← All tables

gold_formations

Canonical registry of geological formations: the named rock units wells target and produce from. One row per stratigraphic unit (group, formation, member, or bed, plus broad age buckets where a source reports only a geological age), with its place in the hierarchy and stable links into public stratigraphic references. formation_id columns across our well, completion, and formation-top tables reference this registry, so a name like Wolfcamp means the same unit everywhere.

Access tier: public_aggregate Public. These rows are the public layer: aggregate series and reference records such as companies, formations and rig counts. Where a page publishes them you can read them on the website, and a free account can export the aggregate series behind a view (10 a month).
Primary key: formation_id
Region codes: formations

Columns

Column	Type	Nullable	Description
formation_id	string	no	Stable unit identifier (opaque slug: treat as a key, don't parse it).
canonical_name	string	no	Canonical unit name (e.g. Wolfcamp, Bakken, Montney).
rank	string	no	Stratigraphic rank: `group`, `formation`, `member`, or `bed` per the North American stratigraphic code, plus `age` for time-tier buckets used when only a geological age is reported. Values: group · formation · member · bed · age.
parent_formation_id	string	yes	The containing unit, where one exists (member to formation to group); NULL at the top of a hierarchy.
strat_order_base	float64	yes	Older end of the unit's age range, in millions of years. For a named rock unit this is the base of the age range the name carries across its published usages (not a point age), so for a long-ranging or loosely defined name it can be considerably older than the unit is anywhere. For an age bucket (rank `age`) it is the start of that geological interval. Two units are reliably ordered by comparing these values only where their age ranges do not overlap. NULL where the source records no age. A published range is not always usable for ordering: see `strat_order_withheld_reason`.
strat_order_top	float64	yes	Younger end of that same age range, in millions of years. For an age bucket (rank `age`) it is the end of that geological interval. Together with the older end it gives the unit's full age span: where two units' age ranges do not overlap, this pair of values orders them by age; where the ranges overlap, neither value orders them. NULL where the source records no age. A published range is not always usable for ordering: see `strat_order_withheld_reason`.
strat_order_withheld_reason	string	yes	Why this unit's published age range must not be used to ORDER it against another unit. Normally empty, and the range then means what it says. `interval_label` means the source's only age for this unit is a bare geological-interval label (the start and end of a named period, carried unchanged) rather than a range measured from where the name has actually been mapped. The range is still shown, because it is the age the source records; we simply do not sequence rocks on it, since it cannot be told apart from a measured range and ordering on it silently places rocks in the wrong order.
macrostrat_strat_name_id	int32	yes	Macrostrat stratigraphic-name id, where the unit is anchored there.
macrostrat_concept_id	int32	yes	Macrostrat concept id, where available.
geolex_unit_id	string	yes	USGS Geolex unit id (US units), where available.
weblex_gscc_id	string	yes	Canadian WEBLEX / GSC lexicon id, where available.
lithology	string	yes	Dominant lithology, where recorded (e.g. sandstone, limestone, shale).
source	string	no	Where the registry row came from: public stratigraphic databases or our own curation.

How these numbers are built is on methodology; the machine twin of this page is data-dictionary.json.