Geochemical (major oxides, trace and rare earth elements) studies were carried out on the siliciclastic rocks of the Antimonio and Río Asunción formations to interpret the paleoweathering conditions and provenance. The weathering indices like the Chemical Index of Alteration (CIA) and Plagioclase Index of Alterations (PIA) indicate a low to moderate intensity of chemical weathering. The chondrite normalized REE patterns of the Antimonio and Río Asunción formations have LREE enriched, flat HREE patterns with a negative Eu anomaly. However, a few samples from these formations show a positive or an absence of the Eu anomaly, suggesting that the sediments were dominantly derived from felsic source rocks with a minor contribution from mafic source rocks. The vertical distribution of trace elements and their ratios indicate that sequence I of the Antimonio Formation presents a signature for felsic source rocks, however, in sequence II the sediment source changed, i.e. mafic rocks were recorded (SAAF06 and SAAF07). Sequences III to VI indicate a felsic source rock. The basal and upper parts of sequence VII (samples SARAF02 and SARAF10) of the Río Asunción Formation indicate mafic source rocks, whereas the remaining samples were largely contributed by felsic source rocks. The lower values of ferromagnesian trace elements and their ratios in sequences VIII and IX reveal a felsic source for the upper part of the Río Asunción Formation. The Antimonio and Río Asunción formations received sediments from two different sources: Permo-Triassic granitoids of northwestern Sonora and Precambrian granitoids from Caborca and North American blocks that contributed felsic rocks. Whereas mafic elements were derived from Precambrian amphibolites and Cambrian basalts located north and south of the study area.

在Antimonio和RíoAsunción地层的硅质碎屑岩上进行了地球化学（主要氧化物，痕量和稀土元素）研究，以解释古气候条件和物源。诸如化学变化指数（CIA）和斜长石蜡蚀变指数（PIA）之类的耐候指数表明化学耐候强度低至中等。Antimonio和RíoAsunción地层的球粒晶归一化REE模式具有丰富的LREE富集的扁平HREE模式，负Eu异常。然而，这些地层的一些样品显示出正异常或不存在Eu异常，这表明沉积物主要来自长英质烃源岩，而镁铁质烃源岩贡献较小。微量元素的垂直分布及其比例表明，Antimonio层序I代表了长英质烃源岩的特征，但是在序列II中，沉积物源发生了变化，即记录了镁铁质岩（SAAF06和SAAF07）。层序III至VI表示长英质烃源岩。RíoAsunción组的VII序列的基部和上部（样品SARAF02和SARAF10）表示镁铁质烃源岩，而其余样品则主要由长英质烃源岩贡献。序列VIII和IX中较低的铁磁痕量元素及其比率值揭示了RíoAsunción组上部的长英质来源。Antimonio和RíoAsunción地层从两个不同来源接收沉积物：西北索诺拉（Sonora）的二叠系-三叠纪花岗岩和来自卡波卡和北美地块的前寒武纪花岗岩，构成了长英质岩石。而镁铁质元素来自研究区南北的前寒武纪闪石和寒武纪玄武岩。