During the rainy season, engorged streams flowing from higher elevations to the west—perhaps even the incipient Amazon—would have carried the brown sands with them; moreover, the minerals typical of the Andean highlands appeared only in the sandstone laye
During the rainy season, engorged streams flowing from higher elevations to the west—perhaps even the incipient Amazon—would have carried the brown sands with them; moreover, the minerals typical of the Andean highlands appeared only in the sandstone laye
雨季时，暴涨的河水从高海拔处往西边流（或许包括了早期的亚马逊河），其中夹带了棕色的沙粒；此外，安地斯高地典型的矿物，也只出现在沙岩层中。