Ordovician Early/Lower

Total Carbohydrates. The results of the phenol-sulfuric acid tests for total carbohydrates are listed in Table 1. The Lower and Middle Ordovician dolomites and limestones of this area did not yield detectable total carbohydrates, either because they are absent or because of metamorphic degradation. Palacas (5) and Palacas, Swain, and Smith (6), on the other hand, found traces of glucose and other sugars in Lower and Middle Ordovician rocks of Franklin County, Pa. southeast of the Mt. Union area. It appears that the early and medial Ordovician seas of the Mt. Union area may neither have been receiving much carbohydrate material from the lands nor was much being contributed by organisms to the bottom sediments. 

Kupecz, J.A. Land, L.S. (1994) Progressive recrystallization and stabilization of early-stage dolomite Lower Ordovician Ellenburger Group, west Texas. In Dolomites (Eds Purser, B., Tucker, M Zenger, D.), Spec. Publ. int. Ass. Sediment. 21, 255-279. Blackwell Scientific Publications, Oxford. 

Montanez, I.P. Read, J.F. (1992) Fluid-rock interaction history during stabilization of early dolomites. Upper Knox Group (Lower Ordovician), US Appalachians. J. sediment. Petrol., 62, 753-778. 

Amthor, J.E. Friedman, G.E. (1992) Early- to late-diagenetic dolomitization of platform carbonates lower Ordovician Ellenburger Group, Permian Basin, West Texas. 7. sediment. Petrol., 62, 131-144. 

Mesozoic (Triassic) Province. In the region north of the Ain Sefra-Zouia el-Kahla (Fig. 5.4), the hydrocarbon was generated mainly during the Mesozoic. In the case of Silurian source rocks, represented mainly by radioactive shales, thickness lines were drawn with reference to the Ordovician roof. For the Devonian source rocks, the thickness lines were drawn with reference to the Early Devonian roof (Siegenian). The Lower Devonian roof appears to be the only reliable datum mark for intra-Devonian correlations. 

The sequence of tectonic events in the Akfadou area is derived from an analysis of the tectonic subsidence of the basement surface. The sequence basically repeats the sequence determined for the Takhoukht area stretching through the Ordovician-Devonian, thermal activation during the Permian, and basement stretching in the Early Cretaceous, with thermal activation of the lithosphere from the beginning of the Cretaceous until the present. A high maturation level of organic matter is observed in the lower horizons of the sedimentary section = 1.00-1.19% at depths of 3.0 3.9 km. 

The Order Paterinida is known from the Early Cambrian to the late Ordovician with 11 genera, and is restricted mainly to the Lower-Middle Cambrian (Williams et al., 1998 Williams et al., 2000). Middle Ordovician paterinids are referred to the genus Dictyonites Cooper with a few species from carbonates in Sweden, Ireland,... 

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