Structure of the Merida Andes, Venezuela: relations with the South America-Caribbean geodynamic interaction

被引:135
作者
Audemard, FE
Audemard, FA
机构
[1] FUNVISIS, Venezuelan Fdn Seismol Res, Dept Earth Sci, Caracas 1070A, Venezuela
[2] PDVSA Explorac & Prod, Caracas, Venezuela
关键词
triangular zones; strain partitioning; type-A subduction; crustal models; Merida Andes; Venezuela;
D O I
10.1016/S0040-1951(01)00218-9
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
For over 50 years, several models based on diverse geologic concepts and variable quality of data have been proposed to explain the major structure and history of the Werida Andes (MA), in western Venezuela. Lately, this chain growth and associated flexural basins deepening have been related to incipient type-A subductions of either polarity, accounting for the across-chain asymmetry. However, these recent models have not well integrated the present tectonically active setting driven by neighboring major plate interactions. At present, this chain exhibits ongoing strain partitioning where cumulative right-lateral slip along chain axis is as much as half of, or about the same, as the transverse shortening since late Miocene, thus implying that the NNE-directed Maracaibo block extrusion with respect to the South America (SA) plate is not a secondary feature. Consequently, this paper discusses some limitations exhibited by the SE-directed continental subduction models -Maracaibo crust underthrusting the Merida Andes-in the light of available geological and geophysical data. Besides, it is herein proposed that the Merida Andes structuration is related to a NW-directed, gently dipping, incipient type-A subduction, where chain growth and evolution are similar to those of a sedimentary accretionary wedge (i.e., Barbados), but at crustal scale and with ongoing strain partitioning. This continental subduction is the SE portion of a major orogenic float that also comprises the Perija range and the Santa Marta block. (C) 2002 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:299 / 327
页数:29
相关论文
共 103 条
  • [1] Aggarwal Y., 1983, P S NEOT SIS RIESG G, P26
  • [2] ARGAND E, 1924, C GEOL INT LIEG, P169
  • [3] Audemard F., 1999, Zeitschrift fur Geomorphologie, V118, P1
  • [4] Audemard F.A, 1993, THESIS U MONTPELLIER
  • [5] AUDEMARD FA, 1997, 8 C GEOL VEN PORL VE, V1, P101
  • [6] AUDEMARD FA, 1998, T 3 GEOL C GEOL SOC, V2, P327
  • [7] AUDEMARD FA, 1999, UNPUB SISMICIDAD NEO
  • [8] AUDEMARD FA, 2000, 31 INT GEOL C RIO JA
  • [9] AUDEMARD FA, 1997, TECTONOPHYSICS, V308, P1
  • [10] AUDEMARD FE, 1987, 8 C GEOL VEN PORL, V1, P85