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Late Mesozoic granites are present throughout the Jiaodong Peninsula in eastern China, but the petrogenesis of these granites, the magma sources, and the geodynamic setting of the magmatism remain unclear. This paper presents new zircon U–Pb geochronological and Lu–Hf isotopic and whole‐rock geochemical data for the Late Jurassic Queshan pluton in the Shandong Peninsula, an area that represents the boundary between the Jiaobei and Sulu ultrahigh‐pressure (UHP) terranes. Laser ablation–inductively coupled plasma–mass spectrometry zircon U–Pb dating yields Late Jurassic ages from 158 ± 1 to 153 ± 1 Ma for the pluton in addition to a small number of inherited zircons that yield ages that cluster at 2410, 1831–1776, 750, and 209–202 Ma. Zircons from different samples have similar 176Hf/177Hf values (0.281926–0.282255) and variably negative εHf (t) values that range from −26.5 to −15.1 (weighted mean of −22.9 ± 0.9). The corresponding two‐stage Hf model ages range from 2,869 to 2,154 Ma, with a weighted mean value of 2,645 ± 54 Ma. These data indicate that the magmas that formed the Queshan pluton were derived from multiple sources, including the lower crust of the North China (NCC) and Yangtze (YC) cratons, as well as collision‐related alkaline rocks. The whole‐rock geochemical compositions of the samples indicate that the granites are weakly peraluminous, are high‐K and calc‐alkaline with I‐type affinities, and have high contents of Sr, low contents of Y and Yb, high (La/Yb)N and Sr/Y values, and positive Eu anomalies (δEu = 1.20–1.65), indicating an adakitic affinity. This indicates that the Queshan granites formed from magmas generated by partial melting of a thickened region of the crust (>50 km) associated with eclogite, garnet amphibolite, or amphibolite residual material. The genesis of the Late Jurassic granites are also likely to have been influenced by the collisional orogeny between the NCC and YC and continued subduction of the Izanagi Plate. Thickening of the lower crust associated with this continental collisional event occurred before the magmatism, with further compression and thickening of the lower crust caused by the low‐angle subduction of the Izanagi Plate beneath northeastern China being the main geodynamic driver of the formation of the granites in this region. [ABSTRACT FROM AUTHOR]

Microbial carbonate has been increasingly recognized as an important player for sediment production and building up of organosedimentary deposits. The integrated spatio‐temporal pattern of microbial facies is important for understanding carbonate production processes in a carbonate platform. This paper focuses on the sedimentary facies and development of a microbe‐dominated platform in the Cambrian North China Platform (the Zhangxia Formation of the Cambrian Series 3) in Shandong Province, China. In the entire Zhangxia platform, deposition started with oolite‐dominated shoal‐lagoon system with rare microbialites. The shoal‐lagoon system in the western part of the study area kept up with sea‐level rise and formed a flat‐topped platform, whereas that in the eastern part failed to keep up and thus drowned. The platform top then changed to a microbe‐dominated carbonate platform consisting of thrombolite, stromatolite, dendrolite, and Epiphyton framestone. The initial significant microbialites were biohermal thrombolite and dendrolites, which subsequently changed into wider biostromal forms. The morphologic change was largely due to initial rapid rise in sea level and the following deceleration. Extensive biostromes of laterally coalesced thrombolite–Epiphyton bioherms occur in the shale‐dominated eastern part. These microbialites then perished by platform‐wide drowning. The vast initial development of microbialite facies of the Zhangxia Formation in the Shandong area was important for the establishment of an extensive microbialite‐dominated carbonate factory made by combination of an absence of reef‐building metazoans and possible transition of seawater chemistry from aragonite sea to calcite sea in the Cambrian Series 3. It is comparable to the other carbonate environments lacking dominant metazoan reef builders after the mass extinctions. [ABSTRACT FROM AUTHOR]

The Qibaoshan ore area is located in Wulian town, Shandong Province, which is an important polymetallic metallogenic zone containing gold, copper, lead, and zinc. The polymetallic mineralization is mostly related to the Qibaoshan complex. The Qibaoshan complex is composed mainly of pyroxene diorite, andesitic porphyrite, pyroxene andesite porphyrite, amphibole andesite porphyrite, diorite porphyrite, and granodiorite porphyry, among which granodiorite–porphyry is the main wall rock of gold and copper ore body, whereas lead and zinc mineralization is closely related to diorite porphyrite. A combined study of laser ablation–inductively coupled plasma–mass spectrometry zircon U–Pb dating and geochemical analyses (major and trace elements) for 5 Mesozoic plutons from the Qibaoshan complex was carried out to determine their ages, petrogenesis, and tectonic setting. The U–Pb zircon ages measured by laser ablation–inductively coupled plasma–mass spectrometry indicate that the Qibaoshan complex was emplaced in 3 stages, represented by the ~175 Ma pyroxene diorite, ~129 Ma andesitic porphyrite/ porphyrite, ~125 Ma granodiorite‐porphyry, and ~112 Ma diorite porphyrite. Systematic diagenetic chronology and rock geochemistry show that formation of ~175 Ma pyroxene diorite in Qibaoshan ore‐concentrated area is possibly related to the transformation environment from compression to extension of the Sulu orogenic belt and/or of the subduction of the Pacific Plate, whereas the formation of the Early Cretaceous subvolcanic rock has a volcanic arc affinity related to subduction of the Pacific Plate. Based on the previous studies, this paper argues that the metallogenic age of Qibaoshan polymetallic ore‐concentrated area is 125–105 Ma, which is formed in the volcanic arc dynamics environment of the Pacific Plate subduction in the Late Yanshanian. In addition, a small amount of 610–799 Ma and 1.8 Ga was developed in the samples of the pyroxene diorite and andesitic porphyrite, suggesting their source may have great affinities with South China. [ABSTRACT FROM AUTHOR]