...A. M. Hall; M. F. Thomas; M. B. Thorp Abstract Examination of the diamondiferous sediments of the Birim River floodplain in Ghana using radiocarbon dating allows the recognition of three chronostratigraphic units: 13000–11000, 9000–7000, and 2100 years BP to the present, while older sediments rest...

... Republic of Congo 47 Alluvial DIAGO 3 Kanowa, Democratic Republic of Congo 35 Alluvial DIAGO 4 Tshikapa, Democratic Republic of Congo 24 Alluvial Mineral Services 5 Birim River, Ghana 30 Alluvial Mineral Services 6 Bria, Central African Republic 14 Alluvial Mineral Services...

...: the case of the Birim diamond placer, Ghana J geol Soc London 1985 142 777 87 Hallbauer D. K. Utter T. Geochemical and morphological characteristics of gold particles from recent river deposits and the fossil placers of the Witwatersrand Mineralium Deposita 1977 12 293 306...

...) in a kimberlite dike located near Masontown in southeastern Pennsylvania, U.S.A. ( e.g. , Meyer 1976 ). The samples in this study (xenocrysts and peridotite xenoliths) are from a dike of fresh hypabyssal kimberlite 1–2 m wide that is exposed in a drainage adjacent to the Monongahela River in southeastern...

... komatiite incorporated the diamonds and the mantle indicator minerals from a well size-sorted, preexisting paleoplacer. The most important diamond field sourced from Paleoproterozoic rocks in Africa is located in the head-waters of the Birim River, near Akwatia, Ghana, where diamonds...

...Figure 73. West Africa placer deposits as labeled on the map (Kono, Tongo, Mano and Lofa Rivers, Tortiya, Séguéla, Banankoro, Bounoudou, Kindia, Birim River, Bonsa River). Primary magmatic kimberlite and CROL mines/deposits as follows: Ko, Koidu; To, Tongo; Dr, Droujba; Se, Séguéla. ...

... region in which one or more river open and is freely connected with the ocean ( Pritchard., 1967 and Potter et al., 2010 ). They are usually found at the interface of the fluvial and marine environments ( Dyer, 2019 ). It is primarily influenced by tides, waves, sea and freshwater inflow and sediment...

... sedimentary blocks but also, in places, of vertical aggradation and scour units which have dates falling into the same pattern of clusters and hiatuses. Preliminary analyses of the data from the River Birim floodplain in Ghana also suggest that gravel calibre and diamond grades may differ systematically among...

... : the case of the Birim diamond placer, Ghana . Journal of the Geological Society , London , 142 , 777 – 787 . Hancock , G.S. , Anderson , R.S. and Whipple , K.X. , 1998 . Beyond power: bedrock river incision process and form . In: J.K. Tinkler and E. Wohl (Editors...

...; Page, 1975 ) cut the White thrust ( Fig. 2 ), indicating most thrust displacement occurred prior to their emplacement. Ok Tedi occurs along a NNE-trending zone of intrusive rocks that extends from the Nong River prospect in the north to Mount Anju in the south ( Fig. 1 ). This coincides with the Ok...

.... , Nash , W.P. & Dan Hausel , W. ( 1995 ): Mantle indicator minerals in ant mounds and conglomerates of the southern Green River Basin, Wyoming . Wyoming Geol. Assoc., Field Conference Guidebook . Meyer , H.O.A. ( 1987 ): Inclusions in diamond . In Mantle Xenoliths ( P.H...

.... , and Navon , O. ( 2001 ) Brine inclusions in diamonds: A new upper mantle fluid . Earth and Planetary Science Letters , 187 , 323 – 332 . Kopylova , M.G. , Gurney , J.J. , and Daniels , L.R.M. ( 1997 ) Mineral inclusions in diamonds from the River Ranch kimberlite, Zimbabwe...

... 91.07 0.355 0.0045 0.430 0.236 47 Gurney et al. (1979) River Ranch 92.39 0.165 93.62 90.30 0.369 0.0071 0.420 0.290 22 Kopylova et al. (1997) Majgawan 92.21 0.110 92.88 91.81 0.395 0.0056 0.430 0.360 11 Sobolev et al. (1993) Venetia 93.31 0.046 0.360...

... of metallic Fe–Ni blebs (bright) coating the periphery of a ferropericlase ((Mg, Fe)O) inclusion, liberated from a lower mantle diamond of the Rio Sorriso river deposits, Brazil (after Hayman et al. 2005 ). If the mantle below ∼250 km does have a stable Fe 0 component, this has significant...

... of the Ellice Hills map area and new constraints on the regional geology of the Committee Bay area, Nunavut . Geological Survey of Canada Current Research C22 , 1 – 11 . Skulski T. Sanborn-Barrie M. Sandeman H . ( 2003b ) Geology, Walker Lake and Arrowsmith River area, Nunavut...

... Eagles, Karsten Gohl, and Robert D. Larter 10 July Evolving force balance during incipient subduction —Michael Gurnis, Chad Hall, and Luc Lavier 10 July Geochemistry of Paleoproterozoic metasedimentary rocks from the Birim diamondiferous field, southern Ghana: Implications for provencance...

... of the Songhua River, c. 35 km east from Harbin city, at an altitude of 180 m above sea-level. The Huangshan section is a type section of the Huangshan Formation of the middle Pleistocene. The section is c. 70 m thick and is composed of four lithological units, which are, from the lowest upward...

... and Soedirdja (1986) . North Bintuni is modified from Koesoemadinata (1978) and Visser and Hermes (1962 , p. 91–94). Beseri River-1 well is from Rossetter (1978) . Lengguru is modified from Brash et al. (1991) and Visser and Hermes (1962 , p. 91–94). Waghete is modified from Pieters et al. (1983...

... (Palaeoproterozoic) granitoids in central Côte-d’Ivoire, West Africa: Geochemistry and geochronology : Precambrian Research , v. 87 , p. 33 – 63 . de Kock , G.S. , Armstrong , R.A. , Siegfried , H.P. , and Thomas , E. , 2011 , Geochronology of the Birim Supergroup of the West African...