. Bulletins of American paleontology. Dominican Republic Neocene. 8: E. H. Yokes 21 tion. To distinguish these beds F am herein referring them to an "unnamed formation", to signify the am- biguity present. To the north of the Angostura reef (downstream) at river level, the beds of the typical deep-water Gurabo Formation begin and continue all the way to Santiago. In the vicinity of La Barranca and along Arroyo Ba- bosico, which enters the Rio Yaque del Norte from the west about 8 km upstream from Santiago (Iocs. TU 1403, 1404, 1405), there are a series of shallow-water gravity flows
. Bulletins of American paleontology. Dominican Republic Neocene. 8: E. H. Yokes 21 tion. To distinguish these beds F am herein referring them to an "unnamed formation", to signify the am- biguity present. To the north of the Angostura reef (downstream) at river level, the beds of the typical deep-water Gurabo Formation begin and continue all the way to Santiago. In the vicinity of La Barranca and along Arroyo Ba- bosico, which enters the Rio Yaque del Norte from the west about 8 km upstream from Santiago (Iocs. TU 1403, 1404, 1405), there are a series of shallow-water gravity flows that once again bring shallow-water fos- sils into the very deep facies of the Gurabo Formation. One of these is particularly well-exposed on the road that goes down to the river at La Barranca (Text-fig. 17). Here(loc. TU 1449) again we see a typical Cercado fauna, with Stigmaulax sulcatiis (Born, 1778), Aphera islacolonis (Maury, 1917). several species of Olividae and other shallow-water species, in beds that on the basis of planktic foraminifers must have been depos- ited in at least 200 m of water. The muricid fauna of the Dominican Republic Neo- gene is amazingly rich. There is a representative of almost every subgeneric group present in the western Atlantic, plus some that were not previously known to occur (see Table 2). PALEOECOLOGY A total of 61 species of Muricidae (divided into 34 subgenera) have been identified from the beds of the Yaque Group. Of these the largest number, 42, arc from the Gurabo Formation; only 20 come from the more shallow Cercado Formation and of these only six do not also occur in the Gurabo (five being shallow- water thaidincs), which confirms our field observation that the Gurabo and the Cercado are only lateral facies of each other. The deep-water Mao Formation is nor- mally devoid of muricids, but in a shallow-water grav- ity flow along the lower reaches of the Rio Gurabo, there are eight muricid species, all but two of which also occur in t
Size: 1663px × 1503px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorpaleontologicalresearchinstitutionit, bookcentury1900
