In other words, each flow stacked against previous flows on the slopes on the valley floor and stair-step their way up slope.Ī few miles east of the vent for the Carrizozo lava flow field is a small area of older lava flows that are generally included in any discussion of recent volcanism in this area. As a result the surface of the lava flow where the highway crosees actually slopes up to the west.
It appears to be one giant flow, but the flow field really consists of multiple small lobes of lava that flowed side by side down the floor of the valley. Most of the flow south of Highway 380 lies within the White Sands Missle Range. The Carrizozo lava flow field extends from its source a few kilometers north of the current Highway 380 southward to the extreme northern end of White Sands. ZimbelmanĪ few skylights occur in lava tubes along the traverse from the margins of the flow to the vent area (Little Black Peak). So the last material erupted was more pyroclastic. The last material probably was gas-rich and lava-volume-poor. As with the vent area of the McCartys lava flow in El Malpais, the vent cone of the Carrizozo lava flow represents the last activity at the location from which most of the lava flows were erupted. The vent area for the Carrizozo lava flow field, Little Black Peak. These results make the Carrizozo flow field the second youngest volcanism in New Mexico (Anthony et al., 1998), after only the McCartys flow field in western New Mexico. Cosmogenic (isotopic changes induced by exposure to high energy particles) studies indicate exposure ages of 4800 yrs (Anthony et al., 1998) to 5200 yrs (Dunbar, 1999) for the Carrizozo flow field. However, chemical analyses to date have revealed no evidence for distinct differences between the upper and lower lavas. Various researchers (e.g., Anthony et al., 1998 Dunbar, 1999) have distinguished between upper and lower Carrizozo flow units, separated by a narrow “neck” in the medial reach (Keszthelyi and Pieri, 1993). Its location and age is consistent with the regional volcanism elsewhere that is fundamentally associated with the Rio Grande rift (Renault, 1970 Faris, 1980 Anthony et al., 1998). The lava is intermediate in composition between alkalic and tholeiitic basalt. The entire flow covers ~330 km 2 to an estimated thickness of 10 to 15 m, for a total estimated erupted volume of ~4.3 km 3 (Allen, 1951). The Carrizozo flow field (Keszthelyi and Pieri, 1993) is 75 km long from the vent area to the distal margin in the Tularosa Valley (Zimbelman and Johnston, 2002). About the Sandia Mountain Natural History Center.Virtual Tour-Sayaka Ganz: Reclaimed Creations.Sensory Friendly Evenings at the Museum.
0 kommentar(er)
