The “dolomite problem”, which has confused scientists for nearly two centuries, is an important fundamental geological problem. The mineralogical characteristics of carbonate minerals show that the dolomite structure consists of an ordered arrangement of alternating layers of Ca²⁺ and Mg²⁺ cations interspersed with ${\mathrm{C}\mathrm{O}}_3^{2-}$ anion layers normal to the c-axis. The dolomite structure violates the c glide plane in the calcite structure, which means that dolomite has R$\overline{3}$ space group symmetry. The ordered dolomite has superlattice XRD reflections [e.g., (101), (015) and (021)], which distinguish it from calcite and high-Mg calcite. The calculation of thermodynamic parameters shows that modern seawater has a thermodynamic tendency of dolomite precipitation and the dolomitization reaction can be carried out in standard state. However, the latest thermodynamic study shows that modern seawater is not conducive to dolomitization, and that seawater is favorable for dolomitization in only a few regions, such as Abu Dhabi, the Mediterranean and the hypersaline lagoons in Brazil. The kinetic factors of dolomite formation mainly consist of the hydration of Mg²⁺, the presence of sulfate and the activity of carbonate. Current studies have shown that the presence of microorganisms, exopolymeric substances (EPS), organic molecules, carboxyl and hydroxyl functional groups associated with microorganisms and organic molecules, clay minerals with negative charges and dissolved silica facilitate magnesium ions to overcome hydration and thus promote Mg²⁺ incorporation into growing Ca-Mg carbonates. Similarly, the metabolic activity of microorganisms is conducive to the increase in alkalinity. However, the inhibitory effect of sulfate on dolomite formation seems to be overestimated, and sulfate may even be a catalyst for dolomite formation. Combining the carbonate crystallization mechanism with thermodynamic and kinetic factors suggests that the early stage of dolomite precipitation or the dolomitization reaction may be controlled by kinetics and dominated by unstable intermediate phases, while metastable intermediate phases later transform to ordered dolomite via an Ostwald’s step rule.

The Earth’s rotation has been decelerating throughout its history due to tidal dissipation, but the variation of the rate of this deceleration through time has not been established. We present a detailed analysis of eight geological datasets to constrain the Earth’s rotational history from 650 to 240 Mya. The results allow us to test physical tidal models and point to a staircase pattern in the Earth’s deceleration from 650 to 280 Mya. During this time interval, the Earth–Moon distance increased by approximately 20,000 km and the length of day increased by approximately 2.2 h. Specifically, there are two intervals with high Earth rotation deceleration, 650 to 500 Mya and 350 to 280 Mya, separated by an interval of stalled deceleration from 500 to 350 Mya. The interval with stalled deceleration is attributed mainly to reduced tidal dissipation due to the continent-ocean configuration at the time, not to changes in Earth’s dynamical ellipticity from continental assembly or glaciation. Modeling indicates that, except for the very recent time, tidal dissipation is the main driver for decelerating Earth rotation. One potential implication of our findings is that the Earth’s tidal dissipation, along with Earth’s rotation deceleration, may play a role in the evolving Earth.