## 5 Discussion
### Implications for Exploration  
This work reveals that the late-stage granitic magma with high fO\({}_{2}\), which is crystallized into the fine-grained granite, is probably also rich in Au, except for the W-Mo-Cu-Zn-U-Be-Li-Nb-Ta-Sn-Bi-elements [22; 26; 98; 99]. Thus, this would also result in an intimate spatial relationship between the gold orebodies and the fine-grained granite, which is comparable to the other gold deposits worldwide. For example, in the Passa Tres gold deposit located in southern Brazil, the gold-bearing quartz veins occur along the aplitc dikes [100]. In addition, the syenite-associated gold orebodies are found in the Porgera gold deposit, Papua New Guinea [101]; the Abitibi greenstone belt in Canada [102] and the Timbarra gold deposit in Australia [103]. Notably, these deposits commonly are located within the apical portions of small intrusions [104], i.e., the roof zone of the granitic system [105].  
Early Cretaceous gold deposits occurred intensively and widely in the Jiaodong Peninsula in an extensional tectonic regime, as evidenced by the normal movement along the TLF [106] as well as large-scale extension-related magmatism [8; 9; 10] during ca. 130-110 Ma. It has been traditionally accepted that all the gold deposits, including the \"Linglong-type\" and \"Jiaojia-type\", are controlled by either the NE- and NNE-trending regional-scale or lower-order faults [45; 46], with the gold orebodies surrounded by the silicification or seric  
Figure 8: Metallogenic model for the Xiawolong gold deposit. Adapted with permission from Ref. [39; 2023, Elsevier.  
itization alteration envelop [1, 68, 69, 70]. Over 90% of the gold resources are clustered in the Jiaobei uplift, i.e., central and western Jiaodong, which consists of Penglai-Qixia and Zhaoyuan-Laizhou gold metallogenic belts, whereas less than 10% of those in eastern Jiaodong are clustered in the Muping-Rushan gold metallogenic belt [1, 67]. The new and precise geochronologic dates obtained by U-Pb dating on monazite from the gold deposits scattered around Jiaodong indicate that the former was formed during a very transient period in ca. 120 Ma, about 6 m.y. older than the latter [14, 88, 89, 90], suggesting that they are two discrete gold events even though they show a similar geological character and are the same in the genesis. However, this study reveals that the Xiawolong deposit hosted by the fine-grained granitic dikes was formed in ca. 118 Ma, representing another discrete gold event, and is genetically related to the Sanfoshan granitic magmatism, different from the \"Linglong-type\" and \"Jiaojia-type\" deposits hosted by the NNE- to NE-striking faults in Jiaodong. Therefore, we propose that gold exploration in the Jiaodong should not only focus on the fault-hosted Au but also on the fine-grained granite-hosted Au around the apical portions of the late Early Cretaceous small granitic intrusions with high fO\({}_{2}\). This exploration model could also be important for prospecting in other gold ore districts that have a similar tectonic setting.  
In addition, the late Early Cretaceous granitoids in the Jiaodong Peninsula have strong magnetism, which is two orders of magnitude higher than the late Jurassic biotite granite and monzogranite and the Precambrian basement rocks in Jiaodong [107]. However, due to no gold orebodies occurring in the late Early Cretaceous granitoids, the high-precision magnetometric survey was mainly used to determine the concealed rock mass in the past. Nevertheless, this study reveals that the fine-grained granitic dike hosting the Xiawolong deposit is the late-stage crystallization product of the late Early Cretaceous Sanfoshan granitic magma, and the magnetite coexists with the gold-bearing pyrite in the gold ores; thus, it is suggested that the high-precision magnetometric survey could be carried out to determine the striped high magnetic anomaly surrounding the late Early Cretaceous granitoid so as to find the fine-grained granite-hosted Au.