Global weathering of calcium and magnesium silicate rocks provides the long-term sink for atmospheric carbon dioxide (CO(2)) on a timescale of millions of years by causing precipitation of calcium carbonates on the seafloor. Catchment-scale field studies consistently indicate that vegetation increases silicate rock weathering, but incorporating the effects of trees and fungal symbionts into geo...

Introduction: The HEDs make up the largest suite of crustal igneous rocks available from asteroids. Sili-cate clasts in the mesosiderite metal-silicate breccias are also dominated by crustal rocks that resemble the HEDs in many ways. Silicate petrology in both groups of meteorites range from strikingly similar fine-grained basalts to coarse grained orthopyroxenites. Mesosid-erites furthermore c...

Hydrogeochemical investigations had been carried out at the Amol-Babol Plain in the north of Iran. Geochemical processes and factors controlling the groundwater chemistry are identified based on the combination of classic geochemical methods with geographic information system (GIS) and geostatistical techniques. The results of the ionic ratios and Gibbs plots show that water rock interaction me...

The long-term carbon cycle is vital for maintaining liquid water oceans on rocky planets due to the negative climate feedbacks involved in silicate weathering. Plate tectonics plays a crucial role in driving the long-term carbon cycle because it is responsible for CO2 degassing at ridges and arcs, the return of CO2 to the mantle through subduction, and supplying fresh, weatherable rock to the s...

Abstract Weathering of silicate rocks at a planetary surface can draw down CO 2 from the atmosphere for eventual burial and long-term storage in interior. This process is thought to provide essential negative feedback carbonate-silicate cycle (carbon cycle) maintain clement climates on Earth potentially similar temperate exoplanets. We implement thermodynamics determine weathering rates as func...

It is well known that the platinum group element (PGE) mineralization in the Merensky and UG2 chromitite reefs is restricted to a very narrow vertical interval of rocks (Wagner, 1929). In the UG2 chromitite there is essentially no PGE above or below the chromitite layer that rarely exceeds 1 m thick. In the Merensky Reef a very large proportion of the PGE is confined within 1 m vertically in ma...