Search results for "Crustal thickness"
showing 2 items of 2 documents
Noble gas magmatic signature of the Andean Northern Volcanic Zone from fluid inclusions in minerals
2021
Trace volatile elements like He are key for understanding the mantle source signature of magmas and to better constrain the relative roles of subduction and crustal processes to the variability of along-arc chemical and isotopic signatures of magmatic fluids. Here we report on noble gas abundances and isotopic data of Fluid Inclusions (FIs) in eruptive products and/or fumarolic gases from the Colombia-Ecuador segment of Andean Northern Volcanic Zone (NVZ). FIs in olivine phenocrysts from Ecuador (El Reventador, Cotopaxi and Tungurahua) yield air-normalized corrected He-3/He-4 ratios of 7.0-7.4 R-A, within the MORB range (8 +/- 1 R-A). With exception of the Cotopaxi lavas (opx = 50 km at the…
Gravity-derived Moho map for Latvia
2020
A precise understanding of crustal structure is essential to the fields of geodynamics, seismology and certain branches of geophysics. A boundary between the crust and the mantle is known as the MohoroviÄiÄ discontinuity, simply referred to as the âMohoâ. Moho geometry and depth have been extensively studied in Europe, but there are still regions with little information about it. One such area is the northern Baltics, Latvia in particular. So far, only one seismic refraction profile, spanning from Sovetsk (Kaliningrad) to Kohtla-Järve (Estonia), has been used to study the deep structure of the Earth in Latvia. We propose gravity inversion (ParkerâOldenburg algorithm) to gain more insight i…