- roof pendant
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Downward extension of the surrounding rock that protrudes into the upper surface of intrusive rocks.Most intrusions that contain roof pendants are relatively shallow; the roof pendants occur as isolated pieces of the surrounding rock within the intrusive mass. Because roof pendants are exposed by erosion of the overlying rock, their presence indicates that the igneous body is being observed near its upper surface. Roof pendants can be studied to determine some of the conditions that existed at the time of intrusion, such as the temperature and composition of the magma.
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▪ geologydownward extension of the surrounding rock that protrudes into the upper surface of an igneous intrusive body. The intrusions that most commonly contain roof pendants are relatively shallow stocks or batholiths; the roof pendants occur as isolated pieces of the surrounding rock within the intrusive mass. Roof pendants usually are strongly metamorphosed through the processes of contact metamorphism, during which heat and fluids from the intrusion have reconstituted the enclosed rock. The presence of roof pendants indicates that the igneous body is being observed near its upper surface; they are exposed by erosion of the overlying rock. Roof pendants can be studied to determine some of the conditions that existed at the time of intrusion, such as the temperature and fluid composition of the magma.* * *
Universalium. 2010.
