Ocotcat Chroni Repository


CHRONI is a mobile application that presents archived data downloaded from the Geochron database in a customizable format for use by geologists in the field. The purpose of CHRONI is to allow people to archive data, while collecting data in the field. With CHRONI, users do not need to remain stationary. Currently, the CHRONI application only works with Android devices, but an IOS application is in development. The project is led and maintained by CIRDLES, an undergraduate research lab at the College of Charleston in Charleston, South Carolina. The documentation below is essentially a set of step by step instructions on how to operate the software. For auditory and visual learners, youtube video tutorials will be included among the written instructions, so there will be a video demonstration of CHRONI operations from an android phone ( or tablet). This material is based upon work supported by the National Science Foundation under Grant Numbers 0930223 and 1443037. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.


Installation and Beyond

The current documentation applies to Chroni version 1.0.1

Currently, CHRONI only supports Android devices. Due to the current layout sizes, the application works best on tablets.

  1. Install our most recent CHRONI APK from our Releases.
    • Note: if using a computer to download the APK, simply send the file to your device via email.
    • Select the application from the dropdown menu on your device and hit install.
  2. In a location where your device receives internet connection, open the CHRONI application.
    • Internet connection is needed to initialize the application because the default Report Settings file must be fetched from
  3. Congratulations! Your CHRONI application is officially setup! Now, you can utilize the following features:
    • Open - View your aliquot in a custom format as specified by your current Report Settings file
    • History - Review your last ten aliquot files with the click of a button!
    • Profile - Specify your Geochron Portal account information in order to retrieve private aliquot files.

Aliquot Files

Downloading Aliquot Files

An aliquot file is an XML file that contains data on a specifc rock sample. CHRONI uses report settings to display this data in an aliquot data table.

When downloading aliquot files from geochron, simply type in the IGSN number into the download bar of the aliquot activity, then press the download button. To view this aliquot, you then need to open it in the file browser by click the add button, selecting your aliquot, then pressing open.

The other way to download an aliquot is by downloading it from outside of the app. When downloading outside of CHRONI, the aliquot file will be located in the download file of your device. CHRONI has a new import feature where you can click the file you want to pull files from and it will automatically pull aliquot and report setting files and insert them into the correct CHRONI folders. This feature can be accessed from the menu bar.


When on your android tablet, Chroni will be stored in your applications menu. Click on the Chroni icon to open the application and you will arrive at the Home Screen.

  1. Click the open button on the Chroni Home screen and you will arrive at the Aliquot screen. On the Aliquot screen, Current Report Settings will be listed as Default Report Settings.
  2. Click the plus sign next to the Saved Aliquot file input form and choose an Aliquot saved on your device. After you do so, the file name for the aliquot file will appear in the input form.
  3. Click the open button in order to view the Aliquot table. At the top of the table, there are two detail buttons Report Settings and the current name of the Aliquot.
  4. When you click on the Concordia button, you will be redirected to a web browser that will open up a graphical image of the current sample.
  5. When you click on the “Probability Density button, you will also be taken to a web browser that will open up a graphical image of the current sample.
  6. The table itself contains the following information categories:



    -Isotopic Ratios

    You will be able to scroll vertcally and horizontally to observe the information on the given table. In order to return to the Aliquot screen, click the back button.

  7. The GeoChron IGSN file input form requires a GeoChron IGSN, which can be found on the SESAR website after you register your samples.


  1. From the home screen, click the History button to arrive at the History screen.
  2. A table will show the recent Aliquots you have opened within the Chroni application with the following details:

    -Last Opened


    -Report Settings

  3. There are Open buttons to the right of the table, which will allow you to open past aliquots.
  4. The Home button on the bottom of the page will take you back to the Chroni homescreen.

Report Settings

Report settings are XML files created through ET Redux in which the user specifies which data sets and units they would like to display. The user can decide what columns appear, the amount of significant digits they would like to display, and more.

To obtain custom report settings, the user needs to be sent report settings from colleagues or create their own through ET Redux. To access information about using ET Redux, click here.
Once you have downloaded a report setting to your device, you can use the new import feature to put into CHRONI’s file system. Open up the CHRONI menu and then click on the import activity. Select the file you want to import from and click import and it will simply transfer any report settings and/or aliquot files you have in that folder.

  1. From the home screen, click the Report Settings button to arrive at the Report Settings screen.
  2. The Current Settings will be “Default Report Settings.”
  3. Click the plus sign next to the Device file input form to choose a report setting. Then, click the Open button to be taken to the Aliquot table and a notification will say “Your current table info has been stored!”
  4. Click the Cancel button in order to return to Chroni’s home screen.


  1. From the home screen, click the Credentials button to arrive at the Credentials screen.
  2. There are input forms that will request your Username and password associated with your GeoPass account. Enter theses in their respective forms and click validate to log in from your tablet.
  3. You can also click the Home button in order to return to the Home Screen or the Reset button to clear both input fields and get a notification saying “Credentials erased.”


Aliquot - phsyical pieces of a sample whose dates you wish to interpret seperately.

Concordia - clicking this option will open up a web browser and show you an Uncertainty Ellipse Plot.

Fraction - a paired U+Pb analysis

Isotopic Ratios - refers to isotopes whose abundance is affected by processes in nature

Probability Density (Function) - the density of a continuous random variable. This describes the likelihood for the random variable to take on a given value. Clicking this option will open up a web browser and show you a Bar Graph.

Aliquot file - an XML file that contains data on a specifc rock sample. CHRONI uses report settings to display this data in an aliquot data table.


This will be the site of FAQs and navigation assistance.

  1. The home screen that will appear when you first open up CHRONI. After using CHRONI for an extended period of time, you might close the app on one of the other screens and when you reopen the app you will brought back to the screen that was last opened.

  2. Upon clicking “Open,” you will be brought to a screen asking for the title of the a Aliquot and you also have the ability to save aliquots.

  3. You can arrive at the Report Settings screen by either entering an aliquot or from your history page. The table of data that you mean to extract will be located here.

  4. The History page shows the Aliquots that were last opened, the time they were open, and there is a view option, in which you can directly open the Aliquot.
  5. The Profile page displays the entry fields of username and password. Once you have entered that information, you will receive two messages.
    • “Your Geochron Information Profile is saved!”
    • “Validating Credentials”
  6. Please see the About page to learn more about the development of Chroni.

Where can I locate IGSN numbers?

  • Go to and click “Search Geochron”
  • Click “Detrital Interface”
  • Choose one of the red circles in the region you want information on
  • Under “Samples Found” choose one and click “detail”
  • Then click “View Sample Details”
  • The IGSN is located on the “Sample Unique Identifier” line and is the text after “SSR.”
  • The IGSN is nine characters and usually starts with “GEG”

How can I download new report settings?

  • You can create custom report settings by using ET_Redux
  • The ET-Redux Project can tell you more about creating samples
  • Save the report settings as an xml file and send it to your email, then download the file onto your device
  • Save the file in the Chroni Report Settings folder