| The in-situ LA-ICP-MS (laser ablation-inductively coupled plasma mass spectrometry) apatite fission track dating technique has gradually become widely used in thermochronology laboratories due to its safety and efficiency advantages. Based on analysis of the principles of the external detector method and the in-situ LA-ICP-MS method, this study has improved the sample preparation procedures for apatite fission track dating and introduced the experimental protocols for in-situ LA-ICP-MS apatite fission track dating established in the thermochronology laboratory of China University of Petroleum (Beijing). Using the newly established testing procedure, the international reference samples Fish Canyon Tuff and Durango were analyzed, yielding ages of 28.70±2.70 Ma (2σ, MSWD=0.63) and 32.01±0.52 Ma (2σ, MSWD=0.91), respectively. These ages are consistent with the recommended ages within the error range. When applying the LA-ICP-MS method to analyze Jurassic samples from the Qianjiadian basin in Yanqing district, 7 apatite fission track ages ranged from 91.18 to 74.28 Ma, which are in good agreement with the results obtained using the external detector method by previous researchers. Through thermal history modeling, it was revealed that the western segment of the Yanshan region experienced two cooling events: 140-130 Ma and 100-0 Ma, since the Jurassic period. This study demonstrates that the newly established in-situ LA-ICP-MS apatite fission track dating experimental procedure in the laboratory is reliable and offers broader application prospects compared to traditional external detector methods. |