The NNE-directed tectonic escape of the North Andean block (NAB) or sliver (NAS) with respect to South America (SA) is generally accepted now. NAS is detached from continental South America (SA) by a 2000-km-long, NE-SW-trending dominant dextral fault system, known as the Eastern Frontal Front System (EFFS; Pennington's name and acronym kept for simplicity) that extends from the gulf of Guayaquil-Tumbes basin (GGTB) in offshore Ecuador to the Caribbean coasts of Venezuela in the Golfo Triste region. From SW to NE, EFFS comprises the following fault systems: In Ecuador, Puná-Pallatanga-Cosangá-Chingual (CCPP); In Colombia, Afiladores, Sibundoy, Algeciras and Guaicáramo; and in Venezuela, Boconó (BF).

Several estimates of total dextral slip have been calculated along the EFFS. In Ecuador, the Pallatanga fault (part of the CCPP) displaces several large geologic and morphologic units in about 10 km. The net slip of EFFS at this western front of the Western cordillera can be as much as the double (≈20 km) if strain happens to be distributed between sub-parallel faults. Further south, at the very southern tip of the EFFS, from seismic data acquired from the GGTB, an estimate of 13.5–20 km of lengthening of this basin from the Plio-Quaternary boundary has been proposed.

In Colombia, the Algeciras lazy Z-shaped pull-apart basin (Huila Dpt.) provides another estimate. The extent of the Quaternary basin fill measured along the regional fault trend on SGC geologic plate 345, is about 10 km. This is a minimum estimate because the fault shortcuts the basin in more recent times, increasing such slip in at least about 1–2 km. In Venezuela, although more reliable and frequent dextral offsets are of the order of 30 km, a larger 70–80 km offset in Mesozoic rocks was once proposed across BF. A supportive argument to the 30 km net slip along the Mérida Andes axis may be derived from a present mismatch of Bouguer anomaly minima between both adjacent flexural basins of no more than 40 km.

From all the estimates of total slip here compiled along EFFS, we can conclude that the NE tectonic escape of NAS is most likely not larger than 30–35 km. This net slip may vary along EFFS strike, being smaller (close to 20 km) in the south. Therefore, despite the large size of NAS, its escape remains modest at plate scale. Remarkably, EFFS net slip is in the same order of magnitude as the ≈20 km for the Sumatra fault, which is as long as the EFFS (≈1900 km long).

目前，北安第斯山脉（NAB）或银条（NAS）相对于南美洲（SA）的NNE定向构造逃逸已被普遍接受。NAS通过2000公里长，NE-SW趋势的主导性右旋断层系统与南美洲大陆（SA）分离，该系统被称为“东部额锋系统”（EFFS；为简化起见，使用Pennington的名称和首字母缩写词），该系统从厄瓜多尔近岸的瓜亚基尔-图姆贝斯盆地（GGTB）到戈尔福·特里斯特地区的委内瑞拉加勒比海地区的海湾。从西南到东北，EFFS包括以下故障系统：在厄瓜多尔，Puná-Pallatanga-Cosangá-Chingual（CCPP）；在哥伦比亚，Afiladores，Sibundoy，Algeciras和Guaicáramo；委内瑞拉博科诺​​（BF）。

沿EFFS已经计算了总的右旋滑度的一些估计。在厄瓜多尔，帕拉坦加断层（CCPP的一部分）在约10公里处驱替了几个大型地质和形态单元。如果应变恰好分布在次平行断层之间，则EFFS在西部山脉西部前沿的净滑移可高达两倍（≈20km）。在更远的南部，在EFFS的最南端，根据从GGTB采集的地震数据，已经提出了从Plio-第四纪边界延长该盆地13.5-20 km的估计。

在哥伦比亚，阿尔赫西拉斯（Algeciras）懒惰的Z形拉分盆地（Huila Dpt。）提供了另一个估计值。沿着SGC地质板块345上的区域断层趋势测得的第四纪盆地充填程度约为10 km。这是一个最小的估计值，因为断层在最近的时间里使盆地变得直通，至少在大约1-2 km内增加了这种滑移。在委内瑞拉，尽管更可靠，更频繁的右旋偏移量约为30 km，但曾经有人建议在整个高炉中生代岩石中偏移量较大，为70–80 km。沿梅里达安第斯山脉轴向滑动30 km的支持性观点可能来自两个相邻弯曲盆地之间不超过40 km的布格异常极小值的当前不匹配。

从沿EFFS汇总的总滑坡估算值中，我们可以得出结论，NAS的NE构造逃逸最有可能不超过30-35 km。该净滑移量可能随EFFS罢工而变化，在南部较小（接近20 km）。因此，尽管NAS的尺寸很大，但其逃逸程度在板级范围内仍然很小。值得注意的是，EFFS的净滑移与苏门答腊断层的≈20km的数量级相同，后者与EFFS一样长（≈1900km）。