Heritage Western Cape Private Bag X9067 Cape Town 8001 Attention
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21 Dromedarisstreet, Dan Pienaar, Bloemfontein 9301 Suite 158, Private Bag X01, Brandhof, 9324 Tel: +27(0)51-4444700 Fax: 0866973660 E-mail: [email protected] .za Ref. nr.: E1 212/3/2-E1 /10-0224/07 14- 07-2009 Heritage Western Cape Private Bag X9067 Cape Town 8001 Attention : Nicolas Wiltshire Your Ref: HM/OVERBERG/CAPE AGOLHASIVIERFONTEIN 143/PORTION 4 PROPOSED DAM ON PORTION 4 OF VIERFONTEIN 143, NAPIER, CAPE AGULHAS, OVERBERG Please refer to your letter dated 3 March 2009 requesting the following reports by L Rossouw for your assessment and comment as part of the EIA process with ref no. E12/2/3/2-E1/1 0-0224/07. 1. A desktop Paleontological study 2. An Archaeological Impact Assessment Please send us your comment and do not hesitate to contact me or Hanri van Jaarsveld at (051) 444 4700 should you require more information regarding this. Ki nd regards Gys Hoon (Pri. Sci. NaQ DESKTOP PALAEONTOLOGICAL IMPACT ASSESSMENT OF A PROPOSED DAM WALL ON THE KLlPDRIFT RIVER NEAR NAPIER, WESTERN CAPE PROVINCE. L. Rossouw PO Box 28806 Langenhovenpark 9330 E-mail: [email protected] INTRODUCTION A desktop palaeontological impact assessment was conducted for a proposed dam wall near Napier. The assessment was carried out in accordance with National Heritage Resources Act 25 of 1999 with the aim to assess impact on potential palaeontological heritage resources. DESCRIPTION OF THE AFFECTED AREA 1::50 000 topographical map of the area: 3419 DB-DO Elim Site Coordinates: S34 30' 31.34" E19 53' 35.53" The site is located in rugged terrain on the Klipdrift River in the Vlermuiskelderkloof about 3.5 km south of Napier (Fig. 1). The area is made up of low mountains and undulating hills covered by moderately tall, dense restoid, ericoid and proteoid shrubland. PALAEONTOLOGICAL SIGNIFICANCE The palaeontological footprint in the region is mainly associated with: I;J Cenozoic deposits along the coast or inland surficial deposits found along large intermontane valleys and the main courses of the Riviersonderend and Breede Rivers (generally recorded as specific palaeontological localities). I;J Exposures of Table Mountain Group sandstones and overlying Bokkeveld Group shales (Cape Supergroup). Since known fossiliferous geological horizons are used as indicators of fossil distribution in capped sediments, the potential fossil heritage mentioned in this report is related to specific sedimentary units, and not specific palaeontological sites. CENOZOIC SEDIMENTS Old superficial deposits in the region are primarily assigned to the calcareous sediments of the Bredasdorp Group. These sediments are closely linked to past marine transgressions and regressions and are known to be fossiliferous (Table 1). Fossil localities are generally confined to the coastal region where caves, unconsolidated or wind-blown sands, fixed dunes and semi consolidated aeolian sands with calcrete lenses, occasionally yield mammal vertebrate fossils, marine or terrestrial molluscs and other remains (sometimes along with cultural remains in Pleistocene and Holocene deposits). The onset of colder environmental conditions during previous glacial episodes in the Pleistocene is considered to have resulted in the creation of a unique habitat for a number of ungulate fauna along the southwestern Cape coastline. Eustatic sea level lowering during the Last Glacial in the Late Pleistocene would have exposed up to 22500 square kilometers of the Aghulas Bank, forming large areas of relatively fertile, low lying land and so forming a unique coastal plain environment. This had a dramatic effect on the distribution and density of the Cape coastal fauna. Compared to the coastal fynbos and evergreen forest mosaic of the present, faunal evidence from several fossil localities along the southwestern Cape coast suggest that conditions during the Last Glacial Maximum provided a habitat for grazing mammals that preferred grassland and open country vegetation. There is currently no record of Cenozoic palaeontological exposures or localities within the vicinity of the dam wall, where surficial sediments along the Klipdrift River consist of minimally developed, acidic lithosols, derived from Table Mountain Group sandstones. CAPE SUPERGROUP SEDIMENTS The geology immediately north and south of Napier comprises dark-grey fossiliferous shales and mudstones of the early Devonian Gydo Formation (Bokkeveld Group). This is successively replaced in the study area by older marine sediments of the Nardouw Subgroup (Table Mountain Group). The strata are assigned to fluvial, braid-plain and shallow marine Silurian sandstones and thinly layered siltstones characterized by sparse trace assemblages and shelly fossils (brachiopods) (Table 1) . CONCLUDING REMARKS AND RECOMMENDATIONS • Late Cenozoic surficial deposits along the Klipdrift River are derived from Table Mountain Group sandstones and consist largely of acidic 3 soils . The soils are weakly developed and not conducive to the preservation of bone, shell or other kinds of organic material. Accumulation and preservation of intact fossil material within unconsolidated, superficial sediments are highly unlikely. • The underlying geology is made up of late Silurian I early Devonian sandstones of the Nardouw Subgroup (Table Mountain Group). The strata contain trace assemblages and occasional shelly fossils , are considered to be of medium to low palaeontological significance, and may be affected by excavations into bedrock. In case of the latter, the developer must inform Heritage Western Cape accordingly. REFERENCES Anderson , M.E. , et a/. 1999. Devonian (Emsian-Eifelian) fish from the Lower Bokkeveld Group (Ceres Subgroup), South Africa . Journal of African Earth Sciences 29 (1) , 179-194. Johnson, M.R. et. a/. (eds). 2006. The Geology of South Africa. Geological Society of South Africa, Pretoria. Gresse, P.G. & Theron, J.N. 1992. The geology of the Worcester area. Explanation to sheet 3319 (1 : 250000). Geological Survey, Pretoria. Partridge, T.C . & Maud , R.R. 2000. The Cenozoic of Southern Africa. Oxford Monographs on Geology and Geophysics No. 40. Rossouw, L. 2001 . The taxonomic status and palaeoecology of the fossil springbok, Antidorcas australis, as reflected by its postcranial osteomorphology. Unpublished MSc.thesis. University ofthe Witwatersrand. 4 . -.-( ... ., ~e·""_ ' I .', ,~ - ,, ./ '- f •' , , , .> •\ --If. ~;>, l' -·U.I:I • ~ I .- ", Figure 1. 1 : 50 000 topographical map showing the location of the proposed dam wall in the Vlermuiskelderkloof (Klipdrift River) 5 Table 1, Potential fossil heritage at the dam wall locality, Palaeontological Geological Unit ' Rock/Sediment Type Age Fossil Herit~g ~ Significance __ - 1 - -------- ..- -- ~ Geologically young. i Minimally developed, 0 unconsolidated . 'd' rth I d ' d Late '" rf d 't aCI IC I OSO s. erlve 't su ace epasl S I . Cenozoic to None I None ::I'" ( . d ' from Table Mountain <Jl river ralnages. Recent erosional gullies) Group sandstones I ------ I- _.. _-- t- i ~- i -'" Fluvial and shallow, 0 Table Mountain Trace fossils and brachiopod 0 near-shore marine ~ Group. Nardouw Silurian assemblages Medium to Low 'C I sandstones and thinly Subgroup m'" layered siltstones Ol Phase 1 Archaeological Impact Assessment of a proposed dam wall near Napier, Western Cape Province. L. Rossouw PO Box 38806 Langenhovenpark 9330 Executive Summary I;J A Phase 1 Archaeological Impact Assessment was carried out in an area demarcated for the construction of a 50m long x 15m high dam wall in rugged terrain on the Vlermuiskelderkloof River about 3.5 km south of the town of Napier. I;J The area is made up of low mountains and undulating hills covered by moderately tall, dense restoid , ericoid and proteoid shrubland. I;J The substrate is comprised of acidic lithosol soils derived from Table Mountain Group sandstones I;J There is no evidence of building structures or material of cultural significance, places which are associated with living heritage, or archaeological sites within the demarcated area including the access roads. I;J No burial sites or marked graves were located in the survey area. I;J The site is of low archaeological significance. Table of Contents Introduction 4 Archaeological background of the region 4 Description of the Affected Area 6 Results of Survey 7 Statement of Significance 8 Field Rating and Recommendations 8 References 9 Figures and Captions 10 3 Introduction A Phase 1 Archaeological Impact Assessment was carried out in an area demarcated for the construction of a dam wall across the Vlermuiskelderkloof River on Portion 4 of the farm Vierfontein 143, south of Napier (Fig. 1). The footprint covers a 4,5ha area that include a 350m segment of riverbed with overbank deposits, and a 50m wide by 120m long section (preliminary design specification), demarcated for the construction of a dam wall. The survey is required as a prerequisite for new development in terms of the National Environmental Management Act and is also called for in terms of the National Heritage Resources Act 25 of 1999. The site visit and assessment took place in April 2009. Terms of reference Qldentify and map possible archaeological heritage resources in the proposed area of impact; QDetermine and assess the potential impacts of the proposed development on archaeological heritage resources in the proposed areas of impact, and QRecommend mitigation measures to minimize impacts associated with the proposed development. Archaeological background of the region People have been living in South Africa for close on 2 million years