Terminology commonly used to describe glaciovolcanic deposits

• columnar jointing - a jointing consisting of parallel columns with polygonal cross-sections, formed by cooling and contraction, with column size generally decreasing as cooling rates increase
• flaggy jointing - a fine-scale planar jointing commonly which can occur in rapidly cooled lavas
• flow-dominated tuya - a flat-topped, steep-sided glaciovolcanic edifice consisting of stacked lava flows with few or no pillows and little or no fragmental material (e.g. hyaloclastite)
• glaciovolcanism - a synonym for volcano-ice interaction, encompassing subglacial volcanism, ice-marginal volcanism, and supraglacial volcanism
• hackly jointing - chaotic, arcuate jointing with a range of orientations and crosscutting relationships, which can occur in rapidly cooled lavas
• hyaloclastite - a fragmentary, medium to fine-grained rock, consisting of glass clasts (which may or may not be vesicular) most commonly mm to cm across, formed by quench fragmentation or through phreatomagmatic eruption (explosive magma-water interaction)
• hyaloclastite ridge - a linear, steep-sided ridge formed by a subglacial fissure eruption, which may contain any of the internal characteristics of a tuya (e.g. pillows, hyaloclastite, dykes, etc.), although hyaloclastite is usually a major constituent)
• ice-contact volcanism - volcanism in contact with large quantities of ice, often used as a synonym for glaciovolcanism
• ice-marginal volcanism - volcanic eruptions which are subaerial but involve lateral contact between primary eruptive products and ice
• jökulhlaup - a water flood due to subglacial eruption or geothermal heating of the base of a glacier and subsequent large-scale melting
• palagonite - an amorphous yellow glass formed when sideromelane (basaltic glass) within hyaloclastite interacts with surrounding water
• pillow lava- closely-spaced, ellipsoidal, interconnected lava masses which are a few centimeters to more than a meter in diameter, and form through effusive subaqueous or submarine eruption
• pillow breccia - a breccia containing abundant fragments of pillows, which may form when pillows erupt onto a steep slope, roll downhill, and break apart
• pseudopillow jointing- arcuate jointing with associated small, perpendicular, secondary fractures, which occurs at some glaciovolcanic deposits
• sandur - an outwash deposit formed by repeated jökulhlaups, which is commonly hummocky, has a range of bedforms, and contains significant water-transported eruptive materials
• stapar - (plural, stapi) an Icelandic term for a tuya
• subglacial dome - a steep-sided, dome-shaped lava flow or mass with fine-scale jointing, with little or no accompanying primary fragmental material, formed by subglacial eruption
• subglacial mound - a subglacial volcano that never breached the water's surface, which lacks the cap of subaerial lavas seen in tuyas and is thus cone-shaped
• subglacial volcanism - volcanic eruptions beneath ice
• supraglacial volcanism - volcanic eruptions onto the surface of an ice sheet
• tindar - a term sometimes used for hyaloclastite ridge, not generally preferred
• tuya - a flat-topped, steep-sided volcano formed due to subglacial eruption