GEOLOGY AS A COMPONENT OF VINEYARD TERROIR IN THE PROVINCE,

CHRIS BARGMANN CGeol FGS, CAPE WINE MASTER 35th IGC, AUGUST 2016 The Industry

 Vines first grown in Cape Town in 1659 by the Dutch East India Company.

 2015 wine grape vineyards 98,597 ha (Australia 148 000 ha).

 Most planted varietals (2015) - Chenin Blanc, Colombard, Cabernet Sauvignon and Shiraz.

 Less regulation since 1985 – new viticultural areas developed (Elgin, Hamel en Aarde, Darling), less dependence on the co-operative winery system, more experimentation with cultivars, soils and sites. Post 1994 – international markets available, however wines received a mixed reception.

 Today a combination of a better understanding of local Terroir, replanting with varietals to match vineyard sites, increasing numbers of “old vine” & site specific wines and a new generation of progressive winemakers has resulted in South Africa’s wines attracting both local and international acclaim. Grape Varietals and Growing Areas

2000 2005 2010 2015 Wine Grape (Ha) 105,566 101,607 101,016 98,597 2015 Figures Red:White 36:64 46:54 44:56 45:55 SAWIS District Ha % of total % Red % White 15,911 16.1 22.0 11.0 Chenin Blanc % 24.1 18.8 18.3 18.2 15,678 15.9 21.0 12.0 Colombar % 12.2 11.3 11.9 12.0 Robertson 14,264 14.47 13.0 16.0 Sauvignon Blanc % 5.7 7.5 9.5 9.4 13,315 13.5 18.0 10.0 Chardonnay % 6.4 7.8 8.2 7.2 Breedekloof 13,029 13.21 11.0 15.0 Olifants River 10,263 10.41 7.0 13.0 Cab Sauvignon % 9.5 13.4 12.2 11.3 Worcester 8,824 8.95 7.0 11.0 Shiraz % 6.0 9.6 10.0 10.5 Northern Cape 4,687 4.75 1.0 8.0 Pinotage % 7.0 6.4 6.2 7.5 Klein 2,625 2.66 1.0 4.0 Merlot % 5.2 6.8 6.4 6.0 Cinsault % 3.7 2.8 2.0 1.9 Pinot Noir % 0.6 0.5 1.0 1.1

45% Red : 55% White South African Wine of Origin system comprises; 6 Regions (largest) – 24 Districts – 63 wards (smallest) Western Cape Province – Wine Regions

From www.sawis.co.za Western Cape Province – Wine Districts

From www.sawis.co.za Western Cape Province – Wine Wards

From www.sawis.co.za Terroir in the Western Cape Province

Climate - Winter rainfall area, Diurnal temperature variation, Sea breezes, Soil – Structure, Drainage, Water retention ability, Alluvial gravels. Geology – Granite – acid soils + kaolin, – better structured soils, Karoo – calcareous soils. Aspect – Altitude, Slope orientation, Warm or cool slopes - sunlight exposure, Wind exposure. Plus - Viticulture and Winemaking practices Western Cape Province Terroir – Climate

From www.wosa.co.za Western Cape Province Terroir – Rainfall

From www.capewatersolutions.co.za Western Cape Province Terroir – Aspect & Topography

Altitude Sunlight exposure, Exposure to sea breezes Western Cape Province Terroir – Geology

 Late Proterozoic – Malmesbury Group. Marine sediments, predominantly shaley, some conglomerates rare limestone's.

 Cambrian – Cape Granite Suite.

 Cambrian – Klipheuwel Group. Shale and .

 Middle Ordovician to Early Carboniferous – Cape Supergroup. Table Mountain Group , sandstones & , Group sandstones & shales

 Late Carboniferous to Permian – . Dwyka tillite, shales

 Upper Jurassic– Uitenhage Group. Enon conglomerate

 Early Cretaceous – False Bay Dolerites Western Cape Province Terroir – Geology

 Alluvial soils and terraces.

 Residual soils, often loams and duplex types.

 Formation of kaolin and saprolites within granites.

 Formation of calcareous deposits within soils in dryer areas.

 Aeolian soils.

River gravels and soil formation have been ongoing for the whole Cenozoic, resulting in soils of great antiquity. Western Cape Province Terroir – Geology

Wine region / district Age Supergroup Group Formation Main rocktypes Major geological events Cainozoic Residual soils, alluvium, scree Early Cretaceous (False Bay Dolerites Dyke Swarm) Dolerite 136 Ma U Jurassic - E Cretaceous , shale, bentonite age faulting Uitenhage Group 139-123 Ma Enon Formation Conglomerate Major unconformity Permian Waterford Formation Sandstone, siltstone, shale, mudstone Cape Orogeny - (275 - 265 Ma) Tierberg Formation Shale, claystone, mudstone, siltstone Ecca Group Collingham Formation Shale, siltstone, mudstone, tuff Karoo Supergroup Whitehall Formation Shale, tuff Prince Albert Formation Shale Late Carboniferous - Permian Diamictite (302 - 290 Ma) Glaciation, major unconformity Middle Devonian - Early Carboniferous Waaipoort Formation Shale, mudstone, siltstone (387 - 327 Ma) Floriskraal Formation Sandstone, siltstone, sandy shale Kweekvlei Formation Shale, siltstone Witteberg Group Witpoort Formation Sandstone Swartruggens Formation Siltstone, mudstone, sandstone Blinkberg Formation Sandstone Wagen Drift Formation Siltstone, sandy shale, mudstone, sandstone Early Devonian - Mid Devonian Karoopoort Formation Siltstone, sandy shale (409 - 387 Ma) Osberg formation Sandstone, Klipbokkop Formation Siltstone, mudstone, sandstone Wuppertal Formation Sandstone, siltstone, shale Waboomberg Formation Siltstone, shale, mudstone, sandstone Bokkeveld Group Boplaas Formation Sandstone Cape Supergroup Tra-Tra Formation Shale, mudstone, siltstone, sandstone KLEINREGION KAROO Hex River Formation Sandstone Voorstehoek Formation Mudstone, shale, siltstone

BREEDERIVERREGION Gamka Formation Sandstone, siltstone Gydo Formation Shale, mudstone, siltstone

OLIFANTSRIVERREGION Mid Ordovician - Early Devonian Rietvlei Formation Sandstone, siltstone, shale (450 - 409 Ma) Skurweberg Formation Sandstone Goudini Formation Sandstone, siltstone, shale Cederberg Formation Shale Table Mountain Group Glaciation Pakhuis Formation Diamictite, sandstone Peninsula Formation Sandstone Graafwater Formation Sandstone, siltstone, shale Piekenierskloof Formation Sandstone, conglomerate Major unconformity

CAPESOUTHCOAST REGION Middle Cambrian Populierbos Formation Mudstone Kilpheuwel Group (520 - 510 Ma) Magrug Formation Conglomerate, sandstone Early - Middle Cambrian Igneous activity Cape Granite Suite Granite, Granodiorite, Gabbro, Diorite (550 - 515 Ma) Late Proterozoic - Early Cambrian Brandwacht Formation Greywacke, conglomerate, volcanics Saldanian Orogeny (780 - 550 Ma) Porterville Formation Shale, greywacke, minot limestone Norree Formation Greywacke, quartzite, minor limestone, dolomite Formation Grit, conglomerate, greywacke Franschhoek Formation Conglomerate, quartzite Malmesbury Group COASTALREGION Tygerberg Formation Greywacke, shale, siltstone, quartzite Bridgetown Formation Moorreesberg Formation Greywacke Klipplaat Formation Quartz schist Berg River Formation Mica schist, greywacke Western Cape Province Terroir – Geology Western Cape Province Terroir – Geology High rainfall in the west. Dry in the east. Heat summation decreases 550 mm northwest - southeast 2249 degree days Large diurnal variation in the south with breezes from SE and mist forming in the river valley. Varied geology, calcareous 200 mm 780 mm soils and alluvial. 1980 degree days 2076 degree days 280 mm 2181 degree days

327 mm 1968 degree days Western Cape Province Terroir – Geology

Tulbagh Durbanville

Darling

Malmesbury Group Western Cape Province Terroir – Geology

Paarl Pluton

Cape Pluton – Kaolin formation

Kuils River – Helderberg Pluton – Hornfels shale hills on pluton edge Cape Granite Suite Western Cape Province Terroir – Geology Elgin Hamel en Aarde Valley

Elgin

Bokkeveld Group Western Cape Province Terroir – Geology

Nuy – Robertson – Cretaceous Enon Conglomerate Permian Dwyka Tillite based red soil based red soil

Karoo and Uitenhage Groups Western Cape Province Terroir – Geology

Breede River Valley

Cape Pluton Soils Western Cape Province Terroir – Geological Influences

 Granite – Acidic, clay rich soils. Kaolin locally significant.

 Malmesbury Group – Shale / greywacke dominated. Acidic, clay rich soils. Hornfels important on pluton edges, rare limestone's present.

 Table Mountain Group – Sandstones rarely used for vineyards. TMS derived sand is a common component in many vineyard soils.

Region - Loamy calcareous soils, associated with Bokkeveld & Witteberg shales, Dwyka tillite and Enon conglomerate. Only area with significant alkaline soils.

 River gravels commonly utilised in dryer areas where irrigation water is available.

 Topography, altitude and slope orientation Western Cape Province Terroir – Geological Influences

Shiraz – Granite preference? Merlot, Chenin Blanc – Shale preference? A Personal Selection of Terroir Driven Western Cape Wine Producers

Note: Not all vineyards are open to the public, check before visiting. Constantia - Cape Point Vineyards. Cape Granite based soils, on south facing slopes of the Constantiaberg. Unique south facing setting. Sauvignon Blanc. Durbanville – Diemersdal Estate. Malmesbury shale based soils in the Durbanville hills. Cooling Atlantic sea breezes contribute to the iconic Sauvignon Blanc. Stellenbosch – Kanonkop Estate. Granite based soils on the western slopes of the Simonsberg. Benchmark South African Pinotage, also Cabernet Sauvignon. (also - Hartenberg, Tokara, Vergelegen) Elgin - Paul Cluver. Bokkeveld shales in the upland Elgin valley. Cooler climate apple growing area. Chardonnay and Pinot Noir. Hemel en Aarde Valley – Hamilton Russell Vineyards. Pioneer producer from the 1980’s. Bokkeveld shales, breezes from the Walker Bay. Pinot Noir and Chardonnay. (also – Strandveld (Elim)) A Personal Selection of Terroir Driven Western Cape Wine Producers

Robertson – Springfield Estate. On the banks of the Breede River. Gravel and sandy alluvial soils. Sauvignon Blanc, Chardonnay and Cabernet Sauvignon. Robertson – Graham Beck Wines. Pioneer producer on the calcareous red soils of the Karoo inlier between Worcester and Robertson. Sparkling wines and single vineyard shiraz. Franschhoek – Cape Chamonix. On the slopes above Franschhoek, granite bedrock. Utilizes slope and aspect to great effect. Chardonnay and Pinotage. Franschhoek – Boekenhoutsklook Winery. Dynamic producer with a range of site and geology specific wines sourced from beyond their Franschhoek base. Porseleinberg Shiraz (vineyard on kaolin rich soils in the Swartland) is a South African classic. A Personal Selection of Terroir Driven Western Cape Wine Producers

Swartland – AA Badenhorst. A leader in the revival of old vineyard wines in the Swartland. Grenache, Cinsault from the Perdeberg granite. Swartland – Sadie Family Wines Lead the revival of old vineyard wines in the Swartland with remarkable results. These old vines have true sense of place. Cederberg - Cederberg Private Cellar. The Cape’s highest altitude vineyards (1,000m) with unique geology within the Cape Supergroup. Glacial Cederberg & Pakhuis Formations – shale and diamictite. Chenin Blanc, Sauvignon Blanc, Cabernet Sauvignon.