Changes in tectonic activity may have shaped composition of Panama Canal rocks
A chain of volcanoes can often appear in areas where one tectonic plate slides under another. Studying these locations can improve understanding of how Earth’s crust is formed. In a new study, researchers examined volcanic formations along the Panama Canal that formed when the Panama block and the South American plate collided approximately 21 to 25 million years ago.
The researchers found that older volcanic rock types, including rocks from a layer known as the Oligocene Bas Obispo Formation, had more abundant water-borne elements than did rocks from the younger Pedro Miguel Formation. The authors suggest that the collision of the Panama block and South American plate changed tectonic conditions along the Panama Canal. They state that changes in the composition of volcanic rocks likely drove a transition from water-bearing magmas to dry, hot magmas over time, and these magmas in turn caused different types of volcanoes to form.
Asthma and dermatitis may not be linked to vitamin D
Previous research suggests that low vitamin D levels are associated with increased rates of asthma, atopic dermatitis — an itchy inflammation of the skin, and elevated levels of IgE, an immune molecule linked to atopic disease (allergies). However, a new study finds this may not be the case. In the new work, researchers looked at genetic and health data on more than 100,000 individuals from previous large studies to determine whether genetic alterations associated with vitamin D levels predispose people to these conditions. They found no statistically significant difference between rates of asthma (including childhood-onset asthma), atopic dermatitis, or IgE levels in people with or without any of the four genetic changes associated with lower levels of 25-hydroxyvitamin D. More work will be needed to determine if the results hold true in non-European populations and in people with vitamin D deficiency.
Image Credit: Fig 5. Field photo of a fossilized tree trunk within the Cucaracha Formation ash fall tuff. by Farris et al.