Abstract Magnetic surveys are used to identify and monitor hydrothermally altered regions on volcanoes. Commonly such magnetic data interpreted the premise that hydrothermal alteration consumes Fe‐Ti oxides in host rocks, reducing their total magnetization. Here, we report a contrasting observation from Whakaari (White Island) volcano New Zealand. We study properties of 42 conduit‐filling surfi...

Damavand is a fascinating dormant stratovolcano, 60 km to the ENE of Tehran located in the Alborz Mountains. Damavand volcanic products consist of lava flows and pyroclastic fall, flow and surge deposits from different eruption cycles. The volcanic rocks ranges from trachyandesite to trachyadacite and minor basalt. The mineral assemblage consists of potash feldspar (Or43/7), Plagioclase (An25 t...