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Narimalaheinan copper deposit is located in the east section of East Kunlun. Its ore forming belt belongs to Qimantage Dulan Variscan polymetallic metallogenic belt. The study of its tectonic activity provides scientific data for subsequent mineral exploration and the preservation and change of the deposit. Apatite fission track chronology method was used to explore the thermal chronological constraints of tectonic activities in different stages in the area, and the uplift rate and amount were quantitatively calculated. The ages of six apatite samples obtained in this study were (64±4), (59±3), (54±4), (57±4), (51±4), (57±4) Ma, P(χ2)＞5%, indicating a single thermal event reaction. The age of apatite samples is positively correlated with the elevation, indicating that the study area is uplifted as a whole by tectonic activities. The fission track length of apatite sample is (106±19)(123±17) μm. The track length is large, and the sample age value has a positive correlation with the track length, indicating that the older samples have a shorter residence time in the return zone and are less affected by later thermal events. The cooling curve simulation results show that the study area has experienced three stages of evolution: rapid uplift, stable uplift and rapid uplift, and the corresponding uplift amounts are 1 429, 285 and 1 571 m respectively. The thermal history in the area was simulated by HeFTy software, the results show that the thermal evolution in the region is divided into three stages. In the first stage (8065 Ma), the uplift rate is 0095 mm/a and the uplift amount is 1 429 m. There is a rapid uplift event, which records the beginning of the closure of the Yarlung Zangbo ocean and the beginning of the collision between India and Asia. In the second stage (6515 Ma) the uplift rate is 0006 mm/a and the uplift volume is 285 m, which occurrs slow uplift and records the collision event between the Indian plate and the Eurasian plate. In the third stage (15 Ma to now), the uplift rate is 0105 mm/a and the uplift volume is 1 571 m, which records the post collision between the Indian plate and the Eurasian plate, resulting in the rapid uplift of the study area at 15 Ma.

Reconstructing the growth model of the Northeastern Qinghai–Tibet Plateau is of significant importance in understanding its tectonic evolution through time. We present 20 new zircon fission track data on samples collected from the Chakabeishan-Shaliuquan district in the North Qaidam Tectonic Belt (NQTB) to constrain its Mesozoic mineralization and exhumation history. Sample ages and characteristics are differentiated by regional thrust fault systems. The mineralized pegmatite ages with high U concentrations can be divided into two groups of 170–168 Ma and 149–137 Ma, recording exhumation and hydrothermal mineralization events, with average cooling and exhumation rates of 0.074 mm/y and 2.305°C/Ma, respectively. Two ZFT ages groups characterized by low U concentrations at the deposit periphery of 125–106 Ma and 99–80 Ma, respectively, are associated with accelerated cooling and exhumation, with mean values of 7.662°C/Ma and 0.245 mm/y. We suggest that the NQTB was positioned in the high background thermal field in the Triassic, and subsequent tectonic extension resulted in the unroofing, cooling and mineralization of the region. The transition from extensional to contractional deformation in the Cretaceous tectonic setting has reactivated regional thrust fault systems and reset the Jurassic ZFT ages, and this exhumation event was influenced by the closure of the Middle-Tethys and Mongol-Okhotsk Oceans, consistent with the double-sided subduction model. [ABSTRACT FROM AUTHOR]

As industrial computerized tomography (ICT) is widely used in the non-destructive testing of a solid rocket motor (SRM), the problem of how to automatically discriminate defect types and measure defect sizes with high accuracy in ICT images of SRM grains needs to be urgently solved. To address the problems of low manual recognition efficiency and data utilization in the ICT image analysis of SRM grains, we proposed an automated defect analysis (ADA) system for ICT images of SRM grains based on the YOLO-V4 model. Using the region proposal of the YOLO-V4 model, a region growing algorithm with automatic selection of seed points was proposed to segment the defect areas of the ICT images of grains. Defect sizes were automatically measured based on the automatic determination of defect types by the YOLO-V4 model. In this paper, the image recognition performance of YOLO-V4, YOLO-V3, and Faster R-CNN models were compared. The results show that the average accuracy (mAP) of the YOLO-V4 model is more than 15% higher than that of the YOLO-V3 and Faster R-CNN models, the F1-score is 0.970, and the detection time per image is 0.152 s. The ADA system can measure defect sizes with an error of less than 10%. Tests show that the system proposed in this paper can automatically analyze the defects in ICT images of SRM grains and has certain application value. [ABSTRACT FROM AUTHOR]