2006
The following is an update of:
James, K. H., 2006, Arguments for and against the Pacific origin of the Caribbean Plate: discussion, finding for an inter-American origin: In: Iturralde-Vinent, M. A. and E. G. Lidiak (Eds.), Caribbean Plate Tectonics, Geologica Acta, v. 4, no. 1-2, p. 279-302.
In response to:
Pindell, J., L. Kennan, K-P Stanek, W. V. Maresch and G. Draper, 2006, Foundations of Gulf of Mexico and Caribbean evolution: eight controveries resolved: In: Iturralde-Vinent, M. A. and E. G. Lidiak (Eds.), Caribbean Plate Tectonics, Geologica Acta, v. 4, no. 1-2, p. 303-341.
Pindell et al. (2006) present further arguments in support of a Pacific origin ot the Caribbean Plate. Some of these are considered below.
This paper states "other models are highly fixist (James, 2004)" and "are unrealistic and fraught with violations of basic geology and/or plate kinematic history". None of these "violations" is qualified by discussion or data. The paper maintains that Pindell's (1990, 1993) original arguments still stand firm. There is no acknowledgement that these arguments have been challenged and there is no attempt to answer the challenges.
Rotation of Yucatán:
The paper questions the value of rift structures shown on the Exxon (1985) world tectonic map. The paper identifies an alternative (hidden) trend on Yucatán from gravity and magnetic data (interpreted by Tectonic Analysis).
Parallel Jurassic rift structures on both Maya (Yucatán) and Chortis are shown on both Exxon (1985) and IFP (Mascle et al., 1990) geological maps of the Caribbean and they are very apparent on satellite topographic maps. The Yucatán trend continues offshore, via the Holbox F., to the northeast, connecting with Florida via the Catoche Tongue (expression of a Jurassic graben, Marton & Buffler, 1999) and gravity and magnetic trends in the Florida Straits (Shaub. 1983; Gough, 1967). There is no such offshore continuation of the trend supported by this paper and no such structure is apparent on satellite maps. The Sierrita de Ticul, in northwestern Yucatán, is controlled by the N60°W Ticul Fault. This parallels the trends of fracture zones in the western Atlantic (Cuba northwards), Triassic-early Jurassic grabens in southern Maya, Mexico and Central America (Blair, 1988; Richards, 1963; Burkart & Clemons, 1972; Sedlock et al., 1993). Two trends show that Yucatán has not rotated.
Tuffs are stated to be absent from autochthonous Cretaceous sections of northern South America. Tuffs are present in the autochthonous La Luna Fm. of Venezuela. To the north lie equivalent graphitic schists of Las Mercedes Fm. This shows northward increasing silica content and carries lenses of volcanic ash in northernmost outcrops (Wehrmann, 1972). Some units are only lightly metamorphosed and contain concretions identical to those in the Cenomanian – Turonian La Luna and Querecual Fms. (Wehrmann, 1972). Yet further north the Las Mercedes interdigitates with the metamorphic Tacagua Fm., originally tuff or volcanic ash (Dengo 1953; Feo Codecido 1962). Tuffs occur in the Barremian Toco Fm of Trinidad. The overlying Albian Sans Souci Volcanic Fm. is a series of volcanic tuffs, tuff breccias, agglomerates and andesitic lavas that engulfing clay and blocks of limestone (Kugler 1953). Tholeites of the Sans Souci were errupted onto the passive margin of S. America during the Aptian-Santonian, along with limestones, black shales, quartz sandstones and conglomerates of continental provenance (Wadge & MacDonald, 1985). Albian tuff occurs on Tobago (Sharp, 1988) where continental input is noted by Frost and Snoke (1989). The upper Albian Cretaceous Mejillones Group offshore northeastern Venezuela contains arc volcanic rocks (Castro & Mederos 1985).
The paper states that the Caribbean had western (Costa Rica) and eastern (Great Caribbean Arc) plate boundaries since the Albian. Earlier Pindell (2001) wrote: " Models deriving Caribbean lithosphere from the Pacific (Pacific origin) adhere to regional Caribbean geology far better than do models deriving the Caribbean Plate from between the Americas (Intra-American origin)." A primary line of evidence for this is that "the Greater Antilles Arc (Great Arc) is older than the Central American Arc (Santonian, Pindell, 1993), which is predicted by Pacific but not by Intra-American models." The paper gives no explanation for this change in ages of the arcs and does not comment on the demise of a "primary line of evidence."
The paper invokes subduction of the proto-Caribbean along northern South America in order to explain Palaeogene flysch that predates the arrival of the Caribbean Plate. "The occurrence of flysch has been taken by some (no references, but see James, 2005, 2006) to indicate an in-situ origin for the Caribbean Plate." Palaeogene flysch and extremely large allochthons formed around the Caribbean region and in Mexico, Colombia, Ecuador and Peru, not just along northern South America (James, 2005). They record a regional middle Eocene event, recognized long ago (e.g., Hess, 1938) that Pacific models overlook and cannot explain.
The paper concludes:
"The literature is simply too mature for the proposal of ad-hoc regional or sub-regional models based on small, limited or local data sets to mean anything significant. Concerning publications, the peer-review process needs to be tightened up: several recent attempts to build "new" Caribbean models violate so much basic geology, ignore so much geophysical and geochemical data, and/or show a lack of understanding of tectonic synthesis, that they cannot be taken seriously." This proclamation includes no references and neither describes nor disproves the "violated" geology or "ignored" geophysical or geochemical data.
References:
Blair, T. C., 1988, Mixed siliciclastic-carbonate marine and continental syn-rift sedimentation, Upper Jurassic-lowermost Cretaceous Todos Santos and San Ricardo Formations, western Chiapas, Mexico: J. Sedimentary Petrology, 58, 623-636.
Burkart, B., R. E. Clemons, 1972, Late Paleozoic orogeny in northwestern Guatemala: VI Caribbean Geological Conference, Margarita, Venezuela, 210-213.
Castro, M., and A. Mederos, 1985, Litoestratigrafia de la Cuenca de Carúpano: VI Congreso Geologico Venezolano, Caracas, Memoria, Tomo I, P. 201-225.
Dengo, G. 1953, Geology of the Caracas region, Venezuela: GSA Bulletin, v. 64, p. 7-40.
Exxon: Exxon Tectonic Map of the World. World Mapping Project. Exxon Production
Research Company, Houston, Texas, 1985.
Feo-Codecido, G., 1962, Contribution to the geology of north-central Venezuela: Boletin Informativo, Asociacion Venezolana de Geologia, Mineria y Petroleo, v. 5, no. 5, p. 119 - 142.
Frost, C. D. and A. W. Snoke, 1989, Tobago, West Indies, a fragment of a Mesozoic oceanic island arc: petrochemical evidence: J. Geol. Soc. London, v. 146, p. 953-964.
Gough, D. I., 1967, Magnetic anomalies and crustal structure in eastern Gulf of Mexico: AAPG Bull., v. 51, no. 2, p. 200-211.
Hess, H. H., 1938, Gravity anomalies and island arc structure with particular reference to the West Indies: American Philosophical Society Proceedings, v. 79 (1), p. 71-96.
James, K. H., 2005, Palaeocene to middle Eocene flysch-wildflysch deposits of the Caribbean area: a chronological compilation of literature reports, implications for tectonic history and recommendations for further investigation: Transactions, 16th Caribbean Geological Conference, Barbados, Caribbean J. of Earth Sciences, v. 39, p. 29 - 46.
Kugler, H. G., 1953, Jurassic to Recent sedimentary environments in Trinidad Bull. Ass. Suisse des Geol. et Ing. du Petrole, v. 20, no. 59, p. 27-60
Mascle, A., Letouzey, B. Biju-Duval, Becue and T. Rossi, 1990, Geological Map of the Caribbean, Institut Français de Pétrole, 9250 Reuil-Malmaison, France.
Pindell, J. L., 1993, Regional synopsis of the Gulf of Mexico and Caribbean evolution: GCSSEOM Foundation 13th Annual Research Conference, p. 251-274.
Pindell, J. L., 2001, The Pacific Origin of the Caribbean Plate, with emphasis on Cuba: Leicester meeting, 2001, web report.
Pindell, J., G. Draper, L. Kennan, W. V. Maresch and K. P. Stanek, 2002, Evolution of the northern portion of the Caribbean Plate, Pacific origin to the Bahamian collision: 16th Caribbean Geological Conference, Barbados, Abstracts, p. 98.
Richards, H. G., 1963, Stratigraphy of earliest Mesozoic sediments in southeastern Mexico and western Guatemala: Bulletin, American Association of Petroleum Geologists, 47, 1861-1870.
Sharp. W.D., 1988 Tobago, West Indies, geochronological study of a fragment of a composite mesozoic oceanic island arc Ann. GSA Centennial Celebration Mtg. Abstracts, No.11964.
Shaub, F.J., 1983, Origin of the Catoche Tongue: in A.W. Bally (eds.), Seismic Expression of Structural Styles- A Picture and Work Atlas, American Association of Petroleum Geologis Studies in Geology, 15: 2.2.3-129.
Wadge, G. and Macdonald, R., 1985 Cretaceous tholeites of the northern continental margin of South America: the Sans Souci Formation of Trinidad J. Geol. Soc. London, v. 142, p. 297-308
Wehrmann, M., 1972, Geologia de la region de Guatire-Colonia Tovar:
IV Congreso Geologico Venezolano, Caracas, Memoria, Bol. Geol., Pub. Esp. 5, p. 2093-2219.
Arguments update
martes 19 de diciembre de 2006
