Abstract The 1200 km 2 TIS is one of several large-volume zoned intrusive suites emplaced in the Sierra Nevada in the Late Cretaceous (Fig. 4). These suites all have mafic granodioritic outer phases that grade progressively inward to granodioritic or granitic cores (Bateman, 1992), and were intruded at pressures of 1–3 kbar (Ague and Brimhall, 1988). There is a significant mismatch between the wall rocks on the east and west sides of the TIS (Bateman, 1992): the eastern wall is dominated by Jurassic metavolcanic rocks and plutons, whereas the west is dominated by 103 Ma plutonic rocks of the ISYV (Ratajeski et al., 2001) intruded into pre-batholithic metasedimentary rocks. This mismatch may result from intrusion of the TIS into an intrabatholithic shear zone. Geochronologic data indicate that the TIS was assembled over a period of at least 10 m.y. between 95 and 85 Ma and that the Half Dome Granodiorite 1 intruded over a period approaching 4 m.y. (Kistler and Fleck, 1994; Coleman and Glazner, 1997; Coleman et al., 2004; Matzel et al., 2005). Ages of the intrusive rocks decrease regularly from core to rim within the suite. The rocks include the Sentinel Granodiorite (95 Ma), the granodiorite of Kuna Crest and the tonalite of Glen Aulin (93.5-93.1 Ma; assumed to represent the eastern and western parts of the same intrusion; Bateman and Chappell, 1979), the Half Dome Granodiorite (92.8-88.8 Ma), the Cathedral Peak Granodiorite (88.1-86 Ma), and the Johnson Granite Porphyry (85 Ma; Fig. 4).

Abstract The Green River Formation of Wyoming represents a complex sequence of lacustrine, fluvial, and playa strata deposited in and associated with Eocene Lake Gosiute. Detailed mineralogical and organic analysis of 10 cores from the Green River Basin identified correlatable stratigraphic intervals that can be used to interpret the geochemical and sedimentologic history of Lake Gosiute. More than 30 minerals were identified in this study, with graphic correlations and geostatistical evaluations defining 16 major minerals and oil yields, as defined by modified Fischer assay. These relations could be used to define distinct correlatable stratigraphic intervals that, when used in conjunction with known chronostratigraphic volcaniclastic units, could be used to interpret major influences upon the depositional history of Lake Gosiute. The four principal influences upon mineralogical stratigraphy of Lake Gosiute were determined to be (1) deposition and preservation of organic matter, (2) volcaniclastics, (3) periods of evaporation and concentration, and (4) influxes of fresh water accompanied by increased transported detrital material. Climatic variation both on broad and seasonal scales is interpreted to have influenced the mineral suite. The changes among these members have been alternatively interpreted as recording changes in lake-water hydrology, not necessarily related to climate changes ( Carroll and Bohacs, 1999 ; Pietras et al., 2003 ). Wet periods in the history of Lake Gosiute (Tipton and Laney members) were associated with increased organic production and a related mineral suite, whereas dry periods (Wilkins Peak Member) resulted in decreased organic production and the genesis of a prolific suite of saline and evaporite minerals. This systematic investigation of the distribution, chemical composition, and structure of the minerals in these sediments supported a playa-lake depositional model for the members covered by this study for genesis of the Green River Formation inLake Gosiute.

Abstract From its earliest years the Geological Society of London attracted the attention of scientifically- and technically-minded men in Australia and New Zealand. Members ‘at home’ in Britain were also eager for geological information about the antipodes. The publications of the Society acted as a major source of information about the geology of these southern lands, from vertebrate palaeontology and modern glaciation at sea level to ancient glaciations and mineralization (particularly of gold). At least 360 members were active in Australasia in the nineteenth century. Strong antipodean Society membership continued through the twentieth century. What is noteworthy is the number of mining figures, of varying scientific competence, who boasted of their membership. There were significant contributions to the Society’s journals on Australasian geology from the 1820s to the early 1900s. Many topographic features on the maps of both Australia and New Zealand are named for Members and Fellows of the Geological Society. The lists of elected and ‘would-be’ antipodean members include a few enigmatic examples of chicanery, fraud and disappearance.