Paleoelevation estimates for the northern and central proto–Basin and Range from carbonate clumped isotope thermometry

Abstract

[1] Quantitative paleoelevation histories can help explain both why and how widespread Cenozoic extension occurred in the Basin and Range Province of western North America. We present new estimates of preextensional paleoelevations for the northern and central Basin and Range using clumped isotope (Δ 47 ) thermometry of lacustrine carbonates collected from each region. Comparison of carbonate Δ 47 -derived mean annual air temperature (MAAT) estimates (~16 C-20 C) for the Late Cretaceous-Eocene Sheep Pass basin of east central Nevada with published MAAT estimates for the Eocene, coastal northern Sierra Nevada (~20 C-25 C), suggests that the early Paleogene Sheep Pass basin had a paleoelevation of ≤2 km. Such a modest paleoelevation suggests that either (1) the proto-northern Basin and Range did not attain maximum paleoelevations of 3-4 km until the late Eocene-early Oligocene; or (2) the Sheep Pass basin was a local, high-relief (>1 km) setting contained within a >3 km orogenic highland ("Nevadaplano"). Similarity of Δ 47 -derived MAAT estimates (~17 C-24 C) for carbonates from the central Basin and Range and the near-sea level southern Sierra Nevada Bena basin indicate that middle Miocene paleoelevations in the Death Valley region were ≤1.5 km. These fairly low paleoelevations are incompatible with preextensional crustal thicknesses >52 km and indicate that mean elevation change was minor (≤500 m) and lithospheric mass was not conserved during >100% Neogene extension of the central Basin and Range, but was instead likely compensated by synextensional magmatic additions to the crust.

Carbonate clumped isotope paleothermometry: a review of recent advances in CO2 gas evolution, purification, measurement and standardization techniques

“…The rate of outgassing is commonly enhanced by back-flushing helium through the divinyl benzene polymer trap. Lechler et al (2013) report similar Δ 47 external precision between CO 2 gases prepared utilizing a packed GC column or packed U-trap. However, this comparison is limited to one laboratory's purification system.…”

The Confusion Range, west-central Utah: Fold-thrust deformation and a western Utah thrust belt in the Sevier hinterland

“…Paleogene conglomerates, lacustrine limestones, and interbedded volcanics were deposited in local basins and paleochannels, possibly related to early extensional collapse within the plateau (Vandervoort and Schmitt, 1990;Constenius, 1996;Greene and Herring, 1998;Hintze and Davis, 2003;Druschke et al, 2011;Lechler et al, 2013). Widespread pyroclastic volcanism, the "ignimbrite fl areup" (Coney, 1978;Best et al, 2009Best et al, , 2013, began in the late Eocene and continued through the early Miocene.…”

High late Miocene–Pliocene elevation of the Zhada Basin, southwestern Tibetan Plateau, from carbonate clumped isotope thermometry

“…Clumped isotope thermometry is based on the temperature-dependent preference of 13 C and 18 O to form bonds with each other in the carbonate mineral lattice alone (measured using the parameter Δ 47 ), which constrains temperature without the need to assume the isotopic composition of the water from which the carbonate grew (Ghosh et al, 2006a;Eiler, 2007Eiler, , 2011. Previous clumped isotope studies show that the method can be useful for paleoaltimetry (e.g., Ghosh et al, 2006b;Quade et al, 2007;Huntington et al, 2010;Leier et al, 2013;Lechler et al, 2013;Garzione et al, 2014), provided that the samples are well preserved and not reset by diagenesis, and that the paleotemperature calibrations based on modern samples are secure (e.g., Huntington et al, 2010). In this paper we both examine diagenetic resetting and report new data for modern samples to help interpret ancient sample data-from our own study and from four ca.…”

“…In this regard, stable isotopic evidence has assumed a key role in the reconstruction of paleoelevation not just in Tibet (e.g., Rowley et al, 2001;Rowley and Currie, 2006;Quade et al, 2011) but also in other orogens such as the Andes, Sierra Nevada, early Cenozoic Rockies , and Colorado Plateau (e.g., Garzione et al, 2008Garzione et al, , 2014Mulch et al, 2008;Cassel et al, 2009;Huntington et al, 2010;Lechler et al, 2013;Leier et al, 2013;Carrapa et al, 2014). This technique takes advantage of the sensitive relationship between the stable oxygen (δ 18 O mw ) and deuterium (δD mw ) composition of average meteoric water and elevation.…”