---
name: epsl-topic-selection
description: Use when deciding whether a result fits Earth and Planetary Science Letters (EPSL) and how to frame it. EPSL takes concise, high-significance Letters on physical, chemical and mechanical processes of the Earth and planets, and desk-declines regional case studies without process-level insight, so this skill pressure-tests the frontier claim before you invest. It frames the contribution; it does not run analyses.
---

# Topic Selection & Fit (epsl-topic-selection)

EPSL's identity is in its name: **Letters**. The journal wants a short paper whose single result moves
a *frontier* — how planets differentiate, how mantles convect, how faults load, how climate signals
enter the rock record — not a competent study whose relevance stops at one basin, one orogen, or one
sample suite. Deciding fit early saves months, because the frontier-vs-incremental judgment is made at
the editor's desk.

## When to trigger

- Choosing between EPSL and a specialist or regional venue
- Sharpening a dataset into a process-level question
- Worried the paper reads as "another case study from region X"
- Tempted to split one project into companion papers (EPSL discourages this)

## The process-level test

1. **Name the process, not the place.** Does the result constrain a physical, chemical, or mechanical
   process of the Earth or another planet — melting, degassing, core formation, slab dehydration,
   crustal growth, orbital forcing — rather than describing a locality?
2. **Portability.** Would a scientist working on a different continent (or a different planet) change
   how they interpret *their* system because of your result?
3. **Decisiveness.** Does the dataset actually discriminate between competing hypotheses, or is it
   consistent with all of them?
4. **Letter economy.** Can the advance be delivered in a main text near the ~6,500-word cap (re-check
   on the official site) with a handful of figures? If not, the venue or the scope is wrong.

## Fit-versus-redirect decision table

| Your work is... | EPSL fit | Better home |
|-----------------|----------|-------------|
| A locality's geochemistry with no generalizable mechanism | weak | Lithos, Chemical Geology, a regional journal |
| A new constraint that rewrites a global process budget | strong | EPSL Letter |
| Comprehensive method development for one instrument | weak | Chemical Geology, G-cubed, GGR |
| A planetary-interior result from mission or meteorite data | strong | EPSL Letter (planetary scope is explicit) |
| Descriptive stratigraphy or mapping | weak | Basin Research, GSA Bulletin |
| A dense monograph-length argument | wrong format | JGR Solid Earth, GCA |
| A field-wide synthesis you were invited to write | strong | EPSL Frontiers Paper (invitation only) |

## Worked micro-example (illustrative — three framings of one detrital-zircon dataset)

The same 600-grain U-Pb dataset from a foreland basin can land three ways (illustrative):

- **Off-fit:** "Detrital zircon ages from the X Basin constrain its provenance." A locality's
  sediment-routing story — the textbook EPSL desk decline.
- **Borderline:** "Age spectra shift at 30 Ma, coincident with the Y collision." A correlation, but a
  reviewer asks what process was tested.
- **On-fit:** "Foreland age spectra lag exhumation by ~5 Myr (illustrative), quantifying the transit
  time of orogenic detritus — so detrital archives worldwide record mountain building with a
  measurable, correctable delay." Now every basin worker recalibrates their reading of the archive.

The sorting question: finish the sentence "anyone studying [process] on any planet now has to account
for…". If you can only finish "anyone studying [my region]…", reframe or redirect.

## Anti-patterns

- A regional case study whose conclusions never leave the field area — the pattern EPSL editors decline without review
- "First measurement of X in Y" with no hypothesis the measurement discriminates
- Stretching a specialist method paper to look like a process paper
- Planning two companion manuscripts; EPSL states they are against the spirit of concise Letters
- Choosing EPSL because of prestige while the natural readership is a single sub-community

## Output format

```
【Question】one-sentence process-level question
【Process, not place】the Earth/planetary process constrained
【Portability】who outside the region/sub-field must respond
【Decisiveness】hypotheses discriminated
【Letter economy】deliverable near the word cap? [Y/N]
【Verdict】EPSL Letter / reframe / redirect (venue)
【Next】epsl-literature-positioning
```

## Supplementary resources

- [`../../resources/exemplars/library.md`](../../resources/exemplars/library.md) — landmark EPSL papers that cleared the frontier bar
- [`../../resources/official-source-map.md`](../../resources/official-source-map.md) — EPSL aims, scope, and article types