Pumice is a highly vesicular, low-density volcanic rock composed predominantly of silica-rich glass and fine-grained crystals, formed by rapid depressurization and quenching of gas-charged felsic to intermediate magmas during explosive eruptions. As a substance, it is characterized by an interconnected network of gas bubbles, yielding very low bulk density and high porosity, often sufficient to allow flotation on water. Mineralogically, pumice typically contains quartz, feldspar, and minor mafic phases embedded in a glassy matrix. Its high surface area and chemical stability under ambient conditions make it relevant in filtration media, lightweight construction materials, and as a substrate in various geochemical and petrological studies.
Some 350,000 years ago, the center of New Zealand's North Island appeared much different than the mountainous, scrub-covered landscape it is today. Amid a glacial period, temperatures were colder and conditions harsher. Vast ...
Earth Sciences
May 30, 2026
0
100
New research from the University of St Andrews has precisely dated an eruption from Newberry Volcano and discovered that its ash spread more than 5,000 km across the globe, far further than previously thought for an eruption ...
Earth Sciences
May 21, 2026
0
36
Take a tour through volcanic history on the edge of the Sierra Nevada near Mammoth Lakes, California. Between the tall granite peaks to the west and the Basin and Range province to the east, overlapping volcanic complexes ...
Earth Sciences
Apr 8, 2026
0
11
Perseverance has been continuing its sightseeing tour of the Jezero crater rim, with this week's travel itinerary including an up-close look at Pico Turquino. Here, the team hopes to investigate the history recorded in this ...
Planetary Sciences
Dec 3, 2024
0
61
