Effectively addressing marijuana trade is aided by understanding marijuana geographic sources. We analyzed the (87)Sr/(86)Sr of marijuana samples grown in 79 counties across the United States to determine if a primary geologic signal is retained in marijuana, which could therefore be useful for geographic sourcing. The marijuana results were compared with modeled bedrock (87)Sr/(86)Sr values ba...

This thesis explores the life history of six isolated skulls interred in Mound 3 of the Elizabeth site, a Middle Woodland site in the lower Illinois valley. This study employs analyses of osteological features, stable and radiogenic isotopes, and biodistance for a cross-section of the Mound 3 population (n=15), including the isolated crania. Isotopic results reveal significant variation in lead...

[1] Using a simple 3-box model of the ocean-atmosphere system, we simulate the cycling of carbon and strontium in the aftermath of a global glaciation. Model simulations include the delivery of alkalinity to seawater from intense carbonate and silicate weathering under high pCO2 conditions as well as ocean mixing, air-sea gas exchange, and biological productivity. The dC of the first carbonate ...

Highly dispersive strontium carbonate (SrCO3) nanostructures with uniform dumbbell, ellipsoid, and rod-like morphologies were synthesized in methanol solution without any additives. These SrCO3 were characterized by X-ray diffraction, field emission scanning electron microscopy, and N2 adsorption-desorption. The results showed that the reaction temperature and the methanol/water ratio had impor...

Biomineralization is the process of forming hard exoor endoskeltons by biological organisms. The physical properties and the morphology of the composite material that is formed depends on the mode of crystal-growth, which depends on the diffusion of the constituents (metal cations, their anions, and additives). We chose a model system, strontium carbonate / silica, because the precipitation of ...

A simple and precise incremental isoconversional integral method based on Li-Tang (LT) method is proposed for kinetic analysis of solid thermal decomposition, in order to evaluate the activation energy as a function of conversion degree. The new method overcomes the limitation of LT method in which the calculated activation energy is influenced by the lower limit of integration. By applying the...

The carbon-cycle significance of soil carbonate fluxes is subject to large uncertainties because it is not clear precisely how much calcium is derived from atmospheric sources compared with that from the chemical weathering of silicate minerals. In the petrocalcic horizon (calcrete) of a Pleistocene soil from the USDA–SCS Desert Project area near Las Cruces, NM, approximately 1.5 g Ca=cm3 has b...

the qom formation, which hosts the mazraeh celestite deposit, contains dominantly limestones, marl and subordinate evaporites deposited in shallow marine environments. petrographic evidence indicates that the celestite deposits were formed by replacement of limestone. the presence of carbonate inclusions within celestite crystals as well as the pseudomorphic habits of some crystals suggests tha...