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The presence and distribution of preserved organic matter on the surface of Mars can provide key information about the Martian carbon cycle and the potential of the planet to host life throughout its history. Several types of organic molecules have been previously detected in Martian meteorites1and at Gale crater, Mars2–4. Evaluating the diversity and detectability of organic matter elsewhere on Mars is important for understanding the extent and diversity of Martian surface processes and the potential availability of carbon sources1,5,6. Here we report the detection of Raman and fluorescence spectra consistent with several species of aromatic organic molecules in the Máaz and Séítah formations within the Crater Floor sequences of Jezero crater, Mars. We report specific fluorescence-mineral associations consistent with many classes of organic molecules occurring in different spatial patterns within these compositionally distinct formations, potentially indicating different fates of carbon across environments. Our findings suggest there may be a diversity of aromatic molecules prevalent on the Martian surface, and these materials persist despite exposure to surface conditions. These potential organic molecules are largely found within minerals linked to aqueous processes, indicating that these processes may have had a key role in organic synthesis, transport or preservation.

The Cretaceous/Palaeogene mass extinction eradicated 76% of species on Earth1,2. It was caused by the impact of an asteroid3,4on the Yucatán carbonate platform in the southern Gulf of Mexico 66 million years ago5 , forming the Chicxulub impact crater6,7. After the mass extinction, the recovery of the global marine ecosystem—measured as primary productivity—was geographically heterogeneous8 ; export production in the Gulf of Mexico and North Atlantic–western Tethys was slower than in most other regions8–11, taking 300 thousand years (kyr) to return to levels similar to those of the Late Cretaceous period. Delayed recovery of marine productivity closer to the crater implies an impact-related environmental control, such as toxic metal poisoning12 , on recovery times. If no such geographic pattern exists, the best explanation for the observed heterogeneity is a combination of ecological factors—trophic interactions13 , species incumbency and competitive exclusion by opportunists14 —and ‘chance’8,15,16. The question of whether the post-impact recovery of marine productivity was delayed closer to the crater has a bearing on the predictability of future patterns of recovery in anthropogenically perturbed ecosystems. If there is a relationship between the distance from the impact and the recovery of marine productivity, we would expect recovery rates to be slowest in the crater itself. Here we present a record of foraminifera, calcareous nannoplankton, trace fossils and elemental abundance data from within the Chicxulub crater, dated to approximately the first 200 kyr of the Palaeocene. We show that life reappeared in the basin just years after the impact and a high-productivity ecosystem was established within 30 kyr, which indicates that proximity to the impact did not delay recovery and that there was therefore no impact-related environmental control on recovery. Ecological processes probably controlled the recovery of productivity after the Cretaceous/Palaeogene mass extinction and are therefore likely to be important for the response of the ocean ecosystem to other rapid extinction events. Micro- and nannofossil, trace fossil and geochemical evidence from the Chicxulub impact crater demonstrates that proximity to the asteroid impact site did not determine rates of recovery of marine ecosystems after the end-Cretaceous mass extinction.

Fifty‐one new and 309 published thermochronometric ages (nine systems with closure temperatures ranging from ~450 to 70°C) from the Graubünden region of the Central Alps demonstrate that a pronounced thermal mismatch between the Austroalpine allochthon (Alpine “orogenic lid”) and the Pennine zone persisted until at least 29 Ma and, allowably, until circa 18 Ma. The observed mismatch supports previous suggestions that the famous “overthrust” between the Austroalpine allochthon and the Pennine zone, historically regarded as primarily an Eocene top‐north thrust fault, is in fact primarily an Oligocene‐Miocene normal fault that has a minimum of 60 km of displacement with top‐south or top‐southeast sense of shear. Two hallmarks of Alpine geology, deposition of the foredeep Molasse and emplacement of the Helvetic nappes, appear to be coeval, peripheral manifestations of crustal thickening via the interposition of the Pennine zone as a northward intruding wedge between the Austroalpine “lid” and the European cratonic margin, with the Helvetic system (European margin) acting as the “floor” of the wedge. We presume the Penninic wedge is driven by the buoyant rise of subducted crust no longer able to remain attached to the descending slab. If so, emplacement of the Pennine wedge could have occurred mainly after Adria was juxtaposed against cratonic Europe. What causes mountains to rise? The most common setting for their development is a place where the Earth's tectonic plates collide. Like the jaws of a closing vice, the plates squeeze crust between them, greatly deforming it by faulting and folding. One of the best known examples of this complex process is the European Alps, which formed between colliding continental plates of Europe and “Adria” (Italy). The traditional view is that large faults within the Alps are a direct expression of the sliding of the southern margin of the European plate beneath Adria (a process called subduction) to great depths in the Earth (100 km or more). Here we analyze the timing of motion of the largest fault in the Alps of eastern Switzerland (the Austroalpine “overthrust”) using a variety of thermochronometers (heat‐sensitive “clocks” that provide time of cooling). Our results show that the timing and sense of motion on the fault do not reflect relative motion between the two plates as previously believed. Instead, displacement on the faults we now see within the mountain belt mainly occurred late in the collision process, when the mechanical attachment of the subducted European crust to the downgoing plate was lost due to heating, which caused it to buoyantly rise relative to its dense surroundings in the Earth's mantle. Returning this wedge of crust to near the surface greatly thickened the overall crust along the collisional “suture” of the two continents, causing the Alps to rise. Thermal histories of the Austroalpine hanging wall and Pennine footwall, constrained by nine thermochronometric systems, show that they did not thermally equilibrate until after 29 Ma, and possibly not until 18 MaThe thermal data indicate that the Austroalpine‐Pennine contact zone is a top‐south to top‐southeast normal fault with at least 60 km of displacement, active during the main phase of Alpine mountain buildingDevelopment of topography and an orogenic crustal root, as reflected in deposition of the perialpine molasse and deformation of Europe (Helvetics) circa 33‐15 Ma, may result primarily by buoyancy‐driven interposition of the Pennine zone between the Austroalpine “lid” and the European cratonal margin and not from the convergence between Apulia and Europe

A fully coupled two‐dimensional kinematic and thermal model of a steady state accretionary wedge, constrained by an extensive data set of fission track and (U‐Th)/He ages for apatite and zircon, is here used to investigate the development of the Olympic Mountains segment of the Cascadia accretionary wedge. The model has two main free parameters: , the maximum rate of erosion for a generic erosion function operating at the top of the wedge, and α, the distribution of sedimentary accretion into the wedge. The best fit values for and α and their confidence limits are determined through an iterative search of parameter space. This study represents the first time that such inversion methods have been used to quantify the thermal‐kinematic evolution of an accretionary wedge. Our results suggest that horizontal transport plays an important role in the exhumation trajectories experienced by material passing through the Cascadia wedge. At a 95% confidence interval, 80 to 100% of the sedimentary sequence from the subducting Juan de Fuca Plate has been accreted at the front of the wedge offshore of the Olympics over the past 14 m.y. This frontally accreted material must then traverse the entire width of the wedge prior to its eventual exposure in the Olympic forearc high. Assessed in this two‐dimensional framework, the fission track and (U‐Th)/He age data sets from the Olympic Mountains are all best fit by of 0.9–1.0 mm yr−1, despite variation in the timescales relevant to the three chronometers. This result supports the hypothesis that the Olympic Mountains segment of the Cascadia accretionary wedge has been in a flux steady‐state since ∼14 Ma. The demonstration of a flux balance across the Cascadia margin also suggests that margin‐parallel transport has not had a significant role in driving uplift of the Olympic Mountains.

We have measured oxygen isotope ratios in 99 separates of olivine and 14 separates of plagioclase or glass from Hawaiian lavas. These data confirm that the source(s) of some Hawaiian basalts are lower in δ18O than peridotite xenoliths and the source region for mid-ocean ridge basalts (MORB). Our data document correlations between oxygen and radiogenic isotope ratios and consistent differences in δ18O between volcanoes. Low values of δ18O are associated with a ‘depleted’ component that is relatively high in 206Pb/204Pb, low in 3He/4He, and anomalously low in 207Pb/204Pb relative to 206Pb/204Pb. This component is preferentially sampled in lavas from the so-called Kea trend volcanoes (Kilauea, Mauna Kea, Kohala and Haleakala).

Perchlorate (ClO4−) was discovered in Martian soil by the Phoenix lander, with important implications for potential Martian biology, photochemistry, aqueous chemistry, and the chlorine cycle on Mars. Perchlorate was subsequently reported in both loose sediment and bedrock samples analyzed by the Sample Analysis at Mars instrument onboard the Curiosity rover in Gale crater based on a release of O2at 200–500°C. However, the continually wet paleoenvironment recorded by the sedimentary rocks in Gale crater was not conducive to the deposition of highly soluble salts. Furthermore, the preservation of ancient perchlorate to the modern day is unexpected due to its low thermodynamic stability and radiolytic decomposition associated with its long exposure to radioactivity and cosmic radiation. We therefore investigate alternative sources of O2in Sample Analysis at Mars analyses including superoxides, sulfates, nitrate, and nanophase iron and manganese oxides. Geochemical evidence and oxygen release patterns observed by Curiosity are inconsistent with each of these alternatives. We conclude that perchlorate is indeed the most likely source of the detected O2release at 200–500°C, but contend that it is unlikely to be ancient. Rather than being associated with the lacustrine or early diagenetic environment, the most likely origin of perchlorate in the bedrock is late stage addition by downward percolation of water through rock pore space during transient wetting events in the Amazonian. The conclusion that the observed perchlorate in Gale crater is most likely Amazonian suggests the presence of recent liquid water at the modern surface. Perchlorate is a chemical found on Mars that dissolves easily in water, which can keep water from freezing at the cold temperatures found on Mars's surface. It was first discovered in soil, and has been found by the Curiosity rover in rock at Gale crater. Perchlorate should have flowed out of the sandy lake bottom in ancient Gale crater before it turned into rock. Perchlorate is also easily destroyed, so even if it were included in the rock originally, perchlorate should have disintegrated in the following ~3.5 billion years. Because of these dilemmas with finding perchlorate in ancient rocks, we have reevaluated the evidence for perchlorate as observed by Curiosity. Of a number of other chemicals which could explain the data, we find that perchlorate is still the best fit and is probably present. Due to the problems with perchlorate being included in the rock originally and surviving until today, we conclude that it has been added to the rocks recently. This recent addition could happen by perchlorate dissolving in water and flowing into the rock. Such a process suggests that liquid water was present in Gale crater long after Mars became cold and dry. Geology suggests that ancient Gale crater was not conducive to perchlorate deposition; radiolytic decomposition would destroy ancient perchlorateAlternatives to perchlorate are evaluated as sources of pyrolytic O2; perchlorate best explains the dataPerchlorate in Gale crater is most likely young, possibly introduced by downward percolation of thin films of brine