This paper reports results from detrital zircon U–Pb geochronology, Hf isotopic geochemistry, sandstone modal analysis, and palaeocurrent analysis of the early Mesozoic strata within the Ningwu basin, China, with the aims of constraining the depositional ages and sedimentary provenances and shedding new light on the Mesozoic tectonic evolution of the northcentral North China Craton (NCC). The zircons from early Mesozoic sandstones are characterized by three major populations: Phanerozoic (late Palaeozoic and early Mesozoic), late Palaeoproterozoic (with a peak at approximately 1.8 Ga), and Neoarchaean (with a peak at approximately 2.5 Ga). Notably, three Phanerozoic zircons in the Early Triassic Liujiagou Formation were found to have positive ε_Hf(t) values and characteristics typical of zircons from the Central Asian Orogenic Belt (CAOB). Therefore, the CAOB began to represent the provenance of sediment in the sedimentary basins in the northern NCC no later than the Early Triassic (261 Ma), implying that the final amalgamation of the NCC and CAOB occurred before the Early Triassic. The U–Pb geochronologic and Hf isotopic results show that the Lower Middle Triassic sediments were mainly sourced from the Yinshan–Yanshan Orogenic Belt (YYOB), and that a sudden change in provenances occurred, shifting from a mixed YYOB and CAOB source in the Middle Jurassic to a primarily YYOB source in the Late Jurassic. The results of the sandstone modal analysis suggest that the majority of the samples from the Lower Middle Jurassic rocks were derived from either Continental Block or Recycled Orogen sources, whereas all the samples from the Upper Jurassic rocks were derived from Mixed sources. The change in source might be ascribed to the southward subduction and closure of the Okhotsk Ocean and the resulting intense uplift of the YYOB during the Late Jurassic. This uplift likely represents the start of the Yanshan Orogeny.

In order to further reveal the tectonic activity of the central and northern North China Craton (NCC) since late Paleozoic, the Datong coal-bearing basin was selected as the research object. The tectono-thermal events and uplifting cooling events of the basin were retrieved through zircon and apatite fission tracks and vitrinite reflectance measurements. The research shows that the Datong coal-bearing basin experienced three tectono-thermal events with ages of 245–207 Ma (middle–late Triassic), 179 ± 9 Ma (early Jurassic), and 140 Ma to 78 ± 11 Ma (middle–late Cretaceous), respectively. That just coincides with the lamprophyre activity, Kouquan fault activity, and Zuoyun basaltic andesite magmatic activity which surround the Datong coalfield. The basin also experienced three uplift events with the peak ages of 202 ± 18 Ma (late Triassic), 157 ± 7 Ma (late Jurassic), and 45 ± 3 Ma or 36 ± 3 Ma (middle Eocene), respectively. The Datong Permo-Carboniferous and Jurassic coal vitrinite reflectance proved that the average metamorphism temperature is 104–108 °C, even reaching 163–367 °C. The fission track results showed that the paleotemperature was even higher than 170–250 °C from 117 to 282 Ma and 80–120 °C from 20 to 68 Ma, in the Datong coal-bearing basin. The results show that the deep tectonic activities of the NCC were still active in the Mesozoic and even Cenozoic Paleogene.

The petrological, geochemical, and mineralogical composition of the Carboniferous-Permian coal deposit in the Jungar coalfield of inner Mongolia, Northwestern China, were investigated using optical microscopy and field emission scanning electron microscopy in conjunction with an energy-dispersive X-ray spectrometer (SEM-EDX), as well as X-ray powder diffraction, X-ray fluorescence, and inductively coupled plasma mass spectrometry. The Jungar coal is of high volatile C/B bituminous quality with 0.58% vitrinite reflectance and has a low sulfur content of 0.70% on average. Inertinite (mineral-free basis) generally dominates in coal from the lower part of the Shanxi formation, and vitrinite is the major maceral assemblage in the coal from the Taiyuan formation, which exhibits forms suggesting variation in the sedimentary environment. The Jungar coal is characterized by higher concentrations of copper (Cu) in No. 6 coal, at 55 μg/g, and lead (Pb) in No. 4 coal at 42 μg/g. Relative to the upper continental crust, the rare earth elements (REE) in the coal are characterized by light and medium–heavy REE enrichment. The minerals in the Jungar coal are mainly kaolinite, dickite, pyrite, calcite, siderite, quartz, and, to a lesser extent, gypsum and K-feldspar. The enrichment and occurrence of the trace elements, and of the minerals in the coal, are attributed to the fragmental parent rock during diagenesis and coalification. The main elements with high enrichment factors, Cu and Pb, overall exhibit a notably inorganic sulfide affinity and a weak organic affinity. Primary and epigenetic sedimentary environment and the lithology of the terrigenous parent rock are the key factors that influence the occurrence and formation of Cu and Pb in coal. The depositional environment is more influential in the formation of Cu than Pb in coal. Lead is more easily affected by the terrigenous factors than Cu when they are under a similar depositional environment.