GeoLog

Imaggeo

Imaggeo On Monday: Križna jama

Imaggeo On Monday: Križna jama

The Križna jama Cave on the east side of the periodic Cerknica Lake in Slovenia is an underground karstic cave primarily famous as a rich site of bones of the extinct cave bear, Ursus speleus. The eight kilometer long cave is full of stalagmites and stalactites (sometimes called drip-stone decorations) and also boasts 50 underground lakes separated by sinter barriers through which crystal clear wa ...[Read More]

Imaggeo On Monday: Quartz – sericite mylonite, Calamita, Elba

Imaggeo On Monday: Quartz – sericite mylonite, Calamita, Elba

Concomitant thrusting and magmatism resulted in the development of ductile mylonites in the Calamita Schists, part of the contact aureole of the Late Miocene Porto Azzurro pluton. This mylonite is made up of stretched and recrystallized quartz layers, interlayered with thin sericite-rich levels. Sericite resulted from the crushing of contact-metamorphic minerals such as andalusite, cordierite, and ...[Read More]

Imaggeo On Monday: Artificial peridotite takes its gold coat off

Imaggeo On Monday: Artificial peridotite takes its gold coat off

Sometimes in order to test a theory about how processes work below the surface of the Earth, scientists need to recreate minerals found in very specific circumstances. This photograph was taken through a binocular microscope during a critical step of the creation of artificial peridotite: extraction of the artificial peridotite from its gold capsule. The sample is a little cylinder, 3 mm long with ...[Read More]

Imaggeo On Monday: Geometric Microscape of Agate

Imaggeo On Monday: Geometric Microscape of Agate

“Crazy Lace” is an agate collected in Mexico, which offers great opportunities for aesthetic photomicrography. Here we see the common arrangement of fibers of chalcedony (microcrystalline quartz) in parallel bands alternating with black thin layers of Fe oxides. Polarized light photomicrograph, crossed polarizers and red tint plate. width 5.4 mm. Sample kindly provided by Denise M. Har ...[Read More]