The Zimapanners

 

 

 

 

                                                

 

Mining Activity Search
 
1997 


Introduction
Given that the area around Zimapan is historically associated with the mining of tin, copper and other metal-bearing ores, and the fact that the property lies close to a number of abandoned mine shafts, it was thought prudent by the then owner of Zimapan, Brian See, to have a 'mining activity search' carried out in 19971, to assess the level of risk of subsidence, flooding or the likelihood of mining activity being resumed.

Original search report
The original search report made no attempt to summarise its findings, risk assessments or recommendations in any scannable way, so a summary has been provided below. A transcript of the report that was originally drawn up in letter-form by Cornwall Consultants in 1997, has been reproduced by the author of this website, together with notes in the margin and headings, neither of which were provided in their original report. This, together with the summary below, at last makes it possible to clearly see the wood from the trees. 

Summary
This summary combines the main findings of the mining activity search of 1997 and their related risk assessments, with recommendations.
  1. Lodes traverse area in E-NE to W-SW direction. One exploited or prospected lode, 120 metres E-NE of Zimapan, intersects SE corner of the property (see Plan).
    Risk assessment: The risk of mining-related subsidence is "slight". The presence of shafts, lode (outcrop) or unrecorded mine workings are "potentially untoward features" (read: pose a potential risk).2
  2. A shaft called Trenane's Shaft is located in the SW corner of property. A tunnel runs from TS under W side of Zimapan, and is probably an extension of the Deep Adit Level.
    Risk assessment: Deep Adit Level 50 metres, so "risk of subsidence unlikely".
  3. Several major collapses in the Deep Drainage Adit have occurred in the past, caused by heavy or prolonged rainfall.
    Risk assessment: Under such circumstances, rainwater can decant from some of the shafts nearby and can cause (and has caused) localised flooding.
  4. Two unnamed shafts lie E-NE of the property. Consequently, old prospected, unrecorded workings may extend under southern part of the property.
    Risk assessment: Mine shafts are only deemed 'secure' if they have been "plugged with mass or reinforced concrete". Thus, any rotten timber-capped mine shafts in the vicinity are "potentially catastrophic" from a subsidence perspective, if cap collapses.
  5. No plans to resume mining activity were known to report's author.
Recommendations
The mining engineer involved in this search made the following recommendations:
  1. Inspect the dwelling for signs of structural defects caused by subsidence.
  2. Inspect the land surrounding the property for surface subsidence.
  3. Check the location and the condition of Trenane's Shaft.

For the original transcript of this report with notes in the margin by the website author, click Mining Activity Search.


Footnotes
1. 19 years after the owner had purchased the property.
2. Website's author's interpretation of mining engineer's cautious wording.