Santa Ana & Izalco
Izalco, Cerro Verde and Santa Ana volcanoes with the small Conejo and San Marcelino vents in the center middle ground. The foreground is sugar cane. Izalco (lhs) is a small composite cone, 2 km3 in volume. Cerro Verde (middle), with its flatter top, is a small cinder/scoria cone with a wide crater. Santa Ana, in the furthest background (rhs), is a huge composite volcano (>200 km3) with a broad, flat top, the result of its nested craters (below).
Santa Ana's four nested craters and actively steaming crater lake. The upper right shows the SW edge of the Coatepeque caldera (below).
The eastern side of the Coatepeque caldera, El Salvador. The two peninsulas are rhyolite domes, collectively called los Anteojoes (the eyeglasses). This caldera cuts the NE flank of Santa Ana. The countryside around it is blanketed by a sequence of silicic Plinian fall deposits and thick silicic pyroclastic flows, with pronounced swirls of dark, mafic glass intermixed, good examples of magma mixing or at least intermingling.