The North China Craton underwent extensive lithospheric thinning and crustal reworking during the Mesozoic, challenging classic views of craton stability. This period marks a transition from tectonic quiescence to widespread reactivation, but timing and magnitude remain poorly constrained. Here we reconstruct crustal thickness evolution along the southern margin of the North China Craton using strontium to yttrium and lanthanum to ytterbium ratios, plus neodymium isotopic data from granitoids. Thickening began in the Jurassic and peaked around 130 Ma, when crustal thickness exceeded 70 km and palaeoelevation surpassed 5 km, forming a plateau comparable to the Tibetan Plateau. After ~128 Ma, thickness and elevation decreased to 30–40 km and <3 km by 125–110 Ma. These shifts parallel sedimentary, structural and geophysical evidence. We interpret this evolution as two stages: initial thickening from North China–Yangtze collision, followed by extensional collapse and lithospheric thinning likely driven by Paleo-Pacific plate rollback.

The Proto-Tethys Ocean has played a significant role in the geological history of Earth. However, ongoing debates persist regarding the timing and polarity of its early subduction. Volcanic rocks associated with iron deposits in the Bulunkuole Complex, West Kunlun Orogen, offer insights into both the complex’s formation age and Proto-Tethys evolution. This study presents newly obtained zircon U–Pb age data (~536 Ma) along with comprehensive whole-rock major and trace element and Sr–Nd–Hf isotope analyses of these volcanic rocks. Our dataset implies that the Bulunkuole Complex partly formed in the early Paleozoic rather than entirely in the Paleoproterozoic, as previously suggested. Geochemically, the volcanic rocks exhibit enrichments in large ion lithophile elements and light rare earth elements, along with depletions in high-field strength elements. They also display elevated initial ⁸⁷Sr/⁸⁶Sr values (0.71093, 0.72025) and negative εNd(t) values (−5.13, −6.18), classifying them as continental arc volcanic rocks. These geochemical fingerprints, complemented by zircon εHf(t) values (−12.7 to −1.6), indicate that the parental magmas of the volcanic rocks were produced by partial melting of the lithospheric mantle wedge, which had been metasomatized by subducted sediment-derived melts. The available data, in conjunction with previously published findings, strongly suggest that the Proto-Tethys Ocean subducted southward prior to approximately 536 Ma due to the assembly of Gondwana. Subsequent slab rollback may have resulted in a crustal thinning of 9–25 km during 536–514 Ma. Further shifts in subduction dynamics led to the transition from high-angle subduction to either normal or low-angle subduction, facilitating the formation of a thicker crust ranging from 39 to 70 km between 514 and 448 Ma. This study, therefore, provides valuable insights into the early evolution of the Proto-Tethys Ocean and contributes significantly to our understanding of the tectonic history of the West Kunlun Orogen.

The Jiadi gold deposit, situated in the Southwestern region of Guizhou, is a large-scale, recently discovered, basalt-hosted, and fine-grained disseminated gold deposit. This study has unveiled that the tectonic deformation of the Jiadi gold deposit can be categorized into four stages: the Late Paleozoic crustal uplift and brittle deformation (D1-deformation) stage; the Early Yanshanian NW-trending compressive ductile deformation (D2-deformation) stage; the Late Yanshanian NS-trending strike-slip fault (D3-deformation) stage; and the Himalayan EW-trending nappe structure (D4-deformation) stage. The outcomes of the C-O isotope analysis revealed that the fluid responsible for ore formation exhibits the attributes of magmatic water blended with meteoric water, and the metallogenic constituents primarily originate from a deep source. The formation of the Jiadi gold deposit occurred during the D2-deformation stage and extended to the D3-deformation stage. The D2-deformation stage induced hydrothermal activity and rock devolatilization, leading to the generation of CO₂-rich and low-salinity fluids. The D3-deformation stage, which is intimately associated with mineralization, can be classified into three stages: the pyrite stage; the smoky quartz stage; and the sulfide stage. The findings obtained from laser Raman spectroscopy indicate that the inclusions typically comprise CO_2, CH₄, N₂, and SO₂. These deep fluids ascended along the fault to the interlayer fracture zone during the D3-deformation stage. The alteration of the geochemical environment was accompanied by fluid immiscibility or boiling, resulting in the rapid precipitation of metallogenic materials.

The Shibaogou pluton, located in the Luanchuan orefield of western Henan Province in China, is a typical porphyritic granite within the Yanshanian “Dabie-type” Mo metallogenic system. It is mainly composed of porphyritic monzogranite and porphyritic syenogranite. Zircon U-Pb dating results indicate emplacement ages of 150.1 ± 1.3 Ma and 151.0 ± 1.1 Ma for the monzogranite and 148.1 ± 1.0 Ma and 148.5 ± 1.3 Ma for the syenogranite. The pluton is characterized by geochemical features of high silicon, metaluminous, and high-K calc-alkaline compositions, enriched in Rb, U, Th, and Pb, and exhibits high Sr/Y (18.53–58.82), high (La/Yb)_N (9.01–35.51), and weak Eu anomalies. These features indicate a source region from a thickened lower crust with garnet and rutile as residual phases at depths of approximately 40–60 km. Sr-Nd-Pb isotopic analyses suggest that the magmatic source is mainly derived from the Taihua and Xiong’er Groups of the Huaxiong Block, mixed with juvenile crustal rocks from the Kuanping and Erlangping Groups of the North Qinling Accretion Belt. Combined with geological and isotopic characteristics, it is concluded that the Shibaogou pluton formed during the compression–extension transition period associated with the collision between the Yangtze Block and the North China Craton, reflecting the complex partial melting processes in the thickened lower crust. The present study reveals that the magmatic–hydrothermal activity at Shibaogou lasted approximately 5 Ma, showing multi-phase characteristics, further demonstrating the close relationship between the pluton and the Mo-W mineralization.