The Response of Magnesium, Silicon, and Calcium Isotopes to Rapidly Uplifting and Weathering Terrains: South Island, New Zealand
Si, Ca and Mg isotopes do not really correlate with anything. These findings highlight that major (high concentration) elements are used by too many systems (including a nutrients) to be a tracer of a single process.
Trace systems like lithium and uranium isotopes (Robinson et al., 2004; Pogge von Strandmann and Henderson, 2015) show correlations with rock exposure rates, meaning they are useful weathering tracers.
The effect of shell secretion rate on Mg / Ca and Sr / Ca ratios in biogenic calcite as observed in a belemnite rostrum
Belemites, an extinct type of cephalopod, are often used as archives of past seawater chemistry. However, their shells (‘rostrums’) are quite diverse and heterogeneous. This paper investigates how their growth rates influence what chemical signals they record.