This site will hopefully give visitors an idea of who we are, type of scientific problems we address, and how we go about solving them. Enjoy!
News Feed
New Pub: Along strike tectonic evolution of the Neogene Bermejo foreland basin and eastern Precordillera thrust front, Argentina (30-32ºs)
July 2023
Graduate student Zoey Plonka published her thesis work in a special volume in the Journal of South American Earth Sciences. Integrating new measured stratigraphic sections with detrital geo-/thermochronology she showed the time-transgressive along-strike evolution of the Andean foreland initiation and subsequent capture into the Andean orogenic wedge.
The summary figure in all of its glory
UNLV Field Camp
May 2023
After 10 years I returned to Poleta folds to run my first field camp with UNLV. We first spent 1 week out in the Colorado River Extensional Corridor in Nevada mapping igneous and metamorphic rocks of the Dupont detachments. Then headed over to California to enjoy the late spring weather for two weeks mapping the deformed Cambrian strata that makes the Poleta Folds so amazing.
Mapping the Poleta Folds with UNLV undergrads and grad students with a beautiful overlook of Deep Springs Valley
A&M students admiring my favorite Formation the Aztec Sandstone
Aggies in Vegas
January 2023
Friend, colleague, scholar Nick Perez from Texas A&M brought his field geology course out to Boulder City, NV. I helped co-lead them through some of my favorite spots at the Great Unconformity, Sevier thrust belt, and Colorado River Extensional Corridor to create some of their first geologic maps.
Congrats Plonka
December 2022
Zoey finished her masters thesis and graduated this winter. Now she’s off to the gold mines.
Didi sampling Cretaceous pluton that underlies the conglomerate deposits.
Laramide Uplift in the CREC?
November 2022
Doing fieldwork with undergraduate researchers Conner and Didi. Finally made the hoof out to a section of conglomerate facies that may or may not be related to uplift of the Kingman Arch. Hopefully Conner’s research will shed some light on the timing and extent of the deformation event.
New Pub: Broken foreland basins and the influence of subduction dynamics, tectonic inheritance, and mechanical triggers
October 2022
New collaborative review paper on my favorite type of basin, the broken kind. We highlighted the sedimentological, stratigraphic, and structural characteristics of these basins. With a emphasis on the suite of potential geologic preconditions and triggers that can lead to the development of broken foreland basins. Can find it at Earth Science Reviews
Concept of tectonic inheritance in promoting intraplate deformation and development of broken foreland basins
Set up includes NWR 193 Elemental Scientific Laser System with a ThermoFischer iCap quadrupole inductively coupled mass-spectrometer
Time to Ablate Some Zircons
September 2022
The laser ablation system is up and running! Come on down to Nevada Plasma Facility Lab for zircon and apatite U-Pb geochronology and geochemistry. Reach out to me (tomas.capaldi@unlv.edu) for details.
PETM Recorded in the Wasatch?
August 2022
New MS student Ian Gillette and I did some fieldwork out in the UT-ID-WY border area looking for outcrop of the Wasatch Formation. Measured and sampled a beautiful, isolated fluvial channel belt up in the Bear Lake Plateau. Trying to resolve the stratigraphic response to climate variations in a hinterland basin.
Ian standing over a thick cross-bedded conglomerate of the Wasatch Fm. They say Butch Cassidy used these outcrops as hideouts.
Southward transport of Andean fluvial sand gets reworked northward across the Pampean sand sea. Like screaming into the wind.
New Pub: Andean retroarc-basin dune fields and Pampean San Sea (Argentina): Provenance and drainage changes driven by tectonics and climate
August 2022
Another collaborative effort with Eduardo Garzanti (Università di Milano-Bicocca), Alfonsina Tripaldi (Ciudad Universitaria, Buenos Aires) and others to track climatic and tectonic provenance signals across the Holocene Pampean Sand Sea and transcontinental rivers of Argentina using detrital zircon geochronology, sand petrology, and heavy mineral analysis. Can find it at Earth Science Review.
New Pub: Variable thermal histories across the Pyrenees orogen recorded in modern river sand detrital geo-/thermochronology and PECUBE thermokinematic modeling
May 2022
Finally, published our river sand samples from northern and southern Pyrenees that were collected for detrital geo-/thermochronology using apatite, rutile, and zircon U-Pb ages record Pangean and Alpine tectonics and magmatism; and detrital apatite and zircon He dates to track Cretaceous rifting and Pyrenean growth and decay. Coupled with PECUBE thermokinematic modeling of river catchment exhumation and topography through time. We show a new workflow that uses PECUBE models to predict low-T detrital age spectrum from river catchments. Big thanks to collaborators Margo Odlum (UNLV) and Maggie Curry (NC State) for helping get this through. Can find it at Basin Research.
New work flow using Pecube kinematic models to predict detrital thermochronology age distributions over a given catchment area.
Great spatial overlap between broken forelands and slat-slab subduciton
New Pub: The role of flat slab subduction, ridge subduction, and tectonic inheritance in Andean deformation
April 2022
With collaborators Brian Horton (UT Austin) and Nick Perez (Texas A&M) we published new comparisons of Andean topographic, deformation front, and retroarc basin thickness to better understand the role for flat-slab and ridge subduction has on Andean mountain building. Can find it at Geology.
New Pub: Downstream changes in quartz OSL sensitivity in modern river sand reflects sediment source variability: Case studies from Rocky Mountain and Andean rivers
April 2022
Published new quartz luminescence data from modern river sands from North and South America with my postdoc advisor Tammy Rittenour (Utah State). We tried to better understand what OSL sensitivity tells us from sedimentary quartz, and found that the signals preserved in river sand most likely reflect the sediment provenance of the draiange catchments. Can find it at Quaternary Geochronology.
Downstream changes in quartz optically simulated luminescence sensitivity tend to decrease with greater contribution of chert and volcanic quartz grains. More work needs to be done…
GSA Joint Meeting of the Cordillera & Rocky Mountains Sections
March 2022
First in person meeting since 2019! Come join us at the Rendezvous at the Geological Crossroads in Las Vegas. The group will be there showcasing some of our new research.
Capaldi talk Tuesday, March 15, 4:25 pm in CBC 108: Detrital zircon geochronology and quartz OSL track the progressive fill and spill of paleo Bear River Basins of Utah and Idaho.
Duncan talk Wednesday, March 16, 3:25 pm in CBC 112: The Antler orogeny recorded in detrital multi-mineral U-Pb geochronology, southern Nevada.
Plonka talk Thursday, March 17, 1:30 pm in CBC 112: Tracking the Neogene tectonic evolution of the active Andean thrust front using the foreland basin record and detrital geo-/thermochronology, western Argentina.
¡Vamos Argentina!
December 2021
After 18 month delay due Argentina border closing during COVID, Zoey was finally able to make it into the field. We spent most of the time measuring Miocene fluvial-alluvial strata exposed along the Rio San Juan and Sierra Villicum (beautiful outcrop in the image). We also did some vertical transects sampling for geo-/thermochronology in the Eastern Precordillera and Sierra Pie de Palo (ominous range in the background of the image).
We measured that bad boy cm by cm….
Class photo on Permian Kaibab Formation, Overton, NV
Intro to Field Geology
November, 2021
Taught another round of intro field mapping! This time we got to spend some time out in the North Muddy Mountains mapping Permian-Triassic strata in a completely overturned footwall syncline of a Sevier orogeny aged thrust.
The knight is not free: it moves in an L-shaped manner because it is forbidden to take the straight road." -Viktor Shklovsky, Knight's Move, 1923
New Pub: Transcontinental retroarc sediment routing controlled by subduction geometry and climate change (Central and Southern Andes, Argentina)
September, 2021
New collaborative research with Eduardo Garzanti and the Laboratory for Provenance Studies group at Università di Milano-Bicocca. Used sandstone petrography and heavy mineral analysis to track sediment transport across the transcontinental fluvial systems of Argentina. Can find it at Basin Research
Field lecture in an ideally placed amphitheater, Whitney Mesa Nature Preserve.
Stratigraphy in Las Vegas
March, 2021
With COVID still raging we had virtual lectures for our upper-division Sed-Strat course. But we had a few day trips to got out to see some local Pleistocene fluvial rocks of the Las Vegas Formation and Oligocene-Miocene fluvial-lacusterine rocks in the Rainbow Gardens Formation.
New Pub: The detrital zircon record of Phanerozoic magmatism in the southern central Andes
April, 2021
My final PhD chapter is out! Integrated zircon geochronology and geochemistry with spatial and temporal records of magmatism along the South American margin to better understand the deep-time geodynamic and subduction history. Can find it at Geosphere
Zircon geochemistry exhibits a strong spatial trend across the South American subduction margin. Magmatism migrates trenchward, magmatism migrates cratonward, never a miscommunication.
James Duncan carrying rocks up a canyon in the Northern Sierras, CA.
Fieldwork from Vegas craton to Klamath arcs
January 2021
Completed another field campaign for master student James Duncan’s research. Looked at a SW-NW transect of rocks across the once continuous Antler orogenic system from Paleoproterozoic craton in Mojave desert, Carboniferous Antler foreland basin deposits in the Great Basin, and suspect terranes in the Northern Sierras. Hope to get some zircon, apatite, and rutile from these rocks!
Field Geology Lives!
November, 2020
Taught my first class at UNLV. We masked up and socially distanced as we learned field geology locally across the Las Vegas valley and virtually.
A ragtag group of field banditos
Well made it to Henderson, but close enough
Viva Las Vegas!
August, 2020
Made it to Vegas. Its Hot.
New Pub: Neogene retroarc foreland basin evolution, sediment provenance, and magmatism in response to flat slab subduction, western Argentina
May, 2020
It’s finally here, my actual PhD work that focused on understanding the stratigraphic response to flat-slab subduction using the sedimentary record across a suite of retroarc foreland basin sections integrated with arc magmatism trends in western Argentina. You can find it here
Miocene Flat slab subduciton driving Andean orogenesis
Winds of change (Not referring to that bad Scorpions song)
New Pub: Fluvial and eolian sediment mixing during Holocene climate change
November, 2019
Check out our new publication in Frontiers in Earth Science that uses detrital zircons to track changes in the Andean foreland basin sediment routing systems coeval with Holocene climate change.
AGU Chapman Conference on Large Scale Magmatism in the Arctic
October, 2019
Visited Iceland for a conference on Arctic geology to present on subduction driven magmatism in South America… there’s a connection there somewhere. Also, drove the Ring Road to do some pilot sampling of modern rivers across Iceland to look into regional plume-ridge magmatism tempo.
Recent fluvial bar deposits of the Pjórsá River, Iceland
The Grand Canyon State
Going to GSA Phoenix?
September, 2019
I’ll be in Phoenix for some short courses and have a few abstracts showcasing my PhD work. Hope to see you there!
Monday, Sept. 23, 3:45 pm: Timescales of Andean flat-slab subduction, Cordilleran magmatism, and geodynamic evolution
Session 142: Present-day and ancient flat-slab subduction in rock records, geophysical images, and geodynamic models
Tuesday, Sept. 24, 4:30-6:30 pm: Tracking fluvial-eolian transport in the Holocene Andean Foreland of Argentina
Session 202: Recent Advances in Stratigraphy (Poster 293)
Hi Utah,
August, 2019
Made the trek north to green valleys of Logan, Utah where I will be a postdoctoral fellow for the reminder of 2019. I am working with Tammy Rittenour and Joel Pederson to understand the relationships and feedback among Quaternary river network evolution, climate, volcanism, and Lake Bonneville (a.k.a paleo Great Salt Lake) filling and spilling.
Modern Beaver dam analogue to Holocene Lake Bonneville. Maybe it was beavers all along…
Texas longhorns hook en’ em’
Adios Austin!
August, 2019
After 5 years in the lone star state I have finally finished my PhD at the University of Texas at Austin! I worked with Brian Horton focusing on Cenozoic to modern tectonic and stratigraphic evolution of the flat-slab region in western Argentina Andes.