Examples of Dumping Redo Blocks From Archivelogs

More details see MOS note 960780.1
Here are pure examples for reference:

ALTER SYSTEM DUMP LOGFILE '/archive/<dbname>/<instancename>/ArchiveOnLine/<dbname>_709323090_1_8601.arc' DBA MIN 28 21649 DBA MAX 28 21649;
ALTER SYSTEM DUMP LOGFILE '/archive/<dbname>/<instancename>/ArchiveOnLine/<dbname>_709323090_1_8601.arc' DBA MIN 28 144259 DBA MAX 28 144259;
ALTER SYSTEM DUMP LOGFILE '/archive/<dbname>/<instancename>/ArchiveOnLine/<dbname>_709323090_1_8601.arc' DBA MIN 28 145056 DBA MAX 28 145056;

dump file#28  block: 21649
dump file#28  block: 144259
dump file#28  block: 145056