Igwisi Hills

sopka (bez známé erupce za posledních ~12 000 let), Tanzania, Eastern Africa Volcanic Regions

Kde

Tanzania, Eastern Africa Volcanic Regions

Typ (GVP)

Pyroclastic cone(s)

Nadmořská výška

1 146 m

Poloha

-4,889°, 31,933°

Three kimberlitic volcanoes of late Pleistocene or Holocene age are located in the Igwisi Hills, WNW of the city of Tabora in NW Tanzania. They were erupted along a NE-SW-trending rift through a Precambrian granitic gneiss basement and are located on the W side of the Tanzanian Craton far from volcanoes near the Gregory Rift. Two pyroclastic cones with well-preserved craters are present, with a central cone and crater adjacent to the NE crater that contains a solidified lava lake. The NE crater is the largest feature, at 370 m in diameter, and has been breached on the ENE side; this was the source of a lava flow about 1 km long and wide. The SW crater is also breached on the ENE side, with a smaller lava flow on the E flank. Cosmogenic 3He exposure dating of olivine in the lavas has a large uncertainty range, which Brown et al. (2012) variously describes as late Pleistocene/Holocene or "near Holocene" in their text.

Text: Smithsonian Global Volcanism Program.

Údaje o sopce: Smithsonian Global Volcanism Program. Další sopky a průduchy.