Rocks within the Earth are constantly being subjected to forces that bend, twist, and fracture them, causing them to change shape and size. This process is known as deformation. Polyphase deformation occurs over time when rocks are affected, or stressed, by more than one phase of deformation. Geomorphologist Amirhossein Mojtahedzadeh captured this stunning scene whilst on field work. “This p ...[Read More]
Imaggeo on Mondays: On the edge of an ice crevasse
Glaciers are persistent bodies of ice at least 100,000 square metres in area and 50 metres thick. They are mostly found in the polar regions but also in mountain ranges, and represent the largest reservoir of freshwater on Earth. This photo was taken by Zervas Efthimios in August 2009, on the climb towards Lenin Peak in the Pamir mountains, Central Asia. “This crevasse appeared just before ...[Read More]
Imaggeo on Mondays: A mineral under the microscope
Epidote, an abundant rock-forming mineral found in metamorphic rocks, nearly always appears in green, although it may vary in shade and tone. Under a microscope of polarized light, however, it exhibits strong pleochroism, that is, it shows different colors when observed at different angles. The thin section (a laboratory preparation of a mineral or rock sample for use with a polarizing microscope) ...[Read More]
Imaggeo on Mondays: Green river
Thermokarsts occur when solid permafrost melts and soil gives way forming pitted, irregular lands surfaces. They are common in the Arctic, as well as the Himalayas and Swiss Alps. To study them, scientists trace the water using fluorescence dyes, temporarily creating water flows of exotic colours, like the bright green one in this Imaggeo photo. This photo was taken by Simon Gascoin, a researcher ...[Read More]