Yan Chen

• Doctor of Philosophy
• Professor (Associate) at Institute of Geology and Geophysics Chinese Acadamy of Sciences

Early diagenetic nodules with low permeable and weather-resistant structures are considered to be favorable for biosignature preservation. Numerous nodular structures forming in neutral-to-alkaline and saline diagenetic fluids were previously identified at Gale Crater on Mars, yet their astrobiological significance remains poorly understood. In the...

Microbial assemblages inhabiting soils sheltered by rocks are widespread in the hyperarid and hypersaline Dalangtan Playa, which could contribute significantly to the ecological processes in this desert ecosystem. Here, we performed geochemical and metagenomic analyses of soils below and beside rocks in the Dalangtan Playa. Fourier transform infrar...

Searching for life is one of the most important targets of Mars exploration missions. It has been considered that the Martian subsurface, away from the extreme surface environment, is a potentially habitable region for microbial growth. However, the distribution pattern of potential microbial habitats in the Martian subsurface has yet to be evaluat...

The search for organic matter on Mars is one of the major objectives of Mars exploration. However, limited detection of organic signals by Mars rovers to date demands further investigation on this topic. The Curiosity rover recently discovered numerous nodules in Gale Crater on Mars. These nodules have been considered to precipitate in the neutral-...

A variety of aqueous deposits and soils from gullies, fluvial channels, mountain slopes, alluvial fans, playas, polygons, and yardangs have been found on Mars. However, the occurrence of sedimentary organic matter (SOM) in these landscapes under hyperarid and strongly radiative conditions has yet to be fully assessed. With various desiccated landfo...

Biosignature detection is one of the most important goals in Mars exploration missions. Since the Mars Science Laboratory (MSL) mission, the laser-induced breakdown spectrometer (LIBS) has become an essential payload due to its convenience and versatility in profiling elemental chemistry, and the most recent rovers Perseverance and Zhurong both hav...

For decades, the search for potential signs of Martian life has attracted strong international interest and has led to significant planning and scientific implementation. Clearly, in order to detect potential life signals beyond Earth, fundamental questions, such as how to define such terms as “life” and “biosignature”, have been given considerable...

The Qaidam Basin on the northern Tibetan Plateau, China, is one of the driest deserts at high elevations, and it has been considered a representative Mars analogue site. Despite recent advances in the diversity of microbial communities in the Qaidam Basin, our understanding of their genomic information, functional potential and adaptive strategies...

The late Ordovician is characterized by significant environmental changes in global climate, oceanic redox conditions, as well as a major disaster for marine organisms—the Late Ordovician mass extinction (LOME) (ca. 445 Ma). During this event, planktonic and benthic faunas as well as microbial communities were substantially influenced, and changes...

The Ediacaran-Cambrian transition is characterized by the evolution of complex eukaryotes and rapid diversification of metazoans. However, linkages between environmental triggers and evolutionary patterns remain unclear. Here, we present high-resolution records of carbon and nitrogen isotopic data (δ¹³C, δ¹⁵N) for a drill core extending from the ea...

The temporal change of redox conditions of the Yangtze ocean has been revealed by investigating the Ediacaran– Cambrian transition section at Zhalagou, South China. During the earliest Cambrian, cherts and shales were deposited under an anoxic and ferruginous bottom water with significantly increasing total organic carbon and P contents, and negati...

Permian hydrothermal activity in the Tarim Basin may have been responsible for the invasion of hot brines into Ordovician carbonate reservoirs. Studies have been undertaken to explain the origin and geochemical characteristics of the diagenetic fluid present during this hydrothermal event although there is no consensus on it. We present a genetic m...

Cherts of the Piyuancun Formation and black mudstones of the Hetang Formation in Diben Town, Kaihua County, Zhejiang were deposited in a deep water basin of the Lower Yangtze area during the Ediacaran–Cambrian transition (E–C transition), offering an opportunity to reconstruct the ancient redox condition of the deep water basin. Total 53 samples we...