Page 345 - Carbonate Facies in Geologic History

332 The Rise of Rudists ; Middle Cretaceous Facies in Mexico and the Middle East

Gulf of Mexico

.Tontoyuca
To me I.unch,al.

o

B EI Abro foci ..
§ Tomabra Foci ••

D .,.uio Foci ...
D Tamaulipal foci.,

Fig.XI-7. Oil fields and facies of Middle Cretaceous Golden Lane and Poza Rica trends on
Gulf coast of Mexico. Dotted pattern includes breccia and conglomerates of Cretaceous age
along Poza Rica trend and of Eocene age above the EI Abra on the Golden Lane bank. The
Golden Lane lies in the subsurface. The eastern margin of the outcropping Valles Platform is
shown at the Cuesta de EI Abra in the northwest corner of the map. Dashed lines indicate
major facies boundaries. After Lopez-Ramos (1955) and Coogan et al. (1972, Fig. 2)

2. The bank was formed offshore and isolated in the Tampico embayment of
the Early Cretaceous Gulf of Mexico. Its most interior facies along the present
Mexican shoreline includes several anhydrite beds. It is separated from the Valles
platform in the miogeosyncline to the west by a trough only about 60 km wide
(Chicontepec or southern Magiscatzin basin).
3. The Golden Lane bank developed on an igneous basement of sialic rock
which is a southern continuation of the Tamaulipas structural arch and probably