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广东三水盆地内广泛分布有晚白垩纪-始新世火山岩,在化学成分上他们表现为以玄武岩类(SiO2=44.45%～54.46%;K2O+Na2O=3%～6%)和粗面岩-流纹岩(SiO2=59.23%～73.27%;K2O+Na2O=7.5%～12%)为主的双峰式特征。这些火山岩大致由十三期火山活动所形成,其中,早期形成以粗面岩-流纹岩为主的火山岩分布在盆地的边缘,晚期以玄武岩类为主的火山活动出现在盆地的中部。火山岩的时空分布特征反映了随着盆地断陷程度的不断加深导致岩浆由来自浅部岩浆房向深部岩浆房转化的过程。盆地内岩浆岩主要受区域地幔上涌-部分熔融所控制,盆地的断陷过程诱发了不同深度岩浆房内岩浆的喷发。三水盆地火山岩的不对称分布暗示了盆地的东侧向沿海方向的拉伸更加强烈。
Late Cretaceous-Eocene volcanic rocks are widely distributed in the Sanshui Basin in Guangdong Province. They are characterized by basalts (SiO2 = 44.45% ~ 54.46%; K2O + Na2O = 3% ~ 6% - rhyolite (SiO2 = 59.23% ~ 73.27%; K2O + Na2O = 7.5% ~ 12%) based bimodal characteristics. These volcanic rocks are roughly formed by thirteen volcanic activities. In the early stage, volcanic rocks dominated by trachyte-rhyolite are distributed on the margin of the basin. Late basalt-type volcanic activity occurs in the middle of the basin. The temporal and spatial distribution of volcanic rocks reflects the process of magmatic transformation from shallow magma chamber to deep magma chamber as the basin faulting deepens. The magmatic rocks in the basin are mainly controlled by the upwelling-partial melting of the mantle in the basin. The faulting of the basin induced the magma eruption in different depths. The asymmetric distribution of volcanic rocks in the Sanshui Basin suggests that the stretching of the eastern side of the basin towards the coast is more intense.