Cover Letter & Editor Pitch (epsl-cover-letter)

EPSL manuscripts are handled by an editor whose own research sits near the paper's sub-field — geochemistry, geophysics, geodynamics, planetary science (the current editor roster changes; re-check it on the journal site). Your letter is read by a scientist who can evaluate the claim directly, so it must be a precise scientific argument for significance, not marketing. Its three jobs: state the frontier advance, demonstrate letters fit, and make the editor's reviewer search easy.

When to trigger

• Writing the cover letter for a new EPSL submission
• Choosing the editor whose remit matches the paper (where the system allows a preference)
• Assembling suggested and opposed reviewers with conflict statements
• Re-pitching after a desk decline at another high-bar venue

What the letter must do

1. Open with the advance, quantified. Two or three sentences: the process question, what your result establishes, and the number that carries it — written for a scientist-editor, without superlatives.
2. Argue portability explicitly. One sentence on why readers beyond the study region or method community need the result; this is the desk-screen axis regional studies fail.
3. Show letters fit. Confirm one decisive result, main text within the cap, no companion manuscript in play.
4. Flag the cross-disciplinary reviewer pairing. If the paper joins two sub-fields, say so and suggest reviewers from each — it tells the editor you understand how EPSL will referee it.
5. State integrity basics. Original work, not under consideration elsewhere, all authors approve, preprint status if any, data deposited (name the repositories), competing interests declared.
6. Suggest clean reviewers. Several qualified names with no recent co-authorship, shared institution, or advising ties; opposed reviewers named soberly with a one-line reason if needed.

The subject editor's silent questions

Editor asks silently	Weak letter	Letter that survives
Is this a frontier advance?	"we present new data from X"	"this is the first measurement that separates hypothesis A from B, at ±… precision"
Will non-specialists care?	portability unstated	"any interpretation of [archive/process] must now correct for…"
Is it a Letter?	length/scope unmentioned	"a single result, 5,900-word main text"
Can I referee it fairly?	reviewer list from one clique	reviewers spanning both sub-fields, conflicts stated
Are the data real and open?	silence	"full tables at EarthChem (DOI), code at Zenodo (DOI)"

Worked micro-example (illustrative — pitching the detrital-lag paper)

• Weak hook (desk-decline risk): "We report 600 new detrital-zircon U-Pb ages from the X Basin together with bedrock thermochronology, and discuss the provenance of the basin fill." An editor files this under regional provenance.
• Strong hook: "We provide the first direct measurement of the lag between mountain exhumation and its appearance in the sedimentary record — 5.0 ± 1.2 Myr (illustrative) — by dating both ends of one sediment-routing system. Detrital archives are read worldwide as if this lag were zero; our result makes that reading correctable." Process, number, portability — in three sentences.

The conversion move is always the same: replace what was measured where with what everyone else must now do differently.

Anti-patterns

• A letter that inventories the dataset but never states what it decides
• "Novel," "unprecedented," "paradigm" doing the work that a number should do
• Ignoring the regional-study objection when the title contains a place name
• Suggesting only reviewers from the authors' collaboration network
• Omitting data-deposition, preprint, or competing-interest statements
• A letter longer than a page

Output format

【Hook】advance + number + portability in ≤3 sentences
【Letters fit】one result + within cap + no companion paper
【Editor】subject remit matched (re-check current roster)
【Reviewers】suggested (both sub-fields) + conflicts stated; opposed if any
【Integrity】originality / authors / preprint / data DOIs / COI
【Length】one page? [Y/N]
【Next】epsl-review-process

Supplementary resources

• ../../resources/official-source-map.md — journal home and editor roster (re-check before naming anyone)
• ../../resources/exemplars/library.md — abstracts whose significance framing translates to strong hooks