VALENCIA, Limestone

CRETACEOUS ( ? )

State of Carabobo, Venezuela

Author of name: R. A. Liddle, 1928.

Original reference: R. A. Liddle, 1928, correlation table.

Original description: R. A. Liddle, 1928, p. 72.

The "Ordovician or Silurian, Valencia limestone" which appears in the correlation table by Liddle, 1928, and is referred to in several places in the text (fig. 3, facing p. 54, where it is called "Valencia beds"; p. 69, 72, 75, 76, and fig. 5, p. 77, though in these contexts no formal formational name is used) is based on a misconception. Presumably every Venezuelan geologist is familiar with the history of this comedy of errors, which has recently been fully resumed by Dusenbury and Wolcott (1949, p. 19-20) and was mentioned by Schuchert (1935, p. 690) and Liddle (1946, p. 74). For the benefit of outsiders, the facts may again be summed up, as follows:

In 1904, F. Drevermann published a short note on the occurrence of "Lower Silurian" in Venezuela, identifying and illustrating two species (Calymene senaria Conrad and Orthoceras cf. olorus Hall) said to have been collected by Wilhelm Klein, a marine machinist, from a marmolized limestone near Valencia. ("Lower Silurian", in European usage, of course is the same as the Ordovician of English and American geologists: in addition, the fossils cited, which in modern nomenclature would be called Flexycalymene senaria (Conrad) and Spyroceras olorum (Hall) are characteristic of the Trenton stage of the American Ordovician). However, in 1905, Schuchert wrote a short review of Drevermann's paper, in which he pointed out that the illustrations did not agree with the species named, but looked remarkably like species from the Niagaran (Middle Silurian s.s.) from Wiseonsin; he therefore, doubted the provenance of the fossils. Klein, asked for further information about the fossils, said that they might have eome from Newport News, Virginia.

Liddle (1928, p. 69, 72) however, unaware of the questions raised about the fossils, quoted Drevermann's paper, as mentioned above, and utilized these supposed Paleozoic fossils to support his correlation of at least part of the schists of the Coast Range as Paleozole. Gerth (1932, p. 87) mentions Drevermann's findings as "not confirmed".

In 1928, after the appearance of Liddle's book, Schuchert returned to the question of the "so-called 'Lower Silurian' fossils", and was able to examine the fossils themselves, which were lent him by Prof. Salomon of Heidelberg University. Schuchert, thus, was able to verify that the matrix of the fossils did not in the least resemble the black marmolized limestone which outcrops in the vicinity of Valencia, but is a white fine-grained dolomite identical with Niagaran dolomite in Joliet, Illinois (Schuchert 1928). Schuchert in 1935 (p. 690) reviews the circumstances, and therefore, includes the "Valencia Schists" in the Caribbean group (believed Cretaceous). Kehrer (1937, p. 66) mentions blue-gray marmolized quartzitie limestones and limy shales which occur in the hills east of Valencia (with reference to Drevermann and Schuchert, 1935) and notes a strong resemblance to metamorphosed Cretaceous of eastern Lara and Yaracuy. Liddle (1946, p. 74-75) corrects his 1928 assignment of the Valencia limestones, but persists in assigning most of the Coast Range schists to "Paleozoic and pre-Paleozoic."

V. M. López (1942) notes the occurrence of limestones as lenses or beds in the metamorphic rocks near Valencia (not described under any formational names). The metamorphics outcrop in two southward-trending spurs which enclose the valley of Valencia. López describes them as predominantly micaceous schists or predominantly calcareous schists, no sharp division being possible; lenses and beds of limestone occur in both areas. They are especially developed in the eastern spur, which terminates at the south in a conspicuous limestone "morro" just north of the highway from Caracas; other important lenses are found at the plant of the Cia. de Cemento Carabobo (NE of Valencia) and in the Portachuelo of Montecerino, farther north. The limestone beds and lenses are described as somewhat dolomitic, those in the Morro de Valencia as extremely so. (López, 1942).

R. J. Smith (1952 p. 357, 362) suggests that part of the limestone near Valencia corresponds to the Antimano limestone, part (with the calcareous schists) to the Las Mercedes formation of the Caracas group.

The term Valencia limestone might have a limited usefulness, in the event of a detailed study of the geology of the region.

Frances de Rivero