Arsenic is one of the toxic trace elements in coals, which is harmful to both the ecological environment and human health. Based on published literature and the data obtained by our research group, a total of 5314 As concentrations of Chinese coals were analyzed. The arithmetic mean of arsenic content in Chinese coals is 6.97 mg/kg. Choosing the percentage of provincial coal resources in nation...

Mawsoniidae are a fossil family of actinistian fish popularly known as coelacanths, which are found in continental and marine paleoenvironments. The taxon is considered monophyletic, including five valid genera (Axelrodichthys, Chinlea, Diplurus, Mawsonia and Parnaibaia) and 11 genera with some taxonomical controversy (Alcoveria, Changxingia, Garnbergia, Heptanema, Indocoelacanthus, Libys, Lual...

BACKGROUND Macelognathus vagans Marsh, 1884 from the Late Jurassic Morrison Fm. of Wyoming was originally described as a dinosaur by Marsh and in 1971 Ostrom suggested crocodilian affinities. In 2005, Göhlich and collaborators identified new material of this species from Colorado as a basal crocodylomorph. However, a partial skull found in association with mandibular and postcranial remains was...

at the boundary between jurassic and cretaceous, because of late kimmerian movements, the sea ragressed from many areas of north and cantral iran, and many continental areas rose, which included a number of differentiated basins. the boundary between jurassic and cretaceous in these parts of iran is usually marked by a big diastem or by red, clastic and evaporitic sediments. the whole or part o...

In (Part I), it was stated that red beds, conglomerates and salt were considered azoic and problematic rocks, but Paleopalynology and Inorganic Geochemistry proved to be useful for placing them in time and space. In the early last century, in Mexican NE region, only three Mesozoic red bed units were differentiated, dated as Late Triassic to Late Jurassic. It was important stratigraphically to p...

Red beds, conglomerates and salt were considered azoic and problematic rocks, but Paleopalynology and Inorganic Geochemistry proved to be useful for placing them in time and space. In the early last century, in Mexican NE region, only three Mesozoic red bed units were differentiated, dated as Late Triassic to Late Jurassic. It was important tratigraphically to place them properly as they were c...

After asking participants to propose analogies favoring a zerodeficit policy, Blanchette and Dunbar (2000) obtained a high proportion of base analogs lacking superficial similarities with the target, thus questioning the validity of a long experimental tradition demonstrating their centrality on retrieval. Through the use of culturally shared bases, we overcame two limitations in their study th...

red beds, conglomerates and salt were considered azoic and problematic rocks, but paleopalynology and inorganic geochemistry proved to be useful for placing them in time and space. in the early last century, in mexican ne region, only three mesozoic red bed units were differentiated, dated as late triassic to late jurassic. it was important tratigraphically to place them properly as they were c...

Sedimentologic, stratigraphic, and geochronologic data from strata of early Mesozoic age in the central Mojave block elucidate the paleogeographic and tectonic evolution of the magmatic arc in the southern U.S. Cordillera. A sequence of calcareous siltstone, volcaniclastic conglomerate, tuff, and quartzose sandstone records the transition from shallow-marine rocks of the Fairview Valley Formati...