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The relationship between the [[delta].sup.13] C of dissolved inorganic carbon (DIC) and modern mollusk aragonite from rivers was calibrated for the purpose of reconstructing DIC paleochemistry from the shell record. The [[delta].sup.13]C values of aragonitic bivalves (Dreissena polymorpha, Corbicula fluminea), prosobranch gastropods (Bithynia tentaculata, Theodoxus fluviatilis, Viviparus viviparus), and an air-breathing pulmonate gastropod (Limnea auricularia) were analyzed from several locations on the Rhone River (-13.7% to -6.0%) and its major tributary, the Saone River (-11.4% to--10.2%). The [[delta].sup.13][C.sub.DIC] varied from -11.5% to -7.5%, and the [[delta].sup.13]C of particulate inorganic matter (POM) varied from -31.7% to -25.4%. At a given site, the [[delta].sup.13]C of all species except the pulmonate were within 1% of each other. Whole-shell [[delta].sup.13]C correlated positively with [[delta].sup.13][C.sub.DIC], with a slope close to unity. Bioaragonite-DIC fractionations were 0-1.5% for bivalves and 0-2.7% for gastropods (excluding the pulmonates). Applying these fractionations, bivalves that live in open water are a reliable proxy, monitoring the average [[delta].sup.13][C.sub.DIC] value to within its natural ~2% temporal variation within the growth period. For the suspension feeders (bivalves) using POM as a food source, the [[delta].sup.13]C of whole shells and bulk POM indicated that the incorporation of carbon derived from respiratory sources lay in the range 10-30%. Fine-scale analyses of growth increments of C. fluminea could not be related simply to [[delta].sup.13]C DIC because metabolic and seasonal variations in [[delta].sup.13][C.sub.DIC] produced similar isotopic fluctuations ([less than or equal to] 2.5%).

To estimate vertical thermal gradients and paleo-water depths to marine platforms we present a new method based on the difference between [Delta]18O values of contemporaneous brachiopod carbonate and fish phosphate. Present-day marine fauna of well-known ecology from the surface to the sea floor record isotopic temperatures that agree with measured temperatures. We predict distributions of isotopic data that result from sampling strategy, basin morphology, and fauna ecology and discuss limitations. Application of the method to the Jurassic Paris-London basin gives vertical thermal variations of up to 14 [degrees] C associated with depths varying from a few meters to 170 [+ or -] 30 m. The estimated depths are minimum values and are greater than those estimated from sedimentological criteria for this ancient epicontinental sea.

The external or internal origin of C[O.sub.2] and [H.sub.2]O in marbles and metabasites from a large-scale granulite section is related to their structural setting: outside shear zones, within major shear zones ([approximately equal to]25 km wide by >340 km long), or within minor shear zones (

Pressure is one of the key variables in Earth science, ranging from an extremely small fraction of 1 atm in the upper atmosphere (~1 Pa or ~[10.sup.-5] atm) to probably [...]