i am delighted to announce completion of the second issue of the new journal of “geopersia”, a product of the new era of replacing the persian language journals with specific english-language ones. our purpose is to provide a journal that offers a multi-disciplinary analysis of issues concerning geology subjects (i.e. sedimentology, stratigraphy, paleontology, petroleum geology, engineering geo...

Proterozoic rivers flowed through barren landscapes, and lacked interactions with macroscopic organisms. It is widely held that, in the absence of vegetation, fluvial systems featured barely entrenched channels that promptly widened over floodplains during floods. This hypothesis has never been tested because of an enduring lack of Precambrian fluvial-channel morphometric data. Here we show, th...

Texture analysis holds significant promise for improving the science return of remote planetary exploration. Communications with exploration spacecraft suffer significant latency and bandwidth constraints; onboard image understanding can summarize large datasets and select representative images for transmission. We present image texture descriptors that satisfy the strict computational requirem...

The discovery of remarkably rounded pebbles by the rover Curiosity, within an exhumed alluvial fan complex in Gale Crater, presents some of the most compelling evidence yet for sustained fluvial activity on Mars. While rounding is known to result from abrasion by inter-particle collisions, geologic interpretations of sediment shape have been qualitative. Here we show how quantitative informatio...

Since the early l990s the Chicxulub crater on Yucatan, Mexico, has been hailed as the smoking gun that proves the hypothesis that an asteroid killed the dinosaurs and caused the mass extinction of many other organisms at the Cretaceous-Tertiary (K-T) boundary 65 million years ago. Here, we report evidence from a previously uninvestigated core, Yaxcopoil-1, drilled within the Chicxulub crater, i...