Folds anticline

Folds are features related to compressional, ductile deformation (Fig. 5.10). They form some of the largest reservoir structures known. A fold pair consists of anticline and syncline. 

The deposit lies in the core of a 2-3 km wavelength, tight, shallow to moderate Northeast-plunging anticline that folds the Upper Victoria Lake Supergroup, the black, pyritic Caradocian shale, and the Badger Group. 

A common structural trap, the anticline, is an upward bulge in the rock layers which forms an arch capable of holding oil under its apex. The buoyancy of oil and gas carries them upward through porous rock layers into the apex until they are trapped by an impermeable layer. Anticlinal type of folded structure is shown in Fig. 2. Reservoirs formed by folding of the rock layers or strata usually have the shapes shown in Fig. 2(a) and (b). These traps were filled by upward migration of oil and/or gas through the porous strata or beds to the location of Ihe trap. Further movement was arrested by a combination of the forms of the structure and the seal or cap rock provided by the formation covering the structure. 

In the 1990-ies Georgian geological institutions were carrying out survey studies in order to determine and investigate some favourable structures for UGS facilities. These appropriate structures of brachyanticlines and anticlinal domes within folds consisting also of such rocks can be used as gas reservoirs (mainly cracked sandstones, tuff sandstones and tuff breccias). They are displayed at depths around 1000-1500 meters - sometimes even more than 2000 meters - and are covered with waterproof and gas-proof limestone rocks, with capacities estimated at 1-1.5 bcm [8],... 

The deposit is situated in the Gardabani region, on the right bank of the river Iori, 30 km to the East of Tbilisi, and 7 km from the Vaziani railway station. It is situated on the East end of the Teleti structure lowland and is made up by sediments of the Upper Cretaceous, the Lower, Middle and Upper Eocene and Oligocene. In the arch of the fold there are dome-shaped brachy-anticline, where oil was found and quarrying was carried out. 

This area is 20 km northeast of Poti, to the West Chaladidi anticline of the Pontain-Meotian (Miocene) sediments. It is in the lower part of the above-mentioned Ochamchire-Kulevi block (3), near the south border of (III) the intermountain cavity zone, at the southwest edge of the Poti-Abedati and the Senaki-Tsaishi. On the Poti-Abedati fail line the Abedati, Nokalakevi and the Eki mountain over thrust sheet folds are displayed intermittently, which corresponds to the lower structural floor disjunctive break zones [9]. On the mentioned fail line, from the northeast to southwest, the relocation of epicentres of the Samegrelo earthquake (1941) is specified. 

This general structure, however, is affected by anticlinal and synclinal folds arranged in the direction of the Variscan orogeny (SW—NE) and is cut by SSE-NNW faults. 

In Russia, steam flooding technique has been applied with best economic results at the Okha oil field located on the Sakhalin Island in the Far East. Here, under relatively favorable geological conditions, oil has been recovered by steaming ever since 1968 [19]. Selected for the EOR project was the petroliferous bed No. IV in block No. X located on the central of an (anticlinal) fold. 

The coal mining field is broad and gentle fold which is composed by anticline NO.l, syncline N0.2, anticline N0.3 and N0.4 from west to east. Tectonic line direction is N60° 70°W, and turn... 

Sikeshu coal mine in Wusu city is located in north tianshan eugeosyncline north-edge in the west piedmont depression of Urumqi mountain. It is a meso-cenozoic depression formed on the Paleozoic basement. Under yanshan movement and himalayan movement, piedmont depression of Urumqi mountain in the mesozoic strata form a series of fasciculation or minor axis fold, form kinds of anticline and syncline structures, mainly including Kerry Ackert—the four tree river anti-... 

Folds These are flexures formed when horizontal strata to fold upon compression as shown in Figure 2.14. The rising arches of the folded strata are called anticlines and depressed troughs are called synclines. On a large scale they give rise to domes and basins. 

Taylor Nunatak in Fig. 5.16 extends parallel to the ice-flow direction of the Shackleton Glacier for about 6 km and the elevation of its summit is 1,570 m. The rocks exposed in its nearly vertical slope that faces the glacier consist of ashfall tuffs, ashfall flows, and marble. The rocks have been folded into a large anticline indicated by a reversal of dip from 70° north at the northern end of the nunataks to 70° south at its southern end. However, the lithologic compositions of the north and south limbs do not match, perhaps because the structure is a fault rather than an anticline. The crest of the nunatak is covered by a sill of Ferrar Dolerite (Middle Jurassic) which is about 12 m thick. The Taylor Formation on Taylor Nunatak is composed of approximately equal proportions of... 

Anticline An upward fold or arch of rock strata. 

Syncline A fold in rock in which the strata dip inward from both sides toward the axis the opposite of anticline. 

At Suria, potash is mined on the southern flank of the Suria anticline. One or two of the four potash beds are recovered (in two mines) from depths between 550 and 880 m. The potash beds dip at angles up to 20 and have generally been thickened there are a number of barren and folded zones. The lower (A) bed may average 6.5 m thick with ore averaging 20.6% K2O. The upper bed (B) averages 5.5 m at 27% K2O. A portion of the overlying carnallite bed has been converted to sylvinite, which is also mined [95]. 

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