Paleolakes

Chloride-bearing deposits on Mars record high-elevation lakes during the waning stages of Mars' wet era (mid-Noachian to late Hesperian). The water source pathways, seasonality, salinity, depth, lifetime, and paleoclimatic drivers of these widespread lakes are all unknown. Here we combine reaction-transport modeling, orbital spectroscopy, and new volume estimates from high-resolution digital terrain models, in order to constrain the hydrologic boundary conditions for forming the chlorides. Considering a T = 0 °C system, we find: (1) individual lakes were >100 m deep and lasted decades or longer; (2) if volcanic degassing was the source of chlorine, then the water-to-rock ratio or the total water volume were probably low, consistent with brief excursions above the melting point and/or arid climate; (3) if the chlorine source was igneous chlorapatite, then Cl-leaching events would require a (cumulative) time of >10 yr at the melting point; (4) Cl masses, divided by catchment area, give column densities 0.1 – 50 kg Cl/m^2 , and these column densities bracket the expected chlorapatite-Cl content for a seasonally-warm active layer. Deep groundwater was not required. Taken together, our results are consistent with Mars having a usually cold, horizontally segregated hydrosphere by the time chlorides formed.

Based on the data from scholars papers but principally in (1), I've made a GIS data set for the late Pleistocene lake cycles on the southern Bolivian Altiplano.

I've prepared three different data sets: two to work with, and another Google Earth data set only for view the results. Also as an end work I've made some videos showing animations of lakes up fill (different lakes), in these videos 'the direction in which the lake fills' are not real in all cases, see (1) to elucidate the up fill direction at the Laca hydrologic divide for each paleolake.

The core work for extracting the shorelines has been done in the GRASS console with the r.lake GRASS module ..., a lot of command lines, see the hist directory in the GRASS project (in one of the huge datasets), here you can see all the commands used to do the work.

For the first time, the study of the fossil record present in laminated bituminous dolostones from the San Chils locality, lower Miocene in age (ca. 19 Ma), located at the Ribesalbes-Alcora Basin, is addressed. The identification of 11 families and three genera belonging to six insect orders (Orthoptera, Thysanoptera, Hemiptera, Coleoptera, Hymenoptera and Diptera) has been carried out. Furthermore, ephippia of cladoceran crustaceans, one bird feather, vertebrate coprolites and plant remains have been found. The San Chils palaeodiversity has been compared to that of La Rinconada, a similar outcrop in the same basin and depositional unit. Both localities correspond to lacustrine deposits and were mined during the past two centuries. This work has increased the palaeontological richness of the Ribesalbes-Alcora Basin with new findings such as specimens of the subfamily Corixinae (Hemiptera: Corixidae), some ant workers (Hymenoptera: Formicidae), a specimen assigned to the genus Exechia (Diptera: Mycetophilidae), ephippia of Daphnia (Ctenodapnia) sp. (Branchiopoda: Cladocera), the possible first report of the genus Sciocoris (Hemiptera: Pentatomidae) for the Neogene fossil record and the possible presence of the family Aeolothripidae (Thysanoptera). The current collection of fossil specimens from San Chils is small, but shows that it shared similar palaeoenvironmental conditions to that of La Rinconada, both in the lake waters and in the surroundings. The preservation of the specimens is poor due to the weathering they suffered during more than a century exposed outside the mine, but the presence of delicate structures has enabled to classify the outcrop as a Konservat-Lagerstätte, like La Rinconada.

Liquid water was flowing on the surface of Mars in the past, leaving behind a wide range of geomorphic features. The ancient major Martian water fluxes vanished about 3.5 Ga. Meteoritic impacts, wind-erosion, gravity-related phenomena, tectonic deformations and volcanic activities deeply altered the landforms during the ages. Hence, the reconstruction of water-shaped landscapes is often complicated. Fluvial and lacustrine terraces analysis and correlation is a useful approach to understand and reconstruct the past changes in Martian landscape evolution. These features are commonly used as reference for the top of water bodies on Earth, since they are void of the uncertainties or errors deriving from erosional or slumping processes that could have acted on the valley flanks or in the plateau, where the hydrological network was carved in. The study area is located in the western hemisphere of Mars, in the Memnonia quadrangle, between latitude 9˚10'-9˚50'South and longitude 167˚0'-167˚30' West and it constitutes a transition region between the southern highlands of Terra Sirenum and the northern lowlands of Lucus Planum. Many water-shaped features have already been described near the study area, the most prominent of them being the Ma'adim Vallis and the Mangala Valles system. Our results derive from the observations and the analysis of HRSC images (12.5 m spatial resolution) and Digital Elevation Models (DEMs) derived from the MEX-HRSC (75 m resolution), that allow the identification of elevation differences up to the tens of meter scale. We were able to reconstruct six main evolutionary stages of a complex hydrologic systems consisting of two main palaeorivers (up to 5 km wide) connected one another by a palaeolake that formed within a meteor crater (∼20 km diameter). On the basis of Earth analogs, these stages/terraces should have evolved during a long period of time, at least thousands years long. Furthermore, crater counting date back the deactivation of the system to ca 3.5±0.1 Ga ago, suggesting the presence of a stable environment with subaerial water fluxes during the Late Hesperian, very close to the liquid-water disappearance. Apart from the above mentioned reasons, the increasing interest and ongoing programs of on-site Martian exploration are additional reasons to study fluviolacustrine depositional environments. Together with the technology improvements that lead to more flexible safety constraints for landing/exploring, the possibility to focus on specific and more detailed scientific aspects is enhanced.

ABSTRACTThe Old Copper Complex (OCC) refers to the production of heavy copper-tool technology by Archaic Native American societies in the Lake Superior region. To better define the timing of the OCC, we evaluated 53 (eight new and 45 published) radiocarbon (14C) dates associated with copper artifacts and mines. We compared these dates to six lake sediment-based chronologies of copper mining and annealing in the Michigan Copper District. 14C dates grouped by archaeological context show that cremation remains, and wood and cordage embedded in copper artifacts have ages that overlap with the timing of high lead (Pb) concentrations in lake sediment. In contrast, dates in stratigraphic association and from mines are younger than those from embedded and cremation materials, suggesting that the former groups reflect the timing of processes that occurred post-abandonment. The comparatively young dates obtained from copper mines therefore likely reflect abandonment and infill of the mines ra...

For the first time, the study of the fossil record present in laminated bituminous dolostones from the San Chils locality, lower Miocene in age (ca. 19 Ma), located at the Ribesalbes-Alcora Basin, is addressed. The identification of 11 families and three genera belonging to six insect orders (Orthoptera, Thysanoptera, Hemiptera, Coleoptera, Hymenoptera and Diptera) has been carried out. Furthermore, ephippia of ladoceran crustaceans, one bird feather, vertebrate coprolites and plant remains have been found. The San Chils palaeodiversity has been compared to that of La Rinconada, a similar outcrop in the same basin and depositional unit. Both localities correspond to lacustrine deposits and were mined during the past two centuries. This work has increased the palaeontological richness of the Ribesalbes-Alcora Basin with new fi ndings such as specimens of the subfamily Corixinae (Hemiptera: Corixidae), some ant workers (Hymenoptera: ormicidae), a specimen assigned to the genus Exechia...

The Arabian Peninsula is a key region for understanding climate change and human occupation history in a marginal environment.  The Mundafan paleolake is situated in the Empty Quarter of Saudi Arabia. Here we report the first discoveries of Middle Paleolithic and Neolithic archaeological sites in association with the paleolake. We associate the human occupations with new geochronological data, and suggest the archaeological sites date to the wet periods of Marine Isotope Stage 5 and the Early Holocene. The archaeological sites indicate that humans repeatedly penetrated the ameliorated, but somewhat marginal, environments of the Empty Quarter. The sites are probably short term occupations, with the Neolithic sites focused on hunting as indicated by points and weaponry. Middle Paleolithic assemblages at Mundafan support a lacustrine adaptive focus in Arabia. Provenancing of obsidian artifacts indicates that Neolithic groups at Mundafan had a wide wandering range, with transport of artifacts from distant sources.