Photos and stuff from HeDWaAZ 2014: Multichron (for more info on HeDWaAZ 2014, scroll down)

The 2014 HeDWaAZ Multichroners
(minus Sid, Alexis, and Pete) (left to right):
Sebastian Zapata, Raul Lugo, Patrick Boyd, Charlotte Caddow, Emma Schneider, Tommy (T-love) Lovell, Stuart Thomson, Erin Abel, Natalia Zakharova, Christine Cassab, and Ellen Buelow

Also muchas gracias for the helpful support from: Uttam Chowdhury, Mark Pecha, George Gehrels, Nicky Giesler, Bobby Bowman, and NSF Grant EAR-1219653 from the Tectonics Program!!!

The intrepid Multichroners analyzed hundreds of zircon and apatite U/Pb dates, and many many zircon, apatite, and hematite (U-Th-Sm)/He dates, combining these with hundreds of AFT dates and other geologic information as parts of nine geologic studies from Alaska to Antarctica to the Andes to southern Illinois!

Alexis Ault looking closely for some of the seven species of native fish in Aravaipa Creek.

On our way out of Aravaipa Canyon on the HeDWaAZ 2014 field trip. It was a pleasant 107 degrees F this day (the last time we did this it was 113).

Ellen Buelow explaining the Miocene cooling ages of apatites from the retroarc foreland of the central Andes!

Natalia Zakharova expounding on the thermal history of the Newark Graben!

Sebastian Zapata holding forth on the tectonic history of the Cordillera Central of Colombia!

Tommy "T-love" Lovell models one of the most remarkable age-eU correlations I've ever seen (and it continues to hold up with more analyses)!

Christine Kassab explaining some systematic regional variations in detrital zircon double-dates coming off of East Antarctica!

Raul Lugo introduces the thermal and exhumational history of core-complexes of Sonora, and some really surprising crystallization ages too!

Charlotte Caddow explains the mysterious sandstone dikes in Precambrian basement of the Colorado Rockies, and their amazing early Silurian hematite ages!

Emma Schneider points out the locations of Sanak-Baranoff belt plutons with beautiful apatite He ages!

Patrick Boyd asks the $64k question about Antarctica, which he then proceeds to answer using multichron on IRD!

Multichron alumni: Send me more photos to put in here!

More background about HeDWaAZ 2014: Multichron

HeDWAZ 2014: Multichron
Geochronology and Thermochronology Workshop at the University of Arizona

The 2014 HeDWAZ workshop at UA will be centered on the theme of "Multichrononometry," the application of multiple geo- and thermochronometers to single geologic specimens to develop integrated formation and thermal histories useful for understanding provenance, crystallization, metamorphism, exhumation, and any other aspects of a sample's history that we can creatively conceive of. This two-week workshop will be is aimed primarily at advanced undergraduate and early-career graduate students who are working on their senior theses or are in the early phases of their graduate research. The goals of the workshop are 1) to provide an opportunity for students to perform geochronologic and thermochronologic analyses on their own samples and 2) to provide some training and experience in the fundamentals of geochronology/thermochronology, diffusion, and analytical techniques, and 3) to provide an opportunity to be creative with geo- and thermochronology.


Previous workshops: Antarctichron, HeDWaAZ, HeDWaY.

HeDWAZ 2014-Multichron Tentative Dates
20 June - 4 July
(arrival 19 June, departure 5 July) (because what other time would you want to visit southern Arizona?)

Instructors: Peter Reiners, Stuart Thomson, Sidney Hemming, & Alexis Ault
with help from Uttam Chowdhury, Mark Pecha, and George Gehrels 




Student Name
Charlotte Cadow
Colorado College
Hematite Helium dating of sandstone injectites’ cement within Faults (HeHe SIC)
Sebastián Zapata
Universidad Nacional de Colombia, Sede Medellín
Temporal and tectonic style of the early Andean Orogeny in the Colombian Andes: structural and chronological constraints
Patrick Boyd
University of Arizona
Determining the paleogeography of the Coast Mountains Batholith, British Columbia, through (U-Th)/He and U/Pb dating
Ellen Buelow
Univ. Wisconsin Eau Claire
Detrital Thermochronology in Neogene Basins of the Southern Andes
Emma Schneider
Carleton College
Thermal history of the Sitka Greywacke and associated Sanak‐Baranof plutons, SE Alaska
Tommy Lovell
Purdue University
Does the North American midcontinent breathe? Determining sediment flux and burial histories of the Illinois Basin with geochronologic and thermochronometric analyses
Natalia Zakharova
Columbia University, LDEO
Determining Basement Age, Detrital Populations and Thermal History of the Newark Basin
Christine Kassab
Indiana University-Purdue University Indianapolis
Constraining cooling/exhumation history of rocks found at Nimrod Glacier and Law Glacier through the use of thermochronology on tills from ice-cored moraines
Raúl Lugo
UNAM, ERNO, Hermosillo, México

Geochronology and thermochronology of Cenozoic two-mica granitoids, central Sonora, México


Rationale and general description

The goal of HeDWAZ 2014-Multichron is to introduce undergraduate and graduate students to geo- and thermochronology through analysis and interpretation of their own samples and data, in the context of their own research projects. Through both hands-on analyses and interpretations, as well as informal lectures and discussions, students will learn fundamentals of radioisotopic dating, laboratory techniques, analytical instrumentation, basics of thermochronologic modeling, and each others' research projects. Each student's project during the workshop will focus on a small set of samples to be dated by some combination of (U-Th)/He, U/Pb, FT, Ar/Ar methods. Ideally, a student's accomplishments at this workshop should complement a larger research project supervised by the student's faculty advisor at his or her home institution.


Applications: Students interested in participating in this workshop should send Peter Reiners (reiners at email dot arizona dot edu) a one-page project description outlining the project rationale, methods, and expected outcomes, by 14 February. Students should also request a short letter of reference/support from their advisor/associated faculty member be sent to the same email address by the same date. Students offered participation opportunities will be notfied by the end of February at the latest.


Important points

[1] During the workshop students will perform AT LEAST (U-Th)/He analyses, modeling, interpretation, and presentation during the workshop. Because the idea is actually to combine information from this low- (or intermediate-) temperature thermochronometer with information from other techniques (U/Pb, FT, Ar/Ar, etc.), some thought should be given to how this will be accomplished. With the help of George Gehrels and colleagues in the Arizona Laserchron Lab here at UA, we will also be able to provide U/Pb dating. With prior planning and communication with our collaborators Sid Hemming and Stuart Thomson we can also provide 40Ar/39Ar and fission-track dating, but these analyses, or at least arrangements for them, should be taken care of before the workshop. Ideally these analyses will have occurred prior to the workshop, so that the interpretations, modeling, and presentation can make use of integration of the different dating techniques.


We will not perform mineral separations, so students should have good clean mineral separates completed and available well before the workshop starts. For students wishing to perform U/Pb, FT, and/or Ar/Ar analyses, please communicate with Pete, Sid, and Stuart.


[2] If you want to do (U-Th)/He dating be prepared for the possibility that your chosen samples/field area may not have usable material for (U-Th)/He dating. This is especially important for apatite He dating, as the method has stringent requirements of crystal morphology and purity. Think about a backup plan, and bring several sets of samples so that you have a better chance of obtaining some data that are useful and interesting.


[3] There is no requirement for direct faculty involvement in the workshop, beyond general supervision of student research and help with data interpretation at the student's home institution. However, if faculty would like to attend and participate in the workshop, they are certainly more than welcome at any point, to learn about the technique and to facilitate future use of the lab by other students or themselves.


[4] Please bear in mind that actually accomplishing everything we want to do and obtaining real, good, usable data with geologic significance for everyone requires proper alignment of various cosmic bodies, good karma, properly functioning analytical equipment, lack of power outages, fully functioning and healthy instructors and lab managers, and you name it. We have done this before and know how to take appropriate steps to maximize the chances of all this. But be aware that sometimes feces happens. We will all work together to avoid and ameliorate fecal outcomes, but there's no guarantee.


Accomodations, food, other logistics

[1] Analyses and room and board (but not student travel) will be covered by HeDWAZ, through funds from NSF's Tectonics program and the ARHDL. Students will stay on campus in a dormitory, in single rooms. These are very close (easy walking distance) to Gould-Simpson, where we will be working. These are pretty standard dorm rooms, and full linen service will be available. Yes, there is air conditioning. I hope.


[1.5] Details on arrival to follow, but students should plan to arrive on campus later in the day on the 19th of June, and leave whenever they want on the 5th of July.


[2] Students will eat in cafeterias and other on-campus food venues that are within easy walking distance. You will have ID cards that allow you to spend a certain amount (should be more than enough for plenty of sustenance!) each day.


[3] Internet and email access is available through the UA Public Wifi. Computers will be available for student use in Gould-Simpson, but if you have a laptop, it might be a good idea to bring it.


[4] We will provide a chemical and laboratory safety training the first day of the workshop, to acquaint students with lab safety and hazards.


[5] There will be a one-day field trip during the workshop, to take a break from labwork and lectures, and to see some regional geology. Hopefully this will be iin Aravaipa Canyon. We will provide vehicles and transportation.


[6] Information about visiting UA, including links to maps and directions.


[7] If you intend to bring your own vehicle, contact Pete for information on parking.



Tentative schedule

The general daily routine will be a combination of laboratory work and one or two lectures and discussions, broken up by lunch.


In order to accomplish everything we need to do and make sure everyone gets at least some data to ponder, the beginning of the workshop will be pretty hectic. The first day will include some orientation, lab safety training, etc. We will also start with sample preparation, and probably some U/Pb analyses right away that day.


A lot of you will spend time doing picking on the microscopes, followed by analyses on the He lines, followed by ICP-MS analyses for U-Th-Sm. Some of you will also do U/Pb dating in the Arizona Laserchron Center. This mostly involves sample picking under the microscopes for the first few days. Because we only have three picking microscopes, and also because no one can or wants to pick for more than a few hours at a time, students will take turns picking, and doing some library research in the first few days. As samples become ready, students will process them on the He line. This means running the laser to extract He, and operating the programs that spike, purify, and measure the gas.


Students will then perform wet chemistry involved with spiking, dissolution, and measurement of U, Th, and Sm on the high-resolution ICP-MS. After calculating ages from their measured data, and making corrections for alpha ejection, students will learn how to interpret He ages, in terms of forward and inverse thermal models, complexities that arise from topography, non-constant geothermal gradients, and other factors.


Finally, students will compile and synthesize their data and relate them to their larger project, and prepare a short presentation for the group on their results.


Tentative Schedule: (subject to change as plans evolve)
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
June 15 June 16 June 17 June 18

June 19

arrive in the afternoon; check into dorm 2-5 pm

June 20

intro lectures; lab safety

Picking clinic

U/Pb dating

June 21

mineral picking (zircs 1st priority);


U/Pb dating

June 22

mineral picking (zircs 1st priority);


U/Pb dating

June 23

mineral picking (zircs 1st priority);

He analyses


U/Pb dating

June 24

mineral picking;

He analyses



June 25

mineral picking;

He analyses



June 26

mineral picking;

He analyses;


spike/acidify all zircs in oven

June 27

He analyses;

spiking, dissolution


zircs HF day 1

June 28

He analyses (aps only);

spiking, dissolution


zircs HF day 2

June 29

He analyses (aps only);

spiking, dissolution

zircs HF day 3
zircs back in oven

June 30

Field trip to Aravaipa Canyon

zircs out of oven
dissolved in HNO3

all remaining aps spiked, dissolved

July 1

He analyses;

ICP-MS analyses;


July 2

ICP-MS analyses;

data interpretation

July 3

data interpretation;

prepare presentations

July 4

final presentations

July 5

leave UA/Tucson


Last updated 26 January 2013