👉 The boulder fluid is a rare, highly viscous, and sticky rock-forming fluid that occurs in specific geological settings, typically associated with the alteration of volcanic rocks and metamorphic terrains. It is composed primarily of clay minerals, particularly smectite, along with water and sometimes dissolved salts and other minerals. This fluid exhibits extremely high viscosity, often exceeding that of molasses, which allows it to flow slowly and form large, cohesive masses known as "boulders." These boulder flows can move over long distances and create distinctive landforms, such as the "boulder fields" or "boulder sheets," which are characterized by their smooth, rounded, and often stacked appearance. The movement of boulder fluid is driven by gravity and can occur in environments with significant water saturation, such as near fault zones or in areas of tectonic activity.
