Ran He

My research focuses on using siderite (iron carbonate, FeCO3), a unique carbonate mineral, to reconstruct ancient Earth environments. Siderite is redox-sensitive and requires specific physiochemical conditions to precipitate and remain stable. This sensitivity makes it particularly valuable for preserving paleoenvironmental information, especially during critical periods in Earth's history when unique conditions favored siderite formation. Siderite offers a key advantage for paleoenvironmental reconstruction due to its low solubility. While other carbonate minerals may undergo dissolution and reprecipitation that can alter their primary geochemical signatures, siderite tends to remain stable and preserve its original environmental record. This stability makes it an exceptional archive of past conditions. To extract paleoenvironmental information from siderite, I employ multiple analytical approaches. I analyze stable isotopes (carbon, oxygen, and clumped isotopes) and integrate these geochemical data with sedimentological and petrographic observations.