Marl deposits

Marl deposits were among the first geologic materials to be applied to agricultural soils, having been used by agriculturists in the pre-Christian era. 

Glauconite is a green monochnic silicate mineral which belongs to the mica group (q.v). It has composition (K,Na)(Fe,Al,Mg)2 (Si,Al)40io(OH)2 and is present in many sandstones and marls deposited as marine sediments. It forms from the alteration of a variety of starting materials, especially Mg,Fe-rich silicate minerals such as biotite (q.v), in a marine environment and therefore occurs... 

In addition, one commercially-produced European natural cement was investigated Prompt, supplied by Vicat, France. The burning temperature for Prompt is up to 1200 °C but covers a wide range. The Prompt cement has been produced for more than 150 years by burning marl deposits at Chartrouse in the Rhone Alps at moderate temperatures [7]. The historic mortars based on the Prompt cement attain a compressive strength of about 20 MPa [8]. 

Marl. This is loose or crumbly deposit that contains a substantial amount of calcium carbonate. 

Marl Loose deposit consisting mainly of CaCOs... 

Reg soils are closely associated with desertic regions. They have developed on stable surfaces where coarse, gravelly desert alluvium is exposed, and are characterized by a well-developed desert pavement and exhibit some well-defined soil horizons. They occur mostly on depositional surfaces where stones and gravels have been deposited since Neogene times. The surfaces commonly consist of stony, unconsolidated sedimentary deposits in which limestone, dolomite, chalk, flint and marl predominate, together with some fines (silt and clay). Sandstone and granite debris have also been reported to contribute to Reg formation. Less frequently, they form on sedimentary bedrock (Fig. 1.5). 

The Ebro headwaters flow on calcareous substratum, specifically sandstone and calcium marls, from the Triassic, Cretacic, and Jurassic. During the Quaternary, at the plain of La Virga (Reinosa), a shallow lake accumulated the deposits of siliceous sandrocks. This old highland lake is now the Embalse del Ebro reservoir. From that point downstream to Conchas de Haro the main channel flows on calcareous rocks from the Cretacic, highly resistant to the erosion. 

At the medium reach, the river flows into the Iberian Depression, with marl and gypsum Miocene deposits in some areas. The dissolution of evaporitic sediments (gypsum, halite, and sodium-sulfates) gives rise to numerous sinkholes. However, subsidence is also being masked by morpho-sedimentary dynamic processes such as aggradation and erosion [12]. 

The Lower Jurrasic deposits include the detritic formation (Hettangian - Lower Sinemurian), the limestone formation (Upper Sinemurian - Pliensbachian) and the marl formation with ammonites and belemnites (Toarcian). 

The Middle Jurassic consists mainly of marls. The Upper Jurassic formations are massive (over 100 m thick) and are made up exclusively of limestones. During Upper Jurassic and Lower Cretaceous the limestone deposits have been uplifted and resulted in a paleo-karst surface that hosts discontinuous bauxite deposits. Lower... 

Cretaceous sedimentation started with the deposition of fresh-water limestones (Hauterivian) followed by successive layers of marine limestones (Barremian), marls (Aptian), marine limestones (Aptian), glauconitic sandstone (Aptian-Albian) and ended with a package of red detritic deposits. 

Limestones vary greatly in color and texture, the latter ranging front dense and hard limestone, e.g.. marble or travertine, which can be suwed and polished, to soft, friable forms, e.g., chalk and marl. Chalk is a very fine-grained white limestone, while marl is an impure deposition product that contains clay and sand. Texture, hardness, and porosity appear to be functions of the degree of cementation and consolidation during the formation of these materials. Color variations arise from the presence of impurities. Some impurities, such as sulfur and phosphorus, make limestone unattractive for metallurgical uses. 

In 1991 it was planned to prepare this deposit for exploration as a UGS facility. The middle Eocene aged tuff-breccias and tuffs with hollow gaps caused by 550-600 m thick cracks. A gas-proof lid was created by the Upper Eocene Tbilisi and Navtlugi strata of shaly clay, intermittent argillites, clay sandstones and marls, at 1000-1100 meter thickness. 

Faust et al. (1959) authigenic lake deposite associated with marl, eastern Morocco analyst J.J. Fahey. 

Post-impact sediments were penetrated by research well Nordlingen-1973 near the center of the basin and described in detail by Jankowski (8). They consist of a "basal unit" overlying the suevite, a 140 m thick laminite series, 60 m of marl and a clay layer at the top. Bituminous sediments mainly occur in the laminite series (Figure 1). In the Nordlingen-1973 well, in which the laminite series was recovered between 256 and 111m depth, Jankowski (8) distinguished four subunits a basal clinoptilolite subunit very rich in organic matter (256-244 m), an analcime subunit with low bitumen concentration (244-195 m), a bituminous subunit (195-145 m) and a diatomaceous subunit with lower bitumen content (145-111 m). Deposition of these sediments was estimated to have extended over a period of 0.3 to 2 Ma (8). 

Mineralogically the sediments of the laminite series consist of carbonates (mainly dolomite and calcite), various clay minerals, zeolites, opal, quartz and rare gypsum (8). The occurrence of gypsum, based on our X-ray diffraction (XRD) data, is restricted to the marl unit. Deposition, according to Jankowski (8), occurred in a periodically evaporitic, stagnant lake. The high bitumen concentrations most probably were responsible for the preservation of unusual minerals such as Mg-rich calcites (up to 25% Mg 9) and bituminous smectites (Muller, G., University of Heidelberg, personal communication, 1989). 

Northern Apennines Marl This sample is from Miocene strata in the Perticara basin (Italy) which consists of gypsum deposits interbedded with bituminous marl layers deposited during the Mediterranean salinity crisis (54). Detailed information on the hydrocarbons and OSC in the bitumen of this sample have been reported elsewhere (9.16.54). 

Marl (CaC03) deposits, removal of siliceous matter... 

North Africa.—The deposits of Algiers were discovered in 1873 and were fully reported upon in 1886. They are of Eocene age and contain 68 to 68 per cent, of calcium phosphate in a soft rock, together with marl, considerable amounts of silica, calcium fluoride and chloride, nodules of gypsum and almost pure limestone. The beds usually are several feet tflick and run continuously from Morocco to Egypt at a distance of over 100 miles from the sea. Those at Constantine (Algiers) are 120 miles from the port of Bona, and those at Gafsa (Tunis) 150 miles from the port of Stax. 

Carbonate-dominated sediments tend to be deposited in low-latitude environments and, therefore, biomarkers for organisms that preferentially colonize warm waters tend to be important signatures in these sediments. Cyanobacterial 2a-methylhopanes (57) (Summons et al., 1999) and 30-norhopanes (Subroto et a/., 1991) are generally elevated in bitumens from carbonates and marls. 

Mixtures of limestone with clays are so-called marl. Other deposits of limestone are marble, travertine, shell limestone and chalk whose properties depend upon their origin. 

Fig. 2-26. Results obtained by the CHIM method over an oil deposit in Byelorussia and schematic geological section 1- Permian-Cretaceous-Quatemary clays, sands, coals 2- marly siliceous clay formations 3- Carboniferous sand-clay formations 4- middle-late Devonian sandstones, aleurolites, marls 5- oil deposit (reproduced with permission from Ryss et al., 1990).

The earliest geologic deposits used as mineral supplements for agricultural soils seem to be chalk and marl. The beneficial effects of these materials on crops were known to the Celts as early as 2500 B.P. The Romans, who learned this practice from the Greeks and Gauls, even classified various liming materials and recommended that one type be applied to grain and another to meadow. However, liming materials were used for nearly 20 centuries before the beneficial effects were shown to be mainly due to the neutralization of excess soil acidity. 

---