First record of lower – Middle Ordovician (Tremadocian – Dapingian) carbon isotope (δ13Ccarb) chemostratigraphy in the Canning Basin, Western Australia; calibrated with geochronology/biostratigraphy and implications for global correlations

Carbon isotope (δ13Ccarb) stratigraphy of the Lower–Middle Ordovician (Tremadocian–Darriwilian) in the Great Basin, western United States: Implications for global correlation

Zhen, Y.Y., Normore, L.S., Dent, L.M. & Percival, I.G., 11 July 2019. Middle Ordovician (Darriwilian) conodonts from the Goldwyer Formation of the Canning Basin, Western Australia. Alcheringa 44, 25–55. ISSN 0311-5518Middle Ordovician conodonts attributed to 46 species were recovered from a stratigraphic interval spanning the Willara, Goldwyer and Nita formations in core sections from the Sally May-2 and Theia-1 petroleum exploration wells in the Canning Basin, Western Australia. The Histiodella serrata, Histiodella holodentata and Eoplacognathus pseudoplanus biozones are recognized in the lower and middle part of the Goldwyer Formation, indicative of an early–middle Darriwilian age. This revised conodont biostratigraphy enables more precise correlation with North America and North and South China. Several biogeographically distinctive conodont species, most likely of North Chinese origin, are recorded from the Goldwyer Formation. Their presence signals a strong palaeobiogeographic connection between the Sino-Korean Craton and the Canning Basin on the western margin of eastern Gondwana during the late Middle Ordovician.Y.Y. Zhen* [yong-yi.zhen@planning.nsw.gov.au], W.B. Clarke Geoscience Centre, Geological Survey of New South Wales, 947–953 Londonderry Road, Londonderry NSW 2753, Australia; L.S. Normore [leon.normore@dmirs.wa.gov.au]; L.M. Dent [louisa.dent@dmirs.wa.gov.au], Department of Mines, Industry Regulation and Safety, Mineral House, Geological Survey of Western Australia, 100 Plain Street, East Perth, WA 6004, Australia; I.G. Percival [ian.percival@planning.nsw.gov.au], W.B. Clarke Geoscience Centre, Geological Survey of New South Wales, 947–953 Londonderry Road, Londonderry NSW 2753, Australia;

The stratigraphic overview presented in this chapter substantially updates and revises the last major review of the Ordovician rocks of Australia and New Zealand published 40 years ago. In the western two-thirds of the present-day continent of Australia, Ordovician sedimentary rocks are restricted to intracratonic basins. The Canning Basin (Western Australia) and Amadeus Basin (central Australia) contain the best known Lower and Middle Ordovician shallow marine successions. The eastern third of the continent, known as the Tasmanides, comprises multiple orogens (i.e. Delamerian, Lachlan, New England, Thomson, Mossman) that formed along the convergent East Gondwana Margin. As a result, volcanic and intrusive rocks are much more common in these orogens than in the intracratonic basins. Their deep-water depositional environments span 31 graptolite biozones. Slope and basinal siliceous sedimentary rocks are constrained by a newly defined set of 12 conodont biozones, complementing the conodont biostratigraphic scheme refined for shallow-water environments from the basal boundary of the Ordovician to the latest Katian. In some places, these conodont biozones are integrated with radiometric ages from tuff interbeds (e.g. Canning Basin). Ordovician graptolitic strata in the Buller Terrane of New Zealand share palaeogeographic links with those in the Bendigo Zone of the western Lachlan Orogen.

Darriwilian (Middle Ordovician) δ13Ccarb chemostratigraphy in the Precordillera of Argentina: Documentation of the middle Darriwilian Isotope Carbon Excursion (MDICE) and its use for intercontinental correlation

Ordovician (Floian-lower Darriwilian) conodont biofacies of the San Juan Formation in the Cerro Viejo of Huaco, Argentine Precordillera

The Lower–Middle Ordovician (Ibexian, Whiterockian) sedimentary rocks exposed at Rancho Las Norias includes the informally named Las Norias formation, which consists of an intercalation of carbonate and clastic sediments with abundant marine fauna. These deposits occur as the most austral sedimentary rocks of Ordovician age for Laurentia, providing a critical link to understand the distribution of Ordovician marine faunas of North America. An investigation of the gastropod fauna from the upper portion of the Las Norias formation, Sonora, Mexico, is undertaken for the first time. The gastropod assemblage includesMaclurites acuminatus, ?Monitorellasp.,Lecanospirasp.,Malayaspiraaff.M.rugosa,Lophospira perangulata, andHormotoma? sp. This assemblage indicates a paleogeographic relationship with Laurentia, including the USA (Nevada), Canada (British Columbia, Newfoundland), Greenland, and the Argentine Precordillera.

Carbon isotope (δ13Ccarb) stratigraphy of the Lower-Upper Ordovician of the Yangtze Platform, South China: Implications for global correlation and the Great Ordovician Biodiversification Event (GOBE)

The conodonts documented by Watson form one of the best-known middle Darriwilian faunas from Australia. The present contribution is based on the re-examination of this material. Thirty-one conodont species from the subsurface Goldwyer and Nita formations of the Santalum 1 A drill core section of the Canning Basin, Western Australia are documented and described, including two new species, Belodina watsoni sp. nov. and Scalpellodus percivali sp. nov. The revised fauna is characterized by diagnostic species, namely Histiodella holodentata, Histiodella triangularis, and Eoplacognathus pseudoplanus. It provides compelling evidence to correlate this stratigraphic interval represented by the upper part of the Goldwyer and overlying Nita formations in the Santalum 1 A drill core section to the Histiodella holodentata or Eoplacognathus pseudoplanus biozones of middle Darriwilian age. However, in the Canning Basin, the faunal change signaled by the disappearance of H. holodentata and appearance of E. pseudoplanus reflects shifting of depositional settings from intermediate to outer shelf environments to shallower inner shelf conditions, coinciding with a regional regression event. New taxonomic data also enable more precise regional correlation of middle Darriwilian rocks across the Canning Basin and the Amadeus and Georgina basins in northern-central Australia.Y.Y. Zhen [yong-yi.zhen@planning.nsw.gov.au], Geological Survey of New South Wales, Division of Mining, Exploration and Geoscience, Department of Regional New South Wales, W.B. Clarke Geoscience Centre, 947–953 Londonderry Road, Londonderry NSW, 2753, Australia.

Paired carbon isotopic analysis of Ordovician bulk carbonate (δ13Ccarb) and organic matter (δ13Corg) spanning the Great Ordovician Biodiversification Event

The Early and Middle Ordovician Orthocerida and Lituitida of Precordilleran Argentina are described, and their systematics and paleogeographic significance are revised. These cephalopods show a strong affinity to coeval faunas of North China, suggesting a location of the Precordillera at middle latitudes in the Southern Hemisphere east of the North China block and relatively close to the Gondwanan margin during the early Middle Ordovician. The descriptive terminology of characters of the septal necks, the position and shape of the siphuncule, and the shape of the connecting ring is improved. The distribution of these characters support an emendation of the Baltoceratidae, Sactorthoceratidae, and Proteoceratidae.Brauliocerasn. gen. (Sactorthoceratidae) andPalorthocerasn. gen. (Orthoceratidae) are erected. The new speciesBraulioceras sanjuanense, Eosomichelinoceras baldisii, Gangshanoceras villicumense, and Rhynchorthoceras minorare proposed.Palorthocerasn. gen. from the Lower OrdovicianOepikodus evaeZone represents the earliest known orthocerid.

The Late Devonian and Early Carboniferous encompassed the decline and of global reef ecosystems during a time of climatic and sea level fluctuation. Frasnian stromatoporoid-coral-microbial reef communities gave way to Famennian microbe-dominated communities. Deep-water Waulsortian mounds characterise parts of the Early Carboniferous, but a range of Visean skeletal and microbial reefs and bioherms represent a period of recovery of shallow marine reef communities. Comparison of reefs in this age from four regions shows that reef development is significantly influenced by tectono-stratigraphic settings. Devonian reef complexes in the Canning Basin, Western Australia grew in an intracratonic basin, representing a classic 'Great Barrier Reef' model. Devonian reef complexes and extensive Early Carboniferous carbonate shelves in South China developed in a pericratonic basin at a passive continental margin, depicting a successive and stable mid-Palaeozoic platform setting. Early Carboniferous reefs in eastern Australia and Japan developed in a forearc basin and on seamounts, respectively.New sections on Devonian platform margins and reef edges in Guilin, South China were compared with those in the Canning Basin. Reef subfacies, reef complex architecture, temporal reef builder associations, and platform cyclicity in the two regions are similar. However, carbonate complexes are more widespread in South China, and have a much thicker sequence. Most Canning Basin reefs grew directly on Precambrian crystalline basement, but in South China, carbonate complexes developed on earlier Devonian siliciclastic sediments. Pre-Frasnian reef facies in South China have more skeletal frameworks than the Canning Basin reefs, and Famennian shoaling margins are more common and more diverse in South China. More platform margin types were recognized in the Canning Basin, possibly owing to relatively less deformation. Studies on the Visean Cannindah reef limestone near Monto; Queensland revealed five primary reef subfacies. The reefs developed on shallow-water oolitic-crinoidal banks with thrombolites contributing to initial reef stabilization. Colonial rugose and tabulate corals formed bafflestone and framestone on the thrombolites. Subsequently, calcimicrobes and microencrusters enhanced reef framework. Up section, reefs were formed by Parachaetetes, sponges and microbes. Cannindah reefs are the largest Lower Carboniferous reefs in eastern Australia (more than 146 m thick) and contain abundant reef-building microbes (Renalcis, Palaeomicrocodium, and Girvanella), microencrusters, and algae. As in other Lower Carboniferous reefs in eastern Australia, sponges, thrombolites, fasciculate rugose corals, and syringoporoid corals are significant in reef building. Cannindah reefs differ from Lower Carboniferous reefs in Akiyoshi limestones, southwest Japan and Tianlin, South China in reef builders, textures, facies, and palaeogeographic settings. Similarities and differences between Devonian reefs in the Canning Basin and South China were primarily controlled by the intracratonic faults and on-shore fringing tectono-sfratigraphy in the Canning Basin versus the pericratonic faults and platform-depression- dominated tectono-stratigraphy in South China. Basically, basin types associated with different tectonic configurations controlled stratigraphic framework, and, in turn, affected the distribution and growth of carbonate platforms. Basement-involved faults controlled reef development and occurrence in both regions. In South China, NE-SW trending faults, with predominantly strike-slip displacements, superposed by NW-SE trending faults, resulted in unique platform-to-intraplatform depressions, which controlled Devonian reefs. The more complex fault system in South China led to more fault-controlled highs for reef formation. Also, different tectonic evolution resulted in a longer reef history in South China. Coral-sponge-microbial patch reefs are common in the limited limestones in the forearc basins of eastern Australia; rare microbialite-coral-bryozoan patch reefs occur in the passive marginal basin of South China; and coral patch reefs rest on top of seamounts now accreted to Japan. Differences in reefs were caused by local palaeoenvironments, nutrition supply, and terrigenous sedhnent influx associated with the different Early Carboniferous tectono-stratigraphic settings in Australia, South China, and Japan. The formation of large Cannindah reefs may represent (1) very abundant microbes, microbialite and microencrusters involved in reef formation; (2) a relatively clean environment without terrigenous clastic material; and (3) a high energy, near wave base, setting. Extensive tidal and restricted platform facies with a large terrigenous influx in the Canning Basin may have excluded Early Carboniferous reef growth there. Rare Early Carboniferous reefs in South China may reflect (1) early reef in forearc basins at active convergent margins following Late Devonian bioevents; (2) glacial events affecting passive continental margins; and (3) the lack of distinct fault-generated topographic highs.

Late Devonian carbon isotope stratigraphy and sea level fluctuations, Canning Basin, Western Australia

Source rock potentiality and reservoir characteristics of the Baluti Formation (Late Triassic), Northern Iraq were examined in order to determine the hydrocarbon generation potential and reservoir properties. A combination of geochemical analyses, stable carbon isotope, 1D-basin modeling and digital log data were used to evaluate the formation. The Total Organic Carbon ratios range from 0.39 to 0.61 wt%, while the quantity of free hydrocarbon and residual hydrocarbon are low (0.05-0.11, 0.40-0.90 mg/g respectively). The average of oxygen index is 318 mg CO2/g TOC, while the hydrogen index is less than 200 mg HC/g TOC, which indicates type III kerogen. The outcomes of the pristane/phytane and Pr/n-C17 with Ph/n-C18 ratios suggest that the formation was deposited under oxic environment. This conclusion is also supported by trace elemental data. According to the average of Ro% of 0.58 and Tmax of 430.1oC, the formation is in the immature to early mature stage. From a plot of 1D-modeled Ro% versus time, it is inferred that the organic matter of the formation had reached early maturation in the Early Paleocene (63Ma). The Baluti is a waxier formation and the degree of waxiness ranges from 1.99-2.55. Regarding, Triterpanes (Tm/Ts) and regular sterane C27-C29 the studied formation has been deposited in the terrestrial environment with high terrigenous input with hot and arid to semiarid climates. This result is supported by stable carbon isotopic data and clay mineralogy. The porosity of the dolomite beds is 10-15%. Based on the cutoff results, the Baluti Formation has only 1.13m net pay of 72m thickness, which means that the formation has poor porosity and permeability in the reservoir beds.

Turonian to Santonian carbon isotope data from the Tethys Himalaya, southern Tibet

Platform margins, reef facies, and microbial carbonates; a comparison of Devonian reef complexes in the Canning Basin, Western Australia, and the Guilin region, South China