The spatial relationships of the widely distributed latest Jurassic–Early Cretaceous igneous rocks in the Tethyan Himalaya, northeastern India, and southeastern Australia are crucial for understanding the breakup of eastern Gondwana. However, available paleomagnetic datasets from the central Tethyan Himalaya are limited. To better constrain the distribution of these igneous rocks, new paleomagnetic data were obtained from the Weimei Formation volcanic rocks in the central Tethyan Himalaya. The tilt-corrected site-mean directions for 11 sites is Ds = 315.4°, Is = −58.4°, ks = 17.2, α95 = 11.3°, corresponding to a paleopole at 9.6° N, 297.3° E with dp/dm = 16.7°/12.4° and a paleolatitude of ~39.1 ± 12.4° S for the study area (29.7° N, 83.7° E). A positive regional fold test and the occurrence of dual polarity suggest that the characteristic remanent magnetization is of pre-fold origin. These new results, together with those from the eastern Tethyan Himalaya, northern India, and southwestern Australia, show that the ~147–130 Ma circum-eastern Gondwana large igneous province spans a latitudinal range of ~40.7–58.1° S, centered at ~49.4° S, which is consistent with the present Kerguelen hotspot (~49.0° S). Integrating other evidence, we consider that the Kerguelen mantle plume played a key role in the breakup of eastern Gondwana.

Abstract The temporal‐spatial relationships of widely distributed latest Jurassic–Early Cretaceous igneous rocks in the Tethyan Himalaya (TH) are crucial for understanding the breakup of eastern Gondwana and the paleogeography of the Neo‐Tethys Ocean. However, no paleomagnetic data are available from the Early Cretaceous volcanic rocks in the central‐western TH. Here, we report the first paleomagnetic and geochronological results from Early Cretaceous volcanic rocks, dated at ∼144‒142 Ma, in the western TH. The tilt‐corrected site‐mean direction for 31 sites is Ds = 303.9°, Is = −58.7° with α95 = 4.3°, yielding a mean pole at 1.9°N, 303.2°E (A95 = 5.0°) and a paleolatitude of 40.8 ± 5.0°S for the Zhongba area. Positive fold and reversal tests support pre‐fold primary magnetizations. Our paleomagnetic and geochronological results, combined with those from the eastern TH, northeastern India, and southwestern Australia, reveal that the latest Jurassic–Early Cretaceous volcanic rocks were emplaced across a paleolatitudinal range from approximately 40.8°S to 55.5°S, with a central paleolatitude of about 48.2°S, which is consistent with the present‐day latitude of the Kerguelen Mantle Plume (KMP). This, along with the affinity of these rocks to the KMP‐related magmatic rocks supports that the latest Jurassic–Early Cretaceous TH igneous rocks originated from the KMP, and that the KMP contributed to the breakup of eastern Gondwana. Comparison of Early Cretaceous paleolatitudes observed from the western TH and Lhasa terrane shows that the latitudinal width of the Neo‐Tethys Ocean was ∼6,600 km at ∼144–142 Ma.

The paper presents the results of the study of geochemistry and U-Pb zircon dating of Cretaceous igneous rocks of the westernmost part of the Badzhal terrane within the Badzhal and Dusse-Alin volcanic zones of the Khingan-Okhotsk magmatic belt. The granites of the Verkhneurmysky pluton and Pravourmyskaya dyke in the Badzhal zone were dated at 100±1 and 93±1 Ma, respectively. The age of diorite in the Suluk-Egono interfluve of the Dusse-Alin zone was estimated at 88±1 Ma, and the ages of three tuff zircon populations were estimated at 88±2, 97±1 and 105.5±1.3 Ma. The dating results indicate that the synorogenic reduced granites of the Verkhneurmysky ore cluster were formed under the transform continental margin regime, which gave rise to the occurrence of a large Albian-Cenomanian magmatic province of Pacific Asia. The magnetite series diorites of the Dusse-Alin zone were formed during the subsequent subduction-related Turonian-Maastrichian stage, but their geochemical characteristics are not typical of suprasubduction magmas. This may indicate a later transition to subduction at this section of the continental margin, or the existence of local extension and/or transcurrent faulting in the subduction settings. The studied igneous rocks of both stages and volcanic zones were formed with significant involvement of material from the mature continental crust, and are characterized by a similar range of εNd(t) values from –0.9 to –2.6 and two-stage Nd model ages from 1.22 to 1.05 Ga.

Timing of mineralization in the Ikuno polymetallic vein-type deposit, southwest Japan: Constraints from zircon U–Pb ages of Late Cretaceous igneous rocks

The Komsomolsk tin ore district is located at the Miaochan Ridge in the Middle Amur River area (Khabarovsk territory) within the Badzhal accretionary terrane of the Sikhote-Alin orogenic belt. The paper presents new results of U-Pb zircon dating of tonalite of the Miaochan complex of the Silinka granitic pluton (99.7±1.1 Ma) and two rhyolites of the lower part of the Kholdami Formation (98.4±1.0 and 98.7±1.2 Ma) from the north-eastern part of the Komsomolsk district. The geochemical characteristics of rocks were also studied, which show that granitoids of the Miaochan complex are I-type granites, and coeval rhyolites of the Kholdami Formation are very peraluminous S-type rocks. New data on the geochemistry and early Cenomanian age of the igneous rocks allows us to consider the ore-magmatic system of the Komsomolsk ore district as part of the previously identified Albian-Cenomanian igneous province of Pacific Asia.

Detrital zircon U–Pb geochronology of the trench-fill sandstone on the Cretaceous Shimanto accretionary complex in SW Japan: Implications for provenance and igneous activity in the eastern edge of East Asia

Tectonic evolution of the Circum-Moesian orocline of the Carpatho-Balkanides: Paleomagnetic constraints

Abstract The northern Andes of southern Colombia contain a rich geologic history recorded by Proterozoic to Cenozoic metamorphic, igneous, and sedimentary rocks. The region plays a pivotal role in understanding the evolution of topography in northwestern South America and the development of large river systems, such as the Amazon, Orinoco, and Magdalena rivers. However, understanding of the basement framework has been hindered by challenging access, security concerns, tropical climate, and outcrop scarcity. Further, an insufficient geochronologic characterization of Andean basement complicates provenance interpretations of adjacent basins and restricts understanding of the paleogeographic evolution of southern Colombia. To address these issues, this paper presents a zircon U-Pb geochronological dataset derived for 24 bedrock samples and 19 modern river samples. The zircon U-Pb results reveal that the Eastern Cordillera of southern Colombia is underlain by basement rocks that originated in various tectonic events since ca. 1.5 Ga, including the accretion of discrete terranes. The oldest rocks, found in the Garzon Massif, are high-grade metamorphic rocks with contrasting Proterozoic protolith crystallization ages. Whereas the SW part of the massif formed during the Putumayo Orogeny (ca. 1.2–0.9 Ga), we report orthogneisses for the NE segment with protoliths formed at ca. 1.5 Ga, representing the NW continuation of the Rio Negro Jurena province of the Amazonian Craton. In contrast, crystalline rocks of the Central Cordillera primarily consist of Permian–Triassic (ca. 270–250 Ma) and Jurassic–Cretaceous (ca. 180–130 Ma) igneous rocks formed in a magmatic arc. In southernmost Colombia, the Putumayo Mountains mainly consist of Jurassic–Cretaceous (180–130 Ma) plutonic and volcanic rocks. Furthermore, we analyzed the heavy mineral abundances in modern river sands in southern Colombia (spanning 1°N–5°N) and found that key minerals such as garnet and epidote can be utilized to trace high-grade metamorphic and igneous lithologies, respectively, in the river catchments. The differentiation of basement ages for separate tectonic provinces, combined with heavy mineral abundances in modern sands, can serve as unique fingerprints in provenance analyses to trace the topographic and exhumational evolution of different Andean regions through time.

Early Cretaceous magmatism in the northern Gyeonggi Massif and the northcentral Yeongnam Massif, Korean Peninsula: Its implications for the Cretaceous tectonic evolution of the Northeast Asia

Mesozoic granitoids in Peninsular Malaysia provide crucial information on the temporal–spatial relationship between the Tethyan and Palaeo-Pacific domains. This paper presents new ages and geochemical data for newly identified Jurassic–Cretaceous granites and meta-granites from East Malaya. These granitoids can be divided into three groups. Group 1 consists of high-K calc-alkaline granites and granodiorites (171–162 Ma) with variable ε Nd ( t ) values of −7.4–+0.5, zircon ε Hf ( t ) values of −7.4–+8.6, and high initial ratios for 206 Pb/ 204 Pb (20.04–20.65), 207 Pb/ 204 Pb (15.73–15.79) and 208 Pb/ 204 Pb (39.80–40.20). The melting of metasedimentary rocks with a juvenile mafic component formed Group 1 samples. Group 2 granite porphyries ( c. 131 Ma) with A-type affinities and Group 3 granitic gneisses ( c. 130 Ma) with I-type affinities share similar ε Nd ( t ) values (−7.2 to −5.5), zircon ε Hf ( t ) values (−10.1–+6.5), and initial ratios for 206 Pb/ 204 Pb (18.81–19.02), 207 Pb/ 204 Pb (15.71–15.77) and 208 Pb/ 204 Pb (38.95–39.59). Although Group 2 and 3 samples were derived from an ‘ancient’ meta-mafic source region, Group 2 shows evidence for the involvement of a juvenile mafic component. All these granitoids are akin to the Permian–Triassic igneous rocks in East Malaya. The Jurassic–Cretaceous igneous rocks in Eastern Peninsular Malaysia were formed during multiple stages of continental rifting in response to Palaeo-Pacific slab rollback pulses rather than by Tethyan evolutionary processes. Supplementary material : Data for the Middle Jurassic–Early Cretaceous granitoids of East Malaya are available at https://doi.org/10.6084/m9.figshare.c.6689085 Thematic collection: This article is part of the Mesozoic and Cenozoic tectonics, landscape and climate change collection available at: https://www.lyellcollection.org/topic/collections/mesozoic-and-cenozoic-tectonics-landscape-and-climate-change

ABSTRACT Mesozoic igneous rocks are widely distributed in the South China Sea (SCS) and its adjacent areas and are exposed in the SCS, South China, Hainan, Indochina, Taiwan, the Philippines, and Borneo; these rocks are mostly dominated by granitoids. This paper presents a complete map of the Mesozoic igneous rocks of the SCS and its adjacent areas. This paper also presents an analysis of geological survey and published data in terms of seismic profiles, ages, geochemistry and isotopic systematics of the Mesozoic igneous complexes of the SCS and its adjacent areas. Three periods of igneous activity can be distinguished: (1) Permian – Triassic that spans from 250–201 Ma; (2) Jurassic (201–145 Ma); and (3) Latest Jurassic/Cretaceous to Maastrichtian (145–66 Ma), of which the Cretaceous is the best preserved and could possibly be the most widespread. Triassic igneous rocks are distributed in the northwestern and southern SCS (Qiongdongnan Basin, Yinggehai-Song Hong Basin, Beibu Gulf Basin, the Dangerous Grounds, and the Reed Bank); Jurassic igneous rocks are distributed in the northern and southern SCS (Pearl River Mouth Basin, Qiongdongnan Basin, Yinggehai-Song Hong Basin, Beibu Gulf Basin, and the Reed Bank); and Cretaceous igneous rocks are distributed in the northern, western and southern SCS. The igneous activity of the SCS is mostly distributed in the continent slope. Mesozoic igneous rocks of the SCS include at least 350 rock masses: the smallest being 0.182 km2, the largest being 5,5,502 km2, and the total area covering 688,539 km2. Mesozoic magmatism in the SCS and its adjacent areas migrated oceanward (southeastward). Our new seismic profiles and the wells from the literature highlight that Jurassic granites occur not only inland of South China but also in coastal South China and the northern and southern SCS. The YING6 well in the northern SCS encountered andesite with an age of 68.24 Ma, which is the youngest age found for the SCS Mesozoic volcanic rocks. The XY1 well in the western SCS encountered granite with an age of 68.9 Ma, which is the youngest age found for the SCS Mesozoic intrusive rocks. The WZ12-3-1 well in the northern SCS encountered granite with an age of 243.3 Ma, which is the oldest age found for the SCS Mesozoic intrusive rocks. The encountered dacite ages (219.1 ± 1.4 Ma) of the NK-1 well in the southern SCS were the oldest ages found for the SCS Mesozoic volcanic rocks. The thickest Mesozoic igneous rocks (>1022.5 m) were encountered in the NK-1 well. Igneous rocks in the SCS and its adjacent areas are closely related to tectonic movements such as faults, plate movement, and mantle-derived igneous fluid ascent. They are controlled by the subduction of the Tethys lithospheric and Paleo-Pacific domains.

Paleo-Pacific subduction in Southeast Vietnam: Evidence from Late Cretaceous intrusive rocks in the Dalat zone

ABSTRACT The geodynamic processes that occurred beneath the Bangong – Nujiang suture zone during the evolution of the Indus – Yarlung Neo-Tethys and Bangong – Nujiang Meso-Tethys are unclear. We conducted a study of Early Cretaceous andesitic rocks from the Nyima area, north – central Tibet, to investigate these processes. The studied rocks have zircon U – Pb ages of 110–104 Ma and negative to positive εHf(t) values (−12.1 to+10.3). These rocks have affinities with trachytes, and have high total alkali contents and Na2O/K2O ratios (5–125). They also have high Sr (281–1409 ppm), Y (21.0–28.5 ppm), and Yb (2.00–2.65 ppm) contents, and exhibit depletions in Nb, Ta, and Ti. Such features indicate these rocks are not adakites, but are similar to typical arc rocks. The geochemical and isotopic data suggest the studied rocks were formed by partial melting of amphibolite-facies oceanic lithosphere, with the addition of enriched sedimentary materials. Based on the regional crustal evolution, we suggest that the Nyima andesitic rocks formed by melting of Bangong – Nujiang oceanic lithosphere. As such, the Early Cretaceous igneous rocks along the central Bangong – Nujiang suture zone were not associated with northward subduction in the Indus – Yarlung Neo-Tethys.

The Pamir orogen was formed by the subducted accretion and amalgamation of Cimmerian terranes from the northern margin of Gondwana with the southern margin of Eurasia. The Mesozoic magmatic rocks are widespread in Pamir and record the tectonic evolution in different stages. The Rushan–Pshart suture zone represents an ancient ocean between Central and Southern Pamir. This paper reports the petrography, geochronology, and geochemistry of Cretaceous granites and diabase dikes that intrude into the Pshart complex. The granites were emplaced between 124 and 118 Ma, based on their zircon U-Pb ages. These granites are characterized by high-K calc-alkaline, low magnesian, and high SiO2, A/CNK, and K2O+Na2O values. They also display strong depletion of Ba, Sr, Eu, and Ti and comparatively weak negative Nb anomalies in spidergrams. Thus, we proposed in this study that these are highly fractionated, strongly peraluminous S-type granites. They were generated by the partial melting of the metasedimentary rocks in the plagioclase stability field and underwent subsequent fractional crystallization during their ascent. The diabase dikes contain low SiO2, and high MgO levels and negative Nb and Ta anomalies, which were interpreted to form in an extensional environment. Late Jurassic–Early Cretaceous closure of the Rushan–Pshart Ocean and subsequent foundering of its oceanic lithosphere caused local extension and upwelling of the asthenospheric mantle. The underplating of mafic magma provided a heat source to melt the metasedimentary-derived granitic that formed in the initial post-collisional environment. The subsequent local extension caused the emplacement of diabase dikes. Based on our new data and combined with data from previous studies, we concluded that the Rushan–Pshart suture zone is the remnant of the Meso-Tethys Ocean and may represent the western continuation of the Bangong–Nujiang suture of the Tibetan Plateau.

Abstract Cretaceous igneous rocks are concentrated in the northern Taebaeksan metallogenic region of South Korea, some of which are related to Fe skarns and/or hydrothermal vein Au–Ag deposits. However, detailed studies on the emplacement age and magma source of igneous rocks supplying this metallogenic area are lacking. In this study, we investigated the emplacement age, magma sources, and geochemical characteristics of seven Cretaceous igneous rocks around the ore deposit, comparing them with previous studies. Zircon U–Pb and mica K–Ar age dating indicated that two magmatism events occurred in the Early Cretaceous (~113.7 ± 0.2 to 104.7 ± 0.5 Ma) and the Late Cretaceous (~85.8 ± 1.1 to 77.6 ± 0.4 Ma). Negative ɛHf(t) values (−2.57 to −22.05 approx.) and the calculated (2.55–1.33 Ga) suggested that the magma source of these igneous rocks was derived from the Proterozoic crust. Whole‐rock geochemical data indicated that the northern Taebaeksan igneous rocks are mostly high‐K calc‐alkaline series, enriched in light rare‐earth elements (LREEs) and large‐ion lithophilic (LIL) elements but depleted in high‐field‐strength (HFS) elements. Although igneous rocks in the northern Taebaeksan metallogenic region have broadly similar magma source characteristics, they can be classified into two groups: one comprises Early Cretaceous intermediate rocks, some of which are related to Au–Ag mineralization, whereas the other includes Late Cretaceous intermediate to felsic rocks, related to Au–Ag or Fe mineralization.

Geochronology, geochemistry, and Sr–Nd–Hf isotopes of the Cretaceous igneous rocks in the Zhilingtou area, SE China, and their geological significance

Detrital zircon U-Pb geochronology of the Lunpola basin strata constrains the Cenozoic tectonic evolution of central Tibet

Periods of cessation, resumption and enhanced arc activity are recorded in the Cretaceous igneous rocks of the Antarctic Peninsula. We present new geochronological (laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U–Pb) analyses of 36 intrusive and volcanic Cretaceous rocks, along with LA-ICP-MS apatite U–Pb analyses (a medium-temperature thermochronometer) of 28 Triassic–Cretaceous igneous rocks of the Antarctic Peninsula. These are complemented by new zircon Hf isotope data along with whole-rock geochemistry and isotope (Nd, Sr and Pb) data. Our results indicate that the Cretaceous igneous rocks of the Antarctic Peninsula have geochemical signatures consistent with a continental arc setting and were formed during the interval c. 140–79 Ma, whereas the main peak of magmatism occurred during c. 118–110 Ma. Trends in ε Hf t (zircon) combined with elevated heat flow that remagnetized rocks and reset apatite U–Pb ages suggest that Cretaceous magmatism formed within a prevailing extensional setting that was punctuated by periods of compression. A noteworthy compressive period probably occurred during c. 147–128 Ma, triggered by the westward migration of South America during opening of the South Atlantic Ocean. Cretaceous arc rocks that crystallized during c. 140–100 Ma define a belt that extends from southeastern Palmer Land to the west coast of Graham Land. This geographical distribution could be explained by (1) a flat slab with east-dipping subduction of the Phoenix Plate, or (2) west-dipping subduction of the lithosphere of the Weddell Sea, or (3) an allochthonous origin for the rocks of Alexander Island. A better understanding of the geological history of the pre-Cretaceous rocks of Alexander Island and the inaccessible area of the southern Weddell Sea is required. Supplementary material: A description of the methods used in this study and the complete dataset are available at https://doi.org/10.6084/m9.figshare.c.6089274

Abstract Mineral chemistry, zircon U-Pb geochronology, and elemental and Sr-Nd-Pb-Hf-O isotopic data for the Early Cretaceous volcanic rocks from the Dabie and East Qinling orogens of China constrain the reworking history of the Yangtze crustal materials in the North China lithosphere. These data provide new insights into the recycling of the deepsubducted crustal materials into the mantle and the transformation process from continental subduction to collision. Our data show that the Early Cretaceous volcanic rocks are characterized by shoshonitic and high-K calc-alkaline basaltic trachyandesite, trachyandesite, and trachyte. They synchronously erupted at ca. 135–120 Ma, and have zircon in situ εHf(t) values ranging from −29.0 to −17.2, and δ18O values from 4.89‰ to 6.84‰. These samples share similar “crust-like” geochemical signatures, whole-rock enrichment in the large-ion lithophile elements, depletion in high field strength elements (Nb/La = 0.12–0.38), highly enriched Sr-Nd isotopic compositions, as well as (206Pb/204Pb)i = 15.97–17.59, (207Pb/204Pb)i = 15.33–15.54, and (208Pb/204Pb)i = 36.87–38.59. The εNd(t) values range from −24.4 to −15.6, −21.8 to −13.1, and −16.8 to −10.9 for the eastern and western North Huaiyang belts of the Dabie Orogen and the East Qinling Orogen, respectively. Such geochemical similarities suggest that the northward deep-subduction of Yangtze crustal materials have been reworked into the North China Craton enriched lithospheric mantle. The spatial pattern of the Early Cretaceous volcanic rocks suggests that the Yangtze subduction extended northward beyond the southern margin of the North China Craton and ran into its interior. The surface and deep lithospheric boundaries are decoupled between the Yangtze Block and North China Craton. The Early Cretaceous igneous rocks in the Dabie–East Qinling Orogen were induced in response to the post-collisional unrooting of the Triassic over-thickened lithosphere coupling.

Temporal variations in the geochemistry of Mesozoic mafic–intermediate volcanic rocks in the northern Great Xing'an Range, Northeast China, and implications for deep lithospheric mantle processes