Paper No. 268-1
Presentation Time: 8:00 AM
CONNECTING VOLCANICS TO VOLATILES: A CLOSER LOOK AT THE GEOCHEMISTRY OF THE VIRUNGA VOLCANIC PROVINCE IN EAST AFRICA
In recent years, volcanic activity along the East African Rift (EAR) has received extensive attention following the rapid onset of seismic and volcanic activity near the Afar triple junction and a pronounced increase in volcanic hazard activity in the Virunga Volcanic Province (Mt. Nyiragongo and Mt. Nyamuragira (Western branch of the EAR)). Here, we present trace element (REEs, HFSE’s, and actinides (Th/U)) and noble gas isotope (e.g. 3He/4He, CO2/3He, CH4/3He, 40Ar/36Ar, 40Ar*/4He) data for a time series of lava samples taken from Nyamuragira (2006 and 2010 eruptions) and Nyiragongo (2002 eruption, and 2005 and 2010 lava lake sample collections) volcanoes to evaluate the character and mantle sources feeding these systems in the Virunga Province. Because of the unique silica-undersaturated and alkali-rich chemical composition, we must first determine the mantle sources and processes that regulate its evolution. Through an evaluation of the trace element data in the context of volatile emissions (CO2, noble gases and their isotopic composition) we explore the mantle processes that lead to the unique lava compositions in the Virunga Volcanic Province and evaluate how the geochemistry changes throughout this volcanically active time period. We will also compare volatile data from this field to other silica-undersaturated and alkali-rich magmatic bodies around the world to provide a global perspective on these unique lava types.