arkL - login

arkL database of stratigraphic data from TimeScaleCreator - introduction

The TimeScaleCreator program is based on a uniquely extensive archive of stratigraphic data compiled by James Ogg, Felix Gradstein and numerous colleagues, as also presented in the GTS2020 volume. The arkL project aims to convert this data into an openly accessible relational database which should:

The current website is a first step toward this. It includes most chronostratigraphic, biostratigraphic and magnetostratigraphic event calibrations and interval definitions from TSC from the Jurassic to the Recent, together with a bibliography and geochemical datasets. Planned developments include extending coverage back through the Phanerozoic, improved referencing linkage, linkage with mikrotax and other taxonomic databases, provision of an API to allow cross-linkage from other websites.

The data presented here should be identical to that provided by the current version of TimeScaleCreator (8.1), apart from minor corrections made during compilation of the database (and possibly some mistakes introduced during compilation). The mySQL database includes tables of events (8000 entries), intervals (6000 entries) and references (5000 entries) together with metadata tables on datasets (80 entries - e.g. Tethyan nannofossils) and TimeScaleCreator columns (500 entries). In addition various proxy curves as contained in TSC are included - e.g. isotope data, orbital cyclicity solutions.

As currently configured the site will primarily be of use to earth scientists working with geological time who need reference data. A basic use case would be to use the TimeScaleCreator program to explore the data and this site to download subsets of data. It will also be possible to use this site to make corrections to the underlying database although these corrections will not immediately be reflected in the publically available version of TSC.

The website allows viewing (and editing) of all the tables. The most immediately useful page will probably be the dataset page as this synthesises single sets of data. Text files of event data can be downloaded from this page - in addition on any page data can be cut and pasted from the tables into spreadsheets such as Excel. The column view page provides data precisely corresponding to single columns on TimeScaleCreator and graphic mock-ups of the corresponding TSC columns. This page is probably easier to browse. The references page may be of use as an online bibliography of stratigraphic literature, and references can be exported in .ris format to allow easy import to reference management software such as EndNote. The other pages are primarily for editors but browsing them may be useful for anyone interested in the system. There is no API yet. This website will not replace TSC as the system for end users/production of high quality multi-column charts.

This project is funded by the TimeScaleCreator Foundation and the Digital Deep Earth Program

Status Nov 2025: the site is under active development, and neither the content or the software are complete or fully checked. The Cenozoic, Jurassic and Cretaceous content is rather complete but has not been checked for compilation errors or updated. The Triassic is nearing completion to a similar level, there is no Palaeozoic data. Please send any feedback and comments to Jeremy Young - jeremy.young@ucl.ac.uk or James Ogg

Editors' login for the arkL database

To do any editing on the arkL database you will need to login with a username and password provided by Jeremy Young. You can, however, browse the system and download data without doing this. NB The database is still under active development and is not open for dispersed editing but corrections are welcome.
Username:
Password :
  
sorry, you are not logged in :-( but you can browse the site, use the menu at top left ;-)
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Database schema

Screenshotoutline database schema for the arkL database
Notes
  1. This schema is indicative only, some fields are omitted, and the linkage lines are not precise
  2. subdatasets are needed where different zonations are based on the same set of events. These are a significant complication to the data structure, so to keep the schema clear no linkages are given to them).
  3. taxon_links will provide the basis for linking to external taxonomic databases such as mikrotax or dinoflaj, these are under development

Database tables summary

DATASETS TABLE

A dataset is a set of interrelated data - e.g. Tethyan ammonites, standard chronostratigraphy. Most datasets include both intervals and events. The dataset table does not contain any basic data but rather metadata about the whole dataset. The actual data is stored in the events and intervals tables.

EVENTS TABLE

An event is a time horizon, such as the first or last occurrence of taxon, or the base of a magnetochron or chronstratigrapihic stage. All event data is stored in one big table. A dataset may contain more than one column of events (eg. zonal events and other events), these are termed sub-columns. To select a set of events for plotting in a TSC column the dataset_id is used together with the sub_column, if relevant.

INTERVALS TABLE

An interval is period of time such as a biostratigraphic zone or a chronostratigraphic stage. All interval data is stored in one big table. A dataset may contain more than one group of intervals (e.g. different zonations based on the same set of events), these are termed sub-datasets. To select a set of intervals for plotting in a TSC column the dataset_id is used together with the sub_dataset and the interval type, if relevant.
Alternative dataset_id - in some cases there is both a standard set of intervals and alternatives and it may be useful to indicate which of the alternatives the intervals in the standard set are derived from - eg in the Late Triassic there are alternative GPTS schemes from the Newark Basin and from marine sediments whilst the standard sequence is derived, in part, from both.

COLUMNS TABLE

The columns table has one row for each column which can be plotted in TSC. Its purpose is to provide the terms needed to define a database query to retrieve the data from the database that TSC needs.

SUB-DATASETS TABLE

Sub-datasets are needed where a single dataset contains two or more separate sets of intervals. They are used
  1. When there are multiple columns of intervals using the same set of events - eg Cretaceous nanno zonations -> each zonation has a separate column. For these rows are added to the sub_dataset table and the sub_dataset is given on the columns table.
  2. When two discrete sets of data share a column/pair of columns (e.g. in pforams the Wade et al 2011 scheme for the Cenozoic uses the same zone/subzone columns as the Caron zonation for the Cretaceous. For these a colshare label is defined and is added both to the relevant rows of the columns table and the sub-datasets table.

POINT-DATA TABLE

TSC also includes comparison data such as oxygen isotope curves and orbital parameters. These are stored as age-value pairs to enable curve plotting. The data for these is stored in a single table with dataset_id used to enable data selection. This type of curve data is tpyically tied to a particlular GPTS and cannot realiably be recalculated to fit a new GPTS.