Controls on intermontane basin filling, isolation and incision on the margin of the Puna Plateau, NW Argentina (~23°S)

Abstract

Intermontane basins are illuminating stratigraphic archives of uplift, denudation and environmental conditions within the heart of actively growing mountain ranges. Commonly, however, it is difficult to determine from the sedimentary record of an individual basin whether basin formation, aggradation and dissection were controlled primarily by climatic, tectonic or lithological changes and whether these drivers were local or regional in nature. By comparing the onset of deposition, sediment-accumulation rates, incision, deformation, changes in fluvial connectivity and sediment provenance in two interrelated intermontane basins, we can identify diverse controls on basin evolution. Here, we focus on the Casa Grande basin and the adjacent Humahuaca basin along the eastern margin of the Puna Plateau in northwest Argentina. Underpinning this analysis is the robust temporal framework provided by U-Pb geochronology of multiple volcanic ashes and our new magnetostratigraphical record in the Humahuaca basin. Between 3.8 and 0.8 Ma,~120 m of fluvial and lacustrine sediments accumulated in the Casa Grande basin as the rate of uplift of the Sierra Alta, the bounding range to its east, outpaced fluvial incision by the R ıo Yacoraite, which presently flows eastward across the range into the Humahuaca basin. Detrital zircon provenance analysis indicates a progressive loss of fluvial connectivity from the Casa Grande basin to the downstream Humahuaca basin between 3 and 2.1 Ma, resulting in the isolation of the Casa Grande basin from 2.1 Ma to <1.7 Ma. This episode of basin isolation is attributed to aridification due to the uplift of the ranges to the east. Enhanced aridity decreased sediment supply to the Casa Grande basin to the point that aggradation could no longer keep pace with the rate of the surface uplift at the outlet of the basin. Synchronous events in the Casa Grande and Humahuaca basins suggest that both the initial onset of deposition above unconformities at~3.8 Ma and the re-establishment of fluvial connectivity at~0.8 Ma were controlled by climatic and/or tectonic changes affecting both basins. Reintegration of the fluvial network allowed subsequent incision in the Humahuaca basin to propagate upstream into the Casa Grande basin.

Tectonic Regimes of the Central and Southern Andes: Responses to Variations in Plate Coupling During Subduction

“…Neogene evolution of retroarc regions involved continued eastward advance of deformation and foreland basin evolution, with large‐scale shortening accommodated in the frontal thrust belt (Subandean/Santa Bárbara zone) and minor shortening across most of the orogenic interior (Barnes et al, , ; Echavarria et al, ; Ege et al, ; Gubbels et al, ; Kley & Monaldi, ; Lamb, ; Lamb & Hoke, ; Lease et al, ; McQuarrie et al, ; Uba et al, ). Basin evolution was concentrated in foreland regions east of the thrust front, with topographically isolated basins in intermontane settings and the hinterland plateau (Capaldi et al, ; Carrapa et al, ; Coutand et al, ; Horton, , , , ; Horton et al, ; Jordan & Alonso, ; Levina et al, ; Mosolf et al, ; Murray et al, ; Sempere et al, ; Siks & Horton, ; Sobel et al, ; Strecker et al, ; Streit et al, ). Stable isotope data and geomorphic surfaces suggest that major surface uplift of the hinterland plateau at 18–22°S was accomplished from middle Miocene to present (Garzione et al, , ; Hoke et al, ; Jordan et al, ), with a possibility of much earlier surface uplift in the Puna plateau at 24–26°S (Canavan et al, ; Quade et al, ).…”

Depositional processes and sedimentation pattern in an intermontane basin: Insights from the Imphal Basin, Indo‐Myanmar Range, NE India

“…Evidently, sedimentation patterns varied considerably in these Himalayan intermontane basins. In fact, the sedimentation patterns in inter- (Streit et al, 2017); the sedimentary fill of the Late Eocene/Oligocene-Late Miocene Kağızman-Tuzluca Basin in the north-eastern Anatolia of Turkey was deposited in a fluvial-dominated, interlinked alluvial-fluvial-deltaic-lacustrine setting (Varol et al, 2015); the Permian sedimentary fill of the Villé Basin in the Vosges mountains of eastern France was deposited largely in a fluvial settings, with an intervening phase of lacustrine and fan-delta settings (Carasco, 1989); the Agri Basin of the southern Apennines in…”

“…However, although the Peshawar Basin was dominated by fluvial and alluvial sedimentation, the Kashmir Basin was dominated by lacustrine and deltaic sedimentation, and the Kathmandu Basin was dominated by lacustrine and alluvial sedimentation (cf. (Streit et al, 2017); the sedimentary fill of the Late Eocene/Oligocene-Late Miocene Kağızman-Tuzluca Basin in the north-eastern Anatolia of Turkey was deposited in a fluvial-dominated, interlinked alluvial-fluvial-deltaic-lacustrine setting (Varol et al, 2015); the Permian sedimentary fill of the Villé Basin in the Vosges mountains of eastern France was deposited largely in a fluvial settings, with an intervening phase of lacustrine and fan-delta settings (Carasco, 1989); the Agri Basin of the southern Apennines in In Pinjore and Dehradun basins, however, the pre-existing drainage networks were not dammed to form lakes albeit the surface gradients were reduced to localize sedimentation in alluvial fans and braided streams (cf.…”

Provenance and tectonic implications of Orán Group foreland basin sediments, Río Iruya canyon, NW Argentina (23° S)

“…4.1 Ma (Pingel et al ., ). This timing is supported by stratigraphy from the Casa Grande Basin just to the west, which records uplift of the Sierra Alta around 4.3 Ma (Streit et al ., ).…”