Lava lava flows slowly (0.25 mph), with maximum speeds between 6–30 mph on steep slopes. An exceptional speed of 20–60 mph was recorded following the collapse of a lava lake at Mount Nyiragongo. The physical behavior of lava creates the physical forms of a lava flow or volcano. More fluid basaltic lava flows tend to form flat sheet-like bodies, whereas viscous rhyolite lava flows forms knobbly, blocky masses of rock. General features of volcanology can be used to classify volcanic edifices and provide information on the eruptions which formed the lava flow, even if the sequence of lavas have been buried
Trap rock the Green with trap rock quarried from Eli Whitney's quarry, is a particularly colorful example of a red-orange-brown-colored, natural-faced trap rock. It was also used for foundations and railroad beds in the New Haven area. Well-known examples of outcropping trap rock include both intrusive sills and extrusive lava flows. They include the Palisades Sill, a Triassic, 200 Ma diabase intrusion that forms the Palisade along of the Hudson River in New York and New Jersey. Vast areas of trap rock in the form of thick lava flows and other volcanic rocks comprise the Deccan Traps of India and Siberian Traps