The PLUTO CD-ROM data base contains inorganic geothermal data obtained by the analytical laboratories of the Geologic Division of the U.S. Geological Survey (USGS) for the United States, including Hawaii and Alaska, in support of USGS program activities requiring chemical data. This CD-ROM was produced in accordance with the ISO 9660 standard and can be accessed by any computer system that has the appropriate software to read the ISO 9660 discs; however, the disc is intended for use in a DOS environment.

A PC based system has been developed for the analysis of gamma-ray spectra and for the complete reduction of data from INAA experiments, including software to average the results from multiple lines and multiple countings and to produce a final report of analysis. Graphics algorithms may be called for the analysis of complex spectral features, to compare the data from alternate photopeaks and to evaluate detector performance during a given counting cycle. A database of results for control samples can be used to prepare quality control charts to evaluate long term precision and to search for systematic variations in data on reference samples as a function of time. The entire software library can be accessed through a user-friendly menu interface with internal help.

Apatite-enriched materials from the Peru shelf have been analyzed for their major oxide and rare earth element (REE) concentrations. The samples consist of (1) the fine fraction of sediment, mostly clay material, (2) phosphatic pellets and fish debris, which are dispersed throughout the fine-grained sediment, (3) tabular-shaped phosphatic crusts, which occur within the uppermost few centimeters of sediment, and (4) phosphatic nodules, which occur on the seafloor. The bulk REE concentrations of the concretions suggest that these elements are partitioned between the enclosed detrital material and the apatite fraction. Analysis of the fine-grained sediment with which the samples are associated suggested that this detrital fraction in the concretions should have shale REE values; the analysis of the fish debris suggested that the apatite fraction might have seawater values. The seawater contribution of REE's is negligible in the nodules and crust, in which the apatite occurs as a fine-grained interstitial cement. That is, the concentration of REE's and the REE patterns are predominantly a function of the amount of enclosed fine-grained sediment. By contrast, the REE pattern of the pelletal apatite suggests a seawater source and the absolute REE concentrations are relatively high. The REEP2O5 ratios of the apatite fraction of these samples thus vary from approximately zero (in the case of the crust and nodules) to as much as approximately 1.2 × 10−3 (in the case of the pellets). The range of this ratio suggests that rather subtle variations in the depositional environment might cause a significant variation in the REE content of this authigenic fraction of the sediment.

The distribution of rare earth elements (REE) in ferromanganese nodules from DOMES Site A has been determined by instrumental neutron activation methods. The concentrations of the REE vary markedly. Low concentrations characterize samples from a depression (the valley), in which Quaternary sediments are thin or absent; high concentrations are found in samples from the surrounding abyssal hills (the highlands) where the Quaternary sediment section is relatively thick. Moreover, the valley nodules are strongly depleted in the light trivalent REE (LREE) and Ce compared with nodules from the highlands, some of the former showing negative Ce anomalies.

A data reduction system for the routine instrumental activation analysis of samples is described, with particular emphasis on interactive graphics capabilities for evaluating analytical quality. Graphics procedures have been developed to interactively control the analysis of selected photopeaks during spectral analysis, and to evaluate detector performance during a given counting cycle. Graphics algorithms are also used to compare the data on reference samples with accepted values, to prepare quality control charts to evaluate long term precision and to search for systematic variations in data on reference samples as a function of time.

Eight widespread Pleistocene ash layers of east-central and southern California are characterized and correlated on the basis of chemical composition of volcanic glass (determined by neutron activation, electron probe, and energy-dispersive X-ray fluorescence analysis), stratigraphic criteria, and petrographic characteristics.Irt order of increasing age, these are the Lava Creek B ash bed (formerly referred to as the Pearlette type 0 ash bed; about 0.6 m.y.), the Bishop ash bed (0.73 m.y.), the Glass Mountain-D ash bed (estimated to be about 0.8-0.9m.y.), the Glass Mountain-G ash bed (estimated to be about 1.0-1.1 m.y.), the Bailey ash (1.2 m.y.), the middle white ash of the Manix basin (estimated to be about 1.9 m.y.), the Huckleberry Ridge ash bed (formerly referred to as the Pearlette type B ash bed; about 1.9 m.y.), and the lowermost gray ash of the South Mountain area (Huckleberry Ridge?ash bed; estimated to be about 1.9 m.y.).Three chemical types of the Bishop ash are recognized and assigned to an informal Bishop ash-bed group.The Friant Pumice Member (of the Turlock Lake Formation) of east-central San Joaquin Valley is one of the members of this group.The apparent 0.1-m.y.difference in K-Ar ages of the Friant Pumice Member (0.6 m.y.) and the Bishop Tuff (about 0.7 m.y.) may be due to factors other than differences in the true ages of these tephra units; alternatively, there may be two ash layers that have very similar glass chemistry and are here recognized as belonging to the Friant Pumice Member, but differ in age by as much as 0.1 m.y.The Huckleberry Ridge ash in the Manix basin is correlated with the same ash in Meade County, Kansas, over a distance of about 1,500 km.Results of chemical analyses permit correlation of sedimentary strata deposited in diverse environments: marine, fluvial, and lacustrine.Chemical characteristics of ash layers also permit identification of source areas from which tephra was erupted; the main eruptive centers were the Long Valley-Glass Mountain area of east-central California, the Coso volcanic field of southeastern California, and the Yellowstone area of northwestern Wyoming and eastern Idaho.Systematic chemical depletion trends with time provide a possible independent method of estimating ages of ash layers of the Long Valley-Glass Mountain family.

Bulk chemical analyses are performed for major and minor elements using a variety of techniques on a suite of 9 samples of sea floor massive sulfide deposits from 21?N EPR, Juan de Fuca Ridge and Galapagos Rift. Results indicate that deposits at 21?N and Juan de Fuca are very similar despite a geographic separation of 2300 km and are composed primarily of Zn, Fe, and S, with important minor concentrations of Ag, As, Cd and Ge. The Galapagos Rift massive sulfide is primarily Fe, Cu and S and with important minor contents of only Co and Mo. Au is low, ranging from below detection up to 0.17 ppm. Pt group metals are very low, and average about 0.001 ppm. Consideration of enrichment factors and relative metal abundance suggests that MORB is a sufficient source for all the metals enriched in the sea floor deposits. The economically important metals for the 21?N and Juan de Fuca deposits are primarily Zn and Ag, (97%) with potential by-products of Cu, Cd and possibly, Ge. For the Galapagos Rift, the primary value is with Cu (86%) with potential by-products of Co and Mo. The Galapagos Rift deposit is similar to, but contains about twice the Cu content, of typical ore from the Skouriotisa mine of the Troodos complex of Cyprus. The grade of the 21?N/Juan de Fuca deposits is 4 times greater than that of the Galapagos Rift and about twice that of prime deep-sea manganese nodules.

The concentrations of 32 metals in sediment cores collected from the Continental Shelf off the south-eastern United States are generally uniform with depth. These sediments are predominantly sand with very low organic carbon throughout the core length. The metal concentrations are low compared to those found in average sandstone and to average crustal abundances, and small variations correlate with variations in texture, and in amount of calcium carbonate and organic carbon. No evidence of accumulation of anthropogenic metals was found in these sediments. The data presented are the first compilation of trace metal concentrations in sediment cores of this area and provide a basis for determining the magnitude of future trace metal deposition in these sediments.

The instrumental activation analysis of silicate rocks using epithermal neutrons has been studied using both high resolution coaxial Ge(Li) detectors and low energy photon detectors, and applied to the determination of 23 elements in eight new U.S.G.S. standard rocks. The analytical use X-ray peaks associated with electron capture or internal conversion processes has been evaluated. Of 28 elements which can be considered to be determinable by instrumental means, the epithermal activation approach is capable of giving improved sensitivity and precision in 16 cases, over the normal INAA procedure. In eleven cases the use of the low energy photon detector is thought to show advantages over convertional coaxial Ge(Li) spectroscopy.

The relative precisions obtainable using two digital methods, and three iterative least squares fitting procedures of photopeak integration have been compared empirically using 12 replicate counts of a test sample with 14 photopeaks of varying intensity. The accuracy by which the various iterative fitting methods could analyse synthetic doublets has also been evaluated, and compared with a simple non-iterative approach.

Three Apollo-16 soils, 61220, 63500 and 65500, having diverse properties were separated into six size fractions and analyzed for 8 volatiles and siderophiles. Relative concentrations of an additional 20 elements were determined in 61220 and 63500. The volatile elements Cd, Zn, In and Ga increase in concentration with decreasing grain size; in the finest fractions the increase is roughly parallel to the increase in specific surface area, and a surface correlation is inferred. The total increase from coarsest (177–500 μm) to finest (<5 μm) fraction is by factors of 10–20 for Zn and Cd in soils 61220 and 63500. Concentrations of elements that are good indicators of KREEP (Sm), mare basalts (Fe) and anorthosites (Ca) show nearly no dependence on size. The preservation of the observed surface correlation throughout regolith evolution suggests that the volatile elements are labile on the lunar surface.