2023年4月18日 · Basaltic lava flows, particularly pāhoehoe flows, may have a variety of surface features including hornitos, levees, tumuli, pressure ridges, and squeeze-ups. Highly vesiculated region near the top of a basaltic lava flow in Craters of the Moon National Monument.

2023年12月7日 · Flood basalt lava flow in stacked layers viewed eastward across the Columbia River from Rowena Crest Viewpoint, Oregon. Basalt in the lava flows has formed columnar jointing.

2010年5月6日 · There are three types of basalt lava flows: pillow, pahoehoe, and a'a. Pillow lava. Pillow lavas are volumetrically the most abundant type because they are erupted at mid-ocean ridges and because they make up the submarine portion of seamounts and large intraplate volcanoes, like the Hawaii-Emperor seamount chain.

2024年7月9日 · Young basaltic lava flows, with surfaces that are either smooth and ropy or rough and clinkery, are dramatic landscapes of dark volcanic rock. Depending on how recently the eruptions that formed them occurred, their surfaces may be barren of vegetation and comprise some of the most inhospitable landscapes on the planet and are among some of the ...

Basaltic Lava Flows. Basaltic lava flows are by far the most common type of lava flows on Earth. In fact, approximately 90% of all lava flows have basaltic compositions. Most, if not all, of the 60 national parks that contain lava flows include basaltic ones.

Fluid basalt flows can extend tens of kilometers from an erupting vent. The leading edges of basalt flows can travel as fast as 10 km/h (6 mph) on steep slopes but they typically advance less than 1 km/h (0.27 m/s or about 1 ft/s) on gentle slopes.

Volumetrically, most lava is of basaltic composition. Basaltic melts have overall lower gas contents and are more fluid than their andesitic-to-rhyolitic counterparts. Their higher fluidity (lower viscosity) is a product of their lower SiO 2 (silica) contents.

2024年10月10日 · Basaltic lava flows appear in distinct forms, each with unique surface textures and structures. These variations result from differences in eruption conditions and the environment where the lava cools and solidifies.

2023年11月6日 · Basalt lava flows, though in lesser volume than rhyolites, have erupted throughout the 2.3 million-year volcanic history of the Yellowstone area. The magma feeding these eruptions originated in the upper part of Earth's mantle and resided only briefly in the crust before erupting at the surface.

2024年1月13日 · On March 14, 2023, geologist Nick Zentner points to a “moment in time” when the Ginkgo lava flowed on top of the ancient Columbia River some 16 million years ago.