Business finances "generally remain in good shape and broad indicators of financial stress are low" the Reserve Bank of Australia recited in its half-yearly Financial Stability Review on Friday.A sting followed this boilerplate language, however."In liaison, the major banks note signs of broader stress emerging in mining-exposed geographic regions, where the performance of other business and household loans has deteriorated," the central bank added.Banks are, moreover, "reporting higher rates of non-performance among their resource-related exposures," the RBA said in an overview of its Review. It added a common and factual coda that banks' "lending to the [mining] sector is only a small share of their total lending."The RBA's broadly tolerant overview of asset quality in the mining sector, however, is at odds with the theme of a flurry of sell-side commentary ahead the major bank's profit season in a week or so. The detailed analysis in the Review also appears to paint a much bleaker picture than used to introduce the material in the document.Elaborating, the RBA noted that: "for the resource-related sector, conditions are challenging as commodity prices remain well below their levels of recent years. "This has led to a further significant decline in the earnings of resource-related companies, including the large, low-cost producers. The oil and gas sector has been particularly affected."The RBA wrote that: "the earnings of listed oil and gas companies fell by more than 40 per cent. Most smaller resource producers are struggling to cover costs at current prices, leading some to suspend operations at higher-cost mines."Adjustment is proving thorny, with "additional cost cutting proving progressively more difficult," the RBA said.It explained that: "the steep fall in earnings has weighed on resource-related companies' capacity to meet their debt-servicing obligations. Excluding BHP Billiton and Rio Tinto, net interest expenses absorbed more than one-quarter of resource producers' earnings in 2015," it said.More detailed comments in the Financial Stability Review chime with what might be termed the jaded market consensus."Book value measures of gearing ratios have also increased over recent years, indicating a decline in the ability to repay debt through asset sales should this be required," the RBA said in a nod to current controversies, such as the administration of steel maker and iron ore miner Arrium."When measured using the market value of equity - which may better reflect the realisable value of assets - gearing has increased even more sharply."Consistent with these developments, listed resource-related companies' distances-to-default - market-based measures of default risk using equity prices and reported liabilities - suggest that the financial health of the sector has deteriorated significantly over the past six months."The Reserve Bank concluded Financial Stability Review: "The [mining sector financial] measures are generally at their weakest levels since the financial crisis, unlike the corresponding measures for firms outside this sector. "During that period [that is, during the GFC], these forward-looking measures fell below zero (theoretically suggesting an imminent default) for a number of non-resource-related companies and, of these, around one-third went on to fail."