... with a hammer, free oil can be obtained from the hollow central part of the individual chambers of the ammonites. These chambers are completely separated both by the septa and a layer of secondary calcite which lines each chamber. As much as 1 2 teaspoon of light green oil has been found...

... was collected by the writer from an exposure of “oil shale” on the east side of the Andes Range, in Mendoza province, Argentina. This shale formation, which we have called the “ammonite shale,” carries not only a great many remains of ammonite shells, but also a wealth of impressions and casts of pelecypods...

... of Albian age. They become numerous in the later Cretaceous although they apparently suffer a decline at the end of this period, and they are abundant from the beginning of the Tertiary until the present day. Their first peak of abundance is reached in the Cenomanian just when the ammonites...

... a continuing sea-level fall (reflected in the type-section by temporary loss of oil-shale lithologies and development of carbonate-rich mudstones). Thus, at Aylesbury there are no ammonites representative of the higher part of the Reisiformis Subzone, or of the Encombensis Subzone. Silt then appears...

... Volgian, where a major stratigraphic hiatus was previously assumed. The established zones have variable correlation potential. Different versions of the subdivision of the section based on ammonites are discussed and the proposed scale is justified. A reference level based on calcispheres/calcareous...

...Jeffrey D. Stilwell; Matthew Dixon; Benedikt Lehner; Silvia Gamarra Abstract Jurassic–Cretaceous ammonites are particularly robust fossil tools in global stratigraphy and correlation. The successive evolution and extinction of these cephalopod mollusks was so rapid that many ammonite zones...

... permit its preservation. The La Luna formation contains a profusion of carbonaceous, bituminous, organic matter. The Cogollo contains almost none. This organic matter contains some free petroleum and preliminary tests indicate that additional oil may be generated from it by heating. It seems probable...

... values of 5–10% and kerogen Type III or Type II–III, seem to be degraded as a result of their pre-oil-window maturity (Bojesen-Koefoed et al. 2018 ; Figs 2 , 3b , 4d ). Macrofossils recovered from black shale of the Blokelv-1 borehole are represented by ammonites, belemnites, onychites, bivalves...

..., this is probably an underestimate, given the large porosities recorded elsewhere. This property varies within a reservoir as a function of height above the free energy surface and of porosity and permeability. However, for a given porosity the height variation above the dry-oil production contact...

... (for standards) and was less than ± 0.25‰ (for samples). The error for non-debituminized carbon-free rock residues did not exceed 0.3‰, and for oils – 0.5‰. Microfauna. Microfauna in the Paiyakhskaya section of the Gol’chikha Formation has quite a sporadic distribution, so the sufficient number...

... of Purbeck are a series of silty mudstones in which oil and bituminous shales make up only a minor part of the succession. Neaverson (1924 , p. 149) claimed to have found Pallasioides Zone ammonites in these horizons ‘though in a poor state of preservation’. Arkell (1947 , p. 79) stated of these horizons...

... of North Sea oil. Nature, Lond. 259, 473-5. HALLAM, A. 1963. Observations on the palaeoecology and ammonite sequence of the Frodingham Ironstone (Lower Jurassic). Palaeontology 6, 554-74. - 1967. An environmental study of the Upper Domerian and lower Toarcian in Great Britain. Phil. Trans. R. Soc. B255 393...

...Russell L. Hall; Federico F. Krause; Siegfried D. Joiner; Keith B. Deutsch ABSTRACT New ammonites collected from two sections of the Cardium Formation (Upper Cretaceous; upper Turonian/lower Coniacian) exposed along the Bow River near Seebe, Alberta, indicate there is no biostratigraphic basis...

... standard zones are recorded in the sections under study. The obtained biostratigraphic data and analysis of all known ammonite occurrences make it possible to demonstrate the stratigraphic continuity of the section in the Anabar River region, despite the reduced thickness of the stratigraphic units...

... surface, but free sulphide (H2S) was not released into the bottom waters for any length of time. Pyrite occurs mainly as framboids in bituminous and oil shales, suggesting initial precipita- tion as monosulphides (Goldhaber & Kaplan 1974) as a by-product of bacterial sulphate reduction. The abundance...

..., arenaceous genera most numerous. Sample 14. —Abundant argillaceous spherocrystalline limestone with frequent free spherocrystalline bodies, dull concretionary pyrite present. Very rich fauna of Foraminifera, ostracodes, fish vertebrae, pyritic ammonites and snails, holothurian spicules, echinoid...

... of the Yatria River area during the late Jurassic–early Cretaceous. Fig. 7.  Palaeotemperature estimates for the K. fulgens – H. kochi and D. ramulosus – H. bojarkensis ammonite zones. The plots are modified from Woo et al . (1992) after the model of Railsback et al . (1989) for an ice-free...

...L. G WEEKS Abstract Carbonate concretions that include marine organisms such as ammonites or even the full body of a fish are abundant in Cretaceous shales of the Magdalena Valley of Colombia, South America. The occurrence of carbonate concretions in central basin shale facies is common not only...

... concretions (La Luna lithotope), the Apón formation is again subdivided into three units: the lower, middle, and upper Apón members. The lithologic character, combined with a rich ammonite fauna, makes the middle Apón an outstanding key formation. The Apón formation of Sutton is unchanged but his overlying...

... of the section, the previously published information is contradictory. On the one hand, this species was reported only from the Member XVII that corresponds to the Boreiocephalites borealis ammonite Zone, while the Members XV to XVI were described as belemnite-free deposits [ Meledina et al ., 1987 , p. 60...