bre547-sup-0001-FigureS1.jpgimage/jpg1698K Figure S1. (A) The stratigraphic transect at the head of the quebrada Carachi (Section 3 in Fig. 2) shows Barres sandstone and interbedded lavas of Puerta Tastil member (K/Ar age of 12.78 ± 0.19 Ma; Mazzuoli et al., 2008) folded in a NNE-plunging anticline. (B) At the mouth of the quebrada Lagunillas (Section 8 in Fig. 2), contact between the Puncoviscana Formation (PV) and lower Alfarcito conglomerate (LAC) is both stratigraphic (onlapping) (white line) and tectonic (red line) along a NW-striking fault zone. The subvertical fault planes are oblique with respect to the E-W-oriented outcrop front and have N120° E strike and N30° E dip direction. The basement-derived massive conglomerate (Gmm/cm) with interbedded sandstone (Sm/h) of the lower Alfarcito conglomerate shows syntectonic growth structures.
bre547-sup-0002-FigureS2.jpgimage/jpg3633K Figure S2. Overviews of the stratigraphic and tectonic relations between the granodiorite of the Santa Rosa de Tastil batholith (STR), Las Cuevas member (LC) and lower Alfarcito conglomerate (LAC), to the N (A) and SW (B) of Alfarcito village (Section 1 in Fig. 2). Contacts are either stratigraphic overlapping (dashed lines) or faults (solid lines). The San Bernardo fault thrusts the Santa Rosa de Tastil grey granodiorite over the Miocene volcano-sedimentary deposits of the El Toro basin. Synsedimentary faults deform contacts among the Las Cuevas member, lower Alfarcito conglomerate and granodiorite. The unconformity between the Las Cuevas member and the lower Alfarcito conglomerate represents a hiatus of ca. 4 Ma.
bre547-sup-0003-FigureS3.jpgimage/jpg3233K Figure S3. The stratigraphic transect measured at quebrada Carachi (Section 2 in Fig. 2). (A) Detail of the paraconcordant contact between the lower Alfarcito conglomerate (LAC) and Almagro A member (AA; RGcm facies). (B) Unconformable (15°) and erosive contact between the Almagro A member and lower Alfarcito conglomerate. A boulder conglomerate facies (RGcm) is at the edge of the channel-like incision; sub-horizontally stratified sandstone and mudstone facies (Vsh) aggraded into the channel; a boulder conglomerate facies (VGmm/cm) levels the sequence. The red box is Fig. S3C. (C) Detail (arrow) of flame structures on lacustrine laminated mudstones squeezed upward for the load of overlying conglomerate near the base of the Almagro A member. Hammer is 30 cm long. Representative conglomerate facies of the Almagro A member (Section 4; Fig. 3). Hammer is 30 cm long. (D) Close-up view of a clast of fresh, vesiculated lava showing jigsaw fractures (arrows) infilled by fine-sandy matrix (RGcm facies). (E) Clast-supported, polygenetic pebble–cobble conglomerate facies (VGmm/cm facies).
bre547-sup-0004-FigureS4.jpgimage/jpg1904K Figure S4. Representative conglomerate facies of the Almagro B member. (A) Lower layer is a debris-flow deposit comprising matrix-supported conglomerate (VGmm/cm facies) with subvertical degassing pipes (arrows). Upper bed is a clast-supported coarse breccia from syneruptive debris avalanche (RBcm/mm facies) with basal erosive surface. Exposure is 6 m thick (Section 9). (B) Overview of stacked debris-flow beds (VGmm/cm facies; Section 9). Cobble-boulder conglomerate is matrix- to clast-supported, poorly sorted and with non-homogeneous concentration of clasts. Individual conglomerate clasts are angular to subangular, indicating minimal reworking prior to deposition. Rule is 1 m long. (C) A very coarse, clast-supported, polygenetic boulder conglomerate (VGcm) is at the base of the Almagro B member (Section 4; Fig. 3).

Please note: Wiley Blackwell is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.