The conclusions should reach the objectives. If not, then the paper should be rethought. Any aspect of sedimentary geology is acceptable. Papers involving computer modeling are fine if the emphasis is on the sediments, not the model. All papers submitted should have new and significant information.
Many contributions come from non-native English speakers.
The acceptance of a paper is based strictly on science, not quality of English, but the review process works more efficiently if the English is readable. The science may be difficult to evaluate if the paper is poorly written. It is highly recommended that manuscripts be pre-reviewed by a native English speaker before initial submission. Graduate student research results breathe new life into the Journal providing fresh material. Major revisions at this point are painful for everyone, and if the writing is too turgid, rejection may be the only recourse.