Abstract Diagenesis is the main reason for tight reservoir lithology, complex pore-throat structure, strong heterogeneity, and variable occurrence distribution characteristics of fluid in pore-throat, which directly restricts Chang 8 oil layer group Ordos Basin. Exploration development. Based on analysis a large number cores thin slices, through application scanning electron microscopy, high-pr...

Strata-bound elemental sulfur deposits occur in different circum-Mediterranean Miocene sedimentary successions containing evaporites and high amounts of organic matter. It is widely known that bacterial sulfate reduction processes are the triggering mechanisms involved origin hydrogen sulfide subsequent native sulfur. However, most these successions, there controversy over whether formed basin ...

Pentacyclic triterpenol methyl ethers (PTMEs), germanicol methyl ether (miliacin), 3-methoxyfern-9(11)-ene (arundoin), beta-amyrin methyl ether (iso-sawamilletin), and 3-methoxytaraxer-14-ene (sawamilletin or crusgallin) were characterized in surface sediments of the Cross-River system using gas chromatography-mass spectrometry (GC-MS). Triterpenol esters (mainly alpha- and beta-amyrinyl acetat...

Dolomite or calcite, quartz and kaolinite in various proportions were reacted at 250-300~ temperatures and pressures up to 90 bars in a hydrous environment. Reactions which approached completion produced talc, calcite, montmorillonite, anorthite (both metastable hexagonal and stable triclinic polymorphs) and the rare Ca-zeolite, garronite. These reactions are applicable to diagenesis, low-grade...

[1] Restricted zones of recent dissolution and secondary aragonite infilling were identified in a coral core collected in 1986 from a living massive Porites colony from the central Great Barrier Reef, Australia. Secondary aragonite needles, 20 mm long, cover skeletal surfaces deposited from 1972 to late 1974 and increase bulk density by 10%. Dissolution is observed above this zone, whereas olde...

Carbonate rocks are composed of carbonate minerals that chemically formed in the form solutions, and there organisms involved their formation. The limestone found around Lake Limboto is very interesting, because water lake freshwater while characteristic a marine environment. Diagenesis natural process sedimentary occurs from initial deposition until it reaches limit metamorphism will be formed...

Sediment-hosted marine sulfur cycling has played a significant role in regulating Earth’s surface chemistry over our planet’s history. Microbially-mediated reactions involving are often accompanied by isotope fractionation that, turn, is captured sulfate and sulfide minerals, providing the opportunity to track changes microbial utilization of thus cycle. Studying diagenesis within Bornholm Basi...

Diagenetic dissolution of magnetic minerals has been widely observed in organic-rich sediments from many environments. Organic-rich sediments from the eastern Mediterranean Sea (sapropels), recovered during Leg 160 of the Ocean Drilling Program, reveal a surprising catalogue of magnetic properties. Sapropels, from all sites studied across the eastern Mediterranean Sea, are strongly magnetic and...

1 For copyright reasons several figures are excluded from this eprint version. For access to these, readers are referred to the published version of this manuscript or the cited papers. Abstract The hypothesis that reducing conditions exist in localized zones of high organic matter, termed microniches, was first suggested over a century ago, but only relatively recently have high-resolution tec...