Zircon oxygen isotope ratios have been used to trace the incorporation of sedimentary rocks into magmas. The dramatic increase in maximum zircon δ 18 O values Paleoproterozoic observed global databases coincides with changes surface environments (e.g., rise subaerial and oxidative weathering), implying a connection between elevated these changes. 2.5 2.2 Ga, however, is relatively under-constra...

timely and essential to exchange new ideas in the international community provoke 34 promote studies this field.In collection of Research Topic, 11 contributions were published, with a 36 focus on recent advances sedimentary geochemistry isotopes at whole-rock 37 and/or single mineral scale their applications tectonic environmental published practice examples regional that can be tracked referr...

The majority of caves are formed within limestone rock and hence our understanding of cave microbiology comes from carbonate-buffered systems. In this paper, we describe the microbial diversity of Roraima Sur Cave (RSC), an orthoquartzite (SiO4) cave within Roraima Tepui, Venezuela. The cave contains a high level of microbial activity when compared with other cave systems, as determined by an A...

Fundamental to the ability to monitor a Comprehensive Nuclear-Test-Ban Treaty is a good understanding of the nuclear explosion source. Considerable research has been done on the nuclear explosion source over the past 30 years, with mixed success. Although empirical and numerical models of explosion sources do a fairly good job of matching observed seismic signals, a good explanation of the phys...

Microbial communities in hydrothermal systems exist in a range of macroscopic morphologies including stromatolites, mats, and filaments. The architects of these structures are typically autotrophic, serving as primary producers. Structures attributed to microbial life have been documented in the rock record dating back to the Archean including recent reports of microbially-related structures in...

the nasirabad manganese deposit is located 5 km south of nasirabad, 8 km sw of neyriz in the fars province. structurally, the area is placed in the southeastern part of zagros thrust belt. in this area, the manganese mineralization occurred as ore layers and nodules, interlayered with pichakun radiolarite chert deposits. in this study, mineralogy and geochemistry of uranium, thorium and lead is...