Impact of the Paleoclimate, Paleoenvironment, and Algae Bloom: Organic Matter Accumulation in the Lacustrine Lucaogou Formation of Jimsar Sag, Junggar Basin, NW China

Jiang, Yuhan; Hou, Dujie; Li, Hang; Zhang, Ziming; Guo, Ruibo

doi:10.3390/en13061488

Cited by 18 publications

(9 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Barium (Ba) is always associated with biological metabolism and can be used to represent organic matter input [105,106]. Aluminium (Al) and titanium (Ti) are primarily of detrital origin, therefore P/Ti and Ba/Al are generally considered effective indicators of productivity by eliminating the impact of terrigenous debris [28,107]. The upper member of the Lucaogou source rocks exhibits higher P/Ti and Ba/Al ratios (P/Ti: avg.…”

Section: Productivitymentioning

confidence: 99%

“…Fe and P are indispensable elements for cyanobacterial metabolic activities. As water bodies become enriched in nutrients, there is often a shift in the phytoplankton community toward dominance by cyanobacteria [28,110]. Under this combination of favorable conditions, the Microcystis bloom occurred in the upper member.…”

Section: Productivitymentioning

confidence: 99%

“…However, they did not refer to the hydrocarbon potential of cyanobacterial blooms. In fact, previous studies have revealed that the Lucaogou Formation was deposited mainly in a brackish to saline lacustrine system, with relatively stable and anoxic water conditions [27][28][29]. This kind of paleoenvironment favors microbial growth [8].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Permian Cyanobacterial Blooms Resulted in Enrichment of Organic Matter in the Lucaogou Formation in the Junggar Basin, NW China

et al. 2023

View full text Add to dashboard Cite

The Permian Lucaogou Formation in the Junggar Basin, NW China is the target layer for shale oil exploration, but its hydrocarbon precursors have remained the focus of debate. In this study, we investigated the Lucaogou source rocks throughout Well J10025 by conducting detailed petrological, paleontological, and geochemical analyses for the purpose of revealing the occurrence of cyanobacterial blooms as specific hydrocarbon events in the upper Lucaogou Formation. The morphological characteristics of the microfossils and the geochemical signatures of the microfossil-bearing layers support a biological affinity with Microcystis, a kind of cyanobacteria. Microcystis observed as colonial forms embedded in the upper Lucaogou Formation are of great abundance, indicating the presence of cyanobacterial blooms. They were further evidenced by cyanobacteria-derived biomarkers including low terrestrial/aquatic ratio, high 2α-methylhopane index values, and high abundance of 7- and 8-monomethyl heptadecanes. The blooms occurred in a semiarid and brackish paleoenvironment with anoxic to suboxic water conditions and intermittent volcanic eruptions. Permian Microcystis blooms contributed to the enrichment of organic matter in the upper Lucaogou Formation in two main ways: by directly promoting the accumulation of algal biomass and by creating an oxygen-depleted environment for better preservation of organic matter. This study adds a new record to the geological occurrences of cyanobacterial blooms in the Permian, and provides unique insight into the hydrocarbon generation of Jimsar shale oil in the Junggar Basin.

show abstract

Section: Productivitymentioning

confidence: 99%

Section: Productivitymentioning

confidence: 99%

See 1 more Smart Citation

Permian Cyanobacterial Blooms Resulted in Enrichment of Organic Matter in the Lucaogou Formation in the Junggar Basin, NW China

et al. 2023

View full text Add to dashboard Cite

show abstract

“…As mentioned in [26], the change in paleoclimate resulted in enrichment or depletion of trace elements. The C-value is a good indicator of paleoclimate, and can be calculated using the following formula: C-value = (Fe + Mn + Cr + Ni + V + Co)/(Ca + Mg + Sr + Ba + K + Na) [31][32][33]. Because Fe, Mn, Cr, Ni, V, and Co are commonly concentrated under humid conditions, and Ca, Mg, Sr, Ba, K, and Na are enriched under arid conditions, the C-value may increase due to the climate changing from arid to humid.…”

Section: Paleoclimatementioning

confidence: 99%

Paleo-Sedimentary Environments and Controlling Factors for Enrichment of Organic Matter in Alkaline Lake Sediments: A Case Study of the Lower Permian Fengcheng Formation in Well F7 at the Western Slope of Mahu Sag, Junggar Basin

Chen,

Tang,

Nan

et al. 2023

Processes

View full text Add to dashboard Cite

The Lower Permian Fengcheng formation is a significant source of rocks and a reservoir for the Mahu Sag in the Junggar Basin. Recently, the paleo-environment deposition factors of the P1f formation have become a popular research topic. This research was conducted using data from the F7 well of Mahu Sag, based on the geochemical analysis results of TOC (total organic carbon), REE (rare earth elements), and major and trace elements of 53 samples from P1f (Lower Permian Fengcheng formation), and some deposition factors are discussed. The P1f deposition process was classified into four stages based on paleo-environment elemental indicators. This research describes the deposition process of the evolution of alkaline lakes. The early and preliminary stages of alkali lake evolution are considered as late P1f1 to middle P1f2; the paleoclimate of this process was dry, the reduction conditions increased, and the paleo-productivity and lake salinity were enhanced. The terminal stage of alkali lake evolution is considered as late P1f2 to middle P1f3; in this period, the paleoclimate changed with seasonal cycles, resulting in a decrease in water salinity and an increase in oxidation; the paleo-productivity of the alkaline lake was at a medium level. Until the end of P1f3, the salinity of the lake decreased, and the water body became anoxic and weakly alkaline. Furthermore, the research on TOC and sedimentary parameters confirmed that the deposition of P1f organic matter is affected by multiple types of factors. A relatively warm climate, lack of oxygen, fresh water–brackish water, suitable debris flow, and high primary productivity conditions promoted organic matter deposition.

show abstract

“…Currently, various researchers are employing diverse methodologies for sedimentary environment reconstruction, including biomarker analysis, inorganic geochemical techniques, palaeontological fossil examinations, and palynological studies. Commonly utilised parameters for sedimentary environment assessment include palaeoclimatic conditions, bathymetric depth variations, salinity fluctuations, redox environment changes, and provenance determination [18][19][20][21][22]. The Huanghekou Depression has abundant oil and gas resources, and the Shahejie Formation is a key layer for oil and gas exploration.…”

Section: Introductionmentioning

confidence: 99%

Sedimentary Environment and Enrichment of Organic Matter in the Shahejie Formation, Huanghekou Depression, Bohai Bay Basin, China

Jia,

Hou,

2024

Applied Sciences

View full text Add to dashboard Cite

As a hydrocarbon-rich depression within the Bohai Bay Basin, the Huanghekou Depression is a focal region for exploring hydrocarbons in the eastern China Sea. Previous studies have insufficiently examined the correlation between the enrichment of organic matter and the environments in which it is deposited. Herein, the hydrocarbon potential, palaeoclimate, sedimentary environment, organic matter sources, and organic matter enrichment of the source rocks of the Shahejie Formation in the Huanghekou Depression were investigated using organic and inorganic geochemical indicators. The organic matter type of the source rock in Huanghekou Depression’s Shahejie Formation was predominantly Type II, with a minor presence of Type III. Furthermore, the source rock had a poor-to-good comprehensive evaluation grade in E3s1–2, whereas E2s3 and E2s4 had medium-to-good comprehensive evaluations in their source rocks. In terms of maturity, E3s1 was in an intermediate position between the immature and mature stages and E3s2 and E2s3 were between the low-maturity and mature stages, whereas E2s4 transitioned into full maturity. Biomarkers and sensitive element indicators indicated that the organic matter in E3s1–2 was primarily derived from lower aquatic organisms and algae. This palaeoclimate was characterised by aridity, a water body containing saline and semi-saline water, and a strongly reducing environment resulting from water body stratification, leading to oxygen deficiency. The organic matter in E2s3 was primarily derived from aquatic organisms and algal inputs; these deposits were formed in a reduced environment characterised by relatively low salinity, ranging between semi-saline and freshwater conditions. The organic matter enrichment model of the Shahejie Formation was established based on sedimentary environment, palaeoclimatic, and organic matter source analyses, utilising E3s1–2 as preservation models and E2s3 as the productivity model. This study provides a basis for in-depth exploration and advancement of oil and gas reserves.

show abstract

Impact of the Paleoclimate, Paleoenvironment, and Algae Bloom: Organic Matter Accumulation in the Lacustrine Lucaogou Formation of Jimsar Sag, Junggar Basin, NW China

Cited by 18 publications

References 76 publications

Permian Cyanobacterial Blooms Resulted in Enrichment of Organic Matter in the Lucaogou Formation in the Junggar Basin, NW China

Permian Cyanobacterial Blooms Resulted in Enrichment of Organic Matter in the Lucaogou Formation in the Junggar Basin, NW China

Paleo-Sedimentary Environments and Controlling Factors for Enrichment of Organic Matter in Alkaline Lake Sediments: A Case Study of the Lower Permian Fengcheng Formation in Well F7 at the Western Slope of Mahu Sag, Junggar Basin

Sedimentary Environment and Enrichment of Organic Matter in the Shahejie Formation, Huanghekou Depression, Bohai Bay Basin, China

Contact Info

Product

Resources

About