The volcano edifices from Tazhong-47 exploring area in the middle of Tarim basin are interpreted by 3-D seismological reflection data coupled with physical drilling well logs. Based on seismic profile interpretation and velocity analysis, the structure of the volcano edifices of continental flood basalt (CFB) are studied. The result shows that reflectors beneath the Tazhong-47 volcanic edifice are corresponding to basaltic intrusions, which have average velocity of 5800 m/s, and the clastic wall rocks have average velocity of 3500 m/s. Based on the calculation of the stratigraphical thickness between the two horizontal markers (Permian-Triassic boundary as named “P-top” and top of bioclastic limestone as named “BL-top”) at drilling well, it is found that the basaltic intrusions make the upper layer relative to the lower layer marks move the 159.1 m upward. This is equal to the uplift extent. By using the “velocity pull-up (VPU)” effect, the total thickness of the basaltic sills is calculated to be 167.7 m, which is similar to the uplift extent. This similarity suggests that the uplift at the volcanic center was the result of “forced folding” caused by the intrusion of the magma. This emplacement style is the same as that of the Karoo large igneous province and the North Atlantic igneous province.

Characteristic and origin of “spherical particle” are studied based on contrast analysis of petrography and carbon and oxygen isotope of “spherical particles” in basite drawn from well and typical amygdules in basalt sampled in the field. Results show that “spherical particles” and amygdules are significantly different in microscopic and carbon and oxygen isotopic characteristics although they are similar in macroscopic feature. “Spherical particles” are characterized by non-oscillatory zoning, obvious recrystallization in the rim, and different carbon and oxygen isotopic values in different “spherical particle” of the same sample. Amygdules are characterized by oscillatory zoning, big crystalline particle, and similar carbon and oxygen isotopic values in different amygdule of the same sample. It can be concluded that “spherical particle” stems from magma capturing pieces of sedimentary carbonate, rather than secondary minerals filling vent. As a result, the basite drilled from the Cambrian and Carboniferous strata is intrusive rock, and volcanism may not occur in related strata.

Seismological interpretation revealed that basalts are overlain by rhyolite in the Halahatang area, Northern Tarim, Northwest China. The overlying rhyolite is dated by SIMS zircon U-Pb method, yielding a precise concordia age of 287.3 ±2.0 Ma, which limits the latest eruption age of the underlying basalt and reveals that the eruption age of the main pulse of the Tarim flood basalt is before 287 Ma, not ~275 Ma.

Seismic reflection characteristics of Permian volcanic rocks in the Tarim Basin were summarized and illustrated by using large number of exploration data from Tarim oil field, and then logging-seismic integrated recognition model was established. Meticulous characterization of Permian volcanic rocks?spatial distribution was achieved through comprehensive study of outcrop, drilling, logging and 2D seismic data. The Remnants of the Permian basalt in the Tarim basin cover an area of about 2. 46 ×10⁵ km², and the remnants of the Permian rhyolite cover an area of about 4.04×10⁴ km². As Permian stratas are missed in most area of north and east Tarim Basin, original Pemian volcanic eruption area may be much larger than residual area. This study lays foundation for further understanding of Permian volcanism in Tarim basin.

The late Paleozoic diorites-granitoids emplaced into Precambrian lithological assembleges in Fengshan area, Northern Hebei province are characterized by enrichment in sodium (Na_2O/K_2O>1.0), high Sr, low Y and HREE contents, and their Sr/Y values change from 37.15 to 151.22. Most samples also show positive Eu anomalies and their Eu^* ranges from 0.92 to 1.53. LA-ICP-MS zircon dating and zircon Hf isotope analyses for samples diorite (sample JB6024) and monzogranite (sample JB6037-1) reveal that the diorite and the monzogranite were produced at 315±2.8Ma and 306.6±6Ma, respectively, namely, indicated the two late Paleozoic magmatic episodes in the Fengshan area. Whole rock petrochemistry, Sr-Nd isotopes and zircon Hf isotope indicate that the late Paleozoic Fengshan diorite was produced by the magmatic mixing between mafic magma derived from an EMI-type enriched mantle and felsic magma derived from partial melting of the ancient lower crust, and the granitoids derived from fractional crystallization of the dioritic magma that was obviously contaminated by upper crustal materials during their emplacement.