Planetary Science Institute’s Post

Are you interested in sediment transport on Mars? Then you might like my new paper on "Gravity-Driven Differences in Fluvial Sediment Transport on Mars and Earth"! 🛸 🚀 🛰 https://lnkd.in/e87Q3wrn

Depositional Processes of the Margin Unit, Pasadena CA (JPL) Mar 01, 2024 There has been much discussion and interest regarding the origin of the Margin unit. The Margin unit has gained interest due to the presence of carbonates and its implications for the paleoenvironment and biosignature preservation of ancient Mars. There are several possible origins for the Margin unit, and further analysis of these rocks will shed light on what environment the Margin unit, : Pasadena CA (JPL) Mar 01, 2024 There has

Exploring Monument Rocks: A Kansas Prehistoric Marine Wonderland Exploring Kansas's rich geologic history is not only fascinating but also provides valuable insights into the ancient world. Today's post takes you on a journey through time, to when Monument Rocks was a thriving marine ecosystem.

🔷 Today I am immersing myself in the world of ichnofossils, right here in the stunning Apennines. This mountain range is a geologist's dream, offering a vast array of deep-sea life from the Mesozoic and Cenozoic eras. The rocks here have been silent witnesses to millions of years of biological activity, preserving the traces and trails of ancient organisms in their #deposits. 🔷 Among the ichnofossils, or trace fossils, found here are Zoophycos, Chondrites, Undichna, and Scolicia. Zoophycos, a type of trace fossil often found in deep marine environments, is characterised by a distinctive 'skirt-like' pattern. Chondrites, on the other hand, are a network of small, branching burrows, hinting at the feeding behaviour of the invertebrates (possibly bivalves or worms) that created them. Undichna is intriguing as it is interpreted as the swimming trace of a fish, a direct record of animal behaviour frozen in time. Finally, the Scolicia trace fossils, typically associated with deposit-feeding #sea urchins, are sure to catch your eye with their meandering patterns. 🔷 Each of these ichnofossils provides a window into the past, offering us a glimpse of the ancient deep-sea environments that once existed here. The Apennines thus serve as an invaluable open book of Earth's history, where each layer of rock reveals a new chapter of life's evolution. It is a truly humbling experience to walk these mountains and reflect on the immense span of geological time they represent.

12- #Shallow_Sandy_Seas If the area lies adjacent to an uplifted continental region and there is a drainage pattern of rivers delivering detritus to the coast, the shallow-marine sedimentation will be dominated by terrigenous clastic deposits. Shallow seas that are not supplied by much terrigenous material may be areas of carbonate sedimentation, especially if they are in lower latitudes where the climate is relatively warm. The patterns and characteristics of deposition on shelves and epicontinental seas with abundant terrigenous clastic supply are controlled by the relative importance of 𝒘𝒂𝒗𝒆, 𝒔𝒕𝒐𝒓𝒎 𝒂𝒏𝒅 𝒕𝒊𝒅𝒂𝒍 processes. The deposition environments on continental shelves exhibit variability influenced by factors such as water depth, sediment supply, climate, and the prevalence of wave, tide, and storm processes. The resulting sedimentary features display distinctive characteristics, including cross-bedded sand sheets from strong currents, indicative of shallow marine conditions, texture is generally moderately to well sorted, with bed geometry forming sheets of variable thickness and large lenses created by ridges and bars. Unique sedimentary structures such as hummocky and swaley cross-stratification suggest storm-deposited sands. The presence of specific benthic organisms and trace fossils further supports the identification of shallow marine environments. Shelf sandstone and mudstone successions, occasionally accompanied by limestones during low terrigenous clastic detritus supply, contribute to the diverse nature of these deposits.  Paleocurrents exhibit variable flow directions, reflecting influences from tidal currents, longshore drift. Distinguishing between tempestites and turbidites aids in determining water depth, with the former associated with shelf environments. The presence of certain sedimentary structures, like 𝑯𝑪𝑺–𝑺𝑪𝑺, and a more varied ichnofacies in tempestites compared to deeper water environments, provides additional evidence for shelf deposition. #sedimentology #geology #petroleum #SedimentaryRocks #Geoscience #Paleoenvironments

ICE AGE SANDBLASTING A windkanter (German) or ventifact (English) is a piece of rock with flat or convex facets that were formed as a result of long term exposure to abrasive wind-driven sands. In case three facets are visible (or actually their edges, referred to as 'Kanten' in German), we also call them dreikanter (the German language can be so expressive!). Their facets are often polished and the edges between them are usually sharp. In the Quaternary of northwestern Europe windkanters are characteristic of cold and arid climatic conditions that existed at the end of glacial periods. The most beautiful examples are from finer structured materials like quartzites although examples from other source rocks like granite can also be found. Most windkanters are related to the final phase of the Last Glacial (late Marine Isotope Stage 2) although at some locations, their age of formation might actually be older (a nice cosmogenic dating topic I would say). Exposure seems to be an important factor for their development so the Saalian glacio-tectonic ridges are good sites to hunt for them. I found the nicest ones on the (formerly) exposed flanks of the Saalian Itterbeck-Uelsen glacio-tectonic ridge in the westernmost part of Niedersachsen and adjacent part of the Netherlands (see below). If you have other cool examples of windkanters please post them below :-)! #geology #geoscience #earthscience #mapping #tnogeologicalsurvey #landscape #permafrost #wind #climatechange

Leger et al present PaleoGrIS 1.0 - the first major effort to map the margin chronology of the entire Greenland Ice Sheet during the retreat after the Last Glacial Maximum. They present isochrones with uncertainties, though because the ice sheet retreated inland from the present margin, the mid-Holocene isochrones are considered to be maximum limiting. A massive effort and I applaud the authors for what will be a useful resource. https://lnkd.in/gue3vQu3

🚀⚛️ Impressive flipping of an iceberg: A true show of nature in Argentinian Patagonia 👨🏻🏫 The physics of a flipping iceberg involves buoyancy, density, and stability. Icebergs float because ice is less dense than water, but if their mass distribution changes due to melting or breaking, their center of gravity shifts. This can destabilize the iceberg, causing it to tip or flip to find a new equilibrium. #engineering #science #geology #technology #innovation #sustainability ⏩ Felipe Ochoa Cornejo 👨🏻🏫🇨🇱 for more science, engineering, geology, and technology 📸 By Giovanna Nicotra

🗻 [2023 retrospective] In October, we successfully extracted from the endangered Colle del Lys glacier in the Alps! 🙌 Two ice cores drilled for research and one preserved for Heritage. The team worked for 10 days at an altitude of 4,155 meters in a remote camp set up for the mission. 💦 "The biggest difficulties concerned the first 10 meters of the drilling: a part defined as "firn", a transition layer between snow and ice. In these first 10-15 meters we found quite a lot of liquid water, which infiltrated the first layers and made it more difficult to operate the core barrel. This leads us to say that, even at these altitudes, climate change is acting heavily on the melting of our glaciers." says Jacopo Gabrieli, coordinator of this expedition and glaciologist at Consiglio Nazionale delle Ricerche-ISP. "Then, the drilling operations went very well: we were able to work quickly and extract two ice cores down to the bedrock, which is the rock surface that lies underneath the glacier". 🔬 One of the two 'ice cores' extracted by the researchers will be analyzed in the laboratories of Università Ca' Foscari Venezia, the other will be sent to the #IceMemory Sanctuary in #Antarctica, at the French-Italian base in #Concordia. Read more about this international drilling: https://lnkd.in/dF7NsVrw #drilling #glaciology #icecore #sanctuary #futuregenerations #conservation #teamwork

Satellite mapping of red snow on North American glaciers SCIENCE ADVANCES https://lnkd.in/gCTh6nM6