Lake-Basin Type, Source Potential, and Hydrocarbon Character

Bohacs, Kevin M.; Carroll, Alan R.; Neal, J. E.; Mankiewicz, Paul J.

doi:10.1306/st46706c1

Cited by 125 publications

(1 citation statement)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In CAZ, the same reasoning for sea level can be adapted in lakes settings. The dynamics of accommodation in lake systems are due to tectonic and climatic variations (e.g., Bohacs et al 2000). The region between the uplifted areas and the sea or lake level is connected mainly by fluvial systems.…”

Section: Accommodation and Preservationmentioning

confidence: 99%

Cyclicity and hierarchy in sequence stratigraphy: an integrated approach

et al. 2021

View full text Add to dashboard Cite

With standardized methodology and nomenclature, the sequence stratigraphy aims to characterize multi-scale cyclical units of genetically related rocks into a hierarchical chronostratigraphic framework. From facies to basin scale, the stacking patterns and stratigraphic surfaces are recognized as sequence elements. In parallel, Earth sciences have developed a sophisticated understanding of geological processes (tectonic, climatic, and eustatic) that produce the main cyclicity observed in the sedimentary rock record. This review paper discusses how the elaboration of hierarchical stratigraphic frameworks that incorporate the knowledge of these periodic geological processes -from high-to low-frequencies -as the control of generation and preservation of sequences -from high-to low-resolutions -guarantees objective results in predicting vertical recurrence and the lateral correlation of genetic stratigraphic units. This interpretive approach of cyclic stratigraphic analysis supports the development of effective observable criteria to identify and rank sequences in multiple scales, based on cycle anatomy, recurrence, vertical trends, and mappability. This methodological improvement reduces the inaccuracies and contradictions of traditional conceptual models based on fully preserved three-dimensional depositional systems.

show abstract

Section: Accommodation and Preservationmentioning

confidence: 99%

Cyclicity and hierarchy in sequence stratigraphy: an integrated approach

et al. 2021

View full text Add to dashboard Cite

show abstract

Geochemical characteristics, depositional environment, and controlling factors of Lower Cretaceous shales in Chagan Sag, Yingen‐Ejinaqi Basin

et al. 2017

View full text Add to dashboard Cite

The Lower Cretaceous shales of Chagan Sag, Yingen‐Ejinaqi Basin, are considered as the source rocks of hydrocarbons discovered in the sag. Borehole shales from the Lower Cretaceous were subjected to comprehensive geochemical study to evaluate the quality of source rock, to reconstruct the paleodepositional environment and to determine the controlling factors of organic matter enrichment. Content of present‐day total organic carbon, and hydrogen index, averaging 1.4% and 259.2 mg hydrocarbon/g total organic carbon, respectively reveal poor to fair quality of organic matter. Average value of vitrinite reflectance (Ro) of 1.0% indicates mature organic matter. Maceral composition and biomarker analysis provide evidence for a mixed aquatic and terrigeous organic matter input. Based on Sr/Cu, Sr/Ba, and gammacerane index, we propose that organic matter was deposited in closed hypersaline under hot and arid climate conditions. The ratios of V/(V + Ni), and pristane/phytane (Pr/Ph), as well as the presence of β‐carotene suggest a stratified water column with anoxic bottom water condition. Low to moderate productivity as a result of deficient nutrient supply, the excellent organic matter preservation condition under stratified anoxic water column and high sedimentary rate controlled the quality of source rock. In addition, influence of factors such as content of clay minerals on organic matter enrichment cannot be ignored.

show abstract

Palaeoenvironment and organic matter of the Triassic Chang 9 lacustrine shales, Ordos Basin, China

Liu

Jiang

et al. 2019

Geological Journal

View full text Add to dashboard Cite

The Ordos Basin, a large mainly non-marine basin, is an important petroliferous basin in northern China. The Triassic Chang 9 shales, including the delta plain shale (DPS), delta front shale (DFS), and deep lake shale (DLS), are proven to be the main source rocks in the lower Yanchang Formation (LYF). This study investigates the source rock potential, palaeoenvironment, and organic matter (OM) source. According to the OM thermal maturity, abundance, and type, the shales have excellent source rock potential. The DLS has the highest quality with average TOC of 7.08%, S 1 + S 2 of 14.41 mg HC/g rock, andType II 1 -II 2 . According to correlations of Rb/Sr versus Sr/Cu, the shales were mainly deposited in arid conditions. Based on the major element (S), trace elements (V, Ni, Co, Cr, U, and Th), rare earth element (Ce) concentrations, and biomarkers (Pr, Ph, dibenzofuran, fluorene, and dibenzothiophene), redox conditions for the DPS, DFS, and DLS were oxidizing, sub-oxidizing to sub-reducing, and reducing, respectively. The palaeosalinity was fresh-to brackish-water, ascertained by the trace elements (Sr and Ba) and biomarkers (gammacerane). The water stratification was controlled by the temperature changes and the palaeosalinity differences, and the maximum water depth was 100 m during the Chang 9 deposition. Aquatic microorganisms (e.g., algae, bacteria, and phytoplankton) were the main organic matter sources for the shales, mixed together with terrigenous plants in DPS and DFS. The DLS has the most aquatic microorganisms and has the least higher plant fragments, supported by the higher TOC (up to 14%), lowest vitrinite contents (Avg. = 14.1%), and highest liptinite contents (Avg. = 59.5%). Laterally, the DPS, DFS, and DLS were distributed successively from the lake margin to the depocentre. Vertically, the DLS, DFS, and DPS were developed successively from the bottom lake to the upper lake. The DLS was mainly formed in an environment of highlevel sapropelinite and favourable preservation conditions, and the DPS was mainly

show abstract

Lake-Basin Type, Source Potential, and Hydrocarbon Character

Cited by 125 publications

References 71 publications

Cyclicity and hierarchy in sequence stratigraphy: an integrated approach

Cyclicity and hierarchy in sequence stratigraphy: an integrated approach

Geochemical characteristics, depositional environment, and controlling factors of Lower Cretaceous shales in Chagan Sag, Yingen‐Ejinaqi Basin

Palaeoenvironment and organic matter of the Triassic Chang 9 lacustrine shales, Ordos Basin, China

Contact Info

Product

Resources

About