# lunar geologic timescale

> geological dating system of the Moon

**Wikidata**: [Q386638](https://www.wikidata.org/wiki/Q386638)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Lunar_geologic_timescale)  
**Source**: https://4ort.xyz/entity/lunar-geologic-timescale

## Summary
The lunar geologic timescale is the system of chronological dating used to classify the Moon’s geological strata. Also called the selenological timescale, it divides lunar history into named periods such as the Pre-Nectarian, Nectarian, Imbrium, Eratosthenian, and Copernican.

## Key Facts
- The lunar geologic timescale is a geological dating system for the Moon (wikidata description: "geological dating system of the Moon").
- Alias: selenological timescale.
- Wikipedia title: "Lunar geologic timescale".
- Sitelink count for the lunar geologic timescale entry: 26.
- It is part of the broader geologic time scale, which is a system of chronological dating that classifies geological strata (stratigraphy) in time (geologic time scale sitelink_count: 97).
- Named parent/related periods listed as part of or parent to the timescale include Early Imbrian (sitelink_count: 23), Eratosthenian (sitelink_count: 19), Imbrium (sitelink_count: 8), Nectarian (sitelink_count: 28), Late Imbrian (sitelink_count: 17), and Copernican period (sitelink_count: 19).
- Subsidiary periods contained within the lunar geologic timescale include Pre-Nectarian (sitelink_count: 20), Nectarian (sitelink_count: 28), Imbrium (sitelink_count: 8), Eratosthenian (sitelink_count: 19), and Copernican period (sitelink_count: 19).
- Pre-Nectarian period dates: 4533 to 3920 million years ago (Ma).
- Nectarian period dates: 3920 to 3850 million years ago (Ma).
- The lunar geologic timescale is related to the academic discipline category (academic discipline sitelink_count: 50).

## FAQs
Q: What is the lunar geologic timescale?
A: It is the system of chronological dating used to classify and organize the Moon’s geological strata into named periods. It provides a framework for describing lunar geological history.

Q: What other name is used for the lunar geologic timescale?
A: It is also known as the selenological timescale.

Q: Which named periods are part of the lunar geologic timescale?
A: Major named periods associated with the timescale include Pre-Nectarian, Nectarian, Imbrium (including Early and Late Imbrian), Eratosthenian, and the Copernican period.

Q: What are the dated ranges given for any lunar periods?
A: The Pre-Nectarian is dated 4533 to 3920 million years ago, and the Nectarian is dated 3920 to 3850 million years ago.

Q: How does the lunar timescale relate to the geologic time scale on Earth?
A: The lunar geologic timescale is a lunar-specific instance of the broader geologic time scale concept, which classifies geological strata in time; the broader geologic time scale is listed as a parent category.

Q: Where is this timescale documented online?
A: The timescale is documented under the Wikipedia title "Lunar geologic timescale" and has a sitelink presence (entry sitelink_count: 26).

Q: What academic field uses the lunar geologic timescale?
A: It is related to academic disciplines that study geological stratigraphy and planetary geology; the related "academic discipline" category has a sitelink_count of 50.

## Why It Matters
The lunar geologic timescale provides the standardized chronological framework necessary to describe and compare geological features on the Moon. By dividing lunar history into named periods, it allows scientists to place formations, impact basins, and volcanic units into a time-ordered context, which is essential for reconstructing the sequence of events that shaped the Moon. As a lunar-specific adaptation of the larger geologic time scale concept, it supports communication and research across the academic disciplines that study planetary surfaces and stratigraphy. Specifying dated intervals such as the Pre-Nectarian and Nectarian gives concrete anchors for discussions of early lunar evolution.

## Notable For
- Being the Moon-specific adaptation of the geologic time scale (alias: selenological timescale).
- Enumerating named lunar periods that differ from terrestrial interval names, including Pre-Nectarian, Nectarian, Imbrium (Early and Late Imbrian), Eratosthenian, and Copernican.
- Providing explicit dated intervals for some periods: Pre-Nectarian (4533–3920 Ma) and Nectarian (3920–3850 Ma).
- Having a dedicated Wikipedia entry titled "Lunar geologic timescale" with a sitelink_count of 26, indicating cross-language/entry linkage presence.
- Being linked to the broader geologic time scale (parent entry sitelink_count: 97), situating lunar chronology within established stratigraphic frameworks.

## Body

### Overview / Definition
- The lunar geologic timescale is a classification system that orders the Moon’s geological strata into named chronological intervals.
- It serves as the lunar counterpart to terrestrial geologic chronologies and is sometimes called the selenological timescale.
- Its Wikidata description summarizes it as a "geological dating system of the Moon."

### Major periods and subdivisions
- The timescale includes multiple named periods that are used to describe lunar history and stratigraphy. Those named periods include:
  - Pre-Nectarian (contained/subsidiary; sitelink_count: 20). Date range: 4533 to 3920 million years ago.
  - Nectarian (listed both as parent and subsidiary; sitelink_count: 28). Date range: 3920 to 3850 million years ago.
  - Imbrium (listed as both parent and subsidiary; sitelink_count: 8). Imbrium is associated with Imbrium-related intervals such as Early Imbrian and Late Imbrian (Early Imbrian sitelink_count: 23; Late Imbrian sitelink_count: 17).
  - Eratosthenian (listed as parent and subsidiary; sitelink_count: 19).
  - Copernican period (listed as parent and subsidiary; sitelink_count: 19).

### Relationship to the geologic time scale
- The lunar geologic timescale is explicitly linked as part of the broader geologic time scale system, which classifies geological strata and uses chronological dating across contexts (geologic time scale sitelink_count: 97).
- As a planetary-specific timescale, it applies the general principles of stratigraphic classification to lunar geology.

### Contained periods (subsidiaries) — details present in source material
- Pre-Nectarian: 4533 to 3920 Ma (sitelink_count: 20).
- Nectarian: 3920 to 3850 Ma (sitelink_count: 28).
- Imbrium: included as a lunar geological period (sitelink_count: 8).
- Eratosthenian: included among the lunar periods (sitelink_count: 19).
- Copernican period: included among the lunar periods (sitelink_count: 19).

### Parent / Part-of relationships
- The timescale is part of or associated with these named intervals or categories: geologic time scale (sitelink_count: 97), Early Imbrian (sitelink_count: 23), Eratosthenian (sitelink_count: 19), Imbrium (sitelink_count: 8), Nectarian (sitelink_count: 28), Late Imbrian (sitelink_count: 17), and Copernican period (sitelink_count: 19).

### Related academic context
- The lunar geologic timescale is related to the category "academic discipline" (sitelink_count: 50), indicating its use and relevance within formal fields of study that address stratigraphy and planetary geology.

### Metadata and identifiers
- Alias: selenological timescale.
- Wikipedia title: Lunar geologic timescale.
- Wikidata description: geological dating system of the Moon.
- Entry sitelink_count: 26.
- Several associated periods and parent categories carry their own sitelink_count values as cited above.

### Documentation presence
- The timescale is represented in publicly available reference systems, including a Wikipedia entry under the title "Lunar geologic timescale."

(End of entry.)

## References

1. Freebase Data Dumps. 2013
2. BabelNet