— Iron oxide concretions have a large range of δ 56 Fe values from +0.9‰ to −2.0‰. The most remarkable characteristic of the concretion data is that most samples …

 — Generally, iron oxide minerals occurred in the Paleozoic sequences as pore-filling cement with various sandstone types and are associated with clay minerals and occasionally with calcite cement.

 — Adding oil to a sandstone stops clay diagenesis if the sandstone is oil-wet but probably only slows clay reactions if the sandstone is water-wet. Sandstones tend to be more oil-wet as the Fe-bearing clay content of the sand increases and as oil becomes more enriched in polar compounds.

 — VNIR reflectance spectroscopy is an effective method for determining iron and clay mineral phases of cements in the Navajo Sandstone (Bowen et al., 2007, Seiler, 2008) because the framework grains (quartz and feldspar) do not have distinct absorption features in the visible to near infrared (350–2500 nm) range but the HFOs and clay …

 — Note the replacement of early calcite cement by hematite in the Red Unit; (c) abundant iron cement (mainly hematite and goethite) impacts a floating grain texture in part of the Wajid Sandstone ...

 — Iron mobilized by chemical reduction is precipitated at the oxidation-reduction front as iron mineral cement in the sandstone. Cemented sandstone occurs as …

 — The carbonate cements in tight sandstone reservoirs are diverse, complex, and important determinants of reservoir quality. This study provides a comprehensive analysis of the characteristics and formation mechanism of carbonate cement in the tight sandstone reservoirs of the Xu3 Member within the Xujiahe Formation in the depression …

 — Different contents of Fe-bearing minerals, including biotite, Fe-Ti oxides, pyrite, hematite, goethite, and chlorite that were formed or altered under different redox conditions, resulted in sandstone units with distinct colors. The red sandstone is hematite-rich, indicating a highly oxidizing environment.

Keywords: Sandstone; Siliceous cement; Carbonate cement; Ferruginous cement; Paleohydraulics; Geomorphology; Sandstone landforms Introduction Mineral cement is the most important intrinsic factor in estimating erosion rates in sandstone regions. Its composition is a function of mineral availability in the basin and burial/thermal history of …

 — Sandstones of rift basins (arkoses) and collision-margin basins (litharenites) generally have only a few percent quartz cement; quartzarenites and other quartzose sandstones of intracratonic, foreland and passive-margin basins have the most quartz cement. Clay and other mineral coatings on detrital quartz grains and entrapment of …

 — Iron oxide cements have δ 56 Fe values that are typically negative and as low as −0.74‰. In contrast, iron oxide-stained Navajo Sandstone in close proximity to a …

tivity, allowing focus on the iron oxide mineral cement and evaluation of the parameters affecting the cementation pro-cess. Concretion cement can be hematite or goethite, and …

 — Sandstone is a detrital sedimentary rock that consists of particles smaller than 2 mm in diameter. Quartz (silica-dioxide) is the primary mineral in most sandstones (quartz sandstones), but rock fragments, feldspars, micas, clay minerals and carbonates can also be present (Pettijohn and others 1987).Different minerals and mineral phases such as …

 — Another common cementing agent in sandstone is iron oxide, also called hematite cement. The iron present in the cement will give the sandstone a distinctive red color. According to the Stone Care …

 — Review papers. 1. Clay minerals in sandstones: controls on formation, distribution and evolution: R. H. Worden and S. Morad. 2. Predictive diagenetic clay--mineral distribution in siliciclastic rocks within a sequence stratigraphic framework: J.M. Ketzer, S. Morad and A. Amorosi. 3. Oxygen and hydrogen isotope composition of …

 — We measured δ 56 Fe values of iron-bearing minerals from whole-rock Navajo Sandstone, concretionary iron oxide cements, iron oxide stains that are oriented …

 — Cements mainly include carbonate, clay minerals and silica cements and Other minerals that act as cements include: hematite, limonite, feldspars, anhydrite, gypsum, barite, clay minerals, and zeolite . Silica cement can consist of either quartz or opal minerals. In sandstone where there is silica cement present the quartz grains are …

 — Sandstone. Any sedimentary rock composed of stony grains between 1/16 mm and 2 mm in diameter that are cemented together is a sandstone.. Sandstone forms from beds of sand laid down under the sea or in low-lying areas on the continents. As a bed of sand subsides into the earth's crust, usually pressed down by over-lying sediments, it …

 — The main contents of this paper are as follows: (1) clarify the development characteristics and diagenetic evolution sequence of authigenic clay minerals and carbonate cements in the Ch6 3 tight sandstone; (2) characterize the pore and throat structure and clarify the main reason for the widespread development of micropore …

The three, most common, chemical cements in sedimentary rocks such as sandstone are silica (quartz), calcium carbonate (calcite), and the iron oxides. -Calcite-cemented sandstones are typically light colored, react w acidic -Quartz-cemented sandstones are also light colored, but they do not visibly react with acids and the cementing material is ...

The term siliciclastic refers to sediments composed mostly of silicate minerals. The most common sedimentary rocks – including shale, sandstone, and conglomerate – form from siliciclastic sediments. Other …

 — Researchers have questioned how the pigment-bearing iron minerals get into rocks like sandstone and shale as well as how the minerals are dispersed within the rock. One might suspect that the brightly colored minerals might be sprinkled throughout the sand and clays or cements that composed the sandstone and shale units—something …

Clay minerals are one of the most important groups of minerals that destroy permeability in sandstones. However, they also react with drilling and completion fluids and induce fines migration during hydrocarbon production. They are a very complex family of minerals that are routinely intergrown with each other, contain a wide range of solid solutions and form …

 — The objectives of the paper are, for sandstones, to 1) summarise the main detrital grain types, 2) summarise the main diagenetic mineral cements, 3) summarise the main pore-types, 4) provide illustrative SEM-EDS images of sandstone end-member types, cements and pore-types, 5) detail the main processes that alter the key sandstone …

 — Sandstone is formally defined strictly by particle size, but rocks made of carbonate minerals don't qualify as sandstone. Carbonate rocks are called limestone and given a whole separate classification, so …

Cementation refers to the growth of new minerals between the sediment grains. These new minerals bind the sediment grains together. One form of cementation is growth of quartz rims on the surfaces of pre-existing quartz grains in the sediment. This new mineral growth is a result of water in the pore spaces that dissolves and precipiates quartz.

 — The proportion of matrix to framework is an important determinant of sandstone classification. Arenites have less than 15% matrix, wackes have more than …

 — The formation of hematite and goethite concretions in different sedimentary rocks including sandstones is an important diagenetic process in the geologic history of the Earth. Its interpretation can also contribute to understanding the diagenetic history of Martian iron hydroxide concretions.A case study of iron-rich concretions from Estonian …

 — Sandstone is typically a well-cemented rock, meaning that the sand grains are held together by some type of mineral cement, such as silica, calcium carbonate, or iron oxide. The degree of cementation can …

 — Fine-grained sandstone in Mesozoic red beds of the Colorado Plateau in the southwestern United States contains iron oxide cements (mainly hematite and goethite).