Abstract: In this study, the petrographical and geochemical signatures of the Kestanelik Granitoid outcropping nearthe Şahinli region (Lapseki, Çanakkale) on the Biga Peninsula and associations with Au-Ag mineralization weredetermined. The Late Ediacaran-Early Cambrian Çamlıca metamorphics form the basement of the study area withinthe Karabiga massif in the Sakarya Zone. These metamorphics were thrusted tectonically in the Upper CretaceousÇetmi mélange. The Çamlıca metamorphics are cut by the Eocene Kestanelik Granitoid, and the granodiorite isunconformably overlain by the Soğucak Formation composed of clastic sedimentary rocks. The Şahinli Formationcomprises andesite-basalt, fragmented pyroclastics, basalt dykes and lava flows, and mudstone. Quaternary alluviumunconformably covers all units in the area. The Kestanelik Granitoid is an intrusive mass in the form of a stock andcontains rocks with granite, quartz monzonite and quartz-rich granitoid composition. The main minerals in theserocks are quartz, K-feldspar, plagioclase, amphibole, hornblende and biotite, and there are secondary mineralssuch as sericite, illite, chlorite, smectite, kaolinite, dolomite, hematite, cristobalite and alunite. This granitoid hasundergone strong alteration and argillic, propylitic and silicification alteration are observed. The Kestanelik Granitoid generally has shoshonitic, calc-alkaline, subalkaline and metaluminous character,and was derived from an I-type magma. It has high silica content (64.9-75.49%), and major-trace element changesindicate that plagioclase and K-feldspar fractionation were effective in the development of the granitoid. In thegranitoid, LILE enrichment is quite high on the REE diagram normalized to the primary mantle. Normalized tochondrite, the granitoid is enriched in light REE and depleted in heavy REE, and also has a negative Eu anomaly(Eu/Eu*=0,87). The Kestanelik Granitoid comprises granites of synchronous age to the volcanic arc and collision,and has magmatic ,or crustal origin.