With the recent discovery of new oil fields around the Dongying Depression, Bohai Bay Basin, a better understanding of the origin of its high‐quality lacustrine carbonate reservoirs has become important. The lacustrine carbonates of the upper fourth member of the Eocene Shahejie Formation (ES4s) have been examined using a variety of methods, including core and thin section observations, XRD, SEM, CL and fluid inclusion and isotope testing. The δ13C and δ18O values of the Dongying carbonates differ significantly from Eocene marine values, and the 87Sr/86Sr ratios of carbonate minerals are higher than Eocene marine water and the same as the surrounding Palaeozoic carbonate bedrock. Additionally, the distribution of the carbonates is controlled by the surrounding Palaeozoic carbonate bedrock, all of which indicate their lacustrine origin. Six major carbonate lithofacies are distinguished in the southern gentle slope zone. Bioclastic, oolitic and intraclastic grainstones dominate the littoral to sublittoral zones, while mudstones are mainly distributed in the profundal zone. The ES4s interval is composed of a third‐order depositional sequence that contains several small‐scale, higher frequency depositional cycles. Overall, stacking patterns of high‐frequency depositional cycles are consistent with the general facies variation from basin to shore. Shallow‐water grainstones contain both primary intergranular and secondary dissolution pores, whereas the dolomitized mudstones in the profundal zone contain intercrystalline pores and fractures. Diagenetic processes that improve reservoir quality include dissolution and dolomitization. Reservoir quality was diminished by burial calcite cementation and compaction. High‐quality reservoirs are mostly distributed in dolomitized grainstones and wackestones, which are deposited in the shoal facies of shallow lakes. Variations in reservoir quality in the Dongying Depression are due to a combination of lithofacies type, dissolution intensity, early dolomitization and tectonic‐related deformation. Due to the influx of meteoric waters and shallow burial depth, the grainstones in the littoral zone have the best reservoir quality. Integrated studies have helped to understand the reservoir heterogeneity and hydrocarbon potential of the Dongying lacustrine carbonates. Copyright © 2016 John Wiley & Sons, Ltd.
Calgary, Alberta: July 26, 2016 — Mkango Resources Ltd. (TSXV: MKA; AIM: MKA ) (the \’Corporation\’ or \’Mkango\’), is pleased to announce that it has secured a two-year exclusive option and right to acquire, on commercially standard terms, the worldwide licence for a technology to produce high strength (up to 30%) hydrochloric acid (\’HCL\’) from calcium chloride feed streams (the \’Technology\’) using sulphuric acid, applicable in rare earths processing and other potential industrial appli
Understanding hydrocarbon migration mechanism is a key scientific problem that needs to be resolved for effective hydrocarbon exploration in the Ordovician rocks of the Tazhong area, Tarim Basin. Based on analyses of geological setting and reservoir distribution characteristics, hydrocarbon migration process, and mechanisms in the Ordovician, Tazhong area, were investigated by integrating geological, geophysical, and geochemical parameters. Successfully analysed parameters included logging reservoir properties, seismic attributes, production outputs, fluid properties, and hydrocarbon maturity parameters. Results indicate that hydrocarbons were introduced into the Ordovician through a series of charging positions during 3 accumulation periods — middle Caledonian, late Hercynian, and Himalayan. In total 11 hydrocarbon charging positions were identified at intersection zones of the northeast‐trending faults and northwest‐trending flower strike faults. There are anomalies in all parameters on hydrocarbon charging positions. With increasing distance from the charging positions, anomalies of oil density, wax content, dry gas coefficient, hydrogen sulphide content, gas/oil ratio, well production, 4‐/1‐MDBT ratio of crude oil weakened, and natural gas’ carbon isotope composition becoming lighter along a northwest to southeast direction are present. Evidence from main hydrocarbon pathway systems theory, formation mechanisms of fault intersection zones, and obvious improvement in reservoir properties at intersection zones supports this viewpoint. Further exploration activities in the Ordovician of the Tazhong area should be conducted in the North Slope’s west area, and intersection zones in tectonic up‐dip direction should be emphasized. Copyright © 2016 John Wiley & Sons, Ltd.
The present study discusses the origin and affinity of enigmatic Ediacaran bedding plane structures reported earlier from the Sonia Sandstone of the Marwar Supergroup (Ediacaran to Lower Cambrian). These forms are conspicuously large, non‐carbonaceous and three‐dimensionally preserved. Morphologically, these structures are not comparable with any known plant/animal fossil, trace fossil, microbially induced sedimentary structures (MISS) found in the Ediacaran assemblages or any other extant forms and are invariably associated with MISS. Past researches on these fossils did not resolve their affinity, form and function. The present forms have certain features akin to seaweed organization such as thallus, loop pattern within the thallus, variously positioned nodes/swellings, tapering at the end of thallus, branching pattern and rarely occurring holdfast‐like features. Systematic description, incorporating detailed morphological features, population size, their relationship with associated sediments and stratigraphic distribution, is based on the study of 54 specimens. Subtidal to intertidal models of depositional sedimentary environment, palaeoecology, biogenicity, affinity, taphonomic changes, association of these forms with MISS and other parameters are also discussed. A succession of plausible interpretations is offered; seaweed is the most likely interpretation. The Marwar Supergroup, thus, unravels some of the hitherto enigmatic forms of the Ediacaran Period (635–541 Ma). Copyright © 2016 John Wiley & Sons, Ltd.
Calgary, Alberta: July 12, 2016 — Mkango Resources Ltd. (TSXV: MKA, AIM: MKA) (the \’Corporation\’ or \’Mkango\’), is pleased to announce results of the airborne geophysical survey (the \’Survey\’) covering approximately two thirds of its Thambani licence. The Survey was part of a US$25 million World Bank funded nationwide airborne geophysical programme flown at 250 metre spacing. Radiometrics The Thambani Massif is mainly composed of nepheline-bearing syenite gneiss forming
Book Review Authors Stephen K. Donovan Naturalis Biodiversity Center, Leiden, the Netherlands Search for more papers by this author No abstract is available for this article. Ancillary Article Information DOI 10.1002/gj.2851 View/save citation Format Available Full text: HTML | PDF Copyright © 2016 John Wiley & Sons, Ltd. Request Permissions …
The ichnogenus Tremichnus Brett was established for small round pits in echinoderm endoskeletons, principally crinoids. It is morphologically identical to Oichnus Bromley. It is significant that infestation of the echinoderm test is an integral part of any diagnosis of Tremichnus. This is an unacceptable ichnotaxobase; the diagnosis should only define morphology and, with reservation, substrate, such as unlithified (= soft), lithic or wood. From a recent revival of Tremichnus, Tremichnus paraboloides Brett is a junior homonym of Oichnus paraboloides Bromley; both share a similar morphology. Tremichnus puteolus Brett is more correctly referred to Lacrimichnus Santos et al. Tremichnus excavatus (Donovan and Jagt) could only be force‐fitted into Tremichnus following a drastic revision of the original diagnosis and is here reassigned to Oichnus, as originally described. Copyright © 2016 John Wiley & Sons, Ltd.
Calgary, Alberta: July 6th, 2016 — Mkango Resources Ltd. (TSX-V: MKA; AIM: MKA) (the \’Corporation\’ or \’Mkango\’), is pleased to provide a corporate update on its corporate social responsibility programmes and review of the airborne geophysical data. Corporate Social Responsibility (\’CSR\’) update Since the early days of its exploration programmes, Mkango has implemented a number of successful CSR programmes at its Songwe project in Phalombe in order to enrich the lives of