributed to lithospheric delamination related to India-Asia collision. The preservation of the Duolong ore district mainly benefited from the burial related to the Lhasa-Qiangtang collision. The exhumation and uplift of Duolong ore district was mainly attributed to the India-Asia collision since Paleocene. [ABSTRACT FROM AUTHOR]

In a geochemical and geochronological investigation of Archean and Proterozoic magmatism in the Nellore Schist Belt, we conducted SHRIMP U-Pb analyses of zircons from two cospatial granitic bodies at Guramkonda and Vendodu. The former is a Ba- and Sr-rich hornblende-bearing tonalite, whereas the latter is a Rb-, Zr-, Pb-, Th-, U-, and REE-rich biotite-bearing leucogranite. The Guramkonda tonalite displays a restitic texture with remnants of trapped granitic melt, whereas the Vendodu leucogranite contains residual/partially melted plagioclase grains. Both rock types contain two generations of zircon: tonalite contains a group of euhedral zoned zircons enclosed within plagioclase and a group of subhedral patchy zircons associated with trapped melt (quartz + feldspar matrix), and leucogranite also contains a group of doubly terminated euhedral zircons included within orthoclase as well as a group of zircons with visible cores mantled by later rim growth. Cathodoluminescence images also clearly document two distinctly textured varieties of zircon: the tonalite contains a population characterized by narrowly spaced uninterrupted oscillatory zoning and a second population lacking zoning but exhibiting a random distribution of dark (U-rich) and light (U-poor) regions; the leucogranite contains U-rich zoned zircons and U-poor zircon cores mantled by U-rich rims. The REE chemistry of zircon cores from the Vendodu leucogranite is very similar to the REE of zoned zircons from the Guramkonda tonalite. Zircon ages from both plutons exhibit bimodal distributions in U-Pb concordia diagrams. The tonalite defines an age of 2,521 Ma ± 5 Ma for zoned magmatic zircons and 2,485 Ma ± 5 Ma for unzoned newly precipitated zircons, whereas the leucogranite has an age of 2,518 Ma ± 5 Ma for U-poor zircon cores (relics of the tonalite pluton) and 2,483 Ma ± 3 Ma for U-rich zoned magmatic zircons. The trace element geochemistry of the ~2,520 Ma zircons is distinctly different from the ~2,485 Ma zircons, irrespective of the host rock. Our textural, CL image, and SHRIMP U-Pb analyses document the origin of the leucogranite by partial melting of the tonalite. High alkalis (NaO + KO), Rb, Nb, HREE, FeO/MgO and low Ca, Al, Ba, Sr, and large negative Eu anomalies characterize the leucogranite as a thermal minimum melt, whereas the very low K and Rb of the tonalite attests to its residual nature. We suggest that the leucogranite formed by high-T (900-950°C), moderate-pressure (<10 kbar) dehydration partial melting of the tonalite under reducing conditions. The calculated source compositions of the leucogranite melt and the tonalite residue show strong similarities to melts that are considered to have been produced in a subduction-zone environment. The leucogranite probably formed in a post-collisional realm immediately after accretion of the tonalitic crust. [ABSTRACT FROM AUTHOR]