The degree of chemical weathering in soils increases with mean annual precipitation (P; mm) and mean annual temperature (T; C). We have quantified these relationships using a database of major-element chemical analyses of 126 North American soils. The most robust relationship found was between P and the chemical index of alteration without potash (CIA-K): with . Another strong relationship was found between P and

The geological record encodes the relationship between climate and atmospheric carbon dioxide (CO ₂ ) over long and short timescales, as well as potential drivers of evolutionary transitions. However, reconstructing CO ₂ beyond direct measurements requires the use of paleoproxies and herein lies the challenge, as proxies differ in their assumptions, degree of understanding, and even reconstructed values. In this study, we critically evaluated, categorized, and integrated available proxies to create a high-fidelity and transparently constructed atmospheric CO ₂ record spanning the past 66 million years. This newly constructed record provides clearer evidence for higher Earth system sensitivity in the past and for the role of CO ₂ thresholds in biological and cryosphere evolution.

Existing empirically derived compaction curves for marine sediments fail to estimate the compaction of paleosols, flood-plain sediments, and peats as indicated by deformation of clastic dikes, dinosaur footprints, and sandstone paleochannels. Yet compaction esti- mates are vital to reconstructing paleoclimate and geochemical profiles of paleosols, to modeling sediment accumulation rates of nonmarine rocks, and to tectonic flexural mod- eling of molasse facies. This paper presents a compaction equation and physically derived constants that make geologically realistic estimates of compaction of paleosols and other nonmarine sediments. A protocol for the application of the equation is suggested that would allow the following equation to solve for burial compaction (C as a fraction of original thickness) given depth of burial (D in km) as: C 52 Si/((F0 /e Dk) 2 1). This equation can be applied to nonmarine sedimentary rocks or paleosols given appropriate empirical data on the physical constants in the equation, such as initial solidity ( Si), initial porosity (F0), and the corresponding curve-fitting constant (k). Data on physical constants useful for this equation are compiled here for a range of paleosol and nonmarine sediment types.