Jurassic limestone

The high coastal escarpments composed of Jurassic limestones recover complicated geological folds broken by tectonic faults and overthrusts. At the sites where intrusive rocks are developed, remarkable capes are formed. The largest of them are capes Ayu Dag, Medved Gora, Ai Todor, Nikita, Foros, Laspi, Sarych, and Aia. 

Lincolnshire, U.K. Molasse, Austria 1400 Jurassic, limestone Andrews and Lee (1980) Andrews et al. (1985)... 

The sampling site is located about 180 km south-east of Munich in the Berchtesgaden National Park between the mountains Jenner (1800 m), Watzmann (2700 m) and Hagengebirge (2200 m). The area belongs to the Kalkalpen (Jurassic limestone) and the slopes are built up by micaceous and marl limestones. The mean annual temperature at an altitude of about 1550 m is 2.2°C with precipitation of 1757 mm in 1997, where 50% falls as snow. 

Joint is a discontinuity, fracture or parting in a rock, involving no displacement. Jurassic limestone was deposited in the Jurassic period 135 to 180 million years ago. 

Grain Size (d in mm) Qnartz Stuben Sandstone Jurassic Limestone Triassic Limestone NRA Sample... 

In this district the deposits occur in the Permian basin of Lodeve in the folded north Pyrenean foreland on the eastern border of the Montagne Noire. The basin has an area of about 150km and is a diamond-shaped, southwest-northeasttrending depression, 26 km long, dominated by the 200-300m high Jurassic limestone plateau (Figs. 20 and 21). 

For example, the many deepwater fields located in the Gulf of Mexico are of Tertiary age and are comprised of complex sand bodies which were deposited in a deepwater turbidite sequence. The BP Prudhoe Bay sandstone reservoir in Alaska is of Triassic/ Cretaceous age and was deposited by a large shallow water fluvial-alluvial fan delta system. The Saudi Arabian Ghawar limestone reservoir is of Jurassic age and was deposited in a warm, shallow marine sea. Although these reservoirs were deposited in very different depositional environments they all contain producible accumulations of hydrocarbons, though the fraction of recoverable oil varies. In fact, these three fields are some of the largest in the world, containing over 12 billion barrels of oil each ... 

Other Deposits. Those deposits which cannot be classified as one of the previous 14 deposit types are called other. These include the uranium deposits in the Jurassic Todilto Limestone in the Grants district in New Mexico (17). 

Important metallic ore deposits include Besshi (Kieslager)-type (strata-bound cupriferous pyritic deposits), strata-bound Mn-Fe-type, skam-type, Kuroko-type and vein-type. Dominant non-metallic deposits are limestone, clay, native sulfur, zeolite, silica and gypsum deposits. The deposits are divisible into three groups, based on their ages of formation Carboniferous-Jurassic, Cretaceous-Paleogene and Tertiary-present. 

The Yamizo Mountains are mostly occupied by Paleozoic-Mesozoic sedimentary rocks, mainly of Jurassic age (e.g., Sashida et al., 1982) with a small amount of intrusive granitoids of unknown ages. The Paleozoic-Mesozoic sedimentary rocks have been called the Yamizo Formation (Kanomata, 1961). It is composed chiefly of shale, sandstone, alternating beds of shale and sandstone, and a small amount of limestone and chert. The succession of the geologic units and geologic structure of the Yamizo Formation have been left pending due to complex structure such as upturned beds (Kasai, 1978) and submarine land sliding (Aono et al., 1985). 

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... 

Non-metamorphic equivalents of this Th-free mineralization may be sought in some rare limestone-hosted U-occurences, such as the Jurassic Todilto lacustrine formation in the Grant Uranium Belt (Rawson Richard 1980), the Cretaceous Toolebuc marine formation in Eromanga Basin (Ramsden 1982), the Mesoproterozoic Vempale marine formation in Cuddapah Basin (Sinha et al. 1989), and the Cretaceous Probeer marine formation in the Huab deposit (Hartleb 1988). 

Rawson, R. Richard, R. 2002. Uranium in Todilto Limestone (Jurassic) of New Mexico... 

Carboniferous to Permian redbeds of the Pictou Group (Bell 1929). In the area surrounding the Bay of Fundy, there was also a Jurassic-Triassic sedimentary basin (Fundy Group) developed in which sandstones, shales, basalts and minor limestone were deposited. During the Cretaceous fluvial quartz sands and kaolin of the Chaswood Formation were deposited throughout the Maritimes, but only a few outliers have been preserved (Stea Pullan 2001). 

The Ligurian complex tectonically superimposed on the Tuscan units, consisting of middle to late Jurassic ophiolites and radiolarites plus Cretaceous to Eocene pelagic limestones and flysch sequences. 

The Lincolnshire limestone Jurassic aquifer in eastern England provides another insight into a phreatic-confined system. Isotopic data were reported (Dowing et al., 1977) from a number of wells in this system, located in the... 

Fig. 7. Schematic north—south cross-section through San Antonio and the Muil Field (see Fig. 1). Jurassic and Lower Cretaceous sediments (the aquifer ) are shown by the limestone Pattern since most are carbonates. They are overlain by Upper Cretaceous clay and chalk. The northern-most outcrops are associated with the Balcones Fault zone near San Antonio. The shallow part of the section is underlain by Paleozoic basement , or by Triassic rocks further south. Jurassic salt is shown by solid hatchures. Darkened areas at A, B and C depict the three producing zones, the Stuart City Reef Trend (the carbonate platform margin), the Karnes Trough and the Atascosa Trough, respectively. Note the faulting associated with them. The temperature axis is speculative below 5 km.

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